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Aberrant FGFR4 signaling has been implicated in the development of several cancers, making FGFR4 a promising target for cancer therapy. Several FGFR4-selective inhibitors have been developed, yet none of them have been approved. Herein, we report a novel series of 1,6-naphthyridine-2-one derivatives as potent and selective inhibitors targeting FGFR4 kinase. Preliminary structure-activity relationship analysis was conducted. The screening cascades revealed that 19g was the preferred compound among the prepared series. 19g demonstrated excellent kinase selectivity and substantial cytotoxic effect against all tested colorectal cancer cell lines. 19g induced significant tumor inhibition in a HCT116 xenograft mouse model without any apparent toxicity. Notably, 19g exhibited excellent potency in disrupting the phosphorylation of FGFR4 and downstream signaling proteins mediated by FGF18 and FGF19. Compound 19g might be a potential antitumor drug candidate for the treatment of colorectal cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Platelet-derived growth factor receptors (PDGFRs) are now considered promising targets for the treatment of osteosarcoma. Herein, the design, synthesis, and structure-activity relationships (SAR) of novel pyrimidine-2,4-diamine derivatives that selectively inhibit PDGFRα/β kinases have been studied. The screening cascades revealed that 7m was the preferred compound among these derivatives, with IC 50 values of 2.4 and 0.9 nM for PDGFRα and PDGFRβ, respectively. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) experiment revealed that 7m has a substantial cytotoxic effect against all osteosarcoma cancer cell lines; 7m also displayed robust antitumor effects and low toxicity in a xenograft model. Additionally, 7m showed excellent bioavailability ( F = 62.9%), suitable half-life ( T 1/2 = 2.12 h), satisfactory metabolic stability, and weak CYP isoform inhibitory activity, suggesting that 7m is a potential drug candidate for PDGFR-driven osteosarcoma.

Previous studies showed that fibroblast growth factor receptor 1 (FGFR1) is an attractive target in gastric cancer therapy. In the current study, we aimed to investigate whether the compound L6123, a novel non-ATP-competitive FGFR1 inhibitor, could show better antitumor activity than the leading compound, nordihydroguaiaretic acid (NDGA), in FGFR1-overexpressing gastric cancer cells. Using an MTT assay, we investigated the inhibitory effect of L6123 on the viability of three gastric cancer cells (MGC-803, SGC-7901, and BGC-823) overexpressing FGFR1, wild-type mouse embryonic fibroblast (MEF), and MEF expressing FGFR1, FGFR2, and FRS2α gene knockout (MEF). We studied the antitumor mechanism of L6123 against the gastric cancer cell line SGC-7901 by western blot analysis. The antitumor effects of L6123 on the gastric cancer cell line SGC-7901 were detected by flow cytometry, Hoechst staining, western blot analysis, and Transwell invasion assay. L6123 had lower IC50 in all three gastric cancer cells than NDGA and showed better inhibitory activity against MEF cells than against MEF cells. In the SGC-7901 gastric cell, L6123 inhibited the FGF2-induced phosphorylation of FGFR1/FRS2α/ERK1/2 in a dose-dependent manner, induced the activation of the apoptosis-related proteins, cleaved-PARP and cleaved-caspase-3, decreased the expression of pro-caspase-3 and Bcl-2, and induced tumor cell apoptosis. L6123 also dose-dependently reduced cell invasion ability, and showed better activity than NDGA at the same concentration. A novel non-ATP-competitive inhibitor L6123 showed excellent antigastric cancer activity by inhibiting the FGFR1 signaling pathway. Thus, we discovered a potential agent for the treatment of FGFR1-overexpressing gastric cancer.

