Abstract: Background and purpose: Clear cell renal cell carcinoma (ccRCC) has become the most common subtype of renal cell carcinoma. ccRCC is  trongly related to metabolism. This study was designed to investigate the effects of silent information regulator 4 (SIRT4) overexpression or glutamine deprivation on the proliferation and apoptosis of ccRCC. Methods: We constructed Caki-2 cell lines stably expressing SIRT4 and SIRT4-H161Y by lentivirus infection. The glutamine deprivation model was constructed by the glutamine-free medium. We detected the proliferation and growth capacity of Caki-2 cells using cell counting kit-8 (CCK-8) assay and clone formation assay. DCFH-DA fluorescent probe was used to monitor intracellular reactive oxygen species (ROS) to evaluate the effect of glutamine on ROS generation. Moreover, the effects of SIRT4 and glutamine deprivation on apoptosis in Caki-2 cell line were analyzed by mitochondrial membrane potential detection, apoptosis detection, and Western blot. Results: SIRT4 overexpression inhibited the proliferation of Caki-2 cells through its inhibition of glutamine metabolism. Meanwhile, restricting glutamine metabolism was accompanied by a reduction of antioxidant NADPH and aggrandizement of intracellular ROS to promote apoptosis. The effects of glutamine deprivation on inhibiting cell proliferation and promoting apoptosis were more obvious than that of overexpression of SIRT4. However, no cell could grow under long-term lack of glutamine. Conclusion: SIRT4 overexpression and glutamine deprivation both could inhibit cell proliferation and promote apoptosis in ccRCC.

Key words: Silent information regulator 4, Clear cell renal cell carcinoma, Proliferation, Apoptosis