miR-877-5p antagonizes the promoting effect of SP on the gastric cancer progression.

ABSTRACT

Gastric cancer is one of the four major tumors in the world and the second leading cause of cancer-related death. It was reported that Substance P (SP), as an oncogenic factor, could regulate the expression of miRNAs in gastric cancer progression. Here, we focused on the role of miR-877-5p in gastric cancer development and the miR-877-5p involvement in the SP-mediated gastric cancer development. The mRNA expression level and cell proliferation were assessed by quantitative real-time PCR and cell counting kit-8 assay, respectively. Flow cytometry was conducted to detect apoptosis, followed by assessing the expression of related apoptosis factors. Dual-luciferase reporter assay was performed to validate the interaction between miR-877-5p and Forkhead cassette M1 (FOXM1). Our results showed that SP treatment significantly increased cell proliferation in gastric cancer. Moreover, the miR-877-5p expression was dose-dependently decreased by SP, whereas FOXM1 expression was markedly increased by SP in gastric cancer cells. miR-877-5p negatively regulated gastric cancer development via inhibiting cell proliferation and promoting apoptosis accompanied by increased cleaved caspase-3, cleaved caspase-9, and Bax protein levels and decreased Bcl-2 level. We confirmed that miR-877-5p could target FOXM1 and negatively regulate its expression. Furthermore, we demonstrated that SP could promote cell proliferation and inhibit apoptosis, while miR-877-5p overexpression reversed the effect of SP on cell proliferation and apoptosis. These results suggest that miR-877-5p overexpression can antagonize the promoting effect of SP on the development of gastric cancer, indicating that miR-877-5p may serve as a promising therapeutic target for gastric cancer.