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Targeted therapy indications for actionable variants in non-small-cell lung cancer (NSCLC) have primarily been studied in Caucasian populations, with limited data on Latin American patients. This study utilized a 52-genes next-generation sequencing (NGS) panel to analyze 1560 tumor biopsies from NSCLC patients in Chile, Brazil, and Peru. The RNA sequencing reads and DNA coverage were correlated to improve the detection of the actionable MET exon 14 skipping variant (METex14). The pathogenicity of MET variants of uncertain significance (VUSs) was assessed using bioinformatic methods, based on their predicted driver potential. The effects of the predicted drivers VUS T992I and H1094Y on c-MET signaling activation, proliferation, and migration were evaluated in HEK293T, BEAS-2B, and H1993 cell lines. Subsequently, c-Met inhibitors were tested in 2D and 3D cell cultures, and drug affinity was determined using 3D structure simulations. The prevalence of MET variants in the South American cohort was 8%, and RNA-based diagnosis detected 27% more cases of METex14 than DNA-based methods. Notably, 20% of METex14 cases with RNA reads below the detection threshold were confirmed using DNA analysis. The novel actionable T992I and H1094Y variants induced proliferation and migration through c-Met/Akt signaling. Both variants showed sensitivity to crizotinib and savolitinib, but the H1094Y variant exhibited reduced sensitivity to capmatinib. These findings highlight the importance of RNA-based METex14 diagnosis and reveal the drug sensitivity profiles of novel actionable MET variants from an understudied patient population. [ABSTRACT FROM AUTHOR]

As part of our continuous efforts to discover novel c-Met inhibitors as antitumor agents, four series of thiazole/thiadiazole carboxamide-derived analogues were designed, synthesised, and evaluated for the in vitro activity against c-Met and four human cancer cell lines. After five cycles of optimisation on structure–activity relationship, compound 51am was found to be the most promising inhibitor in both biochemical and cellular assays. Moreover, 51am exhibited potency against several c-Met mutants. Mechanistically, 51am not only induced cell cycle arrest and apoptosis in MKN-45 cells but also inhibited c-Met phosphorylation in the cell and cell-free systems. It also exhibited a good pharmacokinetic profile in BALB/c mice. Furthermore, the binding mode of 51am with both c-Met and VEGFR-2 provided novel insights for the discovery of selective c-Met inhibitors. Taken together, these results indicate that 51am could be an antitumor candidate meriting further development. [ABSTRACT FROM AUTHOR]

Breast cancer presents a significant challenge due to its heterogeneity and propensity for developing chemoresistance, particularly in the triple-negative subtype. c-Mesenchymal epithelial transition factor (c-Met), a receptor tyrosine kinase, presents a promising target for breast cancer therapy due to its involvement in disease progression and poor prognosis. However, the heterogeneous expression of c-Met within breast cancer subtypes and individual tumors complicates targeted therapy. Also, cancer cells can develop resistance to c-Met inhibitors through various mechanisms, including bypass signaling pathways and genetic mutations. The off-target effects of c-Met inhibitors further limit their clinical utility, necessitating the development of more selective agents. To overcome these challenges, personalized treatment approaches and combination therapies are being explored to improve treatment efficacy while minimizing adverse effects. Novel c-Met inhibitors with improved selectivity and reduced off-target toxicity show promise in preclinical studies. Additionally, targeted delivery systems aim to enhance drug localization and reduce systemic toxicity. Future directions involve refining inhibitor design and integrating c-Met inhibition into personalized treatment regimens guided by molecular profiling. This review explores the mechanisms by which c-Met contributes to chemoresistance in breast cancer and current challenges in targeting c-Met for breast cancer therapy. It discusses strategies to optimize treatment outcomes, ultimately improving patient prognosis and reducing mortality rates associated with this devastating disease.

As part of our continuous efforts to discover novel c-Met inhibitors as antitumor agents, four series of thiazole/thiadiazole carboxamide-derived analogues were designed, synthesised, and evaluated for the in vitro activity against c-Met and four human cancer cell lines. After five cycles of optimisation on structure–activity relationship, compound 51am was found to be the most promising inhibitor in both biochemical and cellular assays. Moreover, 51am exhibited potency against several c-Met mutants. Mechanistically, 51am not only induced cell cycle arrest and apoptosis in MKN-45 cells but also inhibited c-Met phosphorylation in the cell and cell-free systems. It also exhibited a good pharmacokinetic profile in BALB/c mice. Furthermore, the binding mode of 51am with both c-Met and VEGFR-2 provided novel insights for the discovery of selective c-Met inhibitors. Taken together, these results indicate that 51am could be an antitumor candidate meriting further development.

A series of tepotinib derivatives with two chiral centers was designed, synthesized, and evaluated as anticancer agents. The optimal compound (R, S)-12a strongly exhibited antiproliferative activity against MHCC97H cell lines with an IC50 value of 0.002 μM, compared to tepotinib (IC50 = 0.013 μM). Mechanistic studies revealed that compound (R, S)-12a significantly inhibited c-Met activation, as well as the downstream AKT signaling pathway, and suppressed wound closure. Moreover, compound (R, S)-12a induced cellular apoptosis and cell cycle arrest at the G1 phase in a dose-dependent fashion. [ABSTRACT FROM AUTHOR]

