Clear cell renal carcinoma essentially requires CDKL3 for oncogenesis

Clear cell renal cell carcinoma (ccRCC) is the predominant human renal cancer with surging incidence and fatality lately. Hyperactivation of hypoxia-inducible factor (HIF) and mammalian target of rapamycin (mTOR) signaling are the common signatures in ccRCC. Herein, we employed spontaneous ccRCC model to demonstrate the indispensability of an underappreciated Ser/Thr kinase, CDKL3, in the initiation and progression of ccRCC. Ablation of CDKL3 does not affect normal kidney, but abrogates Akt-mTOR hyperactivity and thoroughly prevents the formation and growth of the HIF-agitated ccRCC in vivo. Remarkable clinical correlations also supported the oncogenic role of CDKL3. Mechanism-wise, cytosolic CDKL3 unexpectedly behaves as the adaptor to physically potentiate mTORC2-dependent Akt activation without functioning through kinase activity. And mTORC2 can phosphorylate and stabilize CDKL3 to form a positive feedback loop to sustain the cancer-favored Akt-mTOR overactivation. Together, we revealed the pathological importance and molecular mechanism of CDKL3-mediated Akt-mTOR axis in ccRCC initiation and progression.