Lnc-BM Promotes Gastric Cancer Progression by Regulating Mitochondrial Respiratory Function Through FASTK/MT-ND6 Axis

Objective To explore the role and molecular mechanism of Lnc-BM in the occurrence and development of gastric cancer (GC).

Methods GC tissues and paired adjacent normal tissues of 36 GC patients were collected, and the expression of Lnc-BM was detected by RT-qPCR. Colony formation and CCK-8 assays were used to investigate the proliferation of GC cells. The migration and invasion properties of GC cells were investigated via Transwell assay. RNA pull-down assay was applied to confirm the interaction between FASTK and Lnc-BM. Western blot assay was used to detect FASTK protein level in Lnc-BM overexpressing or knockdown cells. Mitochondrial respiratory capacity and the related proteins expression levels were detected by Seahorse and Western blot assays, respectively. Lnc-BM stably overexpressing GC cells were constructed and then injected subcutaneously into nude mice. The tumor growth was observed.

Results Lnc-BM was highly expressed in GC tissues compared with their paired adjacent normal tissues. Lnc-BM overexpression significantly promoted GC cells proliferation migration and invasion, while Lnc-BM knockdown inhibited GC cells proliferation, migration and invasion (P < 0.05). RNA pull-down experiment demonstrated that Lnc-BM can directly bind to FASTK. Western blot results indicated that overexpression of Lnc-BM increased the protein levels of FASTK, while knockdown of Lnc-BM inhibited the expression of FASTK (P < 0.05). Compared to the control group, overexpression of Lnc-BM increased the levels of mitochondria associated proteins, such as MT-ND6 and TOM20 (P < 0.05). Seahorse results indicated that overexpression of Lnc-BM enhanced mitochondrial respiratory capacity (P < 0.05). Knocking down FASTK in Lnc-BM stably overexpressing cells can reverse the increase in mitochondrial respiratory capacity caused by Lnc-BM overexpression (P < 0.05). In vivo, the results of subcutaneously implanted tumor model in nude mouse showed that Lnc-BM overexpression promoted the tumor growth (P < 0.05).

Conclusion Lnc-BM promotes GC progression by regulating mitochondrial respiratory function through the FASTK/MT-ND6 axis.