Abstract 179: M6A demethylation enzyme FTO upregulates LDHA and promotes glycolysis and invasion and migration in oral squamous cell carcinoma

Abstract

Abstract Objective: To investigate the role of lactate dehydrogenase A (LDHA) in the glycolysis and invasion and metastasis of oral squamous cell carcinoma (OSCC), and to explore the molecular mechanism of fat mass and obesity-associated protein (FTO) regulating LDHA on the glycolysis and invasion and metastasis of OSCC. Methods: Immunohistochemistry and RT-qPCR were performed to detect the expression of LDHA protein and gene in OSCC and adjacent non-cancerous tissues, and their correlation with clinical prognosis and pathological parameters were analyzed. Lentivirus-mediated shRNA silencing of LDHA and lactate dehydrogenase inhibitor (oxamate) were used to establish stable OSCC Cell lines HSC3 and SCC15, Cell Counting Kit-8 and colony formation assay were applied to evaluate cell proliferation, scratch test and Transwell assay were performed to detect cell migration and invasion, Glucose utilization assay and Lactate production assay were carried out to assess cell uptake of glucose and lactate production respectively. The molecular mechanism of FTO regulating LDHA on glycolysis, invasion and metastasis of oral squamous cell carcinoma was further explored, OSCC cell lines HSC3 and SCC15 transfected with siRNAs to silence FTO expression, EpiQuik™ m6A RNA Methylation Quantification Kit was applied to assess the m6A% in total RNA, the effect of FTO on LDHA expression was detected by Western blot and RT-qPCR. The biological function of FTO on oral squamous cell carcinoma cells was demonstrated by cell experiments in vitro. Results: Compared with adjacent non-cancerous tissues, LDHA was highly expressed in OSCC (P<0.001), which was closely related to the differentiation, clinical stage and T stage of OSCC (P<0.05). Silencing LDHA, FTO or treating oxamate in HSC3 and SCC15 cells reduced glucose consumption, lactate production and cell proliferation, invasion and migration (P<0.05). In addition, after FTO silencing, the m6A level of total RNA increased (P<0.05), while the expression level of LDHA protein and mRNA decreased (P<0.01). Conclusion: FTO may promote the expression of LDHA protein and mRNA in a m6A-dependent manner and enhance the ability of glycolysis, proliferation, invasion and metastasis of OSCC. Note: This abstract was not presented at the meeting. Citation Format: Jinsong Hou. M6A demethylation enzyme FTO upregulates LDHA and promotes glycolysis and invasion and migration in oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 179.