Synthesis, Antitumor Activities and Molecular Modelling of 4-Anilinoquinazoline Derivatives as EGFR-TK Inhibitors

New compounds of 4-anilino-6-substituted quinazoline were designed, synthesized and tested for their EGFR-TK and tumor growth inhibitory activities. The synthesized compounds were appended with amides 6 and 7, dithiocarbamate ester 8a–f or urea/thiourea 9–12 moieties at C-6 of the quinazoline ring to work as extra hydrogen bond acceptors. All the synthesized compounds were effective against EGFR-TK activity, particularly, derivatives 8a, 8f and 9 with IC50 values of 0.14±0.003, 0.119±0.003, and 0.115±0.002 μM, respectively, showed the best activities. The three compounds were further assayed for their cytotoxicity against MCF-7, H-69, SKOV-3 and LS-174T cell lines. Multikinase enzymes inhibition activity of compound 9 was further screened including VEGFR-2, c-MER, c-MET and Her-2. Compounds 8a, 8f, and 9 were docked into the ATP binding site of EGFR-TK which also had resemblance binding pattern to erlotinib with extra binding mode with Cys-773 at the gatekeeper of the enzyme. Cell cycle analyses of MCF-7 cells treated with 8a and 9 was measured in addition to other related factors such as Bax, Bcl-2, caspase-9, and PARP-1.

Ponatinib, Lestaurtinib and mTOR/PI3K inhibitors are promising repurposing candidates against Entamoeba histolytica

Dysentery caused by Entamoeba histolytica affects millions of people annually. Current treatment regimens are based on metronidazole to treat invasive parasites combined with paromomycin for luminal parasites. Issues with treatment include significant side effects, inability to easily treat breastfeeding and pregnant women, the use of two sequential agents, and concern that all therapy is based on nitroimidazole agents with no alternatives if clinical resistance emerges. Thus, the need for new drugs against amebiasis is urgent. To identify new therapeutic candidates, we screened the ReFRAME library (11,948 compounds assembled for Repurposing, Focused Rescue, and Accelerated Medchem) against E. histolytica trophozoites. We identified 159 hits in the primary screen at 10 μM and 46 compounds were confirmed in secondary assays. Overall, 26 were selected as priority molecules for further investigation including 6 FDA approved, 5 orphan designation, and 15 which are currently in clinical trials (3 phase III, 7 phase II and 5 phase I). We found that all 26 compounds are active against metronidazole resistant E. histolytica and 24 are able to block parasite recrudescence after drug removal. Additionally, 14 are able to inhibit encystation and 2 (lestaurtinib and LY-2874455) are active against mature cysts. Two classes of compounds are most interesting for further investigations: the Bcr-Abl TK inhibitors, with the ponatinib (EC 50 0.39) as most potent and mTOR or PI3K inhibitors with 8 compounds in clinical development, of which 4 have nanomolar potency. Overall, these are promising candidates and represent a significant advance for drug development against E. histolytica .

Safety Profile of Mutant EGFR-Tyrosine Kinase Inhibitors in Advanced Non-Small Cell Lung Cancer: Meta-Analysis and Literature to Review

Despite the use of platinum-based chemotherapy, lung cancer continues to be the leading cause of cancer related death in the world. To overcome the rate of lung cancer related death, scientists discovered advanced therapies including mutant Epidermal Growth Factor Receptor-tyrosine kinase (EGFR-TK) inhibitors. Included in this study are nine phase 3 randomized controlled trials designed to study the safety profile of mutant EGFR-TK inhibitors in patients with advanced non-small cell lung cancer. The study showed that mutant EGFR-TK inhibitors have an incidence of adverse effects that is far less than platinum-based chemotherapy. Adverse effects reported were tolerable and easily manageable by slowing the infusion rate, decreasing the dosage, and skipping a dosage in symptomatic patients.

A Novel ELISA-Based Peptide Biosensor Assay for Screening ABL1 Activity in vitro: A Challenge for Precision Therapy in BCR-ABL1 and BCR-ABL1 Like Leukemias

The pathogenic role of the overactivated ABL1 tyrosine kinase (TK) pathway is well recognized in some forms of BCR-ABL1 like acute lymphoblastic leukemia (ALL); TK inhibitors represent a useful therapeutic choice in these patients who respond poorly to conventional chemotherapy. Here we report a novel peptide biosensor (PABL)-ELISA assay to investigate ABL1 activity in four immortalized leukemic cell lines with different genetic background. The PABL sequence comprises an ABL1 tyrosine (Y) phosphorylation site and a targeting sequence that increases the specificity for ABL1; additional peptides (Y-site-mutated (PABL-F) and fully-phosphorylated (PPHOSPHO-ABL) biosensors) were included in the assay. After incubation with whole cell lysates, average PABL phosphorylation was significantly increased (basal vs. PABL phosphorylation: 6.84 ± 1.46% vs. 32.44 ± 3.25%, p-value < 0.0001, two-way ANOVA, Bonferroni post-test, percentages relative to PPHOSPHO-ABL in each cell line). Cell lines expressing ABL1-chimeric proteins (K562, ALL-SIL) presented the higher TK activity on PABL; a lower signal was instead observed for NALM6 and REH (p < 0.001 and p < 0.05 vs. K562, respectively). Phosphorylation was ABL1-mediated, as demonstrated by the specific inhibition of imatinib (p < 0.001 for K562, NALM6, ALL-SIL and p < 0.01 for REH) in contrast to ruxolitinib (JAK2-inhibitor), and occurred on the ABL1 Y-site, as demonstrated by PABL-F whose phosphorylation was comparable to basal levels. In order to validate this novel PABL-ELISA assay on leukemic cells isolated from patient’s bone marrow aspirates, preliminary analysis on blasts derived from an adult affected by chronic myeloid leukaemia (BCR-ABL1 positive) and a child affected by ALL (BCR-ABL1 negative) were performed. Phosphorylation of PABL was specifically inhibited after the incubation of BCR-ABL1 positive cell lysates with imatinib, but not with ruxolitinib. While requiring further optimization and validation in leukemic blasts to be of clinical interest, the PABL-based ELISA assay provides a novel in vitro tool for screening both the aberrant ABL1 activity in BCR-ABL1 like ALL leukemic cells and their potential response to TK inhibitors.

