Discovery of N-(1,3,4-thiadiazol-2-yl)benzamide derivatives containing a 6,7-methoxyquinoline structure as novel EGFR/HER-2 dual-target inhibitors against cancer growth and angiogenesis.

Targeting EGFR and HER-2 is an essential direction for cancer treatment. Here, a series of N-(1,3,4-thiadiazol-2-yl)benzamide derivatives containing a 6,7-methoxyquinoline structure was designed and synthesized to serve as EGFR/HER-2 dual-target inhibitors. The kinase assays verified that target compounds could inhibit the kinase activity of EGFR and HER-2 selectively. The results of CCK-8 and 3D cell viability assays confirmed that target compounds had excellent anti-proliferation ability against breast cancer cells (MCF-7 and SK-BR-3) and lung cancer cells (A549 and H1975), particularly against SK-BR-3 cells, while the inhibitory effect on healthy breast cells (MCF-10A) and lung cells (Beas-2B) was weak. Among them, the hit compound YH-9 binded to EGFR and HER-2 stably in molecular dynamics studies. Further studies found thatYH-9could induce the release of cytochrome c and inhibit proliferation by promoting ROS expression in SK-BR-3 cells. Moreover,YH-9could diminish the secretion of VEGF and bFGF factors in SK-BR-3 cells, then inhibited tube formation and angiogenesis. Notably,YH-9could effectively inhibit breast cancer growth and angiogenesis with little toxicity in the SK-BR-3 cell xenograft model. Taken together,in vitroandin vivoresults revealed that YH-9 had high drug potential as a dual-target inhibitor of EGFR/HER-2 to inhibit breast cancer growth and angiogenesis.

Discovery of novel thymidylate synthase (TS) inhibitors that influence cancer angiogenesis and metabolic reprogramming in NSCLC cells.

Based on previous work, further search for more effective and less damaging thymidylate synthase (TS) inhibitors was the focus of this study. After further optimization of the structure, in this study, a series of (E)-N-(2-benzyl hydrazine-1-carbonyl) phenyl-2,4-deoxy-1,2,3,4-tetrahydro pyrimidine-5-sulfonamide derivatives were synthesized and reported for the first time. All target compounds were screened by enzyme activity assay and cell viability inhibition assay. On the one hand, the hit compound DG1 could bind directly to TS proteins intracellularly and promote apoptosis in A549 and H1975 cells. Simultaneously, DG1 could inhibit cancer tissue proliferation more effectively than Pemetrexed (PTX) in the A549 xenograft mouse model. On the other hand, the inhibitory effect of DG1 on NSCLC angiogenesis was verified both in vivo and in vitro. In parallel, DG1 was further uncovered to inhibit the expression of CD26, ET-1, FGF-1, and EGF by angiogenic factor antibody microarray. Moreover, RNA-seq and PCR-array assays revealed that DG1 could inhibit NSCLC proliferation by affecting metabolic reprogramming. Collectively, these data demonstrated that DG1as a TS inhibitor could be promising in treating NSCLC angiogenesis, deserving further investigation.

Synthesis and evaluation of novel HER-2 inhibitors to exert anti-breast cancer ability through epithelial-mesenchymal transition (EMT) pathway.

Human epidermal growth factor receptor 2 (HER-2) is an essential member of the receptor tyrosine kinase (RTK) superfamily and has been reported as a critical method for treating HER-2 positive breast cancer. Here, we retained (E)-4-methyl-2-(4-(trifluoromethyl)styryl)oxazole, a fragment of HER-2 inhibitor Mubritinib, and synthesized 32 novel compounds from it. We screened out the most potential compound Q7j with HER-2 positive breast cancer cells through MTT assays, which possessed low toxicity on normal cells (MCF7-10A). Subsequently, wound healing, transwell, western blotting, and immunofluorescence experiments were performed, and it was found that compound Q7j could suppress cell migration by inhibiting the phosphorylation of HER-2 and affecting the expression of EMT-related proteins. Moreover, the SKBR3 orthotopic xenograft model confirmed that compound Q7j was more effective than Mubritinib in inhibiting the proliferation of cancer cells. In general, compound Q7j was a potential HER-2 inhibitor in treating breast cancer, which may be of great significance for developing and improving HER-2 small molecule inhibitors.

Novel Allosteric Inhibitors of Deoxyhypusine Synthase against Malignant Melanoma: Design, Synthesis, and Biological Evaluation.

Based on the novel allosteric site of deoxyhypusine synthase (DHPS), two series of 30 novel 5-(2-methoxyphenoxy)-2-phenylpyrimidin-4-amine derivatives as DHPS inhibitors were designed and synthesized. Among them, compound 8m, with the best DHPS inhibitory potency (IC50 = 0.014 µM), exhibited excellent inhibition against melanoma cells, which was superior to that of GC7. Besides, molecular docking and molecular dynamics (MD) simulations further proved that compound 8m was tightly bound to the allosteric site of DHPS. Flow cytometric analysis and enzyme-linked immunosorbent assay (ELISA) showed that compound 8m could inhibit the intracellular reactive oxygen species (ROS) level. Furthermore, by western blot analysis, compound 8m effectively activated caspase 3 and decreased the expressions of GP-100, tyrosinase, eIF5A2, MMP2, and MMP9. Moreover, both Transwell analysis and wound healing analysis showed that compound 8m could inhibit the invasion and migration of melanoma cells. In the in vivo study, the tumor xenograft model showed that compound 8m effectively inhibited melanoma development with low toxicity.