Structure Based Multitargeted Molecular Docking Analysis of Selected Furanocoumarins against Breast Cancer

Abstract

Breast cancer is one of the biggest global dilemmas and its current therapy is to target the hormone receptors by the use of partial agonists/antagonists. Potent drugs for breast cancer treatment are Tamoxifen, Trastuzumab, Paclitaxel, etc. which show adverse effects and resistance in patients. The aim of the study has been on certain phytochemicals which has potent actions on ERα, PR, EGFR and mTOR inhibition. The current study is performed by the use of molecular docking as protein-ligand interactions play a vital role in drug design. The 3D structures of ERα, PR, EGFR and mTOR were obtained from the protein data bank and docked with 23 3D PubChem structures of furanocoumarin compounds using FlexX. Drug-likeness property was checked by applying the Lipinski's rule of five on the furanocoumarins to evaluate anti-breast cancer activity. Antagonist and inhibition assay of ERα, EGFR and mTOR respectively has been performed using appropriate in-vitro techniques. The results confirm that Xanthotoxol has the best docking score for breast cancer followed by Bergapten, Angelicin, Psoralen and Isoimperatorin. Further, the in-vitro results also validate the molecular docking analysis. This study suggests that the selected furanocoumarins can be further investigated and evaluated for breast cancer treatment and management strategies.

Figure 1

Representation of selection of compounds by different approaches used in the study.

Figure 2

Molecular docking analysis of XAN. (a) Pose view of interaction of Xanthotoxol with receptors ERα, PR, EGFR and mTOR. (b) Overlay of XAN in active pockets of ERα, PR, EGFR and mTOR. XAN: Xanthotoxol, ERα: Estrogen receptor, PR: Progesterone receptor, EGFR: Epidermal growth factor receptor and mTOR: Mammalian target of Rapamycin.

Figure 3

Molecular docking analysis of BER. (a) Pose view of interaction of BER with receptors ERα, PR, EGFR and mTOR. (b) Overlay of BER in active pockets of ERα, PR, EGFR and mTOR. BER: Bergapten, ERα: Estrogen receptor, PR: Progesterone receptor, EGFR: Epidermal growth factor receptor and mTOR: Mammalian target of Rapamycin.

Figure 4

Molecular docking analysis of ANG. (a) Pose view of interaction of ANG with receptors ERα, PR, EGFR and mTOR. (b) Overlay of ANG in active pockets of ERα, PR, EGFR and mTOR. ANG: Angelicin, XAN: Xanthotoxol, ERα: Estrogen receptor, PR: Progesterone receptor, EGFR: Epidermal growth factor receptor and mTOR: Mammalian target of Rapamycin.

Figure 5

Molecular docking analysis of PSO. (a) Pose view of interaction of PSO with receptors ERα, PR, EGFR and mTOR. (b) Overlay of PSO in active pockets of ERα, PR, EGFR and mTOR. PSO: Psoralen, ERα: Estrogen receptor, PR: Progesterone receptor, EGFR: Epidermal growth factor receptor and mTOR: Mammalian target of Rapamycin.

Figure 6

Molecular docking analysis of ISO. (a) Pose view of interaction of ISO with receptors ERα, PR, EGFR and mTOR. (b) Overlay of ISO in active pockets of ERα, PR, EGFR and mTOR. IMP: Isoimperatorin, ERα: Estrogen receptor, PR: Progesterone receptor, EGFR: Epidermal growth factor receptor and mTOR: Mammalian target of Rapamycin.

Figure 7

Antagonist dose response analysis of selected furanocoumarins (ANG, TAM, XAN, BER, PSO and IMP; µM) and human ERα reporter cells. Where each value is represented as mean ± SEM (n = 3). ANG: Angelicin, TAM: 4-hydroxy Tamoxifen, XAN: Xanthotoxol, BER: Bergapten, PSO: Psoralen and IMP: Isoimperatorin, ERα: Estrogen receptor.

Figure 8

Immunofluorescence analysis of EGFR in MCF-7 cells (n = 3). DAPI: Fluorescent blue (nucleus; FITC green). EGFR expression following treatment with (a) XAN and BER, (b) ANG, PSO, IMP was indicated by its localization to the cell membrane of MCF-7 cells. For immunofluorescence staining was analysed at (x160). EGFR: Epidermal Growth Factor Receptor, ANG: Angelicin, TAM: 4-hydroxy Tamoxifen, XAN: Xanthotoxol, BER: Bergapten, PSO: Psoralen and IMP: Isoimperatorin.

Figure 9

In-vitro mTOR inhibitory activity of the selected furanocoumarins using ELISA where each value is represented as mean ± SEM (n = 3). Comparison: RAP, XAN, BER, ANG, PSO, IMP with UN. ***p < 0.001, **p < 0.01, *p < 0.05 and ^nsp > 0.05. UN: Untreated, RAP: Rapamycin, XAN: Xanthotoxol, BER: Bergapten, PSO: Psoralen and IMP: Isoimperatorin, mTOR: Mammalian target of Rapamycin.

Figure 10

The figure shows an MPR route that gets activated by the stimulation of progesterone receptor and has a role in cell proliferation by upregulation of PKA/cAMP by the activation of CREB/CREM/ATF-1. Activation of PR also upregulates Wnt/β-catenin pathway which leads to cell proliferation and tumorigenesis by the activation of MAPK/SRC by upregulation of transcription factor, Sp1. Activation of EGFR upregulates Ras-MAPK pathway by the phosphorylation of binding domain Grb2 which has an effect on cell proliferation, anti-apoptosis and invasion. Grb2 also upregulates PIP3 by activation of Gab1, PI3K and AKT pathways that is responsible to cell invasion. mTOR complex (mTORC1) is upregulated by certain hormones and growth factors through SOS/Ras/Raf-MEK-ERK pathway or by PI3K-PDK1-PKB pathway or by both. These pathways upregulate Tuberous Sclerosis Complex (TSC1/2) which further downregulate Rheb which is a small G-protein responsible for protein synthesis by S6K-rps6.