This study evaluated the efficacy of niclosamide after the invasion of aggressive TNBC breast CSCs into a 3D bone-mimicking model. Initially, the optional dose required for triggering apoptosis was determined for MDA-MB-231 CSCs (CD44+ and CD24-). Our findings revealed that approximately 50% of the cells showed apoptotic properties, as assessed with Annexin V/7AAD assay and WST-1 at IC50 = 100 μM (6 h). Additionally, this treatment suppressed p-STAT3 protein levels and increased Bax levels (p < 0.05), as determined by Western Blot. The expression of genes associated with metastasis and cell migration (CXCR4, MMP2, MMP9), drug resistance (ABCG1, ABCG2), stemness (OCT4, NANOG) and cell cycle and proliferation (CYCLIN D1) was found to be significantly suppressed (p < 0.05). Therefore, after validating the efficacy of the 100 μM dose on CSCs, cell cycle, ELISA, Western Blot, and RT-qPCR analyses were conducted in the 3D model. It was found that the cells were arrested in the G0-G1 phase (p < 0.05). 100 μM Niclosamide suppressed the levels of EMT markers, Vimentin (p > 0.05) and ZEB1 (p < 0.05). Additionally, RT-qPCR results indicated a significant downregulation of CXCR4, ABCG1, ABCG2, MMP2, OCT4, CCND1, AXIN2, and LGR5 gene expressions following niclosamide treatment in both CD133+ and CD133- groups (p < 0.05). The increase in the Bax protein, a key player in apoptosis induction, along with the decrease in the anti-apoptotic protein Bcl-2, suggests the activation of cell death mechanisms. Notably, its targeted impact on the CD44+/CD24- population suggests that niclosamide could enhance the sensitivity of CSCs to treatment, thereby preventing tumor recurrence.

Triple negative breast cancer (TNBC) is the most malignant subtype of breast cancer that portends a poor prognosis and limited treatment. PTPN2 is a member of the non-receptor protein tyrosine phosphatase family that regulates biological processes by dephosphorylating various signaling molecules. Endoplasmic reticulum stress (ERS) plays a dual regulatory role by promoting both survival and apoptosis. This study aims to elucidate the role of PTPN2 in mediating the pro-apoptotic effects of ERS induced by Thapsigargin (TG), and its influence on the fate of TNBC cells, utilizing both loss-of-function and gain-of-function methodologies. Our findings indicate that PTPN2 modulates TG-induced ERS via the IRE1-XBP1 and PERK/EIF2α/ATF-4 signaling pathways. Furthermore, PTPN2 mitigates the TG-induced reduction in cell proliferation and the concomitant increase in apoptosis. Specifically, PTPN2 appears to inhibit several facets of TG-induced apoptosis, including: (1) Ca2+ elevation in mitochondria, (2) the production of reactive oxygen species (ROS), and (3) Bax/Bcl-2 augmentation which dictates mitochondria-mediated apoptosis. Additionally, we observed that the knockdown of PTPN2 enhances TG-induced autophagy; however, our results suggest that autophagy may serve a protective role against TG-induced apoptosis. Consequently, targeting PTPN2 in conjunction with ERS-inducing agents may represent a promising therapeutic strategy for the treatment of TNBC.

Purpose: The early detection of breast cancer in women under the age of 40 has posed significant challenges. This can be attributed in part to the limited research conducted on the breast cancer in this age group, particularly with regards to large sample sizes. We aimed to address this gap by analyzing and comparing the ultrasound imaging and pathological characteristics of breast cancer in women aged under 40 and those aged 40 and above. Methods: A retrospective assessment was conducted to examine the ultrasound imaging and clinicopathologic characteristics of 555 women with surgically confirmed breast cancers. The patient cohort consisted of 160 individuals below the age of 40 and 395 individuals aged 40 years and above. Results: Our study identified the breast cancer in patients under 40 years was more likely to show regular shape (p = 0.043) compared with tumors in patients who were 40 years and over. Furthermore, in young female patients (<40 years), irregular shape was correlated with the HER2-enriched type (p = 0.02), circumscribed margin (p = 0.001), and a lack of calcifications (p = 0.02) were associated with the triple-negative type. In another group (≥40 years), only a lack of calcifications (p = 0.003) were associated with the triple-negative type. Conclusion: Breast cancer in women under the age of 40 exhibits distinct ultrasonographic characteristics patterns that vary across different immunophenotypes, which may provide certain predictive information for physicians.

Endocrine therapy resistance (ETR) in breast cancer (BC) is a multicausal phenomenon with diverse alterations in the tumor cell interactome. Within these alterations, non-coding RNAs (ncRNAs) such as micro-RNAs (miRNAs) modulate the expression of tumor suppressor genes and proto-oncogenes, such as the ESR1 gene encoding estrogen receptor alpha (ERα). This work aims to review the effects of miRNAs targeting ERα mRNA and their mechanisms related to ETR in BC. A thorough review of the literature and an in silico study were carried out to elucidate the involvement of each miRNA, thus contributing to the understanding of ETR in BC.

Pembrolizumab has been approved for the immunotherapy of programmed death ligand 1 (PD-L1)-positive triple-negative breast cancer (TNBC) based on the KEYNOTE-355 trial. However, cost-effectiveness evidence is limited. The purpose of this study was to evaluate the cost-effectiveness of pembrolizumab plus chemotherapy compared with chemotherapy alone for patients with PD-L1-positive inoperable or metastatic TNBC from a Japanese healthcare perspective.

The cost-effectiveness analysis was performed for pembrolizumab, of which the drug price was determined at 214,498 Japanese yen (JPY), or 1631 US dollars (USD) (1 USD = 131.5 JPY) for KEYTRUDA® (100 mg), using a partition survival model based on the KEYNOTE-355 trial subgroup analysis in Japan. The comparison was made using quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER). One-way deterministic and probabilistic sensitivity analyses (PSA), which evaluate the impact of parameter uncertainty, were performed to assess the robustness and calculate the acceptable probability, defined as the probability of the ICER being below the willingness-to-pay (WTP).

Pembrolizumab plus chemotherapy provided an additional 0.676 QALYs at an incremental cost of 8,503,072 JPY. The ICER for pembrolizumab plus chemotherapy compared with conventional chemotherapy was 12,577,178 JPY (95,644 USD) per QALY. The ICER per QALY was below the willingness-to-pay threshold of 15,000,000 JPY. PSAs revealed that the acceptable probability was 83.9% at 15,000,000 JPY.

