1,4-Thiazepines (TZEPs) featuring enyne modifications represent promising candidates in cancer therapy. We synthesized novel TZEP derivatives and assessed their cytotoxicity, apoptosis induction, EGFR inhibition, and molecular interactions. TZEPs exhibited cytotoxic effects against cancer cell lines, with compounds TZEP6 and TZEP7 showing significant activity. Flow cytometry analysis revealed TZEP7-induced apoptosis across various cancer types. RT-qPCR analysis demonstrated downregulation of antiapoptotic Bcl-2, upregulation of pro-apoptotic Bax, and increased caspase levels following TZEP7 treatment. Additionally, TZEP7 inhibited EGFR kinase activity in cancer cells, with molecular docking confirming strong binding affinities to EGFRWT and mutant EGFRT790M. AdmetSAR analysis indicated favorable pharmacokinetic properties for TZEP7. These findings underscore the potential of enyne-modified TZEPs as selective cytotoxic agents with apoptotic and EGFR inhibitory activities, highlighting their significance in cancer therapy.
© 2024 The Authors. Published by American Chemical Society.

Epidermal growth factor receptor (EGFR) C797S mutation leads to Osimertinib drug resistance by disturbing the covalent biding of Michael acceptor group to the Cys797 residue in the ATP biding cleft. In this manuscript, a class of 2-amine-4-oxyphosaniline pyrimidine derivatives were designed, synthesized and evaluated as new noncovalent reversible EGFR inhibitors against L858R/T790M/C797S (CTL) triple mutant. The kinases inhibitiory activity evaluation showed that four compounds exhibited significant inhibitory activities against CTL (IC50 < 30 nM). In particularly, the most promising compound 7a showed excellent enzymatic inhibitory activity against CTL with IC50 value of 9.9 nM, which was more potent than control compound Osimertinib. Moreover, cell proliferation assays indicated that 7a effectively inhibited H1975-EGFR L858R/T790M/C797S with IC50 value of 0.33 µM. Furthermore, compound 7a displayed good metabolic stabilities in human, rat and mouse liver microsomes, and the putative biding mode of compound 7a with ATP was revealed by molecular docking study. These findings strongly indicated that compound 7a was a promising L858R/T790M/C797S mutant EGFR inhibitor.

B-cell antigen receptor (BCR) signaling is required to maintain the physiological functions of normal B cells and plays an important pathogenic role in B-cell malignancies. Bruton tyrosine kinase (BTK), a critical mediator of BCR signaling, is an attractive target for the treatment of B-cell malignancies. This study aimed to identify a highly potent and selective BTK inhibitor.
Homogeneous time-resolved fluorescence assays were used to screen BTK inhibitors. Typhoon fluorescence imaging and Western blot analysis were used to confirm the effects of SY-1530 on the BCR signaling pathway. Additionally, the anti-tumor activities of SY-1530 were evaluated in TMD8 xenografts and spontaneous canine B-cell lymphoma.
We found a novel irreversible and non-competitive inhibitor of BTK, SY-1530, which provided dose-dependent and time-dependent inhibition. SY-1530 selectively bound to BTK rather than inducible T-cell kinase; consequently, it did not significantly affect T-cell receptor signaling and caused limited off-target effects. SY-1530 blocked the BCR signaling pathway through down-regulation of BTK activity, thus leading to impaired phosphorylation of BTK and its downstream kinases. Moreover, SY-1530 induced apoptosis in a caspase-dependent manner and efficaciously inhibited tumor growth in mouse xenograft models of B-cell malignancy (P < 0.001). SY-1530 also induced positive clinical responses in spontaneous canine B-cell lymphoma.
SY-1530 is an irreversible and selective BTK inhibitor that shows inhibitory effects on B-cell malignancies by blocking the BCR signaling pathway. Therefore, it may be a promising therapeutic approach for the treatment of B-cell malignancies.
Copyright © 2021 Cancer Biology & Medicine.

Inhibition of the epidermal growth factor receptor (EGFR) has been proved to be one of the most promising strategies for the treatment of non-small cell lung cancers. A series of 2-aryl-4-amino substituted quinazoline derivatives were designed and synthesized with the purpose to overcome L858R/T790M/C797S (CTL) triple mutant drug resistance and the biological activity for inhibition of CTL kinases and EGFR wild type (WT) were evaluated. Three compounds (20, 24 and 27) showed excellent inhibitory activities against EGFR kinases triple mutant CTL (IC50 < 1 µM) and high selectivity (IC50: WT/CTL >10000). Cell line evaluation showed that the most potent compound 27 was significantly potent against H1975-EGFR L858R/T790M (IC50 = 3.3 µM) and H1975-EGFR L858R/T790M/C797S (IC50 = 1.2 µM). Compound 27 also exhibited good microsomes stabilities in human, rat and mouse liver species, but low bioavailability. This work would be very useful for discovering new quinazoline derivatives as tyrosine kinase inhibitors targeting triple mutant L858R/T790M/C797S.