An assessment of EGFR and HER2 inhibitors with structure activity relationship of fused pyrimidine derivatives for breast cancer: a brief review

Furan- and Furopyrimidine-Based Derivatives: Synthesis, VEGFR-2 Inhibition, and In Vitro Cytotoxicity

New derivatives 4a-d, 6, 7a-d, 8a-c, 9, 11a, 11b, 12a-f, 13a-c, and 14 were synthesized and evaluated for their VEGFR-2 inhibition. Compounds 4c, 7b, and 7c showed remarkable enzyme inhibition (IC50 = 57.1, 42.5, and 52.5 nM, respectively) relative to sorafenib (IC50 = 41.1 nM) and were assessed for their cytotoxicity versus HepG2, MCF-7, A549, HT-29, and PC3 cancer cell lines in addition to WI-38. Compound 7b displayed nearly equipotent cytotoxicity against A549 and HT-29 (IC50 = 6.66 and 8.51 μM) compared to sorafenib (IC50 = 6.60 and 8.78 μM). Cell cycle analysis and apoptotic assay of 7b in the HT-29 cell line showed cellular growth arrest at the G2/M phase in addition to the induction of apoptosis. Western blot analysis of compound 7b revealed the deactivation of VEGFR-2. Moreover, a wound healing assay of 7b showed inhibition of wound closure. Additionally, molecular modeling studies of compounds 4c, 7b, and 7c were carried out.

Pyrazole, Pyrazoline, and Fused Pyrazole Derivatives: New Horizons in EGFR-Targeted Anticancer Agents

Pyrazole and its derivatives remain popular heterocycles in drug research, design, and development. Several drugs include the pyrazole scaffold, such as ramifenazone, ibipinabant, antipyrine, and axitinib, etc. They have been extensively studied by the scientific community and are said to have a wide range of biological activity, especially anticancer agents targeting EGFR. Overexpression of EGFR signalling promotes tumor growth by inhibiting apoptosis. EGFR dysfunction has been described in multiple cancers, including colon, head and neck, NSCLC, colon, liver, breast, and ovarian cancer. As a result, EGFR represents a prospective target for cancer treatment. Several anti-EGFR drugs are thriving, notably dacomitinib, afatinib, erlotinib, gefitinib, and osimertinib. However, almost all currently available anti-EGFR drugs have limited therapeutic effectiveness due to a lack of selectivity as well as substantial side effects. Furthermore, aberrant EGFR signalling across numerous human malignancies/carcinomas is impeded by gene amplification, protein overexpression, mutations, or in-frame deletions, making EGFR-induced cancer treatment challenging. To overcome such, novel therapeutic anti-EGFR drugs with high efficacy and minimal toxicity are required. To battle cancer and therapeutic resistance to EGFR inhibitors, pyrazole, pyrazoline, and their derivatives have been investigated as a viable pharmacophore for the development of new drugs with better potency, lesser toxicity, and favourable pharmacokinetic characteristics. The present investigation covers the examination of progress toward anti-cancer therapies targeting EGFR via pyrazole, pyrazoline, and fused pyrazole-based compounds. The current study also represents inclusive data on pyrazole-based marketed drugs as well as therapeutic candidates undergoing preclinical and clinical development. Lastly, we have discussed recent advances in the medicinal chemistry of pyrazole-based derivatives with their anti-EGFR significance for the eradication of various cancers and provide the direction toward structure-activity relationship (SAR), including mechanistic studies.

Poly (ADP-ribose) polymerase (PARP) inhibitors as anticancer agents: An outlook on clinical progress, synthetic strategies, biological activity, and structure-activity relationship

Poly (ADP-ribose) polymerase (PARP) is considered an essential component in case of DNA (Deoxyribonucleic acid) damage, response by sensing DNA damage and engaging DNA repair proteins. Those proteins repair the damaged DNA via an aspect of posttranslational modification, known as poly (ADP-Ribosyl)ation (PARylation). Specifically, PARP inhibitors (PARPi) have shown better results when administered alone in a variety of cancer types with BRCA (Breast Cancer gene) mutation. The clinical therapeutic benefits of PARP inhibitors have been diminished by their cytotoxicity, progression of drug resistance, and limitation of indication, regardless of their tremendous clinical effectiveness. A growing number of PARP-1 inhibitors, particularly those associated with BRCA-1/2 mutations, have been identified as potential cancer treatments. Recently, several researchers have identified various promising scaffolds, which have resulted in the resuscitation of the faith in PARP inhibitors as cancer therapies. This review provided a comprehensive update on the anatomy and physiology of the PARP enzyme, the profile of FDA (Food and Drug Administration) and CFDA (China Food and Drug Administration)-approved drugs, and small-molecule inhibitors of PARP, including their synthetic routes, biological evaluation, selectivity, and structure-activity relationship.

