Discovery of Potent c-MET Inhibitors with New Scaffold Having Different Quinazoline, Pyridine and Tetrahydro-Pyridothienopyrimidine Headgroups

Palladium-Catalyzed Synthesis of 1-Alkylidene-2-dialkylaminomethyl Cyclobutane Derivatives via Pd-Catalyzed Alkene Difunctionalization Reactions: Influence of Nucleophile and Water on the Reaction Mechanism

The Pd-catalyzed coupling of 1,5-diene-2-yl triflates with amine nucleophiles affords exomethylenecyclobutanes bearing dialkylaminomethyl groups at C2. The strained carbocyclic products are obtained in moderate to excellent yields, with regioselectivities of up to >95:5 for four-membered ring formation. The mechanism of these reactions, which provides products resulting from anti-addition to alkenes, differs from related reactions involving malonate nucleophiles that provide syn-addition products.

Design, Synthesis and Biological Evaluation of Multi-Target Anti-Cancer Agent PYR26

This study investigates the synthesis of a new compound, PYR26, and the multi-target mechanism of PYR26 inhibiting the proliferation of HepG2 human hepatocellular carcinoma cells. PYR26 significantly inhibits the growth of HepG2 cells (p < 0.0001) and this inhibition has a concentration effect. There was no significant change in ROS release from HepG2 cells after PYR26 treatment. The mRNA expressions of CDK4, c-Met and Bak genes in HepG2 cells were significantly inhibited (p < 0.05), while mRNA expression of pro-apoptotic factors such as caspase-3 and Cyt c was significantly increased (p < 0.01). The expression of PI3K, CDK4 and pERK proteins decreased. The expression level of caspase-3 protein was increased. PI3K is a kind of intracellular phosphatidylinositol kinase. PI3K signaling pathway is involved in signal transduction of a variety of growth factors, cytokines and extracellular matrix and plays an important role in preventing cell apoptosis, promoting cell survival and influencing cell glucose metabolism. CDK4 is a catalytic subunit of the protein kinase complex and is important for G1 phase progression of the cell cycle. PERK refers to phosphorylated activated ERK, which is translocated from cytoplasm to the nucleus after activation, and then participates in various biological reactions such as cell proliferation and differentiation, cell morphology maintenance, cytoskeleton construction, cell apoptosis and cell canceration. Compared with the model group and the positive control group, the tumor volume of the nude mice in the low-concentration PYR26 group, the medium-concentration group and the high-concentration group was smaller, and the organ volume was smaller than that in the model group and the positive control group. The tumor inhibition rates of low-concentration group PYR26, medium-concentration group and high-concentration group reached 50.46%, 80.66% and 74.59%, respectively. The results showed that PYR26 inhibited the proliferation of HepG2 cells and induced apoptosis of HepG2 cells by down-regulating c-Met, CDK4 and Bak, up-regulating the mRNA expression of caspase-3 and Cyt c genes, down-regulating PI3K, pERK and CDK4 proteins and up-regulating the protein level of caspase-3. In a certain range, with the increase in PYR26 concentration, the tumor growth was slower and the tumor volume was smaller. Preliminary results showed that PYR26 also had an inhibitory effect on the tumors of Hepa1-6 tumor-bearing mice. These results suggest that PYR26 has an inhibitory effect on the growth of liver cancer cells, therefore it has potential to be developed into a new anti-liver cancer drug.

Synthesis of new thienylnicotinamidines: Proapoptotic profile and cell cycle arrest of HepG2 cells

Fourteen new thienylnicotinamidines and their analogs 5a-5k, 12, 13a, and 13b were prepared and their antiproliferative potential was evaluated against the growth of 60 cancer cell lines. The tested compounds had a strong antiproliferative efficacy against almost all cancer cell lines, with the average GI₅₀ at ~2.20 µM. The effect of the thienylnicotinamidines on the growth of normal lung fibroblast cells (WI-38) indicated that these derivatives are safe to the normal cells. The selectivity index (SI) ranges from 5.5- to 42.0-fold. The conceivable mechanisms of action of the effective compounds 5d, 5f, 5g, 5i, 5j, and 5k with high SI were investigated. Although the thienylnicotinamidines are similar in structure, they could be divided into three groups as per their effects on gene expression: The first group (5d and 5f) elevated p53 and caspase 3 expression, the second group (5g and 5i) elevated p53 expression, and the last group (5j and 5k) elevated p53 and reduced topoII expression. Many thienylnicotinamides inhibited the vascular endothelial growth factor receptor-2 (VEGFR-2) in cell lysates at concentrations comparable to or better than pazopanib. The data of caspase 3 expression were confirmed by measuring the protein level by Western blot and the activity of the cleaved active enzyme. The ability to arrest the cell cycle and induce apoptosis was confirmed by flow cytometry. Taken together, two derivatives, 5d and 5f, with a distinctive VEGFR-2 inhibitory activity and a proapoptotic and cell cycle arrest profile merit further investigations.

