Aberrant Expression of CCAT1 Regulated by c-Myc Predicts the Prognosis of Hepatocellular Carcinoma

Background: CCAT1 has been reported to be linked with pathogenesis of malignancies including colon cancerand gastric cancer. However, the regulatory effect of CCAT1 in hepatocellular carcinoma (HCC) remains unclear.The purpose of this research was to identify any role of CCAT1 in the progression of HCC. Materials and
Methods:Real time-PCR was performed to test the relative expression of CCAT1 in HCC tissues. A computation screenof CCAT1 promoter was conducted to search for transcription-factor-binding sites. The association of c-Mycwith CCAT1 promoter in vivo was tested by Pearson correlation analysis and chromatin immunoprecipitationassay. Additionally, Kaplan-Meier analysis and Cox proportional hazards analyses were performed.
Results:c-Myc directly binds to the E-box element in the promoter region of CCAT, and when ectopically expressedincreases promoter activity and expression of CCAT1. Moreover, Kaplan-Meier analysis demonstrated that thepatients with low expression of CCAT1 demonstrated better overall and relapse-free survival compared with thehigh expression group. Cox proportional hazards analyses showed that CCAT1 expression was an independentprognostic factor for HCC patients.
Conclusions: The findings demonstrated CCAT1, acting as a potentialbiomarker in predicting the prognosis of HCC, is regulated by c-Myc.