Abstract 5308: CD9, CD63 and CD82 tetraspanins expression profile in vulvar carcinomas.

Abstract

Abstract Background: Vulvar carcinomas are approximately 95 % of all vulvar tumors. This cancer presents good prognosis since early diagnosed, and survival depends of inguinal lymphonode commitment, with about 30% of patients presents lymphonode metastasis. The mechanisms involved in biological behavior of vulvar cancer remain unclear and its treatment involves physical mutilation and psychosocial factors of patients. Therefore, identification of features related with this tumors development or genesis can contribute to its knowledge and treatment. The tetraspanins are proteins that are involved in several biological processes including cell proliferation, adhesion, invasion and migration. Their reduction or lack of expression is frequently reported in metastatic and poor prognosis tumors. Our aim was to analyze CD9, CD63 and CD82 tetraspanins expression profile in vulvar carcinoma compared to normal tissue. Methods: All samples were obtained from Pathology Department of Hospital A. C. Camargo, Sao Paulo, Brazil. TMA block was constructed with 150 paraffin-embedded samples and was used in immunohistochemical assay. The tissue sections were incubated with specific antibodies against CD9, CD63 and CD82, following manufacturer's instruction. The slides were evaluated and scored semiquantitatively by assessing the staining intensity in tumor cells and the frequency of positive cells. Results: The Immunohistochemical analysis showed that all tetraspanins were expressed in tumor samples with different intensity and frequency. CD63 were expressed by a higher samples number (90%), with stronger staining both cytoplasm (79%) and nucleus (11%). Lack of CD63 expression was described in metastatic melanomas lesions, while no metastatic lesions shows higher levels of this protein. Seventy five percent of our samples expressed CD9, exclusively on cellular membrane. CD82 showed positive reaction in 45% of the samples with weakly or moderate staining, both nucleus and cytoplasm. The association of the downregulation of CD9 and/or CD82 with a worse prognosis has been shown in breast, cervical, endometrial, esophageal, head and neck, and others carcinomas. Moreover, CD82 is considered to be an important metastasis suppressor. Conclusion: Our preliminary results showed that tetraspanins may have an important role in vulvar carcinomas and CD82/CD63 nuclear expression must be better investigated. Further analyses are ongoing. Citation Format: Katia C. Carvalho, Rafael M. Rocha, Isabela W. Cunha, Fernando A. Soares. CD9, CD63 and CD82 tetraspanins expression profile in vulvar carcinomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5308. doi:10.1158/1538-7445.AM2013-5308