Basic Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 28, 2021; 27(16): 1785-1804
Published online Apr 28, 2021. doi: 10.3748/wjg.v27.i16.1785
Depletion of MRPL35 inhibits gastric carcinoma cell proliferation by regulating downstream signaling proteins
Ling Yuan, Jia-Xin Li, Yi Yang, Yan Chen, Ting-Ting Ma, Shuang Liang, Yang Bu, Lei Yu, Yi Nan
Ling Yuan, Jia-Xin Li, Yi Yang, Ting-Ting Ma, Pharmacy College of Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
Ling Yuan, Yi Nan, Key Laboratory of Hui Ethnic Medicine Modernization of Ministry of Education, Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
Yan Chen, Traditional Chinese Medicine College, Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
Shuang Liang, Department of Oncology and Endocrinology, Yinchuan Hospital of Traditional Chinese Medicine Affiliated to Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
Yang Bu, Department of Hepatobiliary Surgery, General Hospital of Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
Lei Yu, Department of Infectious Diseases, The Fourth Hospital of Harbin Medical University, Harbin 150001, Heilongjiang Province, China
Author contributions: Nan Y provided the conceptual and technical guidance, designed the study, and revised the manuscript critically for important intellectual content; Yuan L carried out most of in vivo studies, analyzed the data, and wrote the manuscript; Li JX carried out all of in vitro experiments and wrote the manuscript; Yang Y and Ma TT performed parts of in vivo studies; Chen Y conducted statistical analysis of all of the data; Liang S, Bu Y, and Yu L supervised the clinical relevance and coordinated the clinic pathological features; all authors have read and approved the manuscript.
Supported by Ningxia Natural Science Foundation, No. 2020AAC03130.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of Ningxia Medical University (No. 2020-071).
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Ningxia Medical University (IACUC protocol number: 2019-083).
Conflict-of-interest statement: All authors declare no financial or commercial conflict of interest.
Data sharing statement: All data generated or analyzed during this study are included in this published article.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yi Nan, MD, PhD, Professor, Key Laboratory of Hui Ethnic Medicine Modernization of Ministry of Education, Ningxia Medical University, No. 1160 Shengli Street, Yinchuan 750004, Ningxia Hui Autonomous Region, China. 20080011@nxmu.edu.cn
Received: December 22, 2020
Peer-review started: December 22, 2020
First decision: January 23, 2021
Revised: February 4, 2021
Accepted: March 11, 2021
Article in press: March 11, 2021
Published online: April 28, 2021
Processing time: 119 Days and 18 Hours
Abstract
BACKGROUND

Gastric carcinoma (GC) is a digestive system disease with high morbidity and mortality. However, early clinical detection is difficult, and the therapeutic effect for advanced disease is not satisfactory. Thus, finding new tumor markers and therapeutic targets conducive to the treatment of GC is imperative. MRPL35 is a member of the large subunit family of mitochondrial ribosomal protein. MRPL35 shows the characteristic of oncogene in colorectal cancer and esophageal cancer, which promotes the exploration of the correlation between MRPL35 and GC. We proposed that the expression of MRPL35 might be critical in GC.

AIM

To study the effect of MRPL35 knockdown on GC cell proliferation.

METHODS

The expression of MRPL35 in GC was evaluated based on data from the public tumor database UALCAN (http://www.ualcan.path.uab.edu). The effect of the expression of MRPL35 on the prognosis was evaluated with KMplot (http://www.kmplot.com). The expression of MRPL35 was assessed on the tissue microarray by immunohistochemistry and the level of MRPL35 mRNA in 25 pairs of clinical GC tissues and matched adjacent tissues was detected by quantitative reverse transcription-polymerase chain reaction. Celigo cell count assay, colony formation assay, and flow cytometry were used to assess the role of MRPL35 in GC cell proliferation and apoptosis in vitro. Additionally, tumor formation experiment in BALB/c nude mice was utilized to determine the effect of MRPL35 on GC cell proliferation. After knockdown of MRPL35, related proteins were identified by isobaric tags for relative and absolute quantification analysis, and the expression of related proteins was detected by Western blot.

RESULTS

The expression of MRPL35 was up-regulated in GC (P = 1.77 × 10-4). The Kaplan-Meier plots of the overall survival indicated that high expression of MRPL35 was associated with a poor survival in GC. Compared with adjacent tissues, the expression of MRPL35 in GC tissues was increased, which was related to age (P = 0.03), lymph node metastasis (P = 0.007), and pathological tumor-node-metastasis stage (P = 0.024). Knockdown of MRPL35 inhibited GC cell proliferation and colony formation and induced apoptosis. Animal experiment results showed that knockdown of MRPL35 inhibited tumor formation in BALB/c nude mice. Western blotting analysis showed that after knockdown of MRPL35, the expression of PICK1 and BCL-XL proteins decreased, and that of AGR2 protein increased.

CONCLUSION

Collectively, our findings demonstrate that knockdown of MRPL35 inhibits GC cell proliferation through related proteins including PICK1, BCL-XL, and AGR2.

Keywords: Gastric carcinoma; MRPL35; Apoptosis; Proliferation; Tissue microarray; Isobaric tags for relative and absolute quantification

Core Tip: MRPL35 is a member of the large subunit family of mitochondrial ribosomal protein. Our results showed that compared with adjacent tissues, the expression of MRPL35 in gastric carcinoma (GC) tissues was increased significantly, which was related to age, lymph node metastasis, and pathological tumor-node-metastasis stage of GC patients. Knockdown of MRPL35 inhibited GC cell proliferation, clone formation, and tumor formation in BALB/c nude mice, induced apoptosis, reduced the expression of PICK1 and BCL-XL proteins, and increased that of AGR2 protein. These data indicate that MRPL35 might be an oncogene and be used as a new therapeutic target for GC.