The LINC00152/miR-205-5p/CXCL11 axis in hepatocellular carcinoma cancer-associated fibroblasts affects cancer cell phenotypes and tumor growth.

backgroundCXCL11 has been reported to be up-regulated in hepatocellular carcinoma (HCC) tissues and cancer-associated fibroblasts (CAFs), and CAF-secreted CXCL11 has been found to promote HCC cell proliferation and migration. Knowledge on how CAFs promote HCC progression is imperative for the future design of anti-tumor drugs addressing the high rates of disease recurrence. Herein, we propose a mechanism by which LINC00152 positively regulates CXCL11 expression and, subsequently, HCC cell phenotypes and growth characteristics via miR-205-5p in CAFs.

methodsThe expression of LINC00152, miR-205-5p in HCC/non-cancerous tissues, CAFs/NFs and HCC cell lines was determined by RT-qPCR. The CXCL11 expression and secretion were determined by westernblot and ELISA. Different expressions of LINC00152, CXCL11 and miR-205-5p in CAFs were achieved by transfection with corresponding overexpression/knockdown vectors or mimics/inhibitor. The interactions among LINC00152, miR-205-5p and CXCL11 were confirmed by FISH, luciferase, AGO2 and RNA-pulldown assays. Transwell, colony formation and MTT assays were performed to assess the role of CAFs conditioned medium (CM) in HCC cell phenotype. BALB/c nude mice xenografts were used to determine the role of CAFs on HCC growth in vivo.

resultsWe found that in vitro, CM from CAFs transfected with sh-LINC00152 dramatically suppressed HCC cell viability, colony formation and migration, and that CM from CAFs transfected with miR-205-5p inhibitor (CAF-CM (miR-205-5p inhibitor)) exerted opposite effects on HCC cell phenotypes. Exogenous overexpression of CXCL11 in CAFs or CAF-CM (miR-205-5p inhibitor) could partially attenuate the effects of LINC00152 knockdown. In contrast, CM from CAFs transfected with LINC00152 dramatically increased HCC cell viability, colony formation and migration, and CM from CAFs transfected with miR-205-5p mimics (CAF-CM (miR-205-5p mimics)) exerted opposite effects on HCC cell phenotypes. Knockdown of CXCL11 in CAFs or CAF-CM (miR-205-5p mimics) could partially attenuate the effects of LINC00152 overexpression. In vivo, LINC00152 knockdown in CAFs inhibited tumor growth in a mouse model, which could be reversed by CXCL11 overexpression in CAFs. Mechanistically, we found that LINC00152 could act as a ceRNA to counteract miR-205-5p-mediated suppression on CXCL11 by directly binding to miR-205-5p and the 3'UTR of CXCL11.

conclusionOur data indicate that a LINC00152/miR-205-5p/CXCL11 axis in HCC CAFs can affect the proliferative and migrative abilities of HCC cells in vitro and HCC tumor growth in vivo.