Our results showed no relationship between HPV and LS. This result is in accordance with the literature. We have found 26.5% of EBV in our samples. This is a preliminary study, and the follow-up of these patients will elucidate whether EBV could play a role in cases of LS.

Methylation is a chemical modification in which a methyl group (CH3) is added to the cytosine in the promoter region of the gene. It involves a very frequent epigenetic event that is found in many human cancers. Currently, there is no consensus on whether methylation of the p16 gene could be used as a biomarker in cervical intraepithelial neoplasia. The authors studied the presence of methylation of the p16 gene and human papillomavirus (HPV) DNA, and a possible relationship between them in high-grade squamous intraepithelial lesions of the cervix. This case-control study analyzed 27 high-grade squamous intraepithelial lesion samples and 20 normal cytology samples. To detect p16 methylation, methylation-specific polymerase chain reaction was used, and for HPV DNA detection the polymerase chain reaction was performed by using MY09/MY11 and GP5+/GP6+ consensus primers. The presence of methylation of the promoter region of the p16INK4a gene was detected in 55.6% of the samples from the case group, whereas it was detected only in 20% of the samples from the control group (P=0.005). HPV DNA was found in 66.7% of the samples from the case group, whereas only 15% from the control group (P=0.0001). The relationship between the presence of methylation of the p16 gene and HPV DNA did not prove statistically significant in the case group (P=0.67) or the control group (P=0.51). In conclusion, the presence of methylation of the p16 gene constituted an occurrence that was early but independent of the presence of HPV DNA.

This study was conducted to investigate the presence of Epstein-Barr virus (EBV) and human papillomavirus (HPV) and the promoter methylation status of the death-associated protein kinase (DAPK) gene in high-grade intraepithelial lesions. Viral infection was analyzed using polymerase chain reaction (PCR), and promoter methylation status was evaluated using chemical modification by sodium bisulfite followed by PCR. A total of 24 samples were studied. HPV was detected in 16.6%, EBV in 16.6%, and HPV/EBV coinfection in 16.6%. No virus infection was detected in 50% of the samples studied. DAPK promoter methylation was observed in 29.2% of the analyzed samples. There was no significant correlation between DAPK methylation and viral infection. DAPK methylation was detected in 28% of HPV-positive lesions, in 28% of HPV- and EBV-positive lesions, and in 44% (3/7) of the samples without viral infection. There was no observed methylation in samples with isolated EBV infection. In DAPK unmethylated samples, HPV infection was found in 12%, EBV infection in 23%, HPV/EBV coinfection in 12%, and an absence of HPV and EBV infection in 53%. The promoter methylation of the DAPK gene is an important event during carcinogenesis and may have potential clinical application as a marker for the progression and prognosis of cancer.

Methylation of the DAPK and p16 genes, although not sufficient to dictate prognosis of the disease, should not be underestimated because it may form part of a process of genetic and epigenetic alterations that in the future could become relevant to malignant transformation.