Discovery of 9H-pyrimido[4,5-b]indole derivatives as dual RET/TRKA inhibitors

Aberrant RET kinase signaling is activated in numerous cancers including lung, thyroid, breast, pancreatic, and prostate. Recent approvals of selective RET inhibitors, pralsetinib and selpercatinib, has shifted the focus of RET kinase drug discovery programs towards the development of selective inhibitors. However, selective inhibitors invariably lose efficacy as the selective nature of the inhibitor places Darwinian-like pressure on the tumor to bypass treatment through the selection of novel oncogenic drivers. Further, selective inhibitors are restricted for use in tumors with specific genetic backgrounds that do not encompass diverse patient classes. Here we report the identification of a pyrimido indole RET inhibitor found to also have activity against TRK. This selective dual RET/TRK inhibitor can be utilized in tumors with both RET and TRK genetic backgrounds and can also provide blockade of NTRK-fusions that are selected for from RET inhibitor treatments. Efforts towards developing dual RET/TRK inhibitors can be beneficial in terms of encompassing more diverse patient classes while also achieving blockade against emerging resistance mechanisms.

Recent developments of hydroxamic acid hybrids as potential anti-breast cancer agents

Histone deacetylase inhibitors not only possess favorable effects on modulating tumor microenvironment and host immune cells but also can reactivate the genes silenced due to deacetylation and chromatin condensation. Hydroxamic acid hybrids as promising histone deacetylase inhibitors have the potential to address drug resistance and reduce severe side effects associated with a single drug molecule due to their capacity to simultaneously modulate multiple targets in cancer cells. Accordingly, rational design of hydroxamic acid hybrids may provide valuable therapeutic interventions for the treatment of breast cancer. This review aimed to provide insights into the in vitro and in vivo anti-breast cancer therapeutic potential of hydroxamic acid hybrids, together with their mechanisms of action and structure-activity relationships, covering articles published from 2020 to the present.

Development of new thieno[2,3-d]pyrimidines as dual EGFR and STAT3 inhibitors endowed with anticancer and pro-apoptotic activities

In part due to the resilience of cellular feedback pathways that develop therapeutic resistance to targeting the EGFR alone, using EGFR inhibitors alone was demonstrated to be unsuccessful in clinical trials. The over-activation of the signal transducer/activator of transcription 3 (STAT3) during the administration of an EGFR inhibitor is expected to play a substantial part in the failure and resistance of EGFR inhibitor treatment. Therein, we proposed a hypothesis that induced STAT3-mediated resistance to EGFR inhibition therapy could be addressed by a dual inhibition of EGFR and STAT3 method. To this end, we tried to discover new thieno[2,3-d]pyrimidine derivatives "5a-o". Results from the screening on A549 and MCF7 cancer cell lines revealed that compounds 5j and 5k showed two-digit nanomolar with appropriate safety towards the WI-38 cell line. The best molecules, 5j and 5k, were subjected to γ-radiation, and their cytotoxic efficacy didn't change after irradiation, demonstrating that not having to use it avoided its side effects. Compounds 5j and 5k demonstrated the highest inhibition when their potency was tested as dual inhibitors on EGFR 67 and 41 nM, respectively, and STAT3 5.52 and 3.34 nM, respectively, proved with in silico molecular docking and dynamic simulation. In light of the results presented above, the capacity of both powerful compounds to alter the cell cycle and initiate the apoptotic process in breast cancer MCF7 cells was investigated. Caspase-8, Bcl-2, Bax and Caspase-9 apoptotic indicators were studied.

Computational insights into overcoming resistance mechanisms in targeted therapies for advanced breast cancer: focus on EGFR and HER2 co-inhibition

In the present study, the formation of a heterodimer involving both epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) has been explored as a potential therapeutic mechanism to inhibit the progression of breast cancer. Virtual screening using molecular docking resulted in the three hit compounds (ZINC08382411, ZINC08382438, and ZINC08382292) with minimum binding scores and commonly binding to both receptors. Further, MD simulation analysis of these complexes illustrated the high stability of these compounds with EGFR and HER2. RMSD showed that ZINC08382411 displayed the most stable RMSD of 2 - 3 Å when bound to both receptors, suggesting to have strong compatibility with the active site of the receptor. Hydrogen bond analysis showed that ZINC08382411 forms the maximum number of H-bonds (2 to 3) in both EGFR and HER2 bound complexes, with the highest occupancy of 62% and 79%, respectively. Binding free energy calculation showed that ZINC08382411 possesses maximum affinity towards both the receptors with ΔGbind = -129.628 and -164.063 kJ/mol, respectively. This approach recognizes the significance of EGFR and HER2 in breast cancer development and aims to disrupt their collaborative signaling, which is known to promote the antagonistic behavior of cancer cells. By focusing on this EGFR/HER2 heterodimer, the study offers a promising avenue for identifying a potential candidate (ZINC08382411) that may inhibit breast cancer cell growth and potentially improve patient outcomes. The study's findings may contribute to the ongoing efforts to advance breast cancer treatment strategies.Communicated by Ramaswamy H. Sarma.