The pembrolizumab plus chemotherapy is likely to be a cost-effective option compared with conventional chemotherapy for patients with PD-L1-positive inoperable or metastatic TNBC in a Japanese medical environment from a healthcare system.

Circulating tumour DNA (ctDNA)-based detection of molecular residual disease (MRD) presents a strategy to identify patients at high risk of relapse. In this article, we profile early breast cancer patients with an ultrasensitive, whole genome sequencing (WGS)-based, tumour-informed ctDNA platform.

We analysed 617 plasma samples (median 8, range 2-14) from 78 patients (23 triple-negative breast cancer, 35 human epidermal growth factor receptor 2-positive, 18 hormone receptor-positive, and 2 unknown). Samples were collected at diagnosis before therapy, cycle 2 of neoadjuvant chemotherapy, post-surgery after neoad'juvant therapy if administered, every 3 months during the first year, and every 6 months thereafter. Plasma DNA was analysed using the NeXT Personal MRD platform, a tumour-informed WGS approach to produce personalized ctDNA sequencing panels tracking a median of 1451 variants per patient. MRD detection was correlated with clinical outcomes.

ctDNA was detected at levels ranging from 2.19 parts per million (PPM) to 204 900 PPM (median 405 PPM), with 39% of all ctDNA detections in the ultra-low range <100 PPM. Of patients with samples at diagnosis, 98% (49/50) had ctDNA detected before treatment. At a median follow-up of 76 months (range 5-118 months), detection of ctDNA was associated with high risk of future relapse (P < 0.0001; log-rank test) and shortened overall survival (P < 0.0001) with a median lead time from ctDNA detection to clinical relapse of 15 months (range 0.9-61.5 months). MRD was identified in 100% (11/11) of patients who relapsed, with a median level of ctDNA at first MRD detection of 13.1 PPM. No ctDNA-undetected patients relapsed throughout follow-up (64/64). Comparison with exome-powered MRD detection assays showed improved sensitivity and lead time.

A whole genome-powered MRD assay detected breast cancer relapse with a long lead time over clinical relapse, and was strongly associated with relapse-free survival. Rates of ctDNA detection at diagnosis were higher than those reported with exome-based tumour-informed assays.

To determine the beneficiaries of capecitabine in patients with triple-negative breast cancer (TNBC) who failed to achieve pathological complete response (pCR) by analyzing the efficacy of the drug in different HER2 statuses and TNM stages.

The Kaplan-Meier survival curve was plotted to estimate the effect of capecitabine therapy on disease-free survival (DFS) and overall survival (OS). Furthermore, the Cox proportional hazards model was used to analyze the factors that influence DFS and OS.

A total of 296 patients with TNBC who had non-pCR after undergoing neoadjuvant therapy (NAT) were included in this study. There were 152 patients (51.4 %) in the capecitabine group and 144 patients (48.6 %) in the no-capecitabine group. The 3-year DFS and OS rates of the capecitabine group were better than those of the no-capecitabine group (DFS 80.0 % vs. 68.0 % p = 0.012, OS 95.9 % vs. 86.9 % p = 0.011). In addition, the capecitabine group exhibited significantly better DFS and OS than the no-capecitabine group in the HER2-low (DFS p = 0.004, OS p = 0.009) and stage III (DFS p = 0.004, OS p = 0.008) populations but not in the HER2-0 or stage II population.

Adjuvant capecitabine therapy significantly improved the prognosis of patients with TNBC who had residual disease after NAT, and the improvements in the outcomes were significant in patients with HER2-low expression and stage III disease. Other effective treatment methods should be explored for patients with HER2-0 expression or stage II disease.

Triple negative breast cancer, an inherently aggressive disease, is further impaired by the limited therapeutic options and chemotherapy-resistance; hence, elucidating the signaling nodes underlying chemotherapy resistance is of major interest. Focusing on the differentially expressed genes in recurrent TNBC, we identified TRIM29, a ubiquitin ligase belonging to TRIM family, as a uniquely enriched protein in chemoresistant TNBC. Here, we demonstrate that chemoresistant TNBC cells are inherently aggressive, exhibiting elevated growth and migration potential compared to chemosensitive cells, and in particular, they possess higher TRIM29 expression whose expression level modulation results in altered chemosensitivity. TRIM29 overexpression reduces chemotherapy response whereas TRIM29 knockout not only increases chemosensitivity but also reduces TNBC tumor growth. Tumor-dissociated cells maintain TRIM29 knockout status as well as exhibit similar functional alterations as chemoresistant TNBC cells. Mechanistically, RNA-sequencing of parental-chemosensitive, chemoresistant-inherently overexpressing TRIM29 and chemoresistant-TRIM29 knockout TNBC cells reveals a unique set of genes (S100P, SERPINB3, SERPINB4, CEACAM5, CEACAM6 and CDH6) showing significant upregulation with the acquisition of chemoresistance and downregulation with the TRIM29 knockout. Furthermore, an enrichment of β-catenin pathway in chemoresistant TNBC cells is observed. We uncovered a functional network where S100P, a metastasis inducing secretory factor, bidirectionally interacts with TRIM29, and modulates the expression of SERPINB3, SERPINB4, CEACAM5, CEACAM6 as well as β-catenin pathway genes. Showing the functional importance, S100P inhibitor reduces the growth and mammosphere formation in chemoresistant TNBC. Moreover, combining β-catenin inhibitor with chemotherapy shows synergistic inhibition of chemoresistant TNBC cells. Indeed, higher expression of TRIM29, S100P and β-catenin associates with reduced recurrence free survival. This work proposes TRIM29 as an important node that modulates a unique gene network in chemoresistant TNBC and whose biological impact is mediated by modulation of S100P and β-catenin.

Numerous studies have demonstrated that extracellular vesicles (EVs) carry a variety of noncoding RNAs (ncRNAs), which can be taken up by neighboring cells or transported to distant sites via bodily fluids, thereby facilitating intercellular communication and regulating multiple cellular functions. Within the tumor microenvironment, EV-ncRNA, on the one hand, regulate the expression of PD-L1, thereby influencing tumor immune evasion, promoting tumor cell proliferation, and enhancing tumor growth, invasion, and metastasis in vivo. On the other hand, these specific EV-ncRNAs can also modulate the functions of immune cells (such as CD8 + T cells, macrophages, and NK cells) through various molecular mechanisms, inducing an immunosuppressive microenvironment and promoting resistance to anti-PD-1 therapy. Therefore, delving into the molecular mechanisms underlying EV-ncRNA regulation of immune checkpoints presents compelling therapeutic prospects for strategies that selectively target EV-ncRNAs. In this review, we elaborate on the cutting-edge research progress related to EV-ncRNAs in the context of cancer and dissect their pivotal roles in the PD-1/PD-L1 immune checkpoint pathway. We also highlight the promising clinical applications of EV-ncRNAs in anti-PD-1/PD-L1 immunotherapy, bridging basic research with practical clinical applications.

