Down-regulation of Toll-like Receptor TLR4 Is Associated with HPV DNA Integration in Penile Carcinoma.

BACKGROUND/AIM: Development of penile cancers is attributed to HPV-related carcinogenesis. Our aim was to analyze HPV positivity and TLR4, p16ink4a and p53 expression.

MATERIALS AND

METHODS

HPV presence was assessed with virus-specific TaqMan PCR and HPV Genotyping Test in 31 penile cancers. Immunohistochemistry was carried out on tissue microarray.

RESULTS

TLR4 expression was detected in 4 of the 16 HPV positive and 13 of the 15 HPV negative tumors. We found a significant inverse correlation between HPV positivity and TLR4 expression (p=0.0006). Ten of the 16 HPV-positive but none of the 15 HPV-negative tumors expressed p16INK4a. A significant correlation was seen between p53 expression and lack of HPV DNA (p=0.0191) as well as between TLR4 and p53 expression (p=0.0198) in penile cancers.

CONCLUSION

Our findings suggest a protective role of TLR4 expression against HPV DNA integration and the viral and non-viral carcinogenesis of penile cancer.