探討SFN透過降低 Cdc2 和Cyclin B1複合物結合率誘發人類三陰性乳癌細胞細胞週期停滯於G2 / M期

Abstract

Abstract： Ministry of Health and Welfare (MOHW) recently released the top ten causes of death, cancer is still one of the top ten in Taiwan. So the cancer prevention and therapy is the most important now. In recent years, Researchers have found that natural plant materials or biologically active ingredients have strong chemo-preventive effects and may play a role of cancer treatment or therapeutic drugs. The Sulforaphane (SFN) is one of the isothiocyanate groupswithorganosulfur compounds which were from cruciferous vegetables such as broccoli or cabbages. It is produced when the myrosinase transforms glucoraphanin, a glucosinolate, to SFN upon damage to the plant, such as from chewing. This study investigated the anti-tumor activity of sulforaphane (SFN) in the human triple-negative breast cancer cell line, MDA-MB-231. Our results demonstrate the ability of SFN to induce cell cycle G2 / M arrest and inhibit cell growth. The activity of Cdc2 and Cyclin B1 expression at the G2 / M transition is an important factor in determining whether cell cycle arrest occurs before or during mitotic progression. The results of western blot analysis did not reveal significant inhibition of Cdc2; however, an increase in phosphorylation Cdc2Tyr15 expression was observed. Results show that SFN blocks cell mitosis via the inhibition of Cdc25c activity resulting in a decrease in Cdc2 dephosphorylation. This makes it possible for Cdc2 and Cyclin B1 complex to form the maturation-promoting factor (MPF). In this study, Co-Immunoprecipitation (Co-IP) was used to detect the Cdc2 / Cyclin B1 complex association. Our results revealed SFN-induced cell cycle G2 / M Phase delay through the inhibition of activity related to the Cdc2 / Cyclin B1 association. The results of Human cell cycle PCR array analysis revealed a significant increase in CDK5R1 and SERTAD1 gene expression following treatment with SFN. CDK5R1 has been linked to neuronal apoptosis, whereas SERTAD1 is an oncogene shown to promote the survival of various types of cancer cells through the inhibition of cell apoptosis.Western blot analysis revealed that treatment with SFN inhibits SERTAD1 expression and increases the expression of CDK5R1. This is a clear indication that the SFN-induced cell cycle G2 / M Phase delay may be associated with an increase in CDK5R1 and a decrease SERTAD1 expression. These results demonstrate the potential of SFN as an alternative route for the treatment and/or prevention of breast cancer.