Hypoxia increases RCC stem cell phenotype via altering the androgen receptor (AR)-lncTCFL5-2-YBX1-SOX2 signaling axis
Chuanyong Guo, Yin Sun, Wei Zhai, Xudong Yao, Dongkui Gong, Bosen You, Chi‐Ping Huang, Junhua Zheng, Chawnshang Chang
Abstract
BACKGROUND: Early studies indicated that the androgen receptor (AR) could promote renal cell carcinoma (RCC) development and metastasis, but its linkage to RCC progression under hypoxia, remains unclear. RESULTS: Here we found AR expression in RCC cells decreased in response to hypoxia, which might then lead to increase the cancer stem cells (CSC) phenotype through the lncTCFL5-2-modulated YBX1/SOX2 signals. The consequences of such hypoxia-modulated AR/lncTCFL5-2/YBX1/SOX2 signals ablity to alter the CSC phenotype might render RCC cells more resistant to targeted therapy with Sunitinib. Mechanism dissection revealed that AR might alter the lncTCFL5-2/YBX1/SOX2 signaling through transcriptional suppression of the lncTCFL5-2 expression via the AR-response-elements (AREs) on the lncTCFL5-2 promoter. The lncTCFL5-2 interacts with YBX1 to increase its stability, which in turn increases SOX2 expression at a transcriptional level via the YBX1-response-elements (YBX1Es) on the SOX2 promoter. The in vivo mouse model with orthotopic xenografts of RCC cells also validates the in vitro data, and a human RCC sample survey demonstrated the clinical significance of the AR/lncTCFL5-2/YBX1/SOX2 signaling axis for the RCC prognosis, likely as a result of regulating CSC phenotypes. CONCLUSIONS: Together, these findings suggest that hypoxia may increase the RCC CSC phenotype via altering the AR/lncTCFL5-2/YBX1/SOX2 signaling axis and a potential therapy to target this newly identified signal perhaps may help improve the targeted therapy with Sunitinib to better suppress RCC progression.