Up-regulation of SR-BI promotes progression and serves as a prognostic biomarker in clear cell renal cell carcinoma

作者：Xu, Guang-hua; Lou, Ning; Shi, Hang-chuan; Xu, Yu-chen; Ruan, Hai-long; Xiao, Wen; Liu, Lei; Li, Xiang; Xiao, Hai-bing; Qiu, Bin; Bao, Lin; Yuan, Chang-fei; Zhou, Ya-li; Hu, Wen-jun; Chen, Ke; Yang, Hong-mei^*; Zhang, Xiao-ping^*

来源：BMC Cancer, 2018, 18(1): 88.

DOI：10.1186/s12885-017-3761-z

• Scavenger receptor class B type I (SR-BI)
• Clear cell renal cell carcinoma (ccRCC)
• Progression
• Prognostic biomarker

Background: Scavenger receptor class B type I (SR-BI) has been reported to be involved in carcinogenesis of several human cancers. However, it is currently unknown whether SR-BI plays a role in clear cell renal cell carcinoma (ccRCC). Here, we aimed to evaluate a tumor promotive mechanism for SR-BI in ccRCC. @@@ Methods: The expression of SR-BI was evaluated by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blot and immunohistochemistry (IHC) in ccRCC tissues and cell lines. Lipid droplets in ccRCC tissues and normal kidney tissues were examined by Oil Red O (ORO) and hematoxylin-eosin (HE) staining. The correlation between SR-BI mRNA levels and clinicopathological features was analyzed by Pearson's chi-square test or Fisher's exact test. Kaplan-Meier analysis and Cox model were used to evaluate the difference in progression-free survival (PFS) associated with expression of SR-BI. Inhibition of SR-BI was conducted by using small interfering RNA (siRNA). In vitro assays were performed to assess the impact of SR-BI knockdown on cell biological behaviors. High density lipoprotein (HDL)-cholesterol content in ccRCC cells and extracellular media was also measured after transfection with siRNA. @@@ Results: The expression of SR-BI was markedly up-regulated in ccRCC tissues and tumor cell lines. ORO and HE staining revealed huge amounts of lipid droplets accumulation in ccRCC. Clinical analysis showed that over-expression of SR-BI was positively associated with tumor size, grade, distant metastasis and inversely correlated with PFS. Furthermore, SR-BI was proved to be an independent prognostic marker in ccRCC patients. The inhibition of SR-BI attenuated the tumorous behaviors of ccRCC cells, expression of metastasis and AKT pathway related proteins. The content of HDL-cholesterol was reduced in cells while increased in extracellular media after transfection with si-SR-BI. @@@ Conclusions: Our results demonstrate that SR-BI functions as an oncogene and promotes progression of ccRCC. SR-BI may serve as a potential prognostic biomarker and therapeutic target for ccRCC.

• 出版日期2018-1-22
• 单位华中科技大学