Synthesis and biological evaluation of quinoxaline derivatives as specific c-Met kinase inhibitors

A series of novel quinoxaline derivatives were synthesized and evaluated for their inhibitory activity against c-Met kinase enzyme. Most of the tested compounds exhibited potent inhibitory activity. All the synthesized quinoxaline compounds were further examined against c-Met overexpressed human gastric cancer cell line (MKN-45), which showed good inhibitory activity. Among the synthesized compounds, compound 4 exhibited better tumor growth inhibition in the animal model study; we also confirmed its acceptable drug property and highly selective target activity.

Synthesis and Antibacterial Activities of Different Five-Membered Heterocyclic Rings Incorporated with Pyridothienopyrimidine

Certain pyridothienopyrimidine derivatives exhibit antiatheroscleorotic, antibacterial, antiviral, antidepressant, antidiabetic, antihypertensive, anticancer, antihistaminic, antiallergic, anti-inflammatory, spasmolytic, analgesic, and neurotropic activities. 4-Hydrazino-7,9-dimethylpyrido[3',2':4,5]thieno[3,2-d]pyrimidine (1) is a reported pyridothienopyrimidine derivative. In the current study, (1) has been reacted with different reagents to obtain 12 new pyridothienopyrimidine derivatives. The newly synthesized five-membered heterocyclic rings incorporated with pyridothienopyrimidines have been screened for their antibacterial activities. The results encourage further studies on other possible biological activities.

Molecular Targeted Drugs and Treatment of Colorectal Cancer: Recent Progress and Future Perspectives

Nowadays, colorectal cancer is the fourth most common type of tumor all over the world. When diagnosed, ∼50%-60% of tumors have metastasized, thus resulting in a grim prognosis. Chemotherapy is regarded as standard treatment for patients with colorectal cancer, however, limitations of chemotherapy cannot be ignored, such as low selectivity, insufficient concentrations in tumor tissues, and systemic toxicity. Recently, six targeted drugs have been approved by the U.S. Food and Drug Administration (FDA) for treatment of metastatic colorectal cancer (mCRC), including bevacizumab, aflibercept, regorafenib, cetuximab, and panitumumab. The development of these drugs marked significant advancement in the field of mCRC therapy. The addition of biologic agents to chemotherapy has prolonged the median overall survival. Now, many investigational drugs are under clinical trials, of which programmed death (PD)-1/L1 has drawn much attention. In this review, new biologic agents under clinical trials such as MEK/MET/RAS/RAF/PD-1 inhibitors with potentials for mCRC treatment are concluded by describing targeted drugs approved by FDA, to offer new insights into global trends and future development.

Met Receptor Tyrosine Kinase and Chemoprevention of Oral Cancer

Background

We have previously shown that gene expression profiles of oral leukoplakia (OL) may improve the prediction of oral cancer (OC) risk. To identify new targets for prevention, we performed a systematic survey of transcripts associated with an increased risk of oral cancer and overexpressed in OC vs normal mucosa (NM).

Methods

We used gene expression profiles of 86 patients with OL and available outcomes from a chemoprevention trial of OC and NM. MET expression was evaluated using immunohistochemistry in 120 OL patients, and its association with OC development was tested in multivariable analysis. Sensitivity to pharmacological Met inhibition was tested invitro in premalignant and OC cell lines (n = 33) and invivo using the 4-NQO model of oral chemoprevention (n = 20 mice per group). All statistical tests were two-sided.

Results

The overlap of 693 transcripts associated with an increased risk of OC with 163 transcripts overexpressed in OC compared with NM led to the identification of 23 overlapping transcripts, including MET. MET overexpression in OL was associated with a hazard ratio of 3.84 (95% confidence interval = 1.59 to 9.27, P = .003) of developing OC. Met activation was found in OC and preneoplastic cell lines. Crizotinib activity in preneoplastic and OC cell lines was comparable. ARQ 197 was more active in preneoplastic compared with OC cell lines. In the 4-NQO model, squamous cell carcinoma, dysplasia, and hyperkeratosis were observed in 75.0%, 15.0%, and 10.0% in the control group, and in 25.0%, 70.0%, and 5.0% in the crizotinib group (P < .001).

Conclusion

Together, these data suggest that MET activation may represent an early driver in oral premalignancy and a target for chemoprevention of OC.