TP53 mutations are common in breast cancer (BC) and are associated with poor prognosis. GD3 synthase (GD3S/ST8SIA1), a gene associated with breast cancer stem cells, is upregulated in tumors with p53 mutations. However, the functional relationship between GD3S and p53 is unknown. Here, we show that GD3S levels are highest in breast tumors with specific p53 mutations. Functional studies revealed that wild-type (WT) p53 inhibits GD3S expression, whereas mutation in p53 enhances GD3S expression by upregulating GD3S promoter activity. Moreover, we found that GD3S inhibits wild-type p53-induced apoptosis in BC cells, while BC cells harboring gain-of-function p53 mutations are dependent on GD3S for their growth. Mechanistic insights indicate that GD3S strengthens mitochondrial function by regulating their oxygen consumption rate and membrane polarity. Our findings demonstrate that specific GOF p53 mutations rely on GD3S to exert their tumor-promoting effects and that GD3S is a novel anti-apoptotic factor in BC cells. Stabilizing WT p53 and reducing mutant p53 levels downregulates GD3S expression, thereby augmenting apoptosis. GD3S overexpression counteracts the cell death triggered by WT p53 stabilization in BC cells, as well as that triggered by p53 knockdown in cells with specific GOF p53 mutations, which suggests that GD3S helps confer apoptosis resistance.

Triple-negative breast cancer (TNBC) is an aggressive and invasive subtype of breast cancer for which chemotherapy, such as paclitaxel (PTX), remains a primary treatment option. However, resistance to chemotherapy poses a significant challenge, necessitating the development of novel therapeutic strategies. This study aimed to address PTX resistance in TNBC by developing a peptide drug, Charis 1000 (C1K), designed to target transforming growth factor beta (TGF-β) signaling. C1K was synthesized using standard solid-phase peptide synthesis and optimized for enhanced stability. Molecular docking predicted the binding interactions between C1K and TGF-β1, and surface plasmon resonance (SPR) confirmed a moderate binding affinity. The therapeutic potential of C1K was evaluated in TNBC cell lines (4T1, MDA-MB-231, and PTX-resistant MDA-MB-231) and in vivo using a syngeneic 4T1 mouse model. Functional assays demonstrated that C1K inhibited TGF-β-mediated signaling, reduced autophagy, a key mechanism underlying PTX resistance, and significantly enhanced PTX-induced apoptosis. In vivo studies further revealed synergistic effects of C1K and PTX, resulting in enhanced apoptosis in both sensitive and PTX-resistant TNBC cells. These findings suggest that C1K effectively targets TGF-β to inhibit autophagy and potentiate the apoptotic effects of PTX, as a promising combinatorial therapeutic agent for improving treatment outcomes in TNBC patients.

Triple-negative breast cancer (TNBC) is a highly aggressive disease with limited approved therapeutic options. The rapid growth and genomic instability of TNBC cells makes mitosis a compelling target, and a current mainstay of treatment is paclitaxel (Ptx), a taxane that stabilizes microtubules during mitosis. While initially effective, acquired resistance to Ptx is common, and other antimitotic therapies can be similarly rendered ineffective due to the development of resistance or systemic toxicity underscoring the need for new therapeutic approaches. Interrogating CRISPR essentiality screens in TNBC cell lines, we identified PAFAH1B1 (LIS1) as a potential vulnerability in this disease. PAFAH1B1 regulates mitotic spindle orientation, proliferation, and cell migration during neurodevelopment, yet little is known regarding its function in breast cancer. We found that suppressing PAFAH1B1 expression in TNBC cells reduces cell number, while non-malignant cells remain unaffected. PAFAH1B1 suppression alters cell cycle dynamics, increasing mitotic duration and accumulation of cells in the G2/M phase. The suppression of PAFAH1B1 expression also increases DNA double-strand breaks, indicating a requirement for sustained PAFAH1B1 expression to maintain the genomic integrity of TNBC cells. Lastly, PAFAH1B1 silencing substantially enhances these defects in cells that are taxane-resistant and sensitizes both parental and Ptx-resistant TNBC cells to Ptx. These results indicate that LIS1/PAFAH1B1 may be a novel target for the development of new anti-mitotic agents for treating TNBC, particularly in the context of paclitaxel resistance.

Valproic acid (VPA) constitutes a branched-chain, short-chain fatty acid that serves as an antiepileptic medication. It has been increasingly recognized that VPA has presented potential anti-tumor properties, including breast cancer. However, the exploration of novel breast cancer treatment methods necessitates a more comprehensive and in-depth understanding of the novel mechanism of VPA inhibition of breast cancer. It has been proven that farnesyl-diphosphate farnesyltransferase 1 (FDFT1) participate in oncogenesis and development of cancers. However, the effect of FDFT1 on breast cancer is still obscure. Thus, it is important to investigate the potential of VPA to trigger ferroptosis in breast cancer cells via targeting FDFT1.

In this study, the underlying mechanisms of VPA on ferroptosis in breast cancer cells were explored in vitro and vivo. Initially, the effects of VPA on the proliferation of breast cancer cells were assessed utilizing the Cell Counting Kit-8, cell counting, and colony formation assays. Subsequently, the ferroptosis in breast cancer cells treated with VPA were determined through the use of the Lipid Peroxidation malondialdehyde Assay Kit, reduced glutathione and oxidized glutathione disulfide Assay Kit, flow cytometry, transmission electron microscopy, and western bloting. To explore the impact of VPA in combination with ferrostatin-1, Erastin or RSL3, on MDA-MB-231 cell proliferation and ferroptosis, respective CCK-8, colony formation and WB assays were conducted. Thereafter, we assessed whether VPA facilitated ferroptosis in MDA-MB-231 cells by modulating the expression of FDFT1. Finally, the anti-breast cancer effects of VPA in vivo were validated through a xenograft mouse model, and histological examination via hematoxylin-eosin staining and immunohistochemistry staining were employed to delve into the underlying mechanisms of VPA's inhibitory effects on breast cancer cells in vivo.