The c-Met receptor, a pivotal player in oncogenesis and tumor progression, has become a compelling target for anticancer drug development. This review explores the intricate landscape of Structure-Activity Relationship [SAR] studies and molecular binding analyses performed on c-Met inhibitors. Through a comprehensive examination of various chemical scaffolds and modifications, SAR investigations have elucidated critical molecular features essential for the potent inhibition of c-Met activity. Additionally, molecular docking studies have provided invaluable insights into how c-Met inhibitors interact with their target receptor, facilitating the rational design of novel compounds with enhanced efficacy and selectivity. This review highlights key findings from recent SAR and docking studies, particularly focusing on the structural determinants that govern inhibition potency and selectivity. Furthermore, the integration of computational methodologies with experimental approaches has accelerated the discovery and optimization of c-Met inhibitors, fostering the advancement of promising candidates for clinical applications. Overall, this review underscores the pivotal role of SAR and molecular docking studies in advancing our understanding of c-Met inhibition and guiding the rational design of next-generation anticancer agents targeting this pathway., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Breast cancer presents a significant challenge due to its heterogeneity and propensity for developing chemoresistance, particularly in the triple-negative subtype. c-Mesenchymal epithelial transition factor (c-Met), a receptor tyrosine kinase, presents a promising target for breast cancer therapy due to its involvement in disease progression and poor prognosis. However, the heterogeneous expression of c-Met within breast cancer subtypes and individual tumors complicates targeted therapy. Also, cancer cells can develop resistance to c-Met inhibitors through various mechanisms, including bypass signaling pathways and genetic mutations. The off-target effects of c-Met inhibitors further limit their clinical utility, necessitating the development of more selective agents. To overcome these challenges, personalized treatment approaches and combination therapies are being explored to improve treatment efficacy while minimizing adverse effects. Novel c-Met inhibitors with improved selectivity and reduced off-target toxicity show promise in preclinical studies. Additionally, targeted delivery systems aim to enhance drug localization and reduce systemic toxicity. Future directions involve refining inhibitor design and integrating c-Met inhibition into personalized treatment regimens guided by molecular profiling. This review explores the mechanisms by which c-Met contributes to chemoresistance in breast cancer and current challenges in targeting c-Met for breast cancer therapy. It discusses strategies to optimize treatment outcomes, ultimately improving patient prognosis and reducing mortality rates associated with this devastating disease., Competing Interests: 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., (© 2024 The Authors.)

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Important cytogenetic and genetic risk factors for the development of UM include chromosome 3 monosomy, mutations in the guanine nucleotide‐binding proteins GNAQ/GNA11, and loss of the BRACA1‐associated protein 1 (BAP 1). Most primary UMs are treated conservatively with radiotherapy, but enucleation is necessary for large tumours. Despite the effectiveness of local control, up to 50% of UM patients develop metastasis for which there are no effective therapies. Attempts to utilise the targeted therapies that have been developed for the treatment of other cancers, including a range of signal transduction pathway inhibitors, have rarely produced significant outcomes in UM. Similarly, the application of immunotherapies that are effective in cutaneous melanoma to treat UM have also been disappointing. Other approaches that have been initiated involve proteasomal inhibitors and histone deacetylase inhibitors which are approved for the treatment of other cancers. Nevertheless, there have been occasional positive outcomes from these treatments in UM. Moreover, combination approaches in UM have also yielded some positive developments. It would be valuable to identify how to apply such therapies efficiently in UM, potentially via individualised tumour profiling. It would also be important to characterise UM tumours to differentiate the potential drivers of progression from those in other types of cancers. The recent identification of novel kinases and metastatic genes in UM tumours makes the development of new UM‐specific treatments feasible. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Dysregulated HGF/c‐Met signalling has been associated with many human cancers, poor clinical outcomes, and even resistance acquisition to some approved targeted therapies. As such, c‐Met kinase has emerged as an attractive target for anticancer drug discovery. Herein, a series of 6,7‐disubstitued‐4‐(2‐fluorophenoxy)quinoline derivatives bearing α‐acyloxycarboxamide moiety were designed, synthesized via Passerini reaction as the key step, and evaluated for their in vitro biological activities against c‐Met kinase and five selected cancer cell lines. The preliminary structure‐activity relationship demonstrated that α‐acyloxycarboxamide as the 5‐atom linker maintained the potent antitumor potency. Among these compounds, compound 25s (c‐Met IC50 = 4.06 nmol/L) was identified as the most promising lead compound and displayed the most potent antiproliferative activities against A549, HT‐29 and MDA‐MB‐231 cell lines with IC50 of 0.39, 0.20, and 0.58 μmol/L, which were 1.3‐, 1.4‐ and 1.2‐fold superior to foretinib, respectively. The further studies indicated that compound 25s can induce apoptosis of A549 cells and arrest efficiently the cell cycle distribution in G2/M phase of A549 cells. Moreover, compound 25s can also inhibit c‐Met phosphorylation in A549 cells by a dose‐dependent manner. Collectively, these results indicated that compound 25s could be a potential anticancer lead compound deserving for further development. [ABSTRACT FROM AUTHOR]

Antibiotic-induced microbial imbalance, or dysbiosis, has systemic and long-lasting effects on the host and response to cancer therapies. However, the effects on tumor endothelial cells are largely unknown. Therefore, the goal of the current study was to generate matched B16-F10 melanoma associated endothelial cell lines isolated from mice with and without antibiotic-induced dysbiosis. After validating endothelial cell markers on a genomic and proteomic level, functional angiogenesis assays (i.e., migration and tube formation) also confirmed their vasculature origin. Subsequently, we found that tumor endothelial cells derived from dysbiotic mice (TEC-Dys) were more sensitive to ionizing radiotherapy in the range of clinically-relevant hypofractionated doses, as compared to tumor endothelial cells derived from orthobiotic mice (TEC-Ortho). In order to identify tumor vasculature-associated drug targets during dysbiosis, we used tandem mass tag mass spectroscopy and focused on the statistically significant cellular membrane proteins overexpressed in TEC-Dys. By these criteria c-Met was the most differentially expressed protein, which was validated histologically by comparing tumors with or without dysbiosis. Moreover, in vitro, c-Met inhibitors Foretinib, Crizotinib and Cabozantinib were significantly more effective against TEC-Dys than TEC-Ortho. In vivo, Foretinib inhibited tumor growth to a greater extent during dysbiosis as compared to orthobiotic conditions. Thus, we surmise that tumor response in dysbiotic patients may be greatly improved by targeting dysbiosis-induced pathways, such as c-Met, distinct from the many targets suppressed due to dysbiosis. [ABSTRACT FROM AUTHOR]

A series of tepotinib derivatives with two chiral centers was designed, synthesized, and evaluated as anticancer agents. The optimal compound (R, S)-12a strongly exhibited antiproliferative activity against MHCC97H cell lines with an IC50 value of 0.002 μM, compared to tepotinib (IC50 = 0.013 μM). Mechanistic studies revealed that compound (R, S)-12a significantly inhibited c-Met activation, as well as the downstream AKT signaling pathway, and suppressed wound closure. Moreover, compound (R, S)-12a induced cellular apoptosis and cell cycle arrest at the G1 phase in a dose-dependent fashion.

