인체 암세포에서 genistein에 의한 cyclooxygenase-2 및 telomerase의 활성 저하

Abstract

본 연구에서는 대두의 대표적인 생리활성 물질인 genistein의 처리에 따른 암세포의 증식억제에서 telomerase 및 COX-2 활성의 변화 연관성을 조사하였다. 이를 위하여 4가지 종류의 암세포주를 사용하였으며, genistein 처리에 의하여 암세포들의 증식억제에서 백혈병 세포인 U937 세포의 감수성이 감장 높게 나타났으며, genistein 처리에 따라 telomere 조절인자들의 발현이 대부분 억제되었으며, telomerase의 활성도 매우 유의적으로 감소되었다. 또한 genistein처리 농도가 증가함에 따라 COX-2의 발현이 전사 및 번역 수준에서 모두 감소되었으며 이에 따른 <TEX>$PGE_2$</TEX>의 생성 역시 현저하게 감소되었으나, COX-1의 발현에는 큰 변화가 없었다. 이러한 결과들은 genistein의 항암 활성을 이해하는 귀중한 자료로서 활용될 것으로 생각된다. Genistein, an isoflavone in soybean products, is a potential chemopreventive agent against various types of cancer. There are several studies documenting molecular alterations leading to cell cycle arrest at G2/M phase and induction of apoptosis; however, its mechanism of action and its molecular targets on the prostaglandin <TEX>$E_2$</TEX> (<TEX>$PGE_2$</TEX>) production and telomere length regulation in human cancer remain unclear. In this study, we investigated the effect of genistein on the levels of cyclooxygenases (COXs) and telomere regulatory components of several human cancer cell lines (T24, human bladder carcinoma cells; U937, human leukemic cells; AGS, human stomach adenocarcinoma cells and SK-MEL-2, human skin melanoma cells). Genistein treatment resulted in the inhibition of cancer cell proliferation in a concentration-dependent manner. It was found that genistein treatment markedly decreased the levels of COX-2 mRNA and protein expression without significant changes in the expression of COX-1, which was correlated with a decrease in <TEX>$PGE_2$</TEX> synthesis. Genistein treatment also partly inhibited the levels of human telomerase reverse transcriptase (hTERT) as well as human telomerase RNA (hTR) and telomerase-associated protein (TEP)-1, and the activity of telomerase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of genistein.