2,2′-Diphenyl-3,3′-Diindolylmethane: A Potent Compound Induces Apoptosis in Breast Cancer Cells by Inhibiting EGFR Pathway
Figure 5
Inhibition of EGF induced EGFR activation, cell viability and colony formation of MCF7 cells by DPDIM.
(A and B), Effect of DPDIM on EGFR phosphorylation and cell viability in EGF induced cells. MCF7 cells were treated with 100 ng/ml of EGF for 6 hr followed by 10 µM DPDIM for additional 24 hr. (A), Phosphorylation of EGFR in DPDIM treated and untreated cells in the presence or absence of EGF were detected by IB. Results are representative of three independent experiments. Densitometric value of each IB band is mentioned in the figure. Bar graph with SD represents the relative scanned density of phospho EGFR bands of MCF7 cells treated with or without EGF and DPDIM. (*P = 0.002, **P < 0.0001, ***P = 0.0025) (B), Cell viability of these DPDIM treated and untreated cells in the presence or absence of EGF were measured by MTT assay. The bars represent the percent (%) cell viability and standard deviation (SD) obtained from three independent experiments. *indicates P<0.0001 (C), 100 ng/ml of EGF induced or uninduced MCF7 cells treated with either 1 µM or 10 µM DPDIM were plated at a density of 5000 cells per 35 mm dish. EGF/DPDIM or both were fed every alternative day with media exchange. After incubation of 14 days plates were examined under a microscope and representative photographs of the colonies were taken. (D), The average diameters of the colonies were computed and represented by bar graph (n = 3, ***P = 0.0101, **P = 0.0019, *P = 0.003) with SD. (E), Colonies with the diameter of ∼100 µm were counted from three individual 20X microscopic fields. Average number of colonies for each treated and untreated plates were plotted as bar graphs with their representative SD (***P = 0.0078, **P = 0.0048, *P < 0.0001).