Investigation of the effects of carbonic anhydrase-IX inhibition on mTOR protein in Renal Cancer Cell Line (CAKI-2)

Carbonic anhydrase (CA) catalyzes the conversion of carbon dioxide / bicarbonate (CO2 / HCO3-). CA-IX is one of the isoenzymes in the CA enzyme family, which has been shown to be associated with tumor development. Expression of CA-IX increases in tumorous tissues. It is known that phosphorylation of intracellular tails (IC) of CA-IX is associated with cancer. PI3K/Akt/mTOR is a signal transduction pathway which is involved in cell proliferation, survival and differentiation. It shows these effects through the activation of S6K1 and 4EBP1 proteins. The activity of mTOR is high in cancer cells and one of the cancer types with the highest expression is renal cancers. The most common histological type of renal cancers is clear cell renal carcinoma. In this study our aim is to assess the effect of CA-IX inhibition on the mTOR pathway, which is known to be effective in the tumorigenesis process. For this purpose, CAKI-2 human clear cell renal carcinoma cell line was used in our study. The WST-1 cytotoxicity test was performed to determine the effective dose of Rapamycin and Acetazolamide, which are the inhibitors we used in our study, on these cell lines. A hypoxic environment was created and its control was verified by Real Time PCR and Western blot methods. Western blot and immunoflourescence staining studies were conducted to determine the effect of CA-IX inhibition on the mTOR pathway. As a result of the study, it has been shown that AZA has an inhibititory effect on the mTOR signal pathway. However, this effect was found to be statistically insignificant (p> 0.05).The demonstration of this inhibition effect is a pioneer for future studies. The results of the study can make an extremely important contribution to new drug applications to be used in cancer treatment.