Fibroblast growth factor receptor (FGFR) tyrosine kinases have been regarded as a target for cancer treatment, and there is much interest in inhibiting FGF/FGFR signaling by small molecules as a therapeutic approach to cancer. Generally, inhibitors mimics ATP structure and block the binding between ATP and FGFR kinase. Here, two novel, non-ATP-competitive, selective, irreversible FGFR1 inhibitors, A114 and A117, were identified via kinase inhibitory assay from 156 synthetic bisaryl-1,4-dien-3-one derivatives. A "DFG-OUT" inactive conformation binding mode with FGFR1 was predicted by molecular docking. A114 and A117 showed significant anti-tumor activity both in vitro and in vivo via targeting FGFR1.

Fibroblast growth factors (FGFs) signal through FGF receptors (FGFRs), which are a sub-family of the superfamily of receptor tyrosine kinases, to regulate human development and metabolism. Uncontrolled FGF signaling is responsible for diverse array of developmental disorders, most notably skeletal syndromes due to FGFR gain-of-function mutations. Studies in the last few years have provided significant evidence for the importance of FGF signaling in the pathogenesis of diverse cancers, including endometrial and bladder cancers. FGFs are both potent mitogenic and angiogenic factors and can contribute to carcinogenesis by stimulating cell proliferation and tumor angiogenesis. Gene knockout and pharmacological inhibition of FGFRs in in vivo and in vitro models validate FGFRs as a target for cancer treatment. Considerable efforts are being expended to develop specific, small-molecule inhibitors for treating FGFR-driven cancers. Recent reviews on the FGF/FGFR system have focused primarily on signaling, pathophysiology, and functions in cancer. In this article, we review the key roles of FGFR in cancer, provide an update on the status of clinical trials with small-molecule FGFR inhibitors, and discuss how the current structural data on FGFR kinases guide the design and characterization of new FGFR inhibitors., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Endoplasmic reticulum (ER) stress-induced cancer cell apoptosis has become a novel signaling target for development of cancer therapeutic drugs. Curcumin exhibits growth-suppressive activity against a variety of cancer cells. We previously synthesized a series of monocarbonyl analogues of curcumin with strong cytotoxicity against tumor cells. In this study, we found that only compound 19 [(1E,4E)-1,5-bis(2,3-dimethoxyphenyl)penta-1,4-dien-3-one] can induce C/EBP-homologous protein (CHOP) expression in human lung cancer H460 cells. Treatment with 19 induced H460 cell apoptosis in a dose-responsive manner, and this effect was associated with corresponding increases in a series of key components in ER stress-mediated apoptosis pathway, followed by caspase cleavage and activation. However, curcumin at the same concentrations does not display such properties. CHOP knockdown by specific siRNA attenuated 19-induced cell apoptosis, further indicating that the apoptotic pathway is ER stress-dependent. In vivo, 19 showed a dramatic 53.5% reduction in H460 xenograft tumor size after 22 days of treatment. Taken together, these mechanistic insights on the novel compound 19, with nontoxicity, may provide us with a novel anticancer candidate.

The albendazole derivatives (2-methoxyethyl) 5-propylthio-1H-benzimidazole-2-yl carbamate (MEABZ), N1-(2-methoxyethoxycarbonyl)-2-amino-5-propylthiobenzimidazole and N1-(2-methoxyethoxycarbonyl)-2-amino-6-propylthiobenzimidazole (MEABZ isomers A and B) and (2-hydroxyethyl) 5-propylthio-1H-benzimidazole-2-yl carbamate (HEABZ) have been synthesised. The cytotoxicity of these compounds was evaluated against a human colorectal cancer cell line (HT-29) and a human prostate cancer cell line (PC-3). The results demonstrate MEABZ, a new benzimidazole, is up to ten times more cytotoxic than the parent drug albendazole, whereas the MEABZ isomers A and B and HEABZ show no activity. A comparison of the cytotoxicity of these compounds, relative to ABZ, provides structure-activity data for this important class of anticancer agents. The aqueous solubilities of MEABZ encapsulated in Q[n] have been determined by (1)H NMR spectroscopy. The aqueous solubility of MEABZ at a physiologically relevant pH increased by 1200-fold by encapsulation in Q[8], from 8 microM to 9.4 mM, while Q[6,7] encapsulation substantially increased the solubility to more than 2 mM. Encapsulation in Q[7] and Q[8] induced significant upfield shifts for the MEABZ propyl and benzimidazole resonances. The upfield shifts indicate that the propyl and benzimidazole protons are located within the Q[7] and Q[8] cavity upon encapsulation. By contrast, encapsulation in Q[6] induced large upfield shifts for the (1)H resonances from the carbamate functional group, indicating that MEABZ associates with Q[6] at its portals, with only the carbamate group binding within the cavity.