The assay outcomes indicated that VPA impedes the proliferation of breast cancer cells. The findings from the ferroptosis index demonstrated that MDA-MB-231 cells are more sensitive to VPA induced ferroptosis than MCF-7 cells. Subsequent to the introduction of ferrostatin-1 (Fer-1), Erastin or RSL3, it was observed that Fer-1 reversed the ferroptosis facilitated by VPA, whereas Erastin or RSL3, in conjunction with VPA, respectively, induced ferroptosis in MDA-MB-231 cells. We revealed that the downregulation of FDFT1 enhanced proliferation and inhibited ferroptosis of MDA-MB-231 cells. Additionally, we discovered that VPA may facilitate ferroptosis in MDA-MB-231 cells by negatively modulating the levels of the solute carrier family 7 member 11 (SLC7A11) protein through the upregulation of FDFT1 expression. In conclusion, this study elucidated that VPA induced the ferroptosis of MDA-MB-231 cells via targeting FDFT1, representing a novel mechanism underlying its efficacy in potentially inhibiting breast cancer.

Triple-negative breast cancer cells must evade immune surveillance to metastasize to distant sites, yet this process is not well understood. The Eyes absent (EYA) family of proteins, which are crucial for embryonic development, become dysregulated in cancer, where they have been shown to mediate proliferation, migration, and invasion. Our study reveals an unusual mechanism by which EYA3 reduces the presence of cytotoxic natural killer (NK) cells in the premetastatic niche (PMN) to enhance metastasis, independent of its effects on the primary tumor. We find that EYA3 up-regulates nuclear factor κB signaling to enhance CCL2 expression, which, in contrast to previous findings, suppresses cytotoxic NK cell activation in vitro and their infiltration into the PMN in vivo. These findings uncover an unexpected role for CCL2 in inhibiting NK cell responses at the PMN and suggest that targeting EYA3 could be an effective strategy to reactivate antitumor immune responses to inhibit metastasis.

Dysregulation of deubiquitination is essential for cancer growth. However, the role of 26S proteasome non-ATPase regulatory subunit 14 (PSMD14) in the progression of triple-negative breast cancer (TNBC) remains to be determined. Gain- and loss-of-function experiments showed that silencing PSMD14 notably attenuated the growth, invasion, and metastasis of TNBC cells in vitro and in vivo. Overexpression of PSMD14 produced the opposite results. Mechanistically, PSMD14 decreased K63-linked ubiquitination on SF3B4 protein to de-ubiquitin and stabilize SF3B4 protein. Then, SF3B4/HNRNPC complex bound to FADS1 mRNA and promoted exon inclusion in the target mRNA through m6A site on FADS1 mRNA recognized by HNRNPC, thereby up-regulating the expression of FADS1 and activating Akt/mTOR signaling. Exogenous arachidonic acid supplementation combined with PSMD14 knockdown induced synthetic lethality, which was further confirmed in TNBC organoid (PDO) and TNBC patient-derived xenograft (PDX) mouse models. Overall, our findings reveal an oncogenic role of PSMD14 in TNBC progression, which indicates a potential biomarker and ferroptosis-mediated therapeutic strategy for TNBC.

Triple-negative breast cancer (TNBC) is aggressive with poor prognosis. Current strategies include chemotherapy, surgery, and radiotherapy, but face challenges like suboptimal outcomes, low survival, and drug resistance. Thus, novel TNBC therapies are crucial. Activity-based photodynamic therapy (PDT) is a highly regarded cancer treatment strategy known for its spatiotemporal precision, making it a promising option for the treatment of TNBC. In this study, we designed and synthesized three triphenylamine-thiophene (TPATP)-derived ligands binding to mitochondrial DNA G4 (mtG4), which were able to label mitochondria in TNBC cells under red-light excitation, and demonstrated significant phototoxicity through type-I/II process under white-light irradiation, hinting at dual-functional potential for PDT and imaging. The optimal ligand, TP2, was demonstrated to disrupt mitochondrial functions under white-light irradiation, leading to MMP loss, ATP reduction, ROS increase, which further triggered significant apoptosis in TNBC cells.

Triple-negative breast cancer (TNBC) presents significant clinical challenges because of its limited treatment options and aggressive behavior, often associated with poor prognosis. This study focuses on kindlin-2, an adapter protein, and its role in TNBC progression, particularly in hematopoiesis-mediated immune evasion. TNBC tumors expressing high levels of kindlin-2 induce a notable reshaping of hematopoiesis, promoting the expansion of myeloid cells in the bone marrow and spleen. This shift correlated with increased levels of neutrophils and monocytes in tumor-bearing mice over time. Conversely, genetic knockout (KO) of kindlin-2 mitigated this myeloid bias and fostered T-cell infiltration within the tumor microenvironment, indicating the pivotal role of kindlin-2 in immune modulation. Further investigations revealed that kindlin-2 deficiency led to reduced expression of PD-L1, a critical immune checkpoint inhibitor, in TNBC tumors. This molecular change sensitized kindlin-2-deficient tumors to host antitumor immune responses, resulting in enhanced tumor suppression in immunocompetent mouse models. Single-cell RNA sequencing, bulk RNA sequencing, and IHC data supported these findings by highlighting enriched immune-related pathways and increased infiltration of immune cells in kindlin-2-deficient tumors. Therapeutically, targeting PD-L1 in kindlin-2-expressing TNBC tumors effectively inhibited tumor growth, akin to the effects observed with genetic kindlin-2 KO or PD-L1 KO. Our data underscore kindlin-2 as a promising therapeutic target in combination with immune checkpoint blockade to bolster antitumor immunity and counteract resistance mechanisms typical of TNBC and other immune-evasive solid tumors. Implications: Kindlin-2 regulates tumor immune evasion through the systemic modulation of hematopoiesis and PD-L1 expression, which warrants therapeutic targeting of kindlin-2 in patients with TNBC.

Neoadjuvant chemoimmunotherapy followed by adjuvant immunotherapy is the gold standard for treating patients with higher risk early triple-negative breast cancer (TNBC); however, in some cases, these patients undergo surgery followed by chemotherapy-based anthracyclines and taxanes without adhering to the guidelines.

Patients with previously untreated stage I, II, and III TNBC who received adjuvant therapy with either doxorubicin and cyclophosphamide (AC) + docetaxel (AC-D), AC + weekly paclitaxel (AC-WP), epirubicin and cyclophosphamide (EC) + docetaxel (EC-D), or EC + WP (EC-WP); older than 18 years; and diagnosed between January 1st, 2011, and December 31st, 2022, were eligible for the study. Disease-free survival (DFS) is the primary reported end point. Overall survival (OS) and safety were the secondary end points.

