Targeting the MALAT1-miR-206-GLS axis enhances the apoptotic effects of gastric cancer cells by mild hyperthermia treatments

Abstract

Background: To explore the molecular mechanisms and modulatory effects of long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the hyperthermia-induced gastric cancer cell death. Methods: Combined qRT-PCR and GLS activity detection of glutamine metabolism, we demonstrate the difference of expression of MALAT1 and miR-206 in normal or cancer tissue/ several cell lines and the roles of two in regulation of glutamine, respectively. The relation of MALAT1 and miR-206 was research by bioinformatical analysis and luciferase report. In addition, the molecular regulation between apoptotic effects and MALAT1-miR-206-GLS axis in gastric cancer after mild hyperthermia treatments were discovered by western blotting, luciferase report, quantitative real-time PCR (qRT-PCR), GLS activity detection of glutamine metabolism and cell viability test. Results: MALAT1 positively associated with GC by promoting glutamine metabolism under short time hyperthermia treatment, it involved in an adaptive reaction, an increased glutamine metabolism rate which could be further overridden by long time hyperthermia exposures. miR-206 could inhibit glutamine metabolism of GC and target 3’UTR of GLS which has oncogenic functions in GC directly. In addition, miR-206-suppresed glutamine metabolism was through direct targeting GLS. LncRNA MALAT1 inhibited miR-206 expression in GC by sponging it as a competing endogenous RNA. In summary, MALAT1-promoted glutamine metabolism was through the miR-206-GLS axis. Furthermore, we demonstrated effective approaches from the MALAT1-miR-206 axis for enhancing the mild hyperthermia-induced cancer death under a short time. Conclusions: Taken together, the MALAT1-miR-206-glutamine metabolism axis is a new strategy for enhancing the selectivity of hyperthermia treatments specific to GC cells