Vitamin D Affects the Warburg Effect and Stemness Maintenance of Non- Small-Cell Lung Cancer Cells by Regulating the PI3K/AKT/mTOR Signaling Pathway

Background: Non-Small-Cell Lung Cancer (NSCLC) is the most prevalent form of lung cancer, accounting for approximately 85% of all lung cancer cases and resulting in high morbidity and mortality. Previous studies have demonstrated that 1,25-dihydroxy-vitamin-D3 (vitamin D) exhibited anti-cancer activity against breast and prostate cancer. Objectives: The aim of the current study is to investigate the effect of vitamin D on NSCLC and its underlying mechanism. Methods: The effects of vitamin D on stemness maintenance and the Warburg effect in NSCLC cells were investigated both in vitro and in vivo. Results and Discussion: In vitro experiments revealed that vitamin D inhibited glycolysis and stemness maintenance in A549 and NCI-H1975 cells. Both in vitro and in vivo experiments indicated that vitamin D attenuated the expression of metabolism-related enzymes associated with the Warburg effect (GLUT1, LDHA, HK2, and PKM2). In addition, vitamin D down-regulated the expression of stemness-related genes (Oct-4, SOX-2, and Nanog) and the expression of PI3K, AKT, and mTOR. Conclusion: Overall, these findings suggest that vitamin D suppresses the Warburg effect and stemness maintenance in NSCLC cells via the inactivation of PI3K/AKT/mTOR signaling, thereby inhibiting the progression of NSCLC. The current study indicates that vitamin D is a potential candidate in therapeutic strategies against NSCLC.