We included 272 female patients. At a prespecified event-driven data cutoff, with a median follow-up of 26.3 months, the 5-year DFS was 49% (95% CI, 38 to 63) in the AC-D group, 45% (95% CI, 29 to 70) in the AC-WP group, 73% (95% CI, 61 to 100) in the EC-D group, and 72% (95% CI, 44 to 100) in the EC-WP group (hazard ratio [HR], 0.2 [95% CI, 0.06 to 0.67]; P = .08). The 7-year OS was 52% (95% CI, 32 to 83) in the AC-D group, 88% (95% CI, 78 to 99) in the AC-WP group, 95% (95% CI, 88 to 100) in the EC-D group, and 83% (95% CI, 58 to 100) in the EC-WP group (HR, 0.19 [95% CI, 0.06 to 0.66]; P = .03). Most of the grade 3-4 adverse events occurred in the AC-D group, primarily neutropenia, nausea-vomiting, and alopecia.

EC-D was linked to a slightly longer survival free of invasive, noninvasive, or distant disease and a significantly longer OS with fewer adverse events. Further studies are needed to confirm and establish long-term clinical benefits.

Triple-negative breast cancer (TNBC) represents an aggressive subtype of breast cancer, characterized by early metastasis and a poor prognosis. Traditional imaging modalities often lack the sensitivity and molecular specificity required for the early detection of metastatic lesions. In this study, we developed a dual-modal imaging strategy that integrates surface-enhanced Raman scattering (SERS) and bioluminescence imaging probes, utilizing bioorthogonal labeling to track TNBC organ metastasis. The SERS probes were encapsulated with azide-labeled macrophage membranes to extend circulation time and enhance targeting efficiency. Additionally, bioorthogonal metabolic glycolengineering was employed to modify luciferase-labeled tumor cells (4T1-Luc) with bicyclo[6.1.0]nonyne (BCN) groups, facilitating precise binding between the probes and 4T1-Luc cells through click chemistry reactions. This dual-modal imaging approach enabled real-time monitoring of small metastatic lesions with high sensitivity, providing a non-invasive and accurate method for assessing tumor metastasis and therapeutic response in vivo. Our findings indicate that the dual-modal imaging technique, combining SERS and bioluminescence with bioorthogonal labeling, holds significant potential for advanced applications in oncology. STATEMENT OF SIGNIFICANCE: This study devised a surface-enhanced Raman scattering (SERS) and bioluminescence dual-modal imaging strategy integrated with a bioorthogonal label to address the challenge of tracking the metastasis of aggressive triple-negative breast cancer (TNBC). In contrast to conventional methods, this approach facilitated real-time, whole-body monitoring of tumor dissemination through bioluminescence. Simultaneously, it achieved the detection of micro-metastases in organs using SERS, thereby exceeding the sensitivity limitations of existing imaging techniques. Clinical validation with human samples further demonstrated its potential for non-invasive therapeutic assessment and early intervention. By bridging preclinical innovation and clinical requirements, this research offered a transformative tool for precision oncology. It is expected to attract the interest of researchers in the fields of biomedicine, nanotechnology, and cancer therapeutics.

Crossing the blood-brain barrier (BBB) and reaching intracranial tumours is a clinical challenge for current targeted interventions including antibody-based therapies, contributing to poor patient outcomes. Increased cell surface density of human epidermal growth factor receptor 3 (HER3) is associated with a growing number of metastatic tumour types and is observed on tumour cells that acquire resistance to a growing number of clinical targeted therapies. Here we describe the evaluation of HER3-homing nanobiological particles (nanobioparticles (NBPs)) on such tumours in preclinical models and our discovery that systemic NBPs could be found in the brain even in the absence of such tumours. Our subsequent studies described here show that HER3 is prominently associated with both mouse and human brain endothelium and with extravasation of systemic NBPs in mice and in human-derived BBB chips in contrast to non-targeted agents. In mice, systemically delivered NBPs carrying tumoricidal agents reduced the growth of intracranial triple-negative breast cancer cells, which also express HER3, with improved therapeutic profile compared to current therapies and compared to agents using traditional BBB transport routes. As HER3 associates with a growing number of metastatic tumours, the NBPs described here may offer targeted efficacy especially when such tumours localize to the brain.

Amplification of the MYC proto-oncogene is frequently observed in various cancer types, including triple-negative breast cancer (TNBC). Emerging evidence suggests that suppression of local antitumor immune responses by MYC, at least in part, explains the tumor-promoting effects of MYC. Specifically, MYC upregulation was demonstrated to suppress the tumor-cell intrinsic activation of a type I interferon response and thereby hamper innate inflammatory signaling, which may contribute to the disappointing response to immunotherapy in patients with TNBC. In this study, we show that MYC interferes with protein expression and functionality of the STING pathway. MYC-mediated STING downregulation in BT-549 and MDA-MB-231 TNBC cell lines requires the DNA-binding ability of MYC and is independent of binding of MYC to its co-repressor MIZ1. Both STAT1 and STAT3 promote the steady-state expression levels of STING, and STAT3 cooperates with MYC in regulating STING. Conversely, MYC-mediated downregulation of STING affects protein levels of STAT1 and downstream chemokine production. Furthermore, we show that MYC overexpression hampers immune cell activation triggered by DNA damage through etoposide or irradiation treatment and specifically impedes the activation of natural killer cells. Collectively, these results show that MYC controls STING levels and thereby regulates tumor cell-intrinsic inflammatory signaling. These results contribute to our understanding of how MYC suppresses inflammatory signaling in TNBC and may explain why a large fraction of patients with TNBC do not benefit from immunotherapy.

Breast cancer, particularly triple-negative breast cancer (TNBC), evades the body's immune defences, in part by cultivating an immunosuppressive tumour microenvironment. Here, we show that suppressing local steroidogenesis can augment anti-tumour immunity against TNBC. Through targeted metabolomics of steroids coupled with immunohistochemistry, we profiled the existence of immunosuppressive steroids in TNBC patient tumours and discerned the steroidogenic activity in immune-infiltrating regions. In mouse, genetic inhibition of immune cell steroidogenesis restricted TNBC tumour progression with a significant reduction in immunosuppressive components such as tumour associated macrophages. Steroidogenesis inhibition appears to bolster anti-tumour immune responses in dendritic and T cells by impeding glucocorticoid signalling. Undertaking metabolic modelling of the single-cell transcriptomics and targeted tumour-steroidomics, we pinpointed the predominant steroidogenic cells. Inhibiting steroidogenesis pharmacologically using a identified drug, posaconazole, curtailed tumour expansion in a humanised TNBC mouse model. This investigation paves the way for targeting steroidogenesis and its signalling pathways in breast cancer affected by immune-steroid maladaptation.