A quantitative structure-activity relationship (QSAR) study is performed on 48 novel 4,5,6,7-tetrahydrobenzo[D]-thiazol-2 derivatives as anticancer agents capable of inhibiting c-Met receptor tyrosine kinase. The present study is conducted using multiple linear regression, multiple nonlinear regression and artificial neural networks. Three QSAR models are developed after partitioning the database into two sets (training and test) via the k-means method. The obtained values of the correlation coefficients by the three developed QSAR models are 0.90, 0.91 and 0.92, respectively. The resulting models are validated by using the external validation, leave-one-out cross-validation, Y-randomization test, and applicability domain methods. Moreover, we evaluated the drug-likeness properties of seven selected molecules based on their observed high activity to inhibit the c-Met receptor. The results of the evaluation showed that three of the seven compounds present drug-like characteristics.In order to identify the important active sites for the inhibition of the c-Met receptor responsible for the development of cancer cell lines, the crystallized form of the Crizotinib-c-Met complex (PDB code: 2WGJ) is used. These sites are used as references in the molecular docking test of the three selected molecules to identify the most suitable molecule for use as a new c-Met inhibitor. A comparative study is conducted based on the evaluation of the predicted properties of ADMET in silico between the candidate molecule and the Crizotinib inhibitor. The comparison results show that the selected molecule can be used as new anticancer drug candidates.

Two series of aromatic hydrazone derivatives bearing 1 H -pyrrolo[2,3- b ]pyridine moiety ( 7a – r , 8a – i , 12a – b , 13a – c , 16a – d and 17a – e ) were designed, synthesized and evaluated for the IC 50 values against four cancer cell lines (A549, HepG2, MCF-7and PC-3). Two selected compounds ( 7c and 17e ) were further evaluated for the activity against c-Met, Flt-3, VEGFR-2 and EGFR kinases. The data indicated that targets compounds were selective for c-Met kinase. And the most promising compound 7c was further studied in terms of dose-dependent, time-dependent and cell apoptosis. Most of the compounds showed excellent cytotoxicity activity, especially the most promising compound 7c with the IC 50 values of 0.82 ± 0.08 μM, 1.00 ± 0.11 μM, 0.93 ± 0.28 μM and 0.92 ± 0.17 μM against A549, HepG2, MCF-7 and PC-3 cell lines and 0.506 μM against c-Met kinase. Structure–activity relationships (SARs) and docking studies indicated that the activities of the phenyl hydrazone derivatives ( 7a – r and 8a – i ) were superior to that of the heterocyclic hydrazone series ( 12a – b , 13a – c , 16a – d and 17a – e ). What's more, the further studies indicated that the target compounds can induce apoptosis of A549 cells and arrest efficiently the cell cycle progression in G2/M phase of A549 cells. [ABSTRACT FROM AUTHOR]

Biscoumarin derivatives, a dimeric form of coumarin, are well known derivatives of coumarin, occurred in the bioactive metabolites of marine and terrestrial organisms. On account of pharmacological and biological applications, biscoumarins have long been the subject of innumerable enzyme inhibition studies. In this review the pros and cons of enzyme inhibition studies of biscoumarins as urease inhibitors, aromatase inhibitors, NPPs, α -glucosidase inhibitors, α -amylase inhibitors, HIV-1 integrase inhibition, steroid sulfatase inhibitors and c-Met inhibitors are discussed in a systematic way. Moreover, the review discusses the structure activity relationship of biscoumarin scaffold with enzyme inhibitory potency which would unleash new avenues for further development. The purpose of the current review is to disclose the value of biscoumarins as potent and efficient enzyme inhibitor. This review provides a guideline to elaborate the diversity of biscoumarin inhibitors by exploring the effects of electronic groups linked with biscoumarin nucleus. [ABSTRACT FROM AUTHOR]

Aberrant activation of the HGF/c-Met signalling pathways is shown to be related with cell proliferation, progression, metastasis, and worse prognosis in several tumor types, including gastrointestinal cancers, suggesting its value as a stimulating-target for cancer-therapy. Several approaches have been developed for targeting HGF and/or c-Met, and one of them, crizotinib (dual c-Met/ALK inhibitor), is recently been approved by FDA for lung-cancers with ALK-rearrangement. The main aim of current review is to give an overview on the role of c-Met/HGF pathway in gastrointestinal cancer, in preclinical and clinical trials. Although several important matters is still remained to be elucidated on the molecular pathways underlying the antitumor effects of this therapy in gastrointestinal-cancers. Further investigations are warranted to recognize the main determinants of the activity of c-Met inhibitors, for parallel targeting signalling pathway associated/activated via MET/HGF pathway or in response to the cell resistance to anti-c-Met agents. Additionally, identification of patients that might benefit from therapy could help to increase the selectivity and efficacy of the therapy. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of Premna odorata Blanco, Lamiaceae, leaves afforded three new acylated iridoid glycosides 1-3 and two new acylated rhamnopyranoses 9 and 10, in addition to ten known compounds. The structures of the new compounds were confirmed using extensive 1D and 2D NMR analysis. Molecular modeling study suggested the potential of the acylated rhamnopyranoses to bind at the c-Met kinase domain. Cell-free Z'-LYTE™ assay testing revealed the good c-Met phosphorylation inhibitory activity of 9, followed by 8, and 10, with IC50 values of 2.5, 6.9, and 12.7 μM, respectively. The (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay testing against the human c-Met expressing highly invasive MDA-MB-231 suggested compound 9 as the most active with IC50 value of 13.3 μM. Testing of compound 9 against multiple phenotypic breast cancer cell lines including MCF-7, BT-474 cells, and MDA-MB-468 proved enhanced activity against the highly c-Met expressing triple-negative breast cancer cell lines. Acylated rhamnopyranoses are potential novel c-Met inhibitors appropriate for future optimizations to control c-Met-dependent breast malignancies. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A series of novel 4-phenoxyquinoline derivatives containing 3-oxo-3,4-dihydroquinoxaline moiety were synthesized and evaluated for their c-Met kinase inhibitory activity and antiproliferative activity against five cancer cell lines (HT-29, H460, A549, MKN-45 and U87MG) in vitro. Most of the compounds exhibited moderate-to-significant cytotoxicity as compared with foretinib. The most promising compound 41 (with c-Met IC 50 value of 0.90 nM) showed remarkable cytotoxicity against HT-29, H460, A549, MKN-45 and U87MG cell lines with IC 50 values of 0.06 μM, 0.05 μM, 0.18 μM, 0.023 μM and 0.66 μM, respectively, and thus it was 1.22- to 3.50-fold more potent than foretinib. Their preliminary structure-activity relationships (SARs) studies indicate that electron-withdrawing groups on the terminal phenyl rings are beneficial for improving the antitumor activity. [ABSTRACT FROM AUTHOR]

