L I B Kanzaki
University of Brasilia,Brazil
LIB Kanzaki has been working with retroviruses, mainly in the field of HTLV-1/2 epidemiology and recently initiated a research work on endogenous retroviruses, searching for retroviral sequences in neoplastic tissues of patients with different histological types of cancer. Presently he is a professor of Immunology and retrovirology at the University of Brasilia, DF, Brazil.
Actively replicative Endogenous Retrovirus (HERVs) are anciently integrated in the human genome and became stable in inherited material across generations, accounting for 8% of the human genome. Among HERVs group there are the HERV-K and HERV-W. HERV-K virions were seen budding from tumour cells, and viral RNA could be found at higher titers in the plasma of lymphoma and breast cancer patients. Reverse transcriptase and retroviral RNA were detected in plasma samples that simultaneously had HERV-K gag and env proteins, in both mature and pseudo particles. In light of these findings, we propose to initiate a study to evaluate the role of HERV-K among cancer patients in Brasilia, DF, Brazil. After the study approval (number 59/13) by the Commmittee of Ethics, under patients consent, blood samples and neoplastic tissue fragments were collected, in the surgery unit of the “Hospital de Base do Distrito Federal”. All patients had cancer in the neck or had. Thirty-five extracted DNA samples from different histopathological types were amplified with primers to the HERV-K gag region, and 31 samples yield an amplicon band size of 250 bp, as expected to the gag sequence. There are substantial reports in the literature of HERV-K proviral sequences detection among head and neck cancer and also in healthy tissues. Of 35 analysed samples, 10 patients with oral squamous cell carcinoma were previously negative for the presence of Human Papillomavirus gene sequences, but had HERV-K sequences detected. Further analysis will investigate the presence of other HERV-K sequences as env, pol and ltr, in order to better understand the role of these entitites in oncogenesis. Also the obtained amplicons will be sequenced and compared to published and deposited sequences.