Journal of Translational Medicine (Jun 2018)

Knockdown of KLF5 suppresses hypoxia-induced resistance to cisplatin in NSCLC cells by regulating HIF-1α-dependent glycolysis through inactivation of the PI3K/Akt/mTOR pathway

  • Tianxiao Gong,
  • Liuqing Cui,
  • Haili Wang,
  • Haoxun Wang,
  • Na Han

DOI
https://doi.org/10.1186/s12967-018-1543-2
Journal volume & issue
Vol. 16, no. 1
pp. 1 – 10

Abstract

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Abstract Background Hypoxia-mediated chemoresistance has been regarded as an important obstacle in the development of cancer treatment. Knockdown of krüppel-like factor 5 (KLF5) was reported to inhibit hypoxia-induced cell survival and promote cell apoptosis in non-small cell lung cancer (NSCLC) cells via direct regulation of hypoxia inducible factor-1α (HIF-1α) expression. However, the roles of KLF5 in the development of hypoxia-induced cisplatin (DDP) resistance and its underlying mechanism in NSCLC cells remain to be further elucidated. Methods Western blot was performed to determine the protein levels of KLF5, P-glycoprotein (P-gp) and HIF-1α in treated NSCLC cells. Cell survival was examined by MTT assay. The effect of KLF5 knockdown on hypoxia-induced glycolysis was assessed by measuring glucose consumption and lactate production. The effect of KLF5 knockdown on the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway was analyzed by western blot. Results Hypoxia upregulated the expression of KLF5 in NSCLC cells. KLF5 knockdown suppressed hypoxia-induced DDP resistance in NSCLC cells, as demonstrated by the increased cytotoxic effects of DDP and reduced P-gp expression in NSCLC cells in hypoxia. Moreover, KLF5 knockdown inhibited hypoxia-induced HIF-1α expression and glycolysis, and KLF5 knockdown suppressed hypoxia-induced DDP resistance by inhibiting HIF-1α-dependent glycolysis in NSCLC cells. Furthermore, KLF5 knockdown suppressed hypoxia-induced activation of the PI3K/Akt/mTOR pathway in NSCLC cells and KLF5 overexpression promoted hypoxia-induced DDP resistance in NSCLC cells through activation of the PI3K/Akt/mTOR pathway. Conclusions KLF5 knockdown could suppress hypoxia-induced DDP resistance, and its mechanism may be due to the inhibition of HIF-1α-dependent glycolysis via inactivation of the PI3K/Akt/mTOR pathway.

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