Antipsychotics drug aripiprazole as a lead against breast cancer cell line (MCF-7) in vitro

Abstract

Breast cancer is the second leading cause of death among women globally. The existing treatment options for breast cancer are largely associated with severe toxicities, and lower efficacies. Therefore, there is an urgent need for the development of non-toxic effective drugs against breast cancer. For this purpose, drug repositioning strategy was used to evaluate the anti-cancer potential of a library of heterocyclic drugs. The major advantage of drug repurposing is that the pharmacokinetic, pharmacodynamic, and toxicity profiles of drugs are well documented. In the current study, we screened 97 drugs of different chemical classes, and among them aripiprazole, an antipsychotic drug, was found to be sufficiently active against breast cancer cell line MCF-7. Aripiprazole showed a cytotoxicity (IC50 = 12.1 ± 0.40 μM) to MCF-7 cells, comparable to the standard anticancer drug doxorubicin (IC50 = 1.25 ± 0.34 μM). Aripiprazole was also found to be active against other cancer cell lines, including MDA-MB-231 (IC50 = 19.83 ± 0.27 μM), AU565 (IC50 = 18.02 ± 0.44 μM), and BT-474 (IC50 = 36.42 ± 0.12 μM). Aripiprazole significantly inhibited the cell cycle progression at subG0G1 phase, and enhanced apoptosis in MCF-7 breast cancer cells. The drug was also able to significantly increase the nuclear condensation, and modulated the expression of certain genes involved in breast cancer, such as caspases 3, and 9, BAK-1, C-MYC, BCL2L1, BCL-10, and BCL-2. Further studies are needed to explore the effect of aripiprazole on intrinsic and extrinsic pathways of apoptosis in cancer cells.

Fig 1. Antipsychotic drug evaluated in the present study.

Fig 2. Graphical representation of percent inhibition of MCF-7 cell line.

a) Percent inhibition of MCF-7 cells in presence of aripiprazole b) Percent inhibition of MCF-7 cells in presence of doxorubicin (standard inhibitor).

Fig 3. Graphical representation of percent inhibition of MCF 7 cell line in cell viability assay.

Percentages of live and dead cells in control group (blue), in presence of aripiprazole 35 μM (green) and 100 μM (yellow).

Fig 4. Dot plot representing the total cell count (%).

The distribution of viable cells (lower left), dead cells (necrotic) (upper left), early apoptotic (lower right), and late apoptotic cells (upper right) in the four quadrants of dot plots of untreated, aripiprazole treated (12, 24, and 48 μM) MCF-7 cell line. Total 10,000 cells in triplicate were analyzed during sample acquisition.

Fig 5. Analysis of aripiprazole-induced apoptosis in MCF-7 breast cancer cells by DAPI.

a) control (untreated MCF-7), b) aripiprazole 12.5 μM, c) aripiprazole 24 μM, d) aripiprazole 48 μM, and e) camptothecin (50 μM). Images were taken at 20X magnification by using microscope TE-2000, Nikon, Japan. The nuclei were stained with DAPI (blue).

Fig 6. Cell cycle distribution of MCF-7 cells showing percent histogram after 48 hours of treatment.

A) Untreated MCF-7 cells showing no cell population in subG₀G₁ phase, B) Aripiprazole (12 μM) cells showing 9.47% cell population in subG₀G₁, C) Aripiprazole (24 μM) cells showing 11.6% cell population in subG₀G₁ phase, D) Aripiprazole (48 μM) cells showing 57.4% cell population in subG₀G₁ phase, and E) Camptothecin (50 μM) cells showing 4% cell population in subG₀G₁ phase Total 10,000 cells were analyzed in triplicate during sample acquisition.

Fig 7. Graphical representation of fold change in mRNA expression.

mRNA expression of caspase 3, caspase 9, c-myc, BAK1, BCL 1and BCL-10 calculated by comparative CT method (2^-ΔΔCT Method) after the treatment of aripiprazole and camptothecin. β-actin and GAPDH were used as a control gene. CT values were obtained, data was normalized against actin and fold change was calculated by Δ^CT method. The data are mean ± S.E.M. of three independent experiments, P-values, (***P< 0.001, ** P<0.001 and * P<0.05).

Fig 8. Marketed drugs with heterocyclic fragments in their structures.

Different marketed drugs with heterocyclic pharmacophore that play crucial role in their physiochemical properties.