Immunohistochemical study of the over-expressed protein of P57-gene related with HPV31/33 infections in a group of thyroid carcinomatous tissues

The incidence of thyroid cancer has increased during the last three decades. Many studies have been conducted to determine whether there is a link between viral infections and thyroid carcinogenesis. Human Papilloma viruses (HPV) are related to a variety of benign and malignant tumors. P57 is a member of the Cip/Kip family that binds and inhibits all cyclin/CDK complexes, resulting in cell-cycle arrest as well as cell growth.

This retrospective study designed to investigate histopathological expression of thyroid cancer tissues in relation to the concordant HPV31/33 infection and p57 protein over-expressions.

HPV31/33 DNA and P57-gene protein expression were evaluated in 116 thyroid tissues. The samples related to 36 patients with thyroid carcinoma, 40 thyroid adenoma, and 40 normal thyroid tissues. In situ hybridization (ISH) used to identify HPV31/33-DNA, whereas immunohistochemistry (IHC) used to assess P57-gene expression.

Regarding thyroid carcinoma group, HPV31/33DNA-ISH are responses observed in 77.8%, in 30 % of thyroid adenomas group, and in 22.5 %of normal thyroid tissues group. The difference between HPV31/33 in thyroid malignancies and the control group was statistically significant. The p57 protein detected in 75% thyroid cancer tissues and in 52.5 % adenoma thyroid tissues, whereas 35% of the investigated normal thyroid tissues showed IHC-reactions. The difference in the detected percentages of P57 protein was statistically significant in thyroid tissues between the study groupsin relations to the control group.

The significant detection of HPV31/33 along with over-expressed P57-gene in thyroid cancer patients could support a possible role for both HPV 31/33 along with this p57 protein in thyroid pathogenesis and for carcinogenesis.