NKAP promotes renal cell carcinoma growth via AKT/mTOR signalling pathway

Renal cell carcinoma (RCC) is the seventh most common site for malignant tumours worldwide leading to a high risk of death. NKAP is a conserved nuclear protein that has critical roles in the development, maturation, and functional acquisition of T cells, iNKT cells, and cancers. But the function and underlying mechanism of NKAP in RCC is still unknown. Knockdown of NKAP by siRNA interference (siNKAP) was used to explore the roles of NAKP in human RCC cells. Here, we found that siNKAP strongly inhibited the proliferation and motility of Ketr-3 and 786-0 cells and induced cell apoptosis. Furthermore, the expression of anti-apoptotic protein Bcl2 in the siNKAP group was strongly decreased, while the expression of pro-apoptotic proteins Bax, cleaved Caspase-3, and cleaved Caspase-9 was significantly increased. Finally, to identify the potential mechanisms, we detected related proteins of the AKT/mTOR signalling pathway by western blot assay. We found that siNKAP significantly inhibited the expression of cyclin D1 and the phosphorylation of AKT and mTOR. The findings for the first time reveal that the AKT/mTOR signalling pathway is involved in the oncogenic role of NKAP in RCC, which provides an important basis for exploring the molecular regulation mechanism of RCC. SIGNIFICANCE OF THE STUDY: There is an urgent need to study the molecular mechanisms involved in RCC to promote the development of early diagnosis and more effective treatment options. This research provides an important basis for exploring the accurate regulatory mechanism of NKAP in RCC and a novel perspective to find the potential utility of NKAP inhibitors for RCC therapy.