Molecular Modeling of Novel Fluorophoric Thiazolo- [2, 3-B] Quinazolinones to Study Epidermal Growth Factor Receptor Tyrosine Kinase Inhibition Potency

Epidermal growth factor receptor tyrosine kinase (EGFR-TK) is one of the key regulators that exhibit pivotal role in proliferation of cancer cell. Quinazolinones are studiedly widely as effective EGFR-TK inhibitor because of their higher affinity to bind with adenosine triphosphate (ATP) binding site of receptor tyrosine kinases. However, their toxicity due to non-specific binding to tyrosine kinase in non-cancerous normally dividing cells of the body limits its applicability as a cancer therapeutics. In the present investigation a series of thirty-four novel synthesized thiazolo- [2, 3-b] quinazolinones were studied in silico as EGFR-TK inhibitors. All the thirty-four compounds were screened against EGFR-TK domain using multiple software’s (AutoDock Vina, Argus Lab, YASARA, and MOE). The interactions of the ligands with amino acid residues, namely, Lys721, Met769 and Asp831 of the active site were through the functional groups on aryl substituents at position 3 and 5 of the thiazolo- [2, 3-b] quinazolinone scaffold. The methyl substituents at position 8 of the ligands had prominent hydrophobic interactions in the active site cavity of EGFR-TK domain. The compounds 5ab, 5aq, and 5bq were predicted to be non-toxic and drug-like by in silico ADMET investigations. These compounds were considered for further investigation due to their non-toxicity and higher docking score ranking in different docking methods. The molecular dynamics (MD) simulation for 100 ns of docked complexes revealed the stability of these compounds. The binding free energy determined using Molecular Mechanics Generalized Born Model and Solvent Accessibility (MM-GBSA) method indicate that thiazolo- [2, 3-b] quinazolinone has high inhibitory efficacy similar to the standard drug, erlotinib (5ab - 22.45, 5aq -22.23, 5bq -20.76, and erlotinib -24.11 kcal/mol). In silico studies and MD simulations indicated that compounds (5ab, 5aq and 5bq) could be potential EGFR-TK inhibitors and require further validation as cancer therapeutics using carcinoma cell lines.<br><p></p>

Molecular Modeling of Novel Fluorophoric Thiazolo- [2, 3-B] Quinazolinones to Study Epidermal Growth Factor Receptor Tyrosine Kinase Inhibition Potency

Epidermal growth factor receptor tyrosine kinase (EGFR-TK) is one of the key regulators that exhibit pivotal role in proliferation of cancer cell. Quinazolinones are studiedly widely as effective EGFR-TK inhibitor because of their higher affinity to bind with adenosine triphosphate (ATP) binding site of receptor tyrosine kinases. However, their toxicity due to non-specific binding to tyrosine kinase in non-cancerous normally dividing cells of the body limits its applicability as a cancer therapeutics. In the present investigation a series of thirty-four novel synthesized thiazolo- [2, 3-b] quinazolinones were studied in silico as EGFR-TK inhibitors. All the thirty-four compounds were screened against EGFR-TK domain using multiple software’s (AutoDock Vina, Argus Lab, YASARA, and MOE). The interactions of the ligands with amino acid residues, namely, Lys721, Met769 and Asp831 of the active site were through the functional groups on aryl substituents at position 3 and 5 of the thiazolo- [2, 3-b] quinazolinone scaffold. The methyl substituents at position 8 of the ligands had prominent hydrophobic interactions in the active site cavity of EGFR-TK domain. The compounds 5ab, 5aq, and 5bq were predicted to be non-toxic and drug-like by in silico ADMET investigations. These compounds were considered for further investigation due to their non-toxicity and higher docking score ranking in different docking methods. The molecular dynamics (MD) simulation for 100 ns of docked complexes revealed the stability of these compounds. The binding free energy determined using Molecular Mechanics Generalized Born Model and Solvent Accessibility (MM-GBSA) method indicate that thiazolo- [2, 3-b] quinazolinone has high inhibitory efficacy similar to the standard drug, erlotinib (5ab - 22.45, 5aq -22.23, 5bq -20.76, and erlotinib -24.11 kcal/mol). In silico studies and MD simulations indicated that compounds (5ab, 5aq and 5bq) could be potential EGFR-TK inhibitors and require further validation as cancer therapeutics using carcinoma cell lines.<br><p></p>

Design, synthesis, biological evaluation and docking study of novel quinazoline derivatives as EGFR-TK inhibitors

Background: Quinazoline-based compounds have been proved effective in the treatment of cancers for years. Materials & methods: The structural features of several inhibitors of EGFR were integrated and quinazolines with a benzazepine moiety at the 4-position were constructed. Results: Most of the compounds exhibited excellent antitumor activities. Compound 33e showed excellent antitumor activities against the four tested cell lines (IC50: 1.06–3.55 μM). The enzymatic, signaling pathways and apoptosis assay of 33e were subsequently carried out to study the action of the mechanism. Conclusion: Compound 33e with a benzazepine moiety at the 4-position can be screened in this study and provides useful information for the design of EGFR-T790M inhibitors, which deserve additional research.