Discovery of N-phenyl-(2,4-dihydroxypyrimidine-5-sulfonamido) phenylurea-based thymidylate synthase (TS) inhibitor as a novel multi-effects antitumor drugs with minimal toxicity

Design, synthesis and biological evaluation of novel benzimidazole-derived p21-activited kinase 4 (PAK4) inhibitors bearing a 4-(4-methylpiperazin-1-yl)phenyl scaffold as potential antitumor agents

A series of novel 6-(4-(4-methylpiperazin-1-yl)phenyl)-1H-benzo[d]imidazole-based p21-activited kinase 4 (PAK4) inhibitors were designed and synthesized based on the structure of lead compound GNE-2861 and that of anticancer inhibitors reported in our previous studies. All target compounds so designed were preliminarily screened in vitro for anti-tumor potency through kinase inhibitory assays and MTT assays, which revealed that most compounds exhibited significant inhibitory effects on PAK4 enzyme as well as prominent antiproliferative activities against four cancer cell models (A549, NCI-H1975, MDA-MB-231 and SK-BR-3) and low damage to healthy cells. In particular, the hit compound 12i was identified as the most effective and rather selective compound both at the enzyme and cellular level. Meanwhile, molecular docking and dynamic studies disclosed that compound 12i could bind to PAK4 stably via multiple interactions applied between the compound and the enzyme. Further mechanism studies indicated that compound 12i could inhibit the proliferation and suppress the migratory potential of MDA-MB-231 cells by inhibiting the phosphorylation of PAK4 and LIMK1, arresting cell cycle in the G0/G1 phase, inducing apoptosis and promoting ROS production. Notably, compound 12i could effectively inhibit triple-negative breast cancer (TNBC) growth with little toxicity in the MDA-MB-231 cell xenograft model. Taken together, in vitro and in vivo results demonstrated that compound 12i possessed high drug potential as an inhibitor of PAK4 to inhibit the growth and metastasis of TNBC.

Design, synthesis and biological evaluation of novel quinazoline-derived EGFR/HER-2 dual-target inhibitors bearing a heterocyclic-containing tail as potential anti-tumor agents

A series of novel quinazoline-derived EGFR/HER-2 dual-target inhibitors were designed and synthesized by heterocyclic-containing tail approach. The inhibitory activities against four human epidermal growth factor receptor (HER) isozymes (EGFR, HER-2, HER-3 and HER-4) of all new compounds so designed were investigated in vitro. Compound 12k was found to be the most effective and rather selective dual-target inhibitor of EGFR and HER-2 with inhibitory constant (IC50) values of 6.15 and 9.78 nM, respectively, which was more potent than the clinical used agent Lapatinib (IC50 = 8.41 and 9.41 nM). Meanwhile, almost all compounds showed excellent antiproliferative activities against four cancer cell models (A549, NCI-H1975, SK-BR-3 and MCF-7) and low damage to healthy cells. Among them, compound 12k also exhibited the most prominent antitumor activity. Moreover, the hit compound 12k could bind to EGFR and HER-2 stably in molecular docking and dynamics studies. The following wound healing assay revealed that compound 12k could inhibit the migration of SK-BR-3 cells. Further studies found that compound 12k could arrest cell cycle in the G0/G1 phase and induce SK-BR-3 cells apoptosis. Notably, compound 12k could effectively inhibit breast cancer growth with little toxicity in the SK-BR-3 cell xenograft model. Taken together, in vitro and in vivo results disclosed that compound 12k had high drug potential as a dual-target inhibitor of EGFR/HER-2 to inhibit breast cancer growth.

New proapoptotic chemotherapeutic agents based on the quinolone-3-carboxamide scaffold acting by VEGFR-2 inhibition