The platinum complexes trans-[{PtCl(NH3)2}2(micro-NH2(CH2)3NH2(CH2)3NH2)]3+ (CT033) and the corresponding N4-dimethyl linked analogue trans-[{PtCl(NH3)2}2(micro-NH2(CH2)3N(Me)2(CH2)3NH2)]3+ (CT233) have been synthesised, and their cytotoxicity, ability to bind cucurbit[7,8]uril (Q[7,8]) and reaction with cysteine studied. Both platinum complexes show good activity in the L1210 cell line and maintain their activity in the corresponding cisplatin L1210/DDP cell line. However, the N4-dimethyl analogue CT233 is approximately 50-times less active than the CT033 complex. This suggests that the insertion of a positive charge into the linking ligand may not, per se, be responsible for the higher cytotoxicity generally observed for dinuclear platinum complexes linked by polyamines. The upfield shifts of the resonances from the methylene protons in the linking triamine ligand observed in the 1H NMR spectra of either CT033 and CT233 upon addition of either Q[7] or Q[8] indicate that the cucurbituril is positioned over the linking ligand. However, the results show that the protonated secondary amine in CT033 acts as a barrier to encapsulation, with the Q[7,8] being positioned over only one propyl-arm at a time. Alternatively, the entire triamine linking ligand of CT233 is fully encapsulated within the Q[7,8] cavity. Encapsulation by Q[7,8] was found to reduce the rate of reaction of CT033 and CT233 with the thiol containing amino acid cysteine, with a greater rate reduction observed for CT233. These results are consistent with the NMR results of the Q[7,8] binding studies of the two platinum complexes. For CT033 encapsulated in Q[7,8], one of the two platinum centres is completely exposed to the solvent, whereas, for CT233 both platinum centres are simultaneously positioned within the portals of the cucurbit[n]uril, thereby, affording greater protection.

The aqueous solubilities of albendazole encapsulated in cucurbit[6, 7 and 8]urils (Q[6], Q[7] and Q[8]) have been determined by (1)H NMR spectroscopy, and the effect of encapsulation on their cytotoxicities evaluated. Encapsulation in Q[6] and Q[7] increased the aqueous solubility of albendazole by 2000-fold, from 3 microM to 6 mM at pH 6.6, while Q[8]-encapsulation increased the solubility to over 2 mM. Encapsulation in Q[7] and Q[8] induced significant upfield shifts for the albendazole propyl and benzimidazole resonances, compared to those observed for Q[6]-binding and what would normally be expected for the respective functional groups. The upfield shifts indicate that the albendazole propyl and benzimidazole protons are located within the Q[7] and Q[8] cavity upon encapsulation. Alternatively, encapsulation in Q[6] only induced a large upfield shift for the albendazole carbamate methyl resonance, indicating that the drug associates with Q[6] at its portals, with only the carbamate group within the cavity. Simple molecular models based on the observed relative changes in chemical shift could be constructed that were consistent with the conclusions from the NMR experiments. Cytotoxicity assays against human colorectal cells (HT-29), human ovarian cancer cells (1A9) and the human T-cell acute lymphoblastic leukaemia cells (CEM) indicated that encapsulation in Q[7] did not significantly reduce the in vitro anti-cancer activity of albendazole.