[Research on the growth inhibition of T47D cell and reversion of p16 hypermethylation by CDP].
OBJECTIVE
To inquire into the mechanism of CDP (a purified component of Chinese crude drug) in inhibiting the breast cancer T47D cell growth.


METHODS
T47D cells were treated with different concentration of 5-azacytidine (5-aza-CR) and CDP for several days. The growth rate was assessed by cell proliferation experiment (MTT colorimetric assay). The changes in apoptic peak and cell cycle distribution were detected by flow cytometry (FCM). The levels of methylation and unmethylation status of p16 were detected by methylation specific PCR (MSP).


RESULTS
After treatment with the two drugs, the cell growth rate decreased in a dose and time dependent manner (P<0.05). The cell cycle was influenced by the well-chosen concentration of 5-aza-CR (2 micromol/L) and CDP (50 micromol/L): the cell number increased from 65.1% to 71.3%, 84.3% in G0/G1 phase and decreased from 19.4% to 14.3%, 7.2% in S phase. Demethylation on p16 gene occurred after treatment with any of the two drugs for 6 days.


CONCLUSIONS
CDP can reverse p16 hypermethylation and may hence inhibit the proliferation of tumor cells.
Xu
Dan
D
Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Qin
Yang
Y
Sun
Zhi-lin
ZL
Sun
Ze-fang
ZF
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects*; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D004273:DNA, Neoplasm / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D019942:Genes, p16 / Q000187:drug effects*; D006801:Humans
D000972:Antineoplastic Agents, Phytogenic; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004273:DNA, Neoplasm; D004365:Drugs, Chinese Herbal; D015254:DNA Modification Methylases