RGS1 targeted by miR-191-3p inhibited the stemness properties of esophageal cancer cells by suppressing CXCR4/PI3K/AKT signaling.

ABSTRACT

BACKGROUND: Esophageal cancer is one of the most common malignant tumors in the world. It is urgent to prevent the development and progression of esophageal cancer. Cancer stem cells (CSCs) were reported to have the ability to initiate tumorigenesis, and reducing the stem cell-like characteristics of tumors is an important strategy to inhibit the occurrence and development of tumors. miRNAs are key regulators of the stemness of cancer. Here, we aimed to investigate the role and regulatory mechanism of miR-191-3p in the stemness properties of esophageal cancer cells. METHODS: Esophageal cancer cells with stable expression of miR-191-3p were established by lentivirus system. CCK-8 assay, transwell assay, wound healing assay were used to evaluate the effect of miR-191-3p on proliferation and metastasis of esophageal cancer cells. The expression of stemness-related markers (NANOG, OCT4, SOX2), ALDH activity, sphere-forming assay and subcutaneous tumor model in nude mice were performed to evaluate the stemness properties of esophageal cancer cells in vitro and in vivo. Dual-luciferase reporter assay was used to verify the molecular mechanism. RESULT: Here we found that overexpression of miR-191-3p promoted the stemness properties of esophageal cancer cells in vitro and in vivo, including increasing esophageal cancer cell proliferation and metastasis ability, the expression of stemness-related markers NANOG, OCT4, and SOX2, ALDH activity, the number of spheres formed and tumor growth. Bioinformatic analysis and dual-luciferase assay demonstrated that regulator of G protein signaling 1 (RGS1) was the directed target gene of miR-191-3p and attenuated the promotion effect of miR-191-3p on the stemness of esophageal cancer cells. Furthermore, we found that RGS1 knockdown activated the PI3K/AKT pathway by negatively regulating CXCR4 to promote the stemness of esophageal cancer cells. CONCLUSIONS: Our findings revealed that RGS1 targeted by miR-191-3p inhibited the stemness of esophageal cancer cells by suppressing the CXCR4/PI3K/AKT pathway, which provide potential prognostic markers and therapeutic targets in the future.