Breast cancer is the second most common cancer among women in the US, with triple-negative breast cancer (TNBC) accounting for 15-20 % of new diagnoses. TNBC cells lack estrogen and progesterone receptors, and human epidermal growth factor receptor 2, which makes them resistant to standard hormone treatments. Current therapies like chemotherapy and radiation often harm both cancerous and healthy cells, underscoring the need for developing new targeted treatments. ROR1, an oncoprotein that is overexpressed in various cancers, including breast cancer, is minimally present in normal tissues. Targeting ROR1 signaling has been shown to trigger apoptosis and reduce TNBC cell proliferation. A novel macromolecule compound, CPD4, was discovered through in-silico docking for its ability to bind and inhibit the pseudokinase domain of ROR1. In vitro evidence revealed that CPD4 decreases cell viability and induces apoptosis in TNBC cell lines at concentrations of 2-10 μM, while leaving normal breast cells unharmed. CPD4 also blocks migration, invasion, and causes G2/M-phase arrest in TNBC cells. Its mechanism of action involves reducing key downstream markers of ROR1 signaling, particularly the phosphorylation of AKT/GSK3β. In 3D spheroid cultures, CPD4 reduces the size of TNBC spheroids. Moreover, the combination treatment of CPD4 and the standard chemotherapy docetaxel exhibits synergistic efficacy against different TNBC cell lines with a combination index below 0.01. These results suggest that CPD4 holds promise as a therapeutic option for TNBC and could potentially benefit other cancers with ROR1 overexpression.

FANCA is one of the 23 genes whose deficiencies lead to defective DNA interstrand crosslink repair and cancer-prone Fanconi anemia disease. Beyond its functions in DNA repair and tumor suppression, we report that high FANCA expression is strongly associated with breast cancer development. Overexpression of WT-FANCA significantly promotes breast cancer cell proliferation and tumor growth both in vitro and in vivo, while FANCA deficiency severely compromises the proliferation of breast cancer cells, but not non-tumorigenic breast epithelial cells. Heterozygous knockout of FANCA in breast cancer mouse models is sufficient to cause significant reduction of breast tumor growth in vivo. Furthermore, we have shown that high FANCA expression in breast cancer correlates with promoter hypomethylation in a TET-dependent manner, and TET inhibition recapitulates the proliferation defects caused by FANCA deficiency. Our study identifies the oncogenic properties of WT-FANCA and shows that FANCA is a promising target for breast cancer intervention.

Mammographic screening is effective in reducing breast cancer mortality, but the impact of screening on triple-negative breast cancers (TNBCs) outcomes remains debated. This study aims to determine if screen detection is an independent prognostic factor for TNBCs and to analyse the radiological and pathological differences between screen-detected and symptomatic TNBCs.

This retrospective cohort study analysed 353 histologically confirmed TNBC cases diagnosed between 2013 and 2020 at a single institution in Turin, Italy. Cases were categorized into screen-detected and symptomatic groups based on initial presentation. Clinical, radiological and pathological characteristics as well as disease-free survival (DFS) and overall survival (OS) were compared between groups. Statistical analyses included Kaplan-Meier survival curves and Cox proportional hazard models, adjusting for several clinical and biological variables.

50.1% of cases were screen-detected and 49.9% were symptomatic. Screen-detected cases were more commonly smaller (T1 or T2) (96.6%) than symptomatic cases (75%) (p < 0.001). Also, compared to symptomatic tumours, screen-detected ones were more often node negative (62.4% vs. 48%, p = 0.007) and diagnosed at a lower stage (85.4% vs. 63.8%, p < 0.001), with better DFS and OS. Detection method was not an independent prognostic factor, while stage at diagnosis, vascular invasion, histologic type and tumour-infiltrating lymphocytes (TILS) were more significant predictors of prognosis. Radiological and biological features were similar between the two groups.

TNBCs correlate with favourable pathological features and improved survival outcomes in univariate analyses, but these benefits diminish when accounting for traditional prognostic factors. Hence, the better prognosis observed among screen-detected cases is more likely due to stage shift rather than tumour biology.

Standard of care (SoC) for patients with advanced triple-negative breast cancer (TNBC) whose tumors express PD-L1 (combined positive score ⩾ 10) is chemotherapy plus anti-PD-(L)1 inhibitors; however, prognosis and survival for most patients is poor. Datopotamab deruxtecan (Dato-DXd), a novel antibody-drug conjugate comprising a humanized anti-TROP2 IgG1 monoclonal antibody conjugated to a potent topoisomerase I inhibitor payload via a plasma-stable, cleavable, tetrapeptide-based linker, has shown preliminary activity as mono or combination therapy in advanced/metastatic TNBC.

TROPION-Breast05 is an ongoing randomized, open-label, multicenter phase III study. The primary objective is to demonstrate the superiority of Dato-DXd in combination with durvalumab (an anti-PD-L1 antibody) versus SoC treatment in patients with PD-L1-high locally recurrent inoperable or metastatic TNBC.

Patients (⩾18 years) will be randomized 1:1 to receive Dato-DXd (6 mg/kg intravenously (IV) every 3 weeks (Q3W)) plus durvalumab (1120 mg IV Q3W) or investigator's choice of chemotherapy (ICC; paclitaxel, nab-paclitaxel, or gemcitabine plus carboplatin) plus pembrolizumab (200 mg IV Q3W). In selected countries, patients will also be randomized (1:1:1) to a third arm of Dato-DXd monotherapy. The primary study endpoint is progression-free survival (PFS) per blinded independent central review (Dato-DXd plus durvalumab arm vs ICC plus pembrolizumab arm). Overall survival is a key secondary endpoint; other secondary endpoints include PFS (investigator-assessed), objective response rate, duration of response, clinical benefit rate at Week 24 (all assessed in the Dato-DXd plus durvalumab arm vs ICC plus pembrolizumab arm), patient-reported outcomes, and safety.

The study is approved by independent ethics committees or institutional review boards at each study site. All patients will provide written informed consent.

TROPION-Breast05 will assess the potential role of Dato-DXd with or without durvalumab in patients with PD-L1-high advanced or metastatic TNBC. The findings of this trial could lead to a new treatment option for these patients.

