Evaluation of CAMD1 Gene Promoter Hypermethylation in Human Papillomavirus Positive Cytological Samples of Cervical Cancer

Cervical cancer (CC) is the second most common type of cancer among women. A key factor in developing the disease is the human papillomavirus (HPV) infection. Aberrant DNA hypermethylation in gene promoter regions is one of the most well-fined epigenetic alterations in tumors. This study aimed to investigate cell adhesion molecule 1 (CADM1), promoter methylation in HPV serological positive samples in the Iranian population.
Genomic DNA was extracted from cervical smears from patients and healthy patients acting as a control group for this analytical observational case-control investigation. Reverse dot blotting was performed to first identify the presence of HPV DNA infection. After that, each sample was transformed by being treated with sodium bisulfite, and MSP was then used to determine the CADM1 gene's level of methylation.
Among total number of positive HPV samples (n = 52), 63.5% methylated, 23% hemi-methylated, and 13.5% were unmethylated. On the contrary, in the control group (n=38), 11% methylated, 71% hemi-methylated, and 18% were unmethylated (P < 0.0001). Furthermore, comparing the methylation status among high, low and high/low patients indicated that methylation was (66.66, 24.24, and 9.09%), (25, 66.66, and 8.33%), and (14.28, 57.14%, and 28.57%), respectively (P < 0.0001).
The present study confirmed that the methylation status of CADM1 gene was significantly higher in HPV-positive patients than in patients negative for HPV DNA. Moreover, the CADM1 pattern of the gene was associated with the highrisk subtypes of HPV, not with the low-risk ones. Therefore, CADM1 methylation appeared to be a promising biomarker for future studies.