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Targeting epidermal growth factor receptor (EGFR) with tyrosine kinase inhibitors (TKI) has been widely exploited to disrupt aberrant phosphorylation flux in cancer. However, a bottleneck of potent TKIs is the acquisition of drug resistance mutations, secondary effects, and low ability to attenuate tumor progression. We have developed an alternative means of targeting EGFR that relies on protein degradation through two consecutive routes, ultimately leading to cancer cell detachment-related death. We describe furfuryl derivatives of 4-allyl-5-[2-(4-alkoxyphenyl)-quinolin-4-yl]-4H-1,2,4-triazole-3-thiol that bind to and weakly inhibit EGFR tyrosine phosphorylation and induce strong endocytic degradation of the receptor in cancer cells. The compound-promoted depletion of EGFR resulted in the sequestration of non-phosphorylated Bim, which no longer ensured the integrity of the cytoskeleton machinery, as shown by the detachment of cancer cells from the extracellular matrix (ECM). Of particular note, the longer CH3(CH2)n chains in the terminal moiety of the anti-EGFR molecules confer higher hydrophobicity in the allosteric site located in the immediate vicinity of the catalytic pocket. Small compounds accelerated and enhanced EGFR and associated proteins degradation during EGF and/or glutamine starvation of cultures, thereby demonstrating high potency in killing cancer cells by simultaneously modulating signaling and metabolic pathways. We propose a plausible mechanism of anti-cancer action by small degraders through the allosteric site of EGFR. Our data represent a rational and promising perspective in the treatment of aggressive tumors.

The physicochemical properties and antitumor activity of dacarbazine, its analogs, and the new alkylating agent imidazene are reviewed. It is shown that the activity of dacarbazine is superior to most of its analogs. Imidazene exhibits an advantage over dacarbazine with respect to both stability and activity and can be used for the treatment of malignant melanoma and sarcoma of soft tissues and in combined chemotherapy.

A series of substituted 6-alkyl(6H)-3-phenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines have been synthesized by reaction of 3-alkyl-4-amino-5-thio-1,2,4-triazoles with substituted phenacylbromides in the presence of an equimolar amount of KOH. Mass spectra for the dissociative ionization by electron impact, antibacterial activity, and antitumor properties of the synthesized compounds have been studied. It was established that some compounds at doses of 50 -100 mg/kg decrease the growth of sarcomas 45 and 37 by 35 -47%.

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