HER2 Kinase-Targeted Breast Cancer Therapy: Design, Synthesis, and In Vitro and In Vivo Evaluation of Novel Lapatinib Congeners as Selective and Potent HER2 Inhibitors with Favorable Metabolic Stability

HER2 kinase as a well-established target for breast cancer (BC) therapy is associated with aggressive clinical outcomes; thus, herein we present structural optimization for HER2-selective targeting. HER2 profiling of the developed derivatives demonstrated potent and selective inhibitions (IC₅₀: 5.4-12 nM) compared to lapatinib (IC₅₀: 95.5 nM). Favorably, 17d exhibited minimum off-target kinase activation. NCI-5-dose screening revealed broad-spectrum activities (GI₅₀: 1.43-2.09 μM) and 17d had a remarkable selectivity toward BC. Our compounds revealed significant selective and potent antiproliferative activities (∼20-fold) against HER2+ (AU565, BT474) compared to HER2(-) cells. At 0.1 IC₅₀, 15i, 17d, and 25b inhibited pERK1/2 and pAkt by immunoblotting. Furthermore, 17d demonstrated potent in vivo tumor regression against the BT474 xenograft model. Notably, a metastasis case was observed in the vehicle but not in the test mice groups. CD-1 mice metabolic stability assay revealed high stability and low intrinsic clearance of 17d (T_1/2 > 145 min and CL_int(mic) < 9.6 mL/min/kg).

Hybrid Quinazoline 1,3,5-Triazines as Epidermal Growth Factor Receptor (EGFR) Inhibitors with Anticancer Activity: Design, Synthesis, and Computational Study

We report a series of hybrid quinazoline-1,3,5-triazine derivatives as EGFR inhibitors, which were synthesised and tested by using a variety of in vitro, in silico, and in vivo techniques. The derivatives were found to be active against different cancer cell lines and nontoxic against normal ones, with compounds 7 c, 7 d, 7 e, and 7 j being the most potent ones. The derivatives were also evaluated for angiogenesis inhibition potency in chicken eggs, and molecular docking and dynamics simulation studies were carried out to elucidate the fundamental substituent groups essential for their bioactivity. Additionally, a SAR study of the derivatives was performed for future compound optimisation. These studies suggested that the derivatives have a high affinity towards EGFR with favourable pharmacological properties. The most active compound (7 e) was further evaluated for in vivo anticancer activity against DMBA-induced tumours in female Sprague-Dawley rats as well as its effects on plasma antioxidant status, biotransformation enzymes, and lipid profile. The study suggested that 7 e has lead properties against breast cancer and can serve as a starting compound for further development of anti-EGFR compounds.

2,4-Disubstituted Quinazoline Derivatives Act as Inducers of Tubulin Polymerization: Synthesis and Cytotoxicity

BACKGROUND

During last recent years number of anti-tubulin agents were introduced for treatment of diverse kind of cancer. Despite of their potential in treatment of cancer, drug resistance and adverse toxicity such as peripheral neuropathy are some of the negative criteria of anti-tubulin agents.

METHODS

Twenty seven quinazoline derivatives were synthesized using a multicomponent reaction. The cytotoxicity of compounds 1-27 was tested in SRB assays employing five different human tumor cell lines. Effect of two of active compounds on tubulin polymerization was also checked using a commercially available assay kit. Molecular modelling studies were also performed using autodock tools software.

RESULTS

SRB assays showed that compounds 2, 9, 16 and 26, being highly cytotoxic with IC50 values ranging between 2.1 and 14.3µM. The possible mode of action of compounds, 2, 9, 16 and 26, and the taxol binding site of the protein tubulin, an important goal for antimitotic drugs, was also studied by molecular docking, which showed reasonable interactions with tubulin active site, followed by investigation of the effects of compounds 9 and 16 on the polymerization of tubulin. The results showed the tested compounds to be highly active as inducers of tubulin polymerization.

CONCLUSION

Altogether, with respect to obtained results, it is attractive and beneficial to further investigation on quinazoline scaffold as antimitotic agents.