In the current study, we designed and synthesized a series of new quinoline derivatives 10a-p as antiproliferative agents targeting cancer through inhibition of VEGFR-2. Preliminary molecular docking to assess the interactions of the designed derivatives with the binding site of VEGFR-2 (PDB code: 4ASD) displayed binding poses and interactions comparable to sorafenib. The synthesized compounds exhibited VEGFR-2 inhibitory activity with IC50 ranging from 36 nM to 2.23 μM compared to sorafenib (IC50 = 45 nM), where derivative 10i was the most potent. Additionally, the synthesized derivatives were evaluated in vitro for their cytotoxic activity against HepG2 cancer cell line. Seven compounds 10a, 10c, 10d, 10e, 10i, 10n and 10o (IC50 = 4.60, 4.14, 1.07, 0.88, 1.60, 2.88 and 2.76 μM respectively) displayed better antiproliferative activity than sorafenib (IC50 = 8.38 μM). Compound 10i was tested against Transformed Human Liver Epithelial-2 normal cell line (THLE-2) to evaluate its selective cytotoxicity. Furthermore, 10i, as a potent representative of the series, was assayed for its apoptotic activity and cell cycle kinetics' influence on HepG2, its effects on the gene expression of VEGFR-2, and protein expression of the apoptotic markers Caspase-7 and Bax. Compound 10i proved to have a potential role in apoptosis by causing significant increase in the early and late apoptotic quartiles, a remarkable activity in elevating the relative protein expression of Bax and Caspase-7 and a significant reduction of VEGFR-2 gene expression. Collectively, the obtained results indicate that compound 10i has a promising potential as a lead compound for the development of new anticancer agents.

New Natural Eugenol Derivatives as Antiproliferative Agents: Synthesis, Biological Evaluation, and Computational Studies

Semisynthetic modifications of natural products have bestowed us with many anticancer drugs. In the present work, a natural product, eugenol, has been modified synthetically to generate new anticancer agents. The final compounds were structurally confirmed by NMR, IR, and mass techniques. From the cytotoxicity results, compound 17 bearing morpholine was found to be the most active cytotoxic agent with IC₅₀ 1.71 (MCF-7), 1.84 (SKOV3), and 1.1 μM (PC-3) and a thymidylate synthase (TS) inhibitor with an IC₅₀ of 0.81 μM. Further cellular studies showed that compound 17 could induce apoptosis and arrest the cell cycle at the S phase in PC-3 carcinoma. The docking study strongly favors compound 17 to be a TS inhibitor as it displayed a similar interaction to 5-fluorouracil. The in silico pharmacokinetics and DFT computational studies support the results obtained from docking and biological evaluation and displayed favorable pharmacokinetic profile for a drug to be orally available. Compound 17 was found to be a promising TS inhibitor which could suppress DNA synthesis and consequently DNA damage in prostate cancer cells.

Design, synthesis, anticancer activity and molecular docking studies of new benzimidazole derivatives bearing 1,3,4-oxadiazole moieties as potential thymidylate synthase inhibitors

Compounds 10 and 14 arrest the cell cycle at the G1 phase and induce apoptosis without any necrosis in MDA-MB-231 cells.

NIR-activated self-sensitized polymeric micelles for enhanced cancer chemo-photothermal therapy

NIR-activated therapies based on light-responsive drug delivery systems are emerging as a remote-controlled method for cancer precise therapy. In this work, fluorescent dye indocyanine green (ICG)-conjugated and bioactive compound gambogic acid (GA)-loaded polymeric micelles (GA@PEG-TK-ICG PMs) were smoothly fabricated via the self-assembly of the reactive oxygen species (ROS)-responsive thioketal (TK)-linked amphiphilic polymer poly(ethyleneglycol)-thioketal-(indocyanine green) (PEG-TK-ICG). The resultant micelles demonstrated increased resistance to photobleaching, enhanced photothermal conversion efficiency, NIR-controlled drug release behavior, preferable biocompatibility, and excellent tumor accumulation performance. Moreover, upon an 808 nm laser irradiation, the micellar photoactive chromophore ICG converted the absorbed optical energy to both hyperthermia for photothermal therapy (PTT) and ROS as the feedback trigger to the micelles for the tumor-specific release of GA, which could serve as not only a chemotherapeutic drug to directly kill tumor cells but also a heat shock protein 90 (HSP90) inhibitor to realize the photothermal sensitization. As a result, an extremely high tumor inhibition rate (97.9%) of mouse 4 T1 breast cancer models was achieved with negligible side effects after the chemo-photothermal synergistic therapy. This NIR-activated nanosystem with photothermal self-sensitization function may provide a feasible option for the effective treatment of aggressive breast cancers.

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.

