title: Glycyrrhiza polysaccharide induces apoptosis and inhibits proliferation of human hepatocellular carcinoma cells by blocking PI3K/AKT signal pathway.
abstract: To study the antitumor effect of glycyrrhiza polysaccharide (GPS) on human hepatocellular carcinoma cells and its mechanism, GPS was extracted and identified with phenol-sulfuric acid assay, Limulus amebocytes lysate assay, gel permeation chromatography, and infrared spectroscopy analysis. To study its antitumor function, 4-5-week-old imprinting control region mice were subcutaneously implanted with H22 cells and intragastrically subjected to 1 ml GPS (25, 50, and 75 mg/kg/day), 150 mg/kg cyclophosphamide in a dose of 150 mg/kg, or equal volume of phosphate buffered saline as control. Tumor weights were detected 10 days later. Apoptosis of intraperitoneally cultured and GPS-treated H22 cells was identified by flow cytometry and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide. In vitro, the function of GPS on cell proliferation was applied on BEL7402 cells and confirmed by 4,6-diamidino-z-phenylindole staining. Assessment of the effect of GPS on P53 gene was analyzed by real-time PCR and Western blot, and the effects of GPS on phosphatidylinositol-3 kinase (PI3K), AKT, p-PI3K, and p-AKT were analyzed by Western blot. We extracted the GPS, and it dose-dependently inhibited the tumorigenicity of hepatocellular carcinoma cells in nude mice. GPS treatment resulted in a significant (P<0.05) dose-dependent increase in the number of apoptotic cells in vivo and a significant (P<0.05) dose-dependent decrease in hepatocellular carcinoma cell proliferation in vitro. GPS modified multiple key enzymes (p-PI3K, p-AKT, and P53) in P53/PI3K/AKT signaling pathways on DNA or protein levels. Taken together, we extracted the GPS successfully and our findings suggest that GPS functions as a tumor suppressor through influencing the P53/PI3K/AKT pathway in the carcinogenesis of hepatocellular carcinoma and may have therapeutic implications for the clinical management of hepatocellular carcinoma patients.
authors.affiliation: Medical School of Taizhou University, Taizhou, Zhejiang, 318000, China. chenyujia10@163.com
authors.forename: Jiayu
authors.initials: J
authors.lastname: Chen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Jin
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Chibo
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D049109:Cell Proliferation / Q000187:drug effects*; D002850:Chromatography, Gel; D005260:Female; D005434:Flow Cytometry; D006035:Glycyrrhiza / Q000737:chemistry*; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008813:Mice, Inbred ICR; D008819:Mice, Nude; D058539:Phosphatidylinositol 3-Kinase / Q000235:genetics / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010936:Plant Extracts / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal; D011134:Polysaccharides / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013055:Spectrophotometry, Infrared; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D000081082:Phosphoinositide-3 Kinase Inhibitors; D010936:Plant Extracts; D011134:Polysaccharides; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D058539:Phosphatidylinositol 3-Kinase; D051057:Proto-Oncogene Proteins c-akt