Design and Evaluation of Potent EGFR Inhibitors through the Incorporation of Macrocyclic Polyamine Moieties into the 4-Anilinoquinazoline Scaffold

Adenosine triphosphate (ATP)-competitive inhibitors of the epidermal growth factor receptor (EGFR) have provided a significant improvement in the disease outcome of nonsmall cell lung cancer (NSCLC). Unfortunately, some marketed drugs affect a transient beneficial response in EGFR mutant NSCLC patients. We reported a series of potential EGFR inhibitors through incorporation of macrocyclic polyamine into 4-anilinoquinazoline scaffold. It is expected that anilinoquinazoline part effectively bind to EGFR domain, while ATP molecules are captured by a macrocyclic polyamine moiety. In vitro experiments exhibited that most of tested compounds suppressed tumor cell proliferation more strongly than Gefitinib and Lapatinib (dual inhibitor of EGFR/HER2) as controls. In kinase assays, the compound 1f showed excellent dual inhibition activity toward EGFR^WT (IC₅₀ = 1.4 nM) and HER2 (IC₅₀ = 2.1 nM). In vivo pharmacology evaluation of 1f showed significant antitumor activity (TGI = 44.2%) in A549 xenografts mice. The current work provided a feasible solution to optimize anilinoquinazoline-based inhibitors.

Novel series of 6-(2-substitutedacetamido)-4-anilinoquinazolines as EGFR-ERK signal transduction inhibitors in MCF-7 breast cancer cells

Epidermal growth factor receptor (EGFR) signaling pathway has been previously investigated for its significant role in the progression of different types of malignant tumors, where development of small molecules targeting EGFR is well known strategy for design of antitumor agents. Herein, we report the design and synthesis of two series of 6-(2-substitutedacetamido)-4-anilinoquinazolines (6a-x and 13a-d) as EGFR inhibitors. All the newly synthesized quinazoline derivatives were in vitro evaluated for their anti-proliferative activity towards MCF-7 (Breast Cancer) and HepG2 (Hepatocellular carcinoma) cell lines. In particular, compound 6n showed significant inhibitory activity against MCF-7 and HepG2 cell lines (IC₅₀ = 3 and 16 μM, respectively), compared to that of Erlotinib (IC₅₀ = 20 and 25 μM, respectively). Western blotting of 6n at MCF-7 cell line revealed the dual inhibitory activity of 6n towards diminishing the phosphorylated levels for EGFR and ERK. Also, ELISA assay confirmed the anti-EGFR activity of compound 6n (IC₅₀ = 0.037 μM). Finally, a molecular docking study showed the potential binding mode of 6n within the ATP catalytic binding site of EGFR, exhibiting similar binding mode to EGFR inhibitor Erlotinib.

Design, synthesis and biological evaluation of some novel quinazolinone derivatives as potent apoptotic inducers

Aim: Novel quinazolinone and triazinoquinazolinone derivatives were designed and synthesized as apoptotic inducers. Methodology/results: Most of the synthesized compounds showed excellent antiproliferative activity against MCF-7 and HCT-116 cell lines, respectively. Compounds 7a, 8a, 8d, 14a and 14d were superior to doxorubicin as activators of caspases 3, 8 and 9 in HCT-116 cell line. The most potent caspase inducers, 8d and 14a showed cell cycle arrest mainly in G1 and S phase, respectively and increased the levels of p53, Bax and the Bax/Bcl-2 ratio compared with doxorubicin in HCT-116 cells with excellent selectivity against CCD-18Co human colon normal cell line. Conclusion: The synthesized compounds can be considered as potent apoptotic inducers interfering with extrinsic and intrinsic apoptotic pathways.

Synthesis and evaluation of 2,9-disubstituted 8-phenylthio/phenylsulfinyl-9H-purine as new EGFR inhibitors

In present study, we described the synthesis and biological evaluation of a new class of EGFR inhibitors containing 2,9-disubstituted 8-phenylthio/phenylsulfinyl-9H-purine scaffold. Thirty-one compounds were synthesized. Among them, compound C9 displayed the IC₅₀ of 29.4 nM against HCC827 cell line and 1.9 nM against EGFR^L858R. Compound C12 showed moderate inhibitory activity against EGFR^{L858R/T790M/C797S} (IC₅₀ = 114 nM). Western bolt assay suggested that compound C9 significantly inhibited EGFR phosphorylation. In vivo test, compound C9 remarkably exhibited inhibitory effect on tumor growth at 5.0 mg/kg by oral administration in established nude mouse HCC827 xenograft model. These results indicate that the 2,9-disubstituted 8-phenylsulfinyl/phenylsulfinyl-9H-purine derivatives can act as potent EGFR(L858R) inhibitors and effective anticancer agents. Additionally, optimization of compound C12 may result in discovering the fourth-generation EGFR-TKIs.

