Published online Aug 21, 2023. doi: 10.3748/wjg.v29.i31.4783
Peer-review started: April 4, 2023
First decision: April 12, 2023
Revised: April 29, 2023
Accepted: July 27, 2023
Article in press: July 27, 2023
Published online: August 21, 2023
Processing time: 136 Days and 5.5 Hours
Esophageal cancer (EC) is a common malignant cancer type and the sixth leading cause of cancer-related mortality worldwide. The main treatment options for esophageal squamous cell carcinoma (ESCC) include surgery, radiotherapy, and chemotherapy. Due to its high invasiveness and high recurrence and metastasis rates, the prognosis of ESCC patients remains poor despite the use of multidisciplinary treatment. The 5-year overall survival rate of ESCC patients is only 30%-40%. However, the prognosis of patients with advanced or metastatic EC is even worse, with a 5-year overall survival rate of less than 15%.
Poly(A)-specific ribonuclease (PARN) is a multifunctional enzyme that plays a crucial role in the occurrence and development of a variety of cancer types. The aim of this study was to explore the relationship between PARN and the proliferation, metastasis and invasion of EC cells to evaluate whether PARN could be a potential biomarker and drug target for the treatment of EC.
The objects of this study are as follows: (1) EC tissues and paired adjacent normal tissues were obtained from 91 patients with EC after surgery; (2) EC lines Eca-109 and TE-1; and (3) Nude mice.
The expression of PARN mRNA was measured using a tissue microarray, and the expression of PARN was also detected using immunohistochemistry. The relationship between PARN expression and clinicopathological features and the survival prognosis of patients was analyzed. The effect of PARN on the proliferation, invasion and migration of Eca-109 and TE-1 EC cells was investigated in vitro by knocking down PARN using shRNA. The effect of PARN on tumor growth in vivo was verified by a nude mouse xenograft model.
Our study found that PARN expression in EC tissues is clearly higher than that in adjacent healthy tissues and is significantly correlated with lymph node metastasis and poor survival. It was confirmed that PARN can promote the growth and proliferation of EC cells. Compared with the control shRNA group, the PARN shRNA group exhibited a significantly increased percentage of cells in the G2/M phase, suggesting that PARN affects the proliferation of carcinoma cells by regulating their cell cycle. Knockdown of the PARN gene promoted apoptosis by regulating apoptotic proteins. Wound healing tests and transwell invasion tests confirmed the promoting effect of PARN on the migration and invasion of EC cells. In the BALB/c nude mouse xenograft model, the apoptosis ratio of Eca-109 and TE-1 cells was significantly increased after PARN knockout, and the cell proliferation rate was significantly decreased, as well as the percentage of cells in G2/M phase arrest.
Our study preliminarily concluded that PARN may inhibit EC cell apoptosis and cell cycle arrest through the PI3K/Akt pathway, thus promoting tumor cell proliferation, invasion and migration and further accelerating the progression of EC.
PARN can be used as a prognostic marker and therapeutic target for the diagnosis and treatment of EC.