CCDC88A Post-Transcriptionally Regulates VEGF via miR-101 and Subsequently Regulates Hepatocellular Carcinoma

Abstract

Background: miR-101 is one of the most abundantly expressed microRNA (miRNA) and exerst a critical role in hepatocellular carcinoma (HCC) by targeting to 3' -untranslated region (UTR) of Girders of actin filaments (CCDC88A) and Vascular endothelial growth factor (VEGF) mRNA, but the underlying molecular mechanism remains to be elucidated. This study aimed to investigate the potential role of CCDC88A on malignancies and stemness by regulating VEGF via miR-101 in HCC.

Methods: Gene Expression Profiling Interactive Analysis (GEPIA) was employed to analyze the relevance of CCDC88A expression with prognosis in HCC. Tissue slides were performed to confirm the protein level of CCDC88A in HCC. Correlation between CCDC88A and VEGF was transcriptionally and post-transcriptionally detected, followed by evaluation of malignancies.

Results: By employing Immunohistochemistry, we found CCDC88A protein was upregulated in HCC tissues, which is closely correlated to poor prognosis and survival rate. Employment of GEPIA revealed the positive correlation between CCDC88A and VEGF in HCC, but not in liver tissue. Silencing of CCDC88A in Huh-7 and SK-HEP-1 cells significantly decreased proliferation, cell cycle phases, migration, invasion, colony formation, and tumor formation. Introduction of miR-101 mimics specifically targeting CCDC88A and VEGF decreased protein levels of both CCDC88A and VEGFA. Notably, inhibition of miR-101 reversed the correlation between CCDC88A and VEGFA protein levels, indicating that CCDC88A and VEGF may exert as a miR-101 sponge. The addition of SKLB1002, a VEGFR2 inhibitor inhibited malignant behaviors, which was further inhibited by the introduction of miR-101 mimics, indicating that CCDC88A regulates malignant behaviors partially via regulating VEGF. Moreover, CCDC88A also promotes the stemness of cancer stem-like cells derived from HCC cells depending on VEGF modification.

Conclusion: Taken together, our findings suggested that the miR-101/CCDC88A/VEGF axis could be a potential therapeutic target of HCC treatment.

Keywords: Girders of actin filaments (CCDC88A); cancer stem-like cells (CSCs); hepatocellular carcinoma (HCC); malignant behavior; microRNA-101; vascular endothelial growth factor (VEGF).