Inhibition of cell-cycle progression in human colorectal carcinoma Lovo cells by andrographolide.
In recent years, attention has been focused on the anti-cancer properties of pure components, an important role in the prevention of disease. Andrographolide (Andro), the major constituent of Andrographis paniculata (Burm. F.) Nees plant, is implicated towards its pharmacological activity. To investigate the mechanism basis for the anti-tumor properties of Andro, Andro was used to examine its effect on cell-cycle progression in human colorectal carcinoma Lovo cells. The data from cell growth experiment showed that Andro exhibited the anti-proliferation effect on Lovo cells in a time- and dose-dependent manner. This event was accompanied the arrest of the cells at the G1-S phase by Andro at the tested concentrations of 0-30 microM. Cellular uptake of Andro and Andro was confirmed by capillary electrophoresis analysis and the intracellular accumulation of Andro (0.61+/-0.07 microM/mg protein) was observed when treatment of Lovo cells with Andro for 12h. In addition, an accumulation of the cells in G1 phase (15% increase for 10 microM of Andro) was observed as well as by the association with a marked decrease in the protein expression of Cyclin A, Cyclin D1, Cdk2 and Cdk4. Andro also inducted the content of Cdk inhibitor p21 and p16, and the phosphorylation of p53. Further immunoprecipitation studies found that, in response to the treatment, the formation of Cyclin D1/Cdk4 and Cyclin A/Cdk2 complexes had declined, preventing the phosphorylation of Rb and the subsequent dissociation of Rb/E2F complex. These results suggested Andro can inhibit Lovo cell growth by G1-S phase arrest, and was exerted by inducing the expression of p53, p21 and p16 that, in turn, repressed the activity of Cyclin D1/Cdk4 and/or Cyclin A/Cdk2, as well as Rb phosphorylation.
Shi
Ming-Der
MD
Department of Medical Technology, College of Medicine and Life Science, Chung Hwa University of Medical Technology, Tainan, Taiwan; Pathology and Laboratory Medicine, Yongkang Veterans Hospital, Tainan, Taiwan.
Lin
Hui-Hsuan
HH
Lee
Yi-Che
YC
Chao
Jian-Kang
JK
Lin
Rong-An
RA
Chen
Jing-Hsien
JH
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism / Q000633:toxicity*; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D004224:Diterpenes / Q000378:metabolism / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D050687:E2F1 Transcription Factor / Q000378:metabolism; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism; D010766:Phosphorylation; D016160:Retinoblastoma Protein / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; C493956:CDKN1A protein, human; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004224:Diterpenes; D050687:E2F1 Transcription Factor; D009363:Neoplasm Proteins; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; C030419:andrographolide