Dapagliflozin induces apoptosis by downregulating cFILPL and increasing cFILPS instability in Caki-1 cells.

Dapagliflozin is a sodium/glucose cotransporter 2 inhibitor used recently to treat patients with type 2 diabetes. A recent study has demonstrated that dapagliflozin induces apoptosis in human renal and breast tumor cells. However, to the best of our knowledge, the molecular mechanism underlying dapagliflozin-mediated apoptosis in Caki-1 human renal carcinoma cells has not been elucidated. The present study demonstrated that the dapagliflozin treatment dose-dependently increased cell death in Caki-1 cells. Dapagliflozin treatment also induced apoptosis as confirmed by FITC-conjugated Annexin V/PI staining. Additionally, treatment with dapagliflozin reduced the expression levels of anti-apoptotic proteins, cellular Fas-associated death domain-like interleukin-1-converting enzyme-inhibitory protein (cFLIP)_L and cFLIP_S in Caki-1 cells. Benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl-ketone inhibited dapagliflozin-induced apoptosis, implying that dapagliflozin–induced apoptosis is regulated by a caspase-dependent pathway. By contrast, N-acetylcysteine had no effect on dapagliflozin–induced apoptosis and downregulation of cFLIP_L and cFLIP_S expression. Furthermore, overexpression of cFLIP_L, but not cFLIP_S, partially inhibited apoptosis induced by dapagliflozin. cFLIP_L and cFLIP_S mRNA levels remained constant in Caki-1 cells after treatment with 0, 20, 40, 60, 80 and 100 µM dapagliflozin. Notably, it was confirmed that cFLIP_S protein levels were reduced due to the increased cFLIP_S instability in dapagliflozin-treated Caki-1 cells. The present study also demonstrated that dapagliflozin had no effect on HK-2 normal human kidney cells. Taken together, the present study revealed that dapagliflozin induced apoptosis via the downregulation of cFLIP_L and an increase in cFLIP_S instability, suggesting that dapagliflozin may be a feasible drug candidate for the treatment of human renal cancer. [ABSTRACT FROM AUTHOR]