Determination of expression of small VCP interacting protein (SVİP) and interacting ubiquitin proteasome system proteins in human embryonal carcinoma cell line

SVIP is a protein that regulates its function and autophagy by binding to p97/VCP, which is involved in protein degradation associated with the endoplasmic reticulum. There are very few studies in the literature about the expression of SVIP in cells and tissues other than the nervous system. Recent studies on SVIP have shown that SVIP is an androgen-sensitive protein and its expression is regulated by androgens. Androgens are important steroid hormones and have great effects on the development of secondary sex characteristics. They also play a role in the initiation and continuation of spermatogenesis in the male reproductive system. Mutations of androgen receptors are often seen in patients with disorders of male reproductive development and can cause male infertility. Infertility is a pathological condition that affects approximately 7% of the population. Testicular tumors are the most common malignant tumors in men between the ages of 15-34. Approximately 95% of testicular tumors arise from germ cells. There are studies showing that the ubiquitin proteasome system (UPS) in the male reproductive system has an effect on infertility. Therefore, investigating the expressions of USP26 and UXT, which are components of the UPS, is important for testicular biology. In the light of this information, in my thesis, to determine the expressions of SVIP and the UPS proteins with which it interacts in human testicular embryonal carcinoma cells (CRL-2073) and to see the effects of suppressed SVIP expression on other proteins after SVIP siRNA transfection, the expressions of SVIP, AR, Ubiquitin, USP26 and UXT were analyzed by immunofluorescence, western blot and qRT-PCT methods. In addition, human Leydig and mouse Sertoli cell lines, which have previously been shown to express SVIP, were used as control groups. When control siRNA and SVIP siRNA groups were compared in CRL-207 cells, SVIP, AR, USP26 and Ubiquitin expressions decreased, while UXT expression increased, according to immunofluorescence and western blot results. According to the qRT-PCR results, SVIP gene expression decreased and AR, Ubiquitin, USP26 and UXT gene expressions increased in the group given SVIP siRNA. As a result, this study demonstrated the expression of SVIP and its interacting UPS proteins in human testicular embryonal carcinoma cells for the first time, making a significant contribution to the literature. Keywords: Embryonal carcinoma, SVIP, UPS, AR.