Evaluating TGF-β1 gene expression and promoter polymorphism in cervical cancer progression

Abstract

This study aims to investigate the TGF-β1 gene, which has significant prognostic value for early detection and diagnosis of cervical cancer, as well as TGF-β1 gene mRNA and protein expression and the association of promoter region (−509 C>T) polymorphisms with cervical cancer (CC) development. Transcriptome analysis, immunohistochemistry, and RT-PCR were conducted to determine the gene expression of TGF-β1. The PCR-SSCP and Sanger sequencing methods were employed to test and validate the TGF-β1 −509C>T promoter polymorphism in cervical squamous cell carcinoma in comparison to control samples. TGF-β1 is a cytokine that plays a role in tumorigenesis as well as physiological and pathological processes. It appeared as one of the most over-expressed genes identified through the clariom D transcriptome microarray, which describes its role in cancer progression. The results showed a significant TGF-β1 upregulation in CC compared to normal cervical tissue was confirmed using immunohistochemistry and real-time PCR. The levels of TGF-β1 were also determined using a receiver operating characteristic (ROC) curve to distinguish diseased from normal individuals. TGF-β1 ROC showed good selectivity in distinguishing malignant CC from non-malignant cervical tissues. The −509 C>T promoter polymorphism in the TGF-β1 gene is found to be significantly more common in the disease group, and in-silico analysis (using the AliBaba2.0 gene regulation tool) confirms its correlation to the loss of myogenin transcription factor binding site, may resulting in TGF-β1 overexpression.