ClinicalTrials.gov identifier: NCT06103864 (Date of registration: 27 October 2023).

BRCA-related hormone receptor (HR)-negative breast cancers (BC) are reported to have aggressive tumor biology but also exhibit chemosensitivity. However, the impact of BRCA1/2 pathogenetic variants (PV) on BC outcomes remains unclear. This study compares survival outcomes for HR-negative BC between BRCA carriers and noncarriers.

From 489 female BRCA-carriers prospectively registered in western Sweden (1996-2017), those with primary HR-negative BC who underwent breast surgery until 2019 were included in the BRCA cohort. For each BRCA-carrier, three BRCA-noncarriers with HR-negative BC were matched based on age, time of diagnosis, and follow-up duration. Overall survival (OS) was analyzed using Kaplan‑Meier estimates and Cox proportional hazard ratios after adjustment for stage, chemotherapy, and surgical technique. A sensitivity analysis was performed to investigate the effect of HER2 status on HR-negative BC diagnosed after 2007.

Among the 106 BRCA carriers, 101 (95%) had a BRCA1 and 5 (5%) a BRCA2 PV. Most of the BRCA-carriers (89/106, 84%) were diagnosed with BC prior to genetic screening. Surgical techniques were similar between BRCA-carriers (n = 106) and noncarriers (n = 318). Chemotherapy was more common among BRCA-carriers (87% vs. 72%, p < 0.001). No significant difference in OS was found between BRCA-carriers and noncarriers among patients with HR-negative BC (adjusted HR: 0.81 [95% confidence interval [CI]: 0.43-1.53], p = 0.51) or considering HER2 status (adjusted HR 0.95 [95% CI: 0.43-2.07], p = 0.89).

This study suggests that BRCA1/2 pathogenic variants do not independently impact survival outcomes in HR-negative BC. However, a moderate association between BRCA status and OS cannot be ruled out.

RNA therapeutics offer a promising approach to cancer treatment by precisely regulating cancer-related genes. While lipid nanoparticles (LNPs) are currently the most advanced nonviral clinically approved vectors for RNA therapeutics, their antitumor efficacy is limited by their unspecific hepatic accumulation after systemic administration. Thus, there is an urgent need to enhance the delivery efficiency of LNPs to target tumor-residing tissues. Here, we conjugated the cluster of differentiation 44 (CD44)-specific targeting peptide A6 (KPSSPPEE) to the cholesterol of LNPs via PEG, named AKPC-LNP, enabling specific tumor delivery. This modification significantly improved delivery to breast cancer cells both in vitro and in vivo, as shown by flow cytometry and confocal microscopy. We further used AKPC-siYT to codeliver siRNAs targeting the transcriptional coactivators YAP and TAZ, achieving potent gene silencing and increased cell death in both 2D cultures and 3D tumor spheroids, outperforming unmodified LNPs. In a breast tumor cell xenografted zebrafish model, systemically administered AKPC-siYT induced robust silencing of YAP/TAZ and downstream genes and significantly enhanced tumor suppression compared to unmodified LNPs. Additionally, AKPC-siYT effectively reduced proliferation in prostate cancer organoids and tumor growth in a patient-derived xenograft (PDX) model. Overall, we developed highly efficient AKPC-LNPs carrying RNA therapeutics for targeted cancer therapy.

Multidrug resistance (MDR) in triple-negative breast cancer (TNBC) leads to treatment failure and tumor recurrence. Dysregulation of the MYC oncogene is associated with the pathogenesis of TNBC and the development of chemoresistance via overexpression of ATP-binding cassette (ABC) transporters. Therefore, in the present study, we aimed to identify molecules from a natural product origin that prevent the development of MDR in TNBC by targeting the MYC signaling.

The cell viability of TNBC was evaluated using sulforhodamine assay. Protein levels were detected by western blots or enzyme-linked immunosorbent assays. Intracellular calcein and hoechst33342 accumulation assay aimed to evaluate the inhibitory ability of phytocompounds on drug-efflux functions of ABCB1 and ABCG2 transporters. The Cancer Genome Atlas (TCGA) database was used to explore clinical genomic data. Furthermore, the zebrafish xenotransplantation model bearing Dil-labeled TNBC cells was applied to testify the in vivo effects of phyto-sesquiterpene lactones.

The results of the present study demonstrated that the phyto-sesquiterpene lactones exhibited an MDR prevention effect by repressing efflux activities of ABCB1 and ABCG2 transporters. Mechanistic studies showed that phyto-sesquiterpene lactones inducted TNBC cell apoptosis and cell cycle G2/M arrested by blocking the STAT3/MYC pathway. Clinical genomic data demonstrated that the percentages of MYC amplification and mRNA were upregulated approximately two-fold higher in the TNBC patients than the non-TNBC breast cancer patients. The survival of patients with an alteration in MYC was significantly lower in TNBC as compared to other subtypes. Moreover, the results of the zebrafish xenograft model confirmed that phyto-sesquiterpene lactones exerted stronger inhibitory effects on TNBC tumor growth in vivo.

In conclusion, these three phyto-sesquiterpene lactones were promising candidates for TNBC treatment and shed light on the prevention of developing MDR TNBC.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype characterized by high recurrence rates, low survival rates, and a lack of therapeutic targets. Regulatory Factor X5 (RFX5) is a critical transcription factor during tumor progression. However, the role of RFX5 involving breast cancer or TNBC has not been studied. This study obtained 60 tumor samples of TNBC for analysis and ascertained that RFX5 is linked with the severe stage. We constructed RFX5 knockdown and overexpression models involving TNBC cells. RFX5 overexpression enhanced TNBC cell proliferation by detecting cell vitality and replication of DNA and analyzing cell cycle data. RFX5 facilitated cell migration and invasion, which were determined by wound healing and Transwell assays. The anti-apoptotic RFX5 properties were confirmed with Hoechst staining and Annexin V/PI apoptosis assays. The Notch pathway was activated in TNBC, and Jagged canonical Notch ligand 1 (JAG1) could enhance TNBC growth and metastasis. RFX5 upregulation elevated JAG1 mRNA and protein levels. Chromatin immunoprecipitation and luciferase reporter assays indicated that RFX5 promoted the transcriptional activation of JAG1 by binding the promoter (- 1890/+ 15 or - 1359/+ 15 area). JAG1 knockdown reduced RFX5-induced expression of Notch signaling-related factors Notch1, NICD, and Hes1. This paper indicated that RFX5 is a transcription factor for JAG1 and established that RFX5 could activate the Notch pathway via transcriptional activation of JAG1 and promote TNBC progression. Targeting RFX5 could be a promising therapeutic approach against TNBC.

