Immunohistochemistry Study of OY-TES-1 Location in Fetal and Adult Human Tissues

OY-TES-1 is reportedly involved in carcinogenesis and spermatogenesis. However, the tissue distribution of OY-TES-1 in the normal human body remains elusive. This study detected OY-TES-1 expression in human fetal and adult normal tissues by immunohistochemistry. We identified a general principle of OY-TES-1 expression. The expression of OY-TES-1 was found in neurons, smooth muscle cells, and cardiac muscle cells from both fetuses and adults. The connective tissue showed no specific staining throughout the fetal and adult samples. With OY-TES-1-positive staining of the epithelium irregular, OY-TES-1 was strongly expressed in the epithelium of the skin and bladder, as well as hepatocytes, pancreatic islets, and acinous cells during the fetal stage but was not detected in the postnatal period. In contrast to the epithelium of blood vessels, the fetal and adult central hepatic vein and glomeruli showed negative expression of the OY-TES-1 protein. Sex-dimorphism was observed in the distribution of OY-TES-1 in male and female germ cells. Collectively, our results indicate that OY-TES-1 is a member of the cancer-testis antigen and autoantigen, with tissue-specific and period-specific expression patterns, revealing potential contributions of OY-TES-1 to the diagnosis and therapeutic treatment for neoplasms and infertility.