C-Met is a receptor tyrosine kinase with multiple functions throughout embryonic development, organogenesis and wound healing and is expressed in various epithelia. The ligand of c-Met is Hepatocyte Growth Factor (HGF) which is secreted among others by mesenchymal stroma/stem (MSC) cells. Physiological c-Met functions are centred around processes that underly cellular motility and invasive growth. Aberrant c-Met expression and activity is observed in numerous cancers and makes major contributions to cell malignancy. Importantly, HGF/c-Met signaling is crucial in the context of communication between cancer cells and the the tumor stroma. Here, we review recent findings on roles of dysregulated c-Met in urogenital tumors such as cancers of the urinary bladder, prostate, and ovary. We put emphasis on novel aspects of cancer-associated c-Met expression regulation on both, HGF-dependent and HGF-independent non-canonical mechanisms. Moreover, this review focusses on c- Met-triggered signalling with potential relevance for urogenital oncogenesis, and on strategies to specifically inhibit c-Met activity. [ABSTRACT FROM AUTHOR]

A series of novel 4-phenoxyquinoline derivatives containing 1,2,4-triazolone moiety were synthesized and evaluated for their in vitro cytotoxic activity against four cancer cell lines (HT-29, H460, A549 and MKN-45). Most of the compounds exhibited moderate-to-significant cytotoxicity. Compounds 33 , 37 , 39 , 44 , 46 , 47 , 53 , 55 , 61 , 64 and 66 were further examined for their inhibitory activity against c-Met kinase. The most promising compound 47 (with c-Met IC 50 value of 1.57 nM) showed remarkable cytotoxicity against HT-29, H460, A549 and MKN-45 cell lines with IC 50 values of 0.08 μM, 0.14 μM, 0.11 μM and 0.031 μM, respectively, and thus it was 1.1- to 2.3- fold more potent than foretinib. Their preliminary structure-activity relationships (SARs) studies indicate that electron-withdrawing groups on the terminal phenyl rings are beneficial for improving the antitumor activity. [ABSTRACT FROM AUTHOR]

Aberrant c-Met activation has been implicated in multiple tumor oncogenic processes and drug resistance. In this study, a series of imidazo[4,5- b ]pyrazine derivatives was designed and synthesized, and their inhibitory activities were evaluated in vitro. Structure–activity relationship (SAR) was investigated systematically and docking analysis was performed to elucidate the binding mode, leading to the identification of the most promising compound 1D - 2 which exhibited significant inhibitory effect on both enzymatic (IC 50 = 1.45 nM) and cellular (IC 50 = 24.7 nM in H1993 cell line) assays, as well as exquisite selectivity and satisfactory metabolic stability in human and rat liver microsomes. [ABSTRACT FROM AUTHOR]

A series of [1,2,4]triazolo[4,3- a ]pyrazine derivatives ( 4a – 4i ) were designed, synthesized and evaluated for their c-Met kinase inhibition and antitumor activity against SNU5 gastric cell line in vitro. Among these compounds, 4d was found to show the highest activity against c-Met and high selectivity against the tumor cells which are believed to be dependent on the c-Met oncogene amplification, because 4d selectively inhibited c-Met while had no effect on other 59 kinases. In vivo efficacy study on human gastric (MKN-45) and human non-small cell lung (NCI-H1993) tumor xenograft in nude mouse demonstrated that 4d · CH 3 SO 3 H had a better inhibiting activity than SGX-523 in a dose-dependent manner. When tested in mice, compound 4d · CH 3 SO 3 H was found to have biological half-lives and plasma exposure values higher than those of JNJ-38877605, and its long-term toxicity and acute toxicity turned out to be acceptable, all of which indicates that 4d · CH 3 SO 3 H is a desirable drug candidate. [ABSTRACT FROM AUTHOR]

Four series of phenylpyrimidine-carboxamide derivatives bearing 1 H -pyrrolo[2,3- b ]pyridine moiety ( 14a – e , 15a – g , 16a – e and 17a – g ) were designed, synthesized and evaluated for the IC 50 values against three cancer cell lines (A549, PC-3 and MCF-7). Four selected compounds ( 15e , 16a – b and 17a ) were further evaluated for the activity against c-Met kinase, HepG2 and Hela cell lines. Most of the compounds showed excellent cytotoxicity activity and selectivity with the IC 50 valuables in single-digit μM to nanomole range. Eleven of them are equal to more active than positive control Foretinib against one or more cell lines. The most promising compound 15e showed superior activity to Foretinib against A549, PC-3 and MCF-7 cell lines, with the IC 50 values of 0.14 ± 0.08 μM, 0.24 ± 0.07 μM and 0.02 ± 0.01 μM, which were 4.6, 1.6 and 473.5 times more active than Foretinib (0.64 ± 0.26 μM, 0.39 ± 0.11 μM, 9.47 ± 0.22 μM), respectively. Structure–activity relationships (SARs) and docking studies indicated that the replacement of phenylpicolinamide scaffold with phenylpyrimidine fragment of the target compounds was benefit for the activity. What’s more, the introduction of fluoro atom to the aminophenoxy part played no significant impact on the activity and any substituent group on aryl group is unfavourable for the activity. [ABSTRACT FROM AUTHOR]

