Abstract 3860: Differential gene expression and HPV in penile carcinoma

Penile cancer (PC) is an invasive epithelium tumor, representing more than 10% of the malignancies in men in some developing countries, mainly in Brazil. Studies on the aetiopathogenesis of this cancer have focused on its association with the HPV. Patients with PC without treatment usually die within 2 years after diagnosis, because of uncontrollable loco regional disease or from distant metastasis. The aim of this study is evaluating the possible role of HPV in the development of PC and the use of the RaSH technique to analyze gene expression in normal tissues and penile tumors. HPV detection was done by PCR with generic primers GP5+/GP6+ and HPV typing was done by direct sequencing. RaSH methodology identified differentially expressed genes, generating subtractive cDNA libraries. The presence of HPV was analyzed in 58 samples of patients with PC. It has been observed high prevalence (85.12%) of HPV. Of the 16 samples sequenced, HPV-16 was found in 14 (87.5%) samples, HPV-11 in 1 (6.3%) and HPV-35 in 1 (6.3%). The RaSH subtractive libraries identified the presence of 57 clones differentially expressed between samples, 30 in tumor samples and 27 in the normal tissue. The genes PBEF1, ANXA1, RPL6 and KIAA1033 were overexpressed in the tumors. On the other hand, the gene p16 was overexpressed in the normal tissue. Finally, the expression of the selected genes was confirmed by qPCR. Only ANXA1 was validated with overexpression in 80% of all samples. It was also analyzed ANXA1 protein expression by immunohistochemistry in 25 samples of penile cancer. It was observed overexpression of ANXA1 protein 100% of PC samples compared to normal tissue. The results obtained are capable of revealing differences in patterns of gene expression between normal and tumor tissues. Moreover, it was observed high prevalence of HPV, suggesting an important role of this virus in penile carcinogenesis. Besides, overexpression of ANXA1 was observed in most of the penile cancer samples and such information will contribute to develop a possible marker for penis tumor diagnostic and prognostic, improving the development of directed therapies against this new putative marker. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3860. doi:10.1158/1538-7445.AM2011-3860