Ginsenoside-Rb1 targets chemotherapy-resistant ovarian cancer stem cells via simultaneous inhibition of Wnt/β-catenin signaling and epithelial-to-mesenchymal transition.
Chemoresistance is a major clinical problem compromising the successful treatment of cancer. One exciting approach is the eradication of cancer stem/tumor-initiating cells (jointly CSCs), which account for tumor initiation, progression, and drug resistance. Here we show for the first time, with mechanism-based evidence, that ginsenoside-Rb1, a natural saponin isolated from the rhizome of Panax quinquefolius and notoginseng, exhibits potent cytotoxicity on CSCs. Rb1 and its metabolite compound K could effectively suppress CSC self-renewal without regrowth. Rb1 and compound K treatment also sensitized the CSCs to clinically relevant doses of cisplatin and paclitaxel. These effects were associated with the Wnt/β-catenin signaling pathway by downregulating β-catenin/T-cell factor-dependent transcription and expression of its target genes ATP-binding cassette G2 and P-glycoprotein. We also identified reversal of epithelial-to-mesenchymal transition as a new player in the Rb1 and compound K-mediated inhibition of CSCs. Rb1 and compound K treatment also inhibited the self-renewal of CSCs derived from ovarian carcinoma patients as well as in xenograft tumor model. Moreover, we did not observe toxicity in response to doses of Rb1 and compound K that produced an anti-CSC effect. Therefore, Rb1 should be explored further as a promising nutraceutical prototype of treating refractory tumors.
School of Biological Sciences, University of Hong Kong, Hong Kong.
Shan
S
Deng
Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
Chris Kong Chu
CKC
Wong
Department of Obstetrics and Gynecology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
Hung-Cheng
HC
Lai
School of Biological Sciences, University of Hong Kong, Hong Kong.
Alice Sze Tsai
AST
Wong
D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D000066673:Cell Self Renewal / Q000187:drug effects; D004195:Disease Models, Animal; D019008:Drug Resistance, Neoplasm; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects* / Q000235:genetics; D005260:Female; D036145:Ginsenosides / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism*; D010051:Ovarian Neoplasms; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D060449:Wnt Signaling Pathway / Q000187:drug effects*; D023041:Xenograft Model Antitumor Assays
D036145:Ginsenosides; D020928:Mitogen-Activated Protein Kinases; D051057:Proto-Oncogene Proteins c-akt; C442759:ginsenoside Rb1; C112772:ginsenoside compound K
Wnt/β-catenin signaling; cancer stem cells; chemoresistance; ginsenoside; ovarian cancer