EXPRESSION OF C-KIT MESSENGER-RIBONUCLEIC-ACID IN HUMAN OOCYTE AND PRESENCE OF SOLUBLE C-KIT IN FOLLICULAR-FLUID

The c-kit protooncogene receptor and its ligand stem cell factor (SCF) regulate the proliferation and survival of germ cells as well as hema topoietic cells and melanocytes. In adult rodent ovary, c-kit and SCF play important roles in follicular development. However, little inform ation about c-kit in the human ovary is available. In this study, we e xamined the expressions of c-kit messenger ribonucleic acid (mRNA) and c-kit protein in human oocytes, granulosa cells, and follicular fluid obtained from the women who underwent in vitro fertilization or lapar oscopic examination. Expression of c-kit mRNA was detected by RT-PCR i n the oocytes and granulosa cells. Western blot analysis showed the pr esence of soluble c-kit protein in the follicular fluid, and lower lev els of c-kit protein were detected in the granulosa cells and the supe rnatant of granulosa cell cultures. The concentration of soluble c-kit in follicular fluid measured by enzyme-linked immunosorbent assay sho wed significant correlation with fluid volume and follicular fluid con centrations of estradiol, testosterone, and androstenedione. In summar y, we found for the first time the presence of c-kit mRNA and soluble c-kit protein in human oocytes and follicular fluid. The results sugge sted that in human ovary, c-kit may play an important role in follicul ar development.