Abstract
Cholesterol homeostasis plays an important role in the maintenance of normal body functions. CYP27A1 is a key enzyme known to regulate cholesterol homeostasis, which catalyzes the conversion of cholesterol to 27-HC and has been implicated in the occurrence and metastasis of various cancer types. The present study aimed to explore the regulatory role of CYP27A1 in the development of clear cell renal cell carcinoma (ccRCC). In particular, the effect of CYP27A1 on the proliferation and migration of ccRCC cells was investigated. The construction of a stable 786-O cell line overexpressing CYP27A1/pLVX was mediated by lentiviral infection. The proliferative capacity was assessed using MTT and colony formation. Wound healing assay was used to measure cell migration. Production of intracellular cholesterol and 27-HC was detected by enzyme-linked immunosorbent assay. The LXRs/ABCA1 pathway of cholesterol metabolism regulation was studied by RT-qPCR and Western blotting analysis after cells were treated with stimulation agents of 27-HC or T0901317 and inhibition agents of siRNA or GSK2033. The results revealed that overexpression of CYP27A1 could increase the intracellular production of 27-HC and inhibit the proliferation and migration of 786-O cells. And the treatment of 786-O cells with 27-HC induced a similar effect. CYP27A1/27HC mediated activation of the liver X receptors (LXRs) could up-regulate the expression of ATP-binding cassette transporter A1 (ABCA1), further resulting in the reduction of intracellular cholesterol contents. All of these findings indicated a regulatory role of CYP27A1 in the proliferation and migration of ccRCC, via activating LXRs/ABCA1 to regulate cholesterol homeostasis.