Exploiting polypharmacology for improving therapeutic outcome of kinase inhibitors (KIs): An update of recent medicinal chemistry efforts

Polypharmacology has been increasingly advocated for the therapeutic intervention in complex pathological conditions, exemplified by cancer. Although kinase inhibitors (KIs) have revolutionized the treatment for certain types of malignancies, some major medical needs remain unmet due to the relentless advance of drug resistance and insufficient efficacy of mono-target KIs. Hence, "multiple targets, multi-dimensional activities" represents an emerging paradigm for innovative anti-cancer drug discovery. Over recent years, considerable leaps have been made in pursuit of kinase-centric polypharmacological anti-cancer therapeutics, providing avenues to tackling the limitation of mono-target KIs. In the review, we summarize the clinically important mechanisms inducing KI resistance and depict a landscape of recent medicinal chemistry efforts on exploring kinase-centric polypharmacological anti-cancer agents that targeting multiple cancer-related processes. In parallel, some inevitable challenges are emphasized for the sake of more accurate and efficient drug discovery in the field.

First Bispecific Inhibitors of the Epidermal Growth Factor Receptor Kinase and the NF-κB Activity As Novel Anticancer Agents

The activation of the NF-κB transcription factor is a major adaptive response induced upon treatment with EGFR kinase inhibitors, leading to the emergence of resistance in nonsmall cell lung cancer and other tumor types. To suppress this survival mechanism, we developed new thiourea quinazoline derivatives that are dual inhibitors of both EGFR kinase and the NF-κB activity. Optimization of the hit compound, identified in a NF-κB reporter gene assay, led to compound 9b, exhibiting a cellular IC₅₀ for NF-κB inhibition of 0.3 μM while retaining a potent EGFR kinase inhibition (IC₅₀ = 60 nM). The dual inhibitors showed a higher potency than gefitinib to inhibit cell growth of EGFR-overexpressing tumor cell lines in vitro and in a xenograft model in vivo, while no signs of toxicity were observed. An investigation of the molecular mechanism of NF-κB suppression revealed that the dual inhibitors depleted the transcriptional coactivator CREB-binding protein from the NF-κB complex in the nucleus.

Combination of 4-anilinoquinazoline, arylurea and tertiary amine moiety to discover novel anticancer agents

In present study, 4-anilinoquinazolines scaffold, arylurea and tertiary amine moiety were combined to design, synthesize gefitinib analogs and discover novel anticancer agents. A series of 4-anilinoquinazoline derivatives (1, 2, 3 and 4) bearing arylurea and tertiary amine moiety at its 6-position were synthesized. Their antiproliferative activities in vitro were evaluated via MTT assay against A431 cell and A549 cell. The SAR of the title compounds was discussed. The compounds 2d, 2i and 2j with potent antiproliferative activities were evaluated their inhibitory activity against EGFR-TK. Compound 2j displayed potent inhibitory activity against EGFR-TK. In addition, compound 2j, at 50 mg/kg, can completely inhibit cancer growth in established nude mouse A549 xenograft model in vivo. These results suggest that the 4-anilinoquinazoline derivatives bearing diarylurea and tertiary amino moiety at its 6-position can serve as anticancer agents and EGFR inhibitors.

Synthesis, reactivity, and biological activity of gold(I) complexes modified with thiourea-functionalized tyrosine kinase inhibitors

Thiourea-modified 3-chloro-4-fluoroanilino-quinazoline derivatives have been studied as potential receptor-targeted carrier ligands in linear gold(I) complexes. The molecules mimic the epidermal growth factor receptor (EGFR) tyrosine kinase-targeted inhibitor gefitinib. Thiourea groups were either directly attached to quinazoline-C6 (compounds 4, 5, and 7) or linked to this position via a flexible ethylamino chain (compound 9). Compound 7 acts as a thiourea-S/quinazoline-N1 mixed-donor ligand, giving the unexpected dinuclear complex [{Au(μ-7-S,N)}2]X2 (X = Cl(-), SCN(-)) (12a,b) (X-ray crystallography, electrospray mass spectrometry). Derivative 9 forms a stable linear complex, [Au(PEt3)(9-S)](NO3) (13). The biological activity of the carrier ligands and corresponding gold(I) complexes was studied in NCI-H460 and NCI-H1975 lung cancer cells. Compound 9 partially overcomes resistance to gefitinib in NCI-H1975, a lung cancer cell line characterized by a L858R/T790M mutation in EGFR (IC50 values of 1.7 and 30 μM, respectively). The corresponding gold complex (13) maintains activity in the low-micromolar concentration range similar to the metal-free carrier. Compound 9 and the corresponding [Au(PEt3)] complex, 13, inhibit EGFR kinase-mediated phosphorylation with sub-micromolar IC50 values similar to those observed for gefitinib under the same assay conditions. Potential mechanisms of action and reactions in biological media of this new type of hybrid agent, as well as shortcomings of the current design are discussed.