Background: Our recent study has shown that inhibitor of differentiation 1 (Id-1) is overexpressed in cervical carcinoma. However, the relationship between Id-1 expression and human papillomavirus (HPV) infection has not been elucidated. In this study, we investigate the association of Id-1 protein expression and HPV infection in cervical carcinoma tissues.

Methods: A total of 56 paraffin-embedded and 12 fresh cervical carcinoma tissues were collected for Id-1 and HPV detection. The Id-1 protein was detected by immunohistochemistry and Western blot in paraffin-embedded and fresh carcinoma tissues. Human papillomavirus DNA was detected and genotyped by using an oligonucleotide microarray and polymerase chain reaction.

Results: The overall HPV prevalence was 82.1%, whereas that of HPV type 16 (HPV-16) was 62.5% in cervical carcinoma. The HPV-positive samples showed higher Id-1 expression levels than the HPV-negative ones (Cochran-Mantel-Haenszel χ² test [χ² _CMH] = 4.39, P < 0.05). The HPV-16-infected samples had higher Id-1 expression levels than the samples with infection of other single HPV genotypes (χ² _CMH = 6.42, P < 0.02). The results of Western blot were correlated to the immunohistochemistry results, showing a higher Id-1 expression level in HPV-infected especially HPV-16-infected carcinoma tissues.

Conclusions: Inhibitor of differentiation 1 expression is correlated to HPV infection in cervical carcinoma, suggesting that Id-1 plays a role in HPV-related cervical carcinogenesis.