Four series of phenylpicolinamide derivatives bearing 1 H -pyrrolo[2,3- b ]pyridine moiety ( 12a – e , 13a – f , 14a – f and 15a – i ) were designed, synthesized and evaluated for the IC 50 values against three cancer cell lines (A549, PC-3 and MCF-7) and c-Met kinase. Five selected compounds ( 13b , 15b , 15d , 15e and 15f ) were further evaluated for the activity against HepG2 and Hela cell lines. Eighteen of the compounds showed excellent cytotoxicity activity and selectivity with the IC 50 valuables in single-digit μM to nanomole range. Seven of them are equal to more active than positive control Foretinib against one or more cell lines. The most promising compound 15f showed superior activity to Foretinib, with the IC 50 values of 1.04 ± 0.11 μM, 0.02 ± 0.01 μM and 9.11 ± 0.55 μM against A549, PC-3 and MCF-7 cell lines, which were 0.62 to 19.5 times more active than Foretinib (IC 50 values: 0.64 ± 0.26 μM, 0.39 ± 0.11 μM, 9.47 ± 0.22 μM), respectively. Structure–activity relationships (SARs) and docking studies indicated that replacement of quinoline nucleus of the previous active compounds with 1 H -pyrrolo[2,3- b ]pyridine moiety maintained even improved the potent cytotoxic activity. The results suggested that the introduction of fluoro atoms to the aminophenoxy part of target compounds or the phenyl group of pyrimidine substituted on C-4 position was benefit for the activity. [ABSTRACT FROM AUTHOR]

An uninformative variable elimination algorithm was combined with the Ridge regression method. This combination makes the penalized Ridge method, which is essentially incapable of deleting or selecting a variable, an efficient descriptor screening method for screening of descriptors in QSAR studies. The importance of descriptors was used to identify uninformative and redundant descriptors. The descriptor importance was defined as the ratio of the mean coefficients to the standard deviation of the coefficients derived from the leave-one-out (LOO) Ridge models. Then, with an iterative algorithm, among 392 molecular descriptors obtained after initial preprocessing, 358 uninformative descriptors were identified and removed from the data set. The remaining 34 descriptors were used for further variable selection and modeling through the smoothly clipped absolute deviation (SCAD) method. The proposed screening method was used to screen and reduce the size of QSAR data containing 63 compounds as c-Met inhibitors with anti-cancer activity. For comparison, the SCAD models were constructed using original high-dimensional data (SCAD), and the reduced-size data via the UVE-Ridge screening method (UVE-Ridge-SCAD). Both models were used to predict biological activities (pIC 50) for compounds in the external test set. The coefficients of determination (R2) and the FIT parameter for the test data predicted using the SCAD model (with 12 selected descriptors) were equal to 0.8042 and 3.78, respectively. The UVE-Ridge-SCAD model (with 9 descriptors) showed R2 and FIT values of 0.9025 and 4.38, respectively. Higher R2 and FIT values indicate the excellent predictive power of the UVE-Ridge-SCAD model. Finally, the UVE-Ridge-SCAD model was used to suggest new high-potency compounds. The accuracy of the proposed compounds was investigated using ligand-receptor interactions. • A new UVE algorithm was successfully combined with the Ridge method. • This combination makes the ridge method as efficient descriptor screening method. • The importance of descriptors were statistically calculated using the LOO Ridge models. • The screening was done using the descriptors ranks via an iterative procedure. • The screening method was for screening of 63 compounds as c-Met inhibitors. [ABSTRACT FROM AUTHOR]

Lung cancer is the most common malignant neoplasm and constitutes the most common neoplastic cause of death globally. The results of therapies employing standard chemotherapy are unsatisfactory. Currently, efforts are being made to personalize the therapy; numerous clinical studies are being conducted around the world to assess the efficacy and safety of agents directed at molecular targets. One of these molecular targets is the c-MET proto-oncogene, whose primary ligand is hepatocyte growth factor (HGF). C-MET hyperactivity has been observed in numerous neoplasms, including non-small-cell lung carcinoma. Prolonged or continuous activity of the receptor leads to excessive cell proliferation and is related to the development or progression of neoplastic disease. C-MET inhibitors can be classified into three groups: small-molecule tyrosine kinase inhibitors of the c-MET receptor (crizotinib, tivantinib, cabozantinib, foretinib), as well as monoclonal antibodies against c-MET (onartuzumab) and against the HGF ligand (ficlatuzumab, rilotumumab). The efficacy and safety of these agents is assessed both in monotherapy and in combination with other molecularly targeted agents. Furthermore, the toxicity profile of c-MET inhibitors is completely different from that of standard chemotherapy. The best understood c-MET inhibitor used in the treatment of non-small-cell lung carcinoma patients is crizotinib. It is registered for patients with the presence of ALK gene rearrangements after the failure of the first line of treatment based on platinum derivatives. The purpose of this present paper is to present clinical studies that assessed the efficacy and safety of c-MET inhibitors for the treatment of non-small-cell lung carcinoma, as well as current indications for the use of these molecules. [ABSTRACT FROM AUTHOR]

A series of novel 4-phenoxyquinoline derivatives containing pyridazinone moiety were synthesized and evaluated for their in vitro cytotoxic activity against five cancer cell lines (HT-29, H460, A549, MKN-45, and U87MG). Most of the compounds exhibited moderate-to-significant cytotoxicity and high selectivity against one or more cell lines. Compounds 15a, 20a, 15b, 15c, 20d, and 16e were further examined for their inhibitory activity against c-Met kinase. The most promising compound 15a (c-Met half-maximal inhibitory concentration [IC50] = 2.15 nM) showed remarkable cytotoxicity against HT-29, H460, and A549 cell lines with IC50 values of 0.10 µM, 0.13 µM, and 0.05 µM, respectively, and thus it was 1.5- to 2.3-fold more potent than foretinib. Their preliminary structure-activity relationships (SARs) studies indicate that electron-withdrawing groups on the terminal phenyl rings are beneficial for improving the antitumor activity. [ABSTRACT FROM AUTHOR]

