Abstract. Ganoderma lucidum is a herbal mushroom known to have many health benefits, including the inhibition of tumor cell growth. However, the effect of Ganoderma lucidum on epithelial ovarian cancer (EOC), the most fatal gynecological malignancy, has not yet been reported. In this study, we determined whether Ganoderma lucidum regulates EOC cell activity. Using several cell lines derived from EOC, we found that Ganoderma lucidum strongly decreased cell numbers in a dose-dependent manner. Ganoderma lucidum also inhibited colony formation, cell migration and spheroid formation. In particular, Ganoderma lucidum was effective in inhibiting cell growth in both chemosensitive and chemoresistant cells and the treatment with Ganoderma lucidum significantly enhanced the effect of cisplatin on EOC cells. Furthermore, Ganoderma lucidum induced cell cycle arrest at the G2/M phase and also induced apoptosis by activating caspase 3. Finally, Ganoderma lucidum increased p53 but inhibited Akt expression. Taken together, these findings suggest that Ganoderma lucidum exerts multiple anti-tumor effects on ovarian cancer cells and can enhance the sensitivity of EOC cells to cisplatin.
IntroductionGanoderma lucidum is a herbal mushroom that has been widely used in preventive medicines in China and other Asian countries for over 2,000 years. It has also become a popular dietary supplement in Western countries. Ganoderma lucidum contains many different bioactive compounds, which mainly include triterpenoids, polysaccharides, nucleotides, sterols, steroids, fatty acids, proteins/peptides and trace elements (1).These substances are known to have many biological activities, including anti-tumor (2), immunomodulatory (3), anti-viral (4), anti-hepatitis (5), antioxidant (6), antihypertensive (7,8) and anti-diabetic activities (9). It has been reported that Ganoderma lucidum extracts can inhibit tumor formation and the proliferation of breast and prostate cancer, hepatoma, melanoma lymphoma and myeloid leukemia cell lines (10-12). Thus, Ganoderma lucidum could be used as a potential therapeutic agent in the form of a dietary supplement for cancer patients.Epithelial ovarian cancer (EOC) is the most common form of ovarian cancer and the leading cause of death from gynecological disorders (13). The high mortality rate of EOC is mainly due to the late diagnosis and the lack of effective treatments for the late stages of the disease (14). The most effective treatment for EOC is surgery plus platinum-based chemotherapy, with drugs such as cisplatin. However, the majority of patients ultimately experience chemoresistance and recurrence of their disease (15). Considering the high mortality rate of ovarian cancer due to the absence of effective treatment in advanced stages or during relapse, new therapeutic strategies are urgently required.In this study, we examined the effects of Ganoderma lucidum on cell proliferation and migration in several ovarian cancer cell lines. Our results show that Ganoderma lucidum inhibits cell growth, migration and...