Detection of the Gonadotropin Releasing Hormone (GnRH) and Its Receptor in Cancer Cell HT-1197 and HT-1376, and Effect of GnRH on Cancer Cell Cycle

Baik, Sang Hoon; Kim, Myeong Ok; Bahk, Jong Yoon

Abstract

Gonadotropin releasing hormone (GnRH) is believed to be pivotal hormone in hypothalamo-pituitary gonadal axis and the hypothalamus is believed as the exclusive organ producing GnRH and pituitary is for GnRH re ceptor until recently. Some reported the exptra-hypothalamic GnRH or extra-pituitary GnRH receptors from decades ago. The aims of this study are to confirm the existence of the GnRH receptor in bladder epithelial cancer cell, HT-1197 and HT-1376, and evaluated the possible role of the GnRH on cell cycle. The GnRH and GnRH receptor were detected by immunohistochemical staining and the effect of GnRH on cell cycle change in both cell line were studied by fluorescence activated cell sorter (FACS). The control cells were cultured at media supplemented with normal serum, and experimental group were cultured at media supplemented with charcoal stripped serum (CSS) which excluding peptide hormones except exogenous GnRH with different concentration. The GnRHs and GnRH receptors were detected at both cell lines and the cell cycle analysis showed that there were little difference in proportion of cell cycle among examined 10,000 cells in both cell lines, neither control nor experimental groups. This study shows that the GnRHs and GnRH receptors exist in bladder cancer cells and GnRH did not influence on the cell cycle progression. With this study, we suppose that the bladder cancer cells produce the GnRH and GnRH receptors and the role of the GnRF produced from the bladder cancer cells might be the autocrine rather than endo-or paracrine factor.