Knockdown of FOXO6 Inhibits Glycolysis and Reduces Cell Resistance to Paclitaxel in HCC Cells via PI3K/Akt Signaling Pathway

Purpose: Previous studies have reported that FOXO6 is highly expressed in hepatocellular carcinoma (HCC) tissues and is associated with the prognosis of HCC patients. However, little research has been carried out to explore the role of FOXO6 in glycolysis of HCC cells and paclitaxel resistance. Today, along with the increasing incidence and mortality of HCC, chemotherapy resistance of HCC also poses a serious challenge. Therefore, this study was set out to investigate the effect of FOXO6 on glycolysis and cytotoxicity of paclitaxel in HCC cells and its potential mechanism. Patients and Methods: The levels of FOXO6 mRNA and protein were detected by qRT-PCR and Western blot, respectively. In addition, paclitaxel-resistant cell lines of HCC cells were established, whose activity was assessed by CCK-8 assay, among which the invasion ability was assessed by Transwell and the apoptosis rate by flow cytometry. What is more, glycolysis levels were evaluated by measuring glucose consumption and lactic acid production, and the protein levels of p-PI3K and p-protein kinase B (Akt) were determined by Western blot. Results: Compared with normal human hepatocytes, FOXO6 was highly expressed in HCC cells, which was of high real value for HCC. FOXO6 knockdown inhibited the proliferation and invasion and induced apoptosis of HCC cells. In addition, FOXO6 knockdown suppressed glycolysis, reversed resistance to chemotherapy in Hep3B/PTX cells and inactivated PI3K and Akt proteins, thus inhibiting the PI3K/Akt signaling pathway. Furthermore, it was found that when activated by 740Y-P, PI3K/Akt signaling pathway could resist the effects of FOXO6 knockdown on the cytotoxicity and glycolysis of paclitaxel in HCC cells. Vice versa, inhibition of PI3K/Akt pathway by LY294002 could resist the effect of FOXO6 overexpression on chemotherapy, cytotoxicity and glycolysis of HCC cells. Conclusion: FOXO6 knockdown can inhibit glycolysis of HCC cells and reduce their resistance to chemotherapy by inhibiting the PI3K/Akt signaling pathway, which may be a new target for the treatment of HCC.