Dong-Wook Park

Oleanolic acid 3-acetate, a minor element of ginsenosides, induces apoptotic cell death in ovarian carcinoma and endometrial carcinoma cells via the involvement of a reactive oxygen species–independent mitochondrial pathway

Objectives Oleanolic acid, a minor element of ginsenosides, and its derivatives have been shown to have cytotoxicity against some tumor cells. The impact of cytotoxic effect of oleanolic acid 3-acetate on ovarian cancer SKOV3 cells and endometrial cancer HEC-1A cells were examined both in vivo and in vitro to explore the underlying mechanisms. Methods Cytotoxic effects of oleanolic acid 3-acetate were assessed by cell viability, phosphatidylserine exposure on the cell surface, mitochondrial release of cytochrome C, nuclear translocation of apoptosis-inducing factor, depolarization of mitochondrial transmembrane potential (ΔΨm), and generation of reactive oxygen species (ROS). In vivo inhibition of tumor growth was also assessed with xenografts in immunocompromised mice. Results Oleanolic acid 3-acetate exhibited potent cytotoxicity toward SKOV3 and HEC-1A cells by decreasing cell viability in a concentration-dependent manner. Importantly, oleanolic acid 3-acetate effectively suppressed the growth of SKOV3 cell tumor xenografts in immunocompromised mice. Furthermore, oleanolic acid 3-acetate induced apoptotic cell death as revealed by loss of ΔΨm, release of cytochrome c, and nuclear translocation of apoptosis-inducing factor with a concomitant activation of many proapoptotic cellular components including poly(ADP-ribose) polymerase, Bcl-2, and caspases-8, caspase-3, and caspase-7. Oleanolic acid 3-acetate, however, caused a decrease in ROS production, suggesting the involvement of an ROS-independent pathway in oleanolic acid 3-acetate–induced apoptosis in SKOV3 and HEC-1A cells. Conclusion These findings support the notion that oleanolic acid 3-acetate could be used as a potent anticancer supplementary agent against ovarian and endometrial cancer. Oleanolic acid 3-acetate exerts its proapoptotic effects through a rather unique molecular mechanism that involves an unconventional ROS-independent but mitochondria-mediated pathway.

Effect of Hepatocyte Growth Factor on the Expression of Matrix Metalloproteinases in the Invasion of Endometrial Cancer Cells in a Three­ Dimensional Coculture System

Matrix metalloproteinase (MMP)-2 and -9 are secreted and translocated from endometrial stromal cells to cancer cells in a steroid-dependent manner. We investigated the paracrine effect of hepatocyte growth factor (HGF) on the expression of MMPs and tissue inhibitor of metalloproteinases (TIMPs) in stromal and endometrial cancer cells, and correlated the results with cancer cell invasiveness in a three-dimensional (3D) coculture. The 3D coculture of endometrial stromal and cancer cell lines (HEC-1A, HEC-IB, or KLE) was maintained in the presence or absence of HGF. Invasion of the cancer cells was quantified by Boyden’s chamber assay. Under the same conditions, the expression of MMP-2 and -9, membrane type-1 matrix metalloproteinase (MT1-MMP), and TIMP-1 and -2 were examined by zymography and reverse transcription-polymerase chain reaction. A significant increase in the invasiveness of all three cancer cells in the presence of HGF was observed by Boyden’s chamber assay. HGF enhanced the activation of MMP-2 and -9 by zymography of MMPs. HGF strongly induced MMP-9 mRNA expression in stromal cells, but had little effect on MMP-2 mRNA. MT1-MMP mRNA was detected only in KLE and stromal cells, and was also increased by the presence of HGF. TIMP-1 and -2 mRNAs were ubiquitous, with no dependence on HGF.