In this paper, a specific design strategy targeting c-met kinase was reported based on docking modeling and topomer comparative molecular field analysis (Topomer CoMFA). A novel U-shape conformation which is distinct from the literature was demonstrated by molecular docking among 68 U-shape c-met inhibitors. According to the docking results, two Topomer CoMFA models with high predictive ability were established based on the two fragment rule. The results from both docking and topomer CoMFA showed that the π-π stacking interaction with Tyr1230 and the hydrogen bond with hinge region play an important role in inhibitory activity. Furthermore, the flexible linker and the adjacent solvent group would be favorable to stabilize the conformation and to enhance the two interactions mentioned above. Based on our patent, 14 new compounds were designed by our design strategy. The binding mode exhibited as expected and their activities were predicted by topomer CoMFA model. The preliminary biological tests showed most of them have potent activity to c-met kinase. Our study would provide guidelines to design some new U-shaped c-met inhibitors with new scaffolds and optimize the current molecules. [ABSTRACT FROM AUTHOR]

Mesenchymal epithelial transition factor (c-Met) is an attractive target for cancer therapy. Three-dimensional pharmacophore hypotheses were built based on a set of known structurally diverse c-Met inhibitors. The best pharmacophore model, which identified inhibitors with an associated correlation coefficient of 0.983 between their experimental and estimated IC values, consisted of two hydrogen-bond acceptors, one hydrophobic, and one ring aromatic feature. The highly predictive power of the model was rigorously validated by test set prediction and Fischer's randomization method. The high values of enrichment factor and receiver operating characteristic (ROC) score indicated the model performed fairly well at distinguishing active from inactive compounds. The model was then applied to screen compound database for potential c-Met inhibitors. A filtering protocol, including druggability and molecular docking, were also applied in hits selection. The final 38 molecules, which exhibited good estimated activities, desired binding mode and favorable drug likeness were identified as potential c-Met inhibitors. Their novel backbone structures could be served as scaffolds for further study, which may facilitate the discovery and rational design of potent c-Met kinase inhibitors. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

[Display omitted] • Somatic c-Met mutations and/or amplifications have been observed in several solid tumors, including renal cell carcinoma and lung cancer. • Aberrant signaling through c-Met promotes pleiotrophic effects including growth, survival, invasion, migration, angiogenesis and metastasis • c-Met inhibitors differ in terms of pharmacodynamic (potency, selectivity) and pharmacokinetic (half-life, exposure) properties that may be clinically relevant. • Improved understanding of the clinical pharmacokinetics of c-Met inhibitors can help avoid drug-drug interactions and optimize schedules for continuous in vivo inhibition of c-Met phosphorylation. c-Met inhibitors are a class of drugs that include nonselective and selective molecules. These drugs can differ in terms of pharmacodynamic and pharmacokinetic properties that may be clinically relevant. c-Met inhibitors with high potency and selectivity may allow achieving optimal c-Met inhibition in c-Met-driven tumors while reducing unwanted off-target toxicities due to activation of multiple kinases. Nonselective drugs can instead be considered in tumors that also recognize other drivers (e.g., ALK, ROS, VEGF). Improved understanding of the clinical pharmacokinetics of c-Met inhibitors can help avoid drug-drug interactions and optimize schedules for continuous in vivo inhibition of c-Met phosphorylation. The current review article provides a detailed overview of the clinical pharmacology of molecules used in c-Met-driven tumors. [ABSTRACT FROM AUTHOR]

Introduction: c-Met tyrosine kinase receptor is a high-affinity ligand of hepatocyte growth factor (HGF). c-Met is widely expressed in a variety of normal human tissues, but shows abnormally high expression, amplification or mutation in tumour tissues such as lung, gastric and breast cancers. Therefore, the use of c-Met as a target can achieve the inhibition of a series of abnormal physiological processes such as tumourigenesis, development and metastasis. A number of small molecule tyrosine kinase inhibitors targeting c-Met have been successfully marketed., Areas Covered: This article reviews recent advances in patented c-Met small molecule inhibitors and their inhibitory activity against various cancer cells from 2018 to date., Expert Opinion: To date, small molecule inhibitors targeting c-Met have demonstrated impressive therapeutic efficacy in the clinical setting. Most recent patents have focused on addressing the direction of c-Met amplification and overexpression. Despite the great success in the development of selective c-Met inhibitors, the effects of bypass secretion and mutagenesis have led to a need for new c-Met small molecule inhibitors that are safe, efficient, selective and less toxic with novel structures and effective against other targets.

A series of novel 4-phenoxypyridine derivatives containing 3-oxo-3,4-dihydroquinoxaline moiety were synthesized and evaluated for their c-Met kinase activities and cytotoxic activities against A549, H460, HT-29 cancer cell lines. Furthermore, acridine orange/ethidium bromide staining, apoptosis, wound-healing assay and transwell migration assay on HT-29 and/or A549 cells of 23w were performed. • A series of novel 4-phenoxypyridine derivatives were designed and synthesized. • The target compounds showed c-Met kinase activities and cytotoxic activities. • Compound 23w showed an IC 50 value of 1.91 nM against c-Met kinase, and more potent than foretinib. • The cytotoxic activities of 23w were more potent than foretinib against HT-29 cells. • Compound 23w could induce cells apoptosis and inhibit cells motility. Blocking c-Met kinase activity by small-molecule inhibitors has been identified as a promising approach for the treatment of cancers. Herein, we described the design, synthesis, and biological evaluation of a series of 4-phenoxypyridine-based 3-oxo-3,4-dihydroquinoxaline derivatives as c-Met kinase inhibitors. Inhibitory activitives against c-Met kinase evaluation indicated that most of compounds showed excellent c-Met kinase activity in vitro, and IC 50 values of ten compounds (23a , 23e , 23f , 23l , 23r , 23s , 23v , 23w , 23x and 23y) were less than 10.00 nM. Notably, three of them (23v , 23w and 23y) showed remarkable potency with IC 50 values of 2.31 nM, 1.91 nM and 2.44 nM, respectively, and thus they were more potent than positive control drug foretinib (c-Met, IC 50 = 2.53 nM). Cytotoxic evaluation indicated the most promising compound 23w showed remarkable cytotoxicity against A549, H460 and HT-29 cell lines with IC 50 values of 1.57 μM, 0.94 μM and 0.65 μM, respectively. Furthermore, the acridine orange/ethidium bromide (AO/EB) staining, cell apoptosis assays by flow cytometry, wound-healing assays and transwell migration assays on HT-29 and/or A549 cells of 23w were performed. Especially compound 23w , which displayed potent antitumor, apoptosis induction and antimetastatic activity, could be used as a promising lead for further development. Meanwhile, their preliminary structure-activity relationships (SARs) were also discussed. [ABSTRACT FROM AUTHOR]

