Mechanism and function of decreased FOXO1 in renal cell carcinoma

Background and Objectives Forkhead box O-class 1 (FOXO1), a putative tumor suppressor, is dysregulated in many cancers. Our study aims to reveal the underlying functions and regulation mechanisms of FOXO1 in renal cell carcinoma (RCC). Methods The clinical significance of FOXO1 expression in surgically resected specimens was assessed by immunohistochemistry. The siRNAs targeted FOXO1 and miR-27a inhibitor were transfected into RCC cells. QRT-PCR, Western blot, and cell proliferation assay were used to assess the expression and function of FOXO1 and miR-27a. Results The positive immunostaining for FOXO1 was low in 51 RCC samples compared with 15 normal kidney tissues. And the expression of FOXO1 was related with RCC subtypes and the grade and stage in clear cell RCC (cRCC) (P?