Molecular Mechanism of the Canonical Oncogenic lncRNA MALAT1 in Gastric Cancer

Background: Experimental evidence has shown that lncRNA MALAT1 is related to proliferation ability, invasion and migration ability, autophagy ability, and chemoresistance in gastric cancer. Moreover, MALAT1 is related to metastasis and patient prognosis in gastric cancer. This review aims to reveal the biological functions and specific mechanisms of MALAT1 in gastric cancer. Methods: After a comprehensive and systematic search in PubMed, various molecular mechanisms of MALAT1 in mediating gastric carcinogenesis are collated and summarized. Results: MALAT1-mediated gastric cancer is involved in a variety of molecular mechanisms. For example, MALAT1 can enhance the proliferation ability of gastric cancer cells by inhibiting the expressions of miR-122, miR-1297, miR-22-3p, miR-202, etc. MALAT1 enhances the metastasis and invasion of gastric cancer by participating in the EMT process, PI3-Akt and other pathways. MALAT1 enhances the proliferation and invasion of gastric cancer by inhibiting the function of the tumor suppressor gene PCDH10. MALAT1 can increase the autophagy ability of gastric cancer cells by inhibiting miR-183 and increasing the level of autophagy markers. MALAT1 enhances chemical resistance by inhibiting UPF1 and miR-30e levels. Conclusions: MALAT1 is tightly linked to gastric carcinogenesis through various molecular mechanisms. Moreover, MALAT1 is also closely associated with chemoresistance and poor prognosis in gastric cancer patients, suggesting the possibility of its use as a clinical therapeutic target and a promising independent risk factor for predicting patient prognosis.