In our continuing efforts to develop novel c-Met inhibitors as potential anticancer candidates, a series of new N -sulfonylamidine derivatives were designed, synthesized via Cu-catalyzed multicomponent reaction (MCR) as the key step, and evaluated for their in vitro biological activities against c-Met kinase and four cancer cell lines (A549, HT-29, MKN-45 and MDA-MB-231). Most of the target compounds showed moderate to significant potency at both the enzyme-based and cell-based assay and possessed selectivity for A549 and HT-29 cancer cell lines. The preliminary SAR studies demonstrated that compound 26af (c-Met IC 50 = 2.89 nM) was the most promising compound compared with the positive foretinib, which exhibited the remarkable antiproliferative activities, with IC 50 values ranging from 0.28 to 0.72 μM. Mechanistic studies of 26af showed the anticancer activity was closely related to the blocking phosphorylation of c-Met, leading to cell cycle arresting at G2/M phase and apoptosis of A549 cells by a concentration-dependent manner. The promising compound 26af was further identified as a relatively selective inhibitor of c-Met kinase, which also possessed an acceptable safety profile and favorable pharmacokinetic properties in BALB/c mouse. The favorable drug-likeness of 26af suggested that N -sulfonylamidines may be used as a promising scaffold for antitumor drug development. Additionally, the docking study and molecular dynamics simulations of 26af revealed a common mode of interaction with the binding site of c-Met. These positive results indicated that compound 26af is a potential anti-cancer candidate for clinical trials, and deserves further development as a selective c-Met inhibitor. Image 1 • 39 novel N -sulfonylamidines were designed and synthesized for biological evaluation. • Compound 26af displayed an IC 50 value of 2.89 nM against c-Met kinase. • 26af inhibited A549 cells by inducing apoptosis and G2/M phase cell cycle arrest. • 26af had desirable pharmacokinetic properties and an acceptable safety profile. • Docking studies indicated the mode of interaction with the binding site of c-Met. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The c-Met kinase has emerged as a promising target for the development of small molecule antitumor agents because of its close relationship with the progression of many human cancers, poor clinical outcomes and even drug resistance. In this study, two novel series of 6,7-disubstitued-4-(2-fluorophenoxy)quinoline derivatives containing α-acyloxycarboxamide or α-acylaminoamide scaffolds were designed, synthesized, and evaluated for their in vitro biological activities against c-Met kinase and four cancer cell lines (H460, HT-29, MKN-45, and MDA-MB-231). Most of the target compounds exhibited moderate to significant potency and possessed selectivity for H460 and HT-29 cancer cell lines. The preliminary structure-activity relationships indicated that α-acyloxycarboxamide or α-acylaminoamide as 5-atom linker contributed to the antitumor potency. Among these compounds, compound 10m (c-Met IC 50 = 2.43 nM, a multitarget tyrosine kinase inhibitor) exhibited the most potent inhibitory activities against H460, HT-29 and MDA-MB-231 cell lines with IC 50 of 0.14 ± 0.03 μM, 0.20 ± 0.02 μM and 0.42 ± 0.03 μM, which were 1.7-, 1.3- and 1.6-fold more active than foretinib, respectively. In addition, concentration-dependent assay and time-dependent assay indicated compound 10m can inhibit the proliferation of H460 cell in a time and concentration dependent manner. Moreover, docking studies revealed the common mode of interaction with the c-Met binding site, suggesting that 10m is a potential candidate for cancer therapy deserving further study. Image 1 • Two series of new c-Met inhibitors were designed and efficiently synthesized. • The first one-pot synthesis of the 5-atom linker via Passerini and Ugi reactions. • Compound 10m showed an IC 50 value of 2.43 nM against c-Met kinase. • Inhibit cancer cell proliferation in a time and concentration dependent manner. • Docking studies revealed the common mode of interaction with c-Met binding site. [ABSTRACT FROM AUTHOR]

A quantitative structure-activity relationship (QSAR) study is performed on 48 novel 4,5,6,7-tetrahydrobenzo[D]-thiazol-2 derivatives as anticancer agents capable of inhibiting c-Met receptor tyrosine kinase. The present study is conducted using multiple linear regression, multiple nonlinear regression and artificial neural networks. Three QSAR models are developed after partitioning the database into two sets (training and test) via the k-means method. The obtained values of the correlation coefficients by the three developed QSAR models are 0.90, 0.91 and 0.92, respectively. The resulting models are validated by using the external validation, leave-one-out cross-validation, Y-randomization test, and applicability domain methods. Moreover, we evaluated the drug-likeness properties of seven selected molecules based on their observed high activity to inhibit the c-Met receptor. The results of the evaluation showed that three of the seven compounds present drug-like characteristics. In order to identify the important active sites for the inhibition of the c-Met receptor responsible for the development of cancer cell lines, the crystallized form of the Crizotinib-c-Met complex (PDB code: 2WGJ) is used. These sites are used as references in the molecular docking test of the three selected molecules to identify the most suitable molecule for use as a new c-Met inhibitor. A comparative study is conducted based on the evaluation of the predicted properties of ADMET in silico between the candidate molecule and the Crizotinib inhibitor. The comparison results show that the selected molecule can be used as new anticancer drug candidates., Competing Interests: The authors declare no conflict of interest., (© 2021 Published by Elsevier Ltd.)

