Novel Quinazoline Derivative Activates FIH-1 in MCF-7 Cells and 7, 12-Dimethylbenz[a]-Anthracene Induced Mammary Gland Carcinoma in Albino Rats

Background: Mammary gland carcinoma is a solid tumor with a hypoxic core due to oxygen deficiency. Factor inhibiting hypoxia-inducible factor-1α (FIH-1) is an oxygen sensor that becomes inactive in a hypoxic environment, making it unable to regulate rapidly proliferating cancer cells. Thus, we hypothesize that the chemical activation of FIH-1 could be a novel mechanism for regulating mammary gland carcinoma. In this study, 6-(5,11-dioxoisoindolo [2,1-a] quinazolin-6(5H,6aH,11H)-yl)-N-(1H-imidazol-2-yl) hexanamide (BBAP-9) was investigated for its anticancer potential. Methods: A library of 67,609 drug-like molecules was virtually screened against FIH-1 based on Lipinski’s rule from the ZINC database. BBAP-9 was selected as a potent FIH-1 activator through docking study, absorption, distribution, metabolism, ex-cretion and toxicity (ADMET) profile, and in vitro 2-oxoglutarate dependent FIH-1 activation assay. Further, its in vitro cy-totoxicity and apoptotic activity were scrutinized against MCF-7 cells using acridine orange/ethidium bromide (AO/EB) and 5,5,6,6^′-tetrachloro-1,1^′,3,3^′-tetraethylbenzimi-dazoylcarbocyanine iodide (JC-1) stainings and its in vivo activity against 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary gland carcinoma in Wistar rats by performing various parameters such as hemodynamic, carmine-alum staining, histology, scanning electron microscopy, and biochemical analysis. Results: Our results demonstrated that BBAP-9 showed a good docking score (–8.162) and a suitable ADMET profile. BBAP-9 activated FIH-1 when scrutinized through a 2-oxoglutarate dependent assay (p < 0.05). BBAP-9 exhibited significant cytotoxicity with half-maximal inhibitory concentration (IC50) of 16.9 ± 0.85 µM (p < 0.05) and induced apoptotic changes in MCF-7 cells, as revealed by AO/EB (p < 0.05) and JC-1 stainings (p < 0.05). Once scrutinized against DMBA-induced mammary gland carcinoma, BBAP-9 restored autonomic dysfunction (p < 0.05), tissue vascularization, morphological architecture, membrane ruffles, and oxidative stress markers [thiobarbituric acid reactive substances (TBARs), protein carbonyl (PC), glutathione (GSH), super oxide dismutase (SOD), and catalase)] toward normal control (p < 0.05). Conclusions: Overall, the current study’s findings demonstrate that BBAP-9 has significant cytotoxicity and apoptotic activity against MCF-7 cells. Moreover, BBAP-9 has chemotherapeutic efficacy on DMBA-induced mammary gland carcinoma, which can be attributed to its propensity to enhance antioxidant profiles and inhibit cellular proliferation, improve surface architecture, soothing membrane ruffles, and decrease lactate effects. Thus, we postulated that BBAP-9 may be a novel FIH-1 activator in mammary gland carcinoma.