Background:
The Epidermal Growth Factor Receptor (known as EGFR) induces cell differentiation
and proliferation upon activation through the binding of its ligands. Since EGFR is thought to be involved in the
development of cancer, the identification of new target inhibitors is the most viable approach, which recently
gained momentum as a potential anticancer therapy.
Objective:
To assess various pyrazole linked pyrazoline derivatives with carbothioamide for EGFR kinase inhibitory
as well as anti-proliferative activity against human cancer cell lines viz. A549 (non-small cell lung
tumor), MCF-7 (breast cancer cell line), SiHa (cancerous tissues of the cervix uteri), and HCT-116 (colon cancer
cell line).
Methods:
In vitro EGFR kinase assay, in vitro MTT assay, Lactate dehydrogenase release, nuclear staining
(DAPI), and flow cytometry cell analysis.
Results:
Compounds 6h and 6j inhibited EGFR kinase at concentrations of 1.66μM and 1.9μM, respectively.
Furthermore, compounds 6h and 6j showed the most potent anti-proliferative results against the A549 KRAS
mutation cell line (IC50 = 9.3 & 10.2μM). Through DAPI staining and phase contrast microscopy, it was established
that compounds 6h and 6j also induced apoptotic activity in A549 cells. This activity was further confirmed
by FACS using Annexin-V-FITC and Propidium Iodide (PI) labeling. Molecular docking studies performed
on 6h and 6j suggested that the compounds can bind to the hinge region of ATP binding site of EGFR
tyrosine kinase in a similar pose as that of the standard drug gefitinib.
Conclusion:
The potential anticancer activity of compounds 6h and 6j was confirmed and need further exploration
in cancer cell lines of different tissue origin and signaling pathways, as well as in animal models of cancer
development.
Ibrutinib targets mutant-EGFR kinase with a distinct binding conformation