ИСТИНА

Background. Visual arrestin is normally expressed in retinal cells only. Consequently, this protein is immunogenic for the immune system due to immune privileged status of the eye. In the process of malignization cells undergo genome rearrangements. Thus, tumor cells start to produce aberrantly a protein or a set of proteins that are not typical for the origin cells of tumor. In particular, visual arrestin was reported to be expressed in melanoma cells and act in melanoma-associated retinopathy. In this study, we analyzed whether the aberrant expression of visual arrestin can be detected in the renal cells carcinoma (RCC). Methods. Tumor tissue samples of 33 patients with diagnosed subtype of RCC or renal oncocytoma and blood sera from 37 patients with diagnosed RCC were collected. Western blot analysis was performed to detect anti-arrestin antibodies in patients’ sera. To reveal the presence of visual arrestin in renal tumor cells, immunohistochemical assay of tumor tissue sections was performed. Results. Western blot analysis revealed, that serum samples from 23 of 37 (62,2%) patients with RCC produced immunostaining of band corresponding to arrestin. Immunohistochemical assay of 33 renal tumor tissue samples revealed arrestin-positive reaction in 4 out of 6 (66%) samples of papillary RCC, in 4 out of 5 (80%) samples of chromophobe RCC, in 4 out of 12 (33%) samples of clear cell RCC, and in 9 out of 10 (90%) samples of renal oncocytoma. Overall, 63,6% of tested by immunohistochemistry samples of renal tumor tissue samples have shown arrestin-positive reaction. Conclusion. Expression of visual arrestin can be detected frequently in different malignant renal tumor cells. Moreover, RCC patients often produce anti-arrestin antibodies in serum. Thus, it is possible to attribute arrestin to the group of cancer-retina antigens.