[The cytotoxicity of indirubin derivative PHII-7 against human breast cancer MCF-7 cells and its mechanisms].
OBJECTIVE
To observe the cytotoxicity of indirubin derivative PHII-7 against human breast cancer MCF-7 cells and to study its primary mechanisms.


METHODS
The proliferation of MCF-7 cells was detected using MTT colorimetry. Annexin V/PI double staining was applied to detect the apoptosis rate of MCF-7 cells. The distribution of cell cycles was detected using PI staining and flow cytometry (FCM). The levels of reactive oxygen species (ROS) in MCF-7 cells were detected by DCFH-DA staining. The mRNA and protein levels of c-fos were detected using RT-PCR and Westem blot analysis.


RESULTS
PHII-7 at different concentrations inhibited the proliferation of MCF-7 cells in a concentration-dependent manner, with the inhibitory rate ranging from 43.13% to 90.90% (P < 0.05). The inhibition was strengthened along with increased concentrations. PHII-7 at different concentrations could induce the apoptosis of MCF-7 cells. The early apoptosis rate was 1.43% +/- 0.02%, 9.14% +/- 0.36%, and 45.79% +/- 8.46%, respectively with the action of 1.25, 2.50, and 5.00 micromol/L PHII-7, respectively, showing dose-dependent manner. FCM analysis found that the proportion of MCF-7 cells in the G0/G1 phase and the S phase decreased after treatment with PHII-7, and the ratio of MCF-7 cells in the G2/M phase obviously increased (P < 0.01). The intra-cellular ROS level was significantly elevated 2 h after pretreatment with PHII-7. The levels of the protooncogene c-fos mRNA and protein were down-regulated in a dose-dependent manner after action of PHII-7.


CONCLUSIONS
PHII-7 exerted obvious in vitro cytotoxic effects on MCF-7 cells. Its mechanisms might be associated with arresting the cell cycle, regulating the redox equilibrium, and down-regulating the expression of the protooncogene.
Department of Pharmacology, Shanxi Medical Univer-sity, Taiyuan.
Rui-Zan
RZ
Shi
Xiao-Ling
XL
Hu
Hong-Wei
HW
Peng
D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects*; D005260:Female; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D061986:MCF-7 Cells
D007211:Indoles; C569642:PHII-7 compound