Chemotherapy remains a standard treatment option for metastatic triple-negative breast cancer (TNBC) but is associated with limited survival. Although some targeted antibody-drug conjugates have demonstrated clinical benefits and are considered standard therapy, persistent unmet medical needs remain due to varying accessibility. The OptiTROP-Breast01 phase 3 trial assessed sacituzumab tirumotecan (sac-TMT) versus chemotherapy in patients with locally recurrent or metastatic TNBC who had received two or more prior therapies, including at least one for metastatic disease. Patients were randomized to sac-TMT (n = 130) or chemotherapy (n = 133). The primary endpoint of progression-free survival (PFS) by blinded independent central review (BICR) was met based on the protocol-specified interim analysis. At final analysis, the median PFS by BICR was 6.7 (95% confidence interval (CI), 5.5-8.0) months with sac-TMT and 2.5 (95% CI, 1.7-2.7) months with chemotherapy (hazard ratio (HR), 0.32; 95% CI, 0.24-0.44; P < 0.00001). Concurrently, at the protocol-specified interim analysis for overall survival (OS), the median OS was not reached (95% CI, 11.2 months to not estimable (NE)) with sac-TMT and 9.4 (95% CI, 8.5-11.7) months with chemotherapy (HR, 0.53; 95% CI, 0.36-0.78; P = 0.0005). The percentage of patients with an objective response was 45.4% with sac-TMT and 12.0% with chemotherapy. The median duration of response was 7.1 (95% CI, 5.6-NE) months with sac-TMT and 3.0 (95% CI, 2.5-NE) months with chemotherapy. The most common treatment-related adverse event with sac-TMT was hematologic toxicity. Sac-TMT demonstrated statistically significant and clinically meaningful improvements in PFS compared to chemotherapy, with a manageable safety profile. The study findings support sac-TMT as an additional effective treatment option for pretreated metastatic TNBC. ClinicalTrials.gov identifier: NCT05347134 .

Neoadjuvant pembrolizumab has shown efficacy in improving pathologic complete response (pCR) rates and survival outcomes in triple-negative breast cancer (TNBC). However, real-world data on its clinical efficacy, safety, and surgical outcomes remain limited.

This retrospective observational study included 331 TNBC patients treated at a single institution from July 2022 to December 2023. Patients received weekly paclitaxel with carboplatin followed by doxorubicin and cyclophosphamide (AC), with or without pembrolizumab. Primary outcomes included pCR rates and surgical de-escalation in the breast and axilla. Secondary outcomes included event-free survival (EFS), overall survival (OS), surgical complications, and persistent immune-related adverse events (irAEs).

The pCR rate was higher in the pembrolizumab group (57.7 %) compared to the control group (49.1 %), with an estimated difference of 8.5 % (p = 0.120). Pembrolizumab enabled 32.7 % of patients initially planned for mastectomy to undergo breast-conserving surgery (BCS). Axillary lymph node dissection (ALND) was avoided in 91 % of pembrolizumab-treated patients versus 86.9 % in the control group. Persistent irAEs were observed in 10.9 % of the pembrolizumab group, with thyroid dysfunction being the most common. Surgical complications were similar between groups. Short-term oncologic outcomes, including EFS and OS, did not differ significantly after a median follow-up of 21 months.

Pembrolizumab demonstrated potential benefits in increasing pCR rates and facilitating surgical de-escalation while maintaining comparable safety to conventional regimens. Persistent irAEs underscore the need for preoperative management and vigilant monitoring. Future studies should identify predictive biomarkers to optimize pembrolizumab's use and assess its long-term impact on survival outcomes.

Breast cancer (BC) is the most frequently diagnosed cancer in women and the second leading cause of death from cancer among women. Metastasis is the major cause of BC-associated mortality. Accumulating evidence implicates Caveolin-1 (Cav-1), a structural protein of plasma membrane caveolae, in BC metastasis. Cav-1 exhibits a dual role, as both a tumor suppressor and promoter depending on the cellular context and BC subtype. This review highlights the role of Cav-1 in modulating glycolytic metabolism, tumor-stromal interactions, apoptosis, and senescence. Additionally, stromal Cav-1's expression is identified as a potential prognostic marker, offering insights into its contrasting roles in tumor suppression and progression. Furthermore, Cav-1's context-dependent effects are explored in BC subtypes including hormone receptor-positive, HER2-positive, and triple-negative BC (TNBC). The review further delves into the role of Cav-1 in regulating the metastatic cascade including extracellular matrix interactions, cell migration and invasion, and premetastatic niche formation. The later sections discuss the therapeutic targeting of Cav-1 by metabolic inhibitors such as betulinic acid and Cav-1 modulating compounds. While Cav-1 may be a potential biomarker and therapeutic target, its heterogeneous expression and context-specific activity necessitates further research to develop precise interventions. Future studies investigating the mechanistic role of Cav-1 in metastasis may pave the way for effective treatment of metastatic BC.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer associated with a poor prognosis and decreased patient survival. It is intimately linked to AXL overexpression and AXL hyperactivation. Here, we explored the therapeutic potential of AX-0085, a small molecule AXL inhibitor. While AX-0085 was previously characterized in the context of lung adenocarcinoma, this study demonstrates its application in triple-negative breast cancer (TNBC) models. AX-0085 exhibited high binding affinity to the ATP binding site located beneath the conserved glycine-rich loop (P-loop) that links the β1 and β2 strands of the AXL kinase domain. Furthermore, it was demonstrated that the benzamide group of AX-0085 and LyS567's Nζ atom could generate a hydrogen bond. AX-0085 efficiently suppressed the AXL/GAS6 signaling pathway activation in TNBC cells in vitro, which in turn prevented AXL/GAS6 signaling-dependent pro-cancerous behavior like cell proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT). In TNBC, an AX-0085-induced cell cycle arrest that took place during the G1 phase reduced the expression of CYCLIN E and CDK2. Additionally, AX-0085 facilitated apoptotic cell death in TNBC. Treatment of AX-0085 on in vivo mouse xenografts transplanted with 4 T1 cells showed a significant tumor reduction. Thus, our findings demonstrate that AX-0085 has an effective therapeutic role in TNBC by inhibiting AXL activation.

To investigate clinicopathologic characteristics and prognosis in secretory breast carcinoma (SBC) and to determine chemotherapy benefits stratified by different subgroups.