Recent Progresses in Conjugation with Bioactive Ligands to Improve the Anticancer Activity of Platinum Compounds

Platinum (Pt) drugs, including cisplatin, are widely used for the treatment of solid tumors. Despite the clinical success, side effects and occurrence of resistance represent major limitations to the use of clinically available Pt drugs. To overcome these problems, a variety of derivatives have been designed and synthetized. Here, we summarize the recent progress in the development of Pt(II) and Pt(IV) complexes with bioactive ligands. The development of Pt(II) and Pt(IV) complexes with targeting molecules, clinically available agents, and other bioactive molecules is an active field of research. Even if none of the reported Pt derivatives has been yet approved for clinical use, many of these compounds exhibit promising anticancer activities with an improved pharmacological profile. Thus, planning hybrid compounds can be considered as a promising approach to improve the available Pt-based anticancer agents and to obtain new molecular tools to deepen the knowledge of cancer progression and drug resistance mechanisms.

Design, synthesis, and in vitro and in vivo anti-angiogenesis study of a novel vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor based on 1,2,3-triazole scaffold

In the past five years, our team had been committed to click chemistry research, exploring the biological activity of 1,2,3-triazole by synthesizing different target inhibitors. In this study, a series of novel indole-2-one derivatives based on 1,2,3-triazole scaffolds were synthesized for the first time, and their inhibitory activity on vascular endothelial growth factor receptor-2 (VEGFR-2) was tested. Most of the compounds had shown promising activity in the VEGFR-2 kinase assay and had low toxicity to human umbilical vein endothelial cells (HUVECs). The compound 13d (IC₅₀ = 26.38 nM) had better kinase activity inhibition ability than sunitinib (IC₅₀ = 83.20 nM) and was less toxic to HUVECs. Moreover, it had an excellent inhibitory effect on HT-29 and MKN-45 cells. On the one hand, by tube formation assay, transwell, and Western blot analysis, compound 13d could inhibit VEGFR-2 protein phosphorylate on HUVECs, thereby inhibiting HUVECs migration and tube formation. In vivo study, the zebrafish model with VEGFR-2 labeling also verified that compound 13d had more anti-angiogenesis ability than sunitinib. On the other hand, molecular docking and molecular dynamics (MD) simulation results showed that compound 13d could stably bind to the active site of VEGFR-2. Based on the above findings, compound 13d could be considered an effective anti-angiogenesis drug and has more development value than sunitinib.

Development of a novel thymidylate synthase (TS) inhibitor capable of up-regulating P53 expression and inhibiting angiogenesis in NSCLC

Introduction

The development of a new type of Thymidylate synthase (TS) inhibitor that could inhibit cancer cells' proliferation and anti-angiogenesis is of great significance for cancer's clinical treatment.

Objectives

Our research hopes to develop a TS inhibitor that is more effective than the current first-line clinical treatment of pemetrexed (PTX) and provide a new reference for the clinical treatment of non-small cell lung cancer (NSCLC).

Methods

We obtained a series of novel TS inhibitors by chemical synthesis. Moreover, TS assay and molecular docking to verify the target compound's inhibitory mode. Use MTT assay, colony-forming assay, flow cytometry, and western blot to verify the compound's inhibitory effect on cancer cell proliferation and its mechanism; and explore the compound’s effect on angiogenesis in vitro and in vivo. Further, explore the hit compound's anti-cancer ability through the xenograft tumor model and the orthotopic cancer murine model.

Results

A series of N-(3-(5-phenyl-1,3,4-oxadiazole-2-yl) phenyl)-2,4-dihydroxypyrimidine-5-sulfamide derivatives were synthesized as TS inhibitors for the first time. All target compounds significantly inhibited hTS enzyme activity and demonstrated significant antitumor activity against five cancer cell lines. Notably, 7f had a high selectivity index (SI) and unique inhibitory effects on eight NSCLC cells. In-depth research indicated that 7f could induce apoptosis by the mitochondrial pathway in A549 and PC-9 cells through the upregulation of wild-type P53 protein expression. Additionally, 7f was shown to inhibit angiogenesis in vitro and in vivo. In vivo studies, compared to PTX, 7f significantly inhibited tumor growth in A549 cell xenografts and had a higher therapeutic index (TGI). Moreover, 7f could prolong the survival of the orthotopic lung cancer murine model more effectively than PTX.

Conclusion

The anti-angiogenic effect of 7f provides a new reference for the development of TS inhibitors and the clinical treatment of NSCLC.