Three series of novel 4-phenoxypyridine derivatives containing 4-methyl-6-oxo-1,6-dihydropyridazine- 3-carboxamide, 5-methyl-4-oxo-1,4-dihydropyridazine-3-carboxamide and 4-methyl-3,5-dioxo-2,3,4,5- tetrahydro-1,2,4-triazine-6-carboxamide moieties were synthesized and evaluated for their in vitro inhibitory activitives against c-Met kinase and cytotoxic activitives against A549, H460, HT-29 cancer cell lines. The results indicated that most of the compounds showed moderate to good antitumor activitives. The most promising compound 26a (with c-Met IC 50 value of 0.016 μM) showed remarkable cytotoxicity against A549, H460, and HT-29 cell lines with IC 50 values of 1.59 μM, 0.72 μM and 0.56 μM, respectively. Their preliminary structure-activity relationships (SARs) studies indicate that 4-methyl-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carboxamide was more preferred as linker part, and electron-withdrawing groups on the terminal phenyl rings are beneficial for improving the antitumor activitives. Furthermore, the colony formation, acridine orange/ethidium bromide (AO/EB) staining, apoptosis, and wound-healing assay of 26a were performed on HT-29 and/or A549 cell lines., 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 © 2020 Elsevier Masson SAS. All rights reserved.)

A series of novel 4-phenoxyquinoline derivatives containing 3-oxo-3,4-dihydro-quinoxaline moiety were synthesized and evaluated for their antiproliferative activity against five human cancer cell lines (A549, H460, HT-29, MKN-45 and U87MG) in vitro. Most of the tested compounds exhibited more potent inhibitory activities than the positive control foretinib. Compound 1b , 1s and 1t were further examined for their inhibitory activity against c-Met kinase. The most promising compound 1s (with c-Met IC 50 value of 1.42 nM) showed remarkable cytotoxicity against A549, H460, HT-29, MKN45 and U87MG cell lines with IC 50 values of 0.39 μM, 0.18 μM, 0.38 μM, 0.81 μM, respectively. Their preliminary structure-activity relationships (SARs) study indicated that the replacement of the aromatic ring with the cyclohexane improved their antiproliferative activity. [ABSTRACT FROM AUTHOR]

Background: The Hepatocyte Growth Factor Receptor (HGFR) c-Met is over-expressed and/or mutated in various human tumor types. Dysregulation of c-Met/HGF signaling pathway affects cell proliferation, survival and motility, leading to tumor growth, angiogenesis, and metastasis. Therefore, c-Met has become an attractive target for cancer therapy., Objective: This study is aimed to evaluate a new series of 4-phenoxypyridine derivatives containing semicarbazones moiety for its cytotoxicity., Methods: A series of novel 4-phenoxypyridines containing semicarbazone moieties were synthesized and evaluated for their in vitro cytotoxic activities against MKN45 and A549 cancer cell lines and some selected compounds were further examined for their inhibitory activity against c-Met kinase. In order to evaluate the mechanism of cytotoxic activity of compound 24, cell cycle analysis, Annexin V/PI staining assay, AO/EB assay, wound-healing assay and docking analysis with c-Met were performed., Results: The results indicated that most of the compounds showed moderate to good antitumor activity. The compound 28 showed well cytotoxic activity against MKN45 and A549 cell lines with IC50 values of 0.25μM and 0.67μM, respectively. Compound 24 showed good activity on c-Met and its IC50 value was 0.093μM., Conclusion: Their preliminary Structure-Activity Relationships (SARs) studies indicated that electronwithdrawing groups on the terminal phenyl rings are beneficial for improving the antitumor activity. Treatments of MKN45 cells with compound 24 resulted in cell cycle arrest in G2/M phase and induced apoptosis in a dose-dependent manner. In addition, AO/EB assays indicated 24 induced dose-dependent apoptosis of A549 and MKN45 cells. Wound-healing assay results indicated that compound 24 strongly inhibited A549 cell motility., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

c-MET pathway over-activation is the signature of malignancy acquisition or chemotherapy resistance of many cancers. We recently demonstrated that type II Testicular Germ Cell Tumours (TGCTs) express c-MET receptor. In particular, we elucidated that the non-seminoma lesions express c-MET protein at higher level, compared with the seminoma ones. In line with this observation, NTERA-2 clone D1 (NT2D1) non-seminoma cells increase their proliferation, migration and invasion in response to Hepatocyte Growth Factor (HGF). One of the well-known adaptor-proteins belonging to c-MET signaling cascade is c-Src. Activation of c-Src is related to the increase of aggressiveness of many cancers. For this reason, we focused on the role of c-Src in c-MET-triggered and HGF-dependent NT2D1 cell activities. In the present paper, we have elucidated that this adaptor-protein is involved in HGF-dependent NT2D1 cell proliferation, migration and invasion, since Src inhibitor-1 administration abrogates these responses. Despite these biological evidences western blot analyses have not revealed the increase of c-Src activation because of HGF administration. However, notably, immunofluorescence analyses revealed that cytoplasmic and membrane-associated localization of c-Src shifted to the nuclear compartment after HGF stimulation. These results shed new light in the modality of HGF-dependent c-Src recruitment, and put the basis for novel investigations on the relationship between c-Src, and TGCT aggressiveness. [ABSTRACT FROM AUTHOR]

Type II testicular germ cell tumors (TGCTs) represent the most frequent malignancy in Caucasian males (20-40 years). Even if diagnosed with disseminated disease, >80% of patients are cured; however, a small percentage of cases progress and result in death. It is commonly accepted that these cancers arise from a disturbed testicular embryonic niche that leads to the block of gonocyte differentiation. The subsequent development of the invasive seminomas and non-seminomas is due to a combination of genetic, epigenetic and microenvironment-based alterations (genvironment). Hepatocyte growth factor (HGF) is present in the testicular microenvironment, together with its receptor c-MET, from early embryonic development to an adult stage. In addition, c-MET is a well-known proto-oncogene involved in the onset and progression of various human cancers. Herein, we have investigated the expression and availability of HGF and c-MET in TCam-2, NCCIT and NT2D1 cells, which are type II (T)GCT representative cell lines, and the effect of c-MET activation/repression on the regulation of cancerous biological processes. We found that NT2D1 cells increase their proliferation, polarized migration, and invasion in response to HGF administration. NCCIT cells respond to HGF stimulation only partially, whereas TCam-2 cells do not respond to HGF, at least according to the investigated parameters. Interestingly, the immunohistochemical study of c-MET distribution in TGCTs confirm its presence in both seminoma and non-seminoma lesions with different patterns. Notably, we found the highest c-MET immunoreactivity in the epithelial elements of the various components of TGCTs: teratoma, yolk sac tumor and choriocarcinoma., Competing Interests