Abstract. Emodin, an anthraquinone derivative from the root and rhizome of Rheum palmatum L., was found to have antitumor effects in different types of cancer by regulating multi-molecular targets. The aim of the present study was to explore the effect of emodin on the migration and invasion of MHCC-97H human hepatocellular carcinoma cells and the underlying molecular mechanisms. Firstly, it was demonstrated that emodin can inhibit cell proliferation and induce apoptosis of cells in a time-and dose-dependent manner, using a MTT assay and flow cytometry, respectively. However, when emodin concentration was <50 µmol/l, it had little effect on the inhibition of proliferation or the induction of apoptosis. Then, it was observed that emodin can significantly suppress cell migration and invasion with a treatment dose <50 µmol/l compared with the control (P<0.05), which was not attributed to a decrease in cell number. Further study demonstrated that emodin significantly suppressed the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 compared with the control, which may be mediated by the activation of the p38 mitogen-activated protein kinases (MAPK) signaling pathway and suppression of extracellular signal regulated kinase (ERK)/MAPK and phosphatidylinositol 3-kinase/Akt signaling pathways. Therefore, the present study, for the first time, used MHCC-97H cells, which have the high potential of malignant invasion, to demonstrate that emodin may inhibit cell migration and invasion.
IntroductionHepatocellular carcinoma (HCC) is one of the most frequent malignancies worldwide, representing the fifth most common cause of cancer in men and the seventh in women, and the third most frequent cause of cancer-related mortality (1-3). Globally, there are ~750,000 new cases of liver cancer reported per year (4). Although surgical resection provides better results in patients with HCC in early stages, the long-term prognosis remains unsatisfactory because many patients are diagnosed at the advanced stage, and tumors have an inherent capacity for invasiveness and metastasis (5,6). At present, chemotherapy is commonly used in the treatment of metastatic HCC. However, this treatment remains ineffective due to its toxicity to normal cells and the rapid development of resistance. Therefore, to further explore the biology of metastasis and develop novel therapeutics that specifically target metastasis and metastatic progression are required (7,8).Increasing attention has been paid to drugs among traditional Chinese medicines, since these materials typically share high safety profiles and can effectively prevent and control metastasis (9,10). Rheum palmatum L. is a plant that has been widely used in Chinese medicine as a laxative for thousands of years. Emodin is an anthraquinone derivative from its root and rhizome (11). It has been reported that emodin possesses a number of biological properties such as anti-inflammatory, antiviral and anti-proliferative effects (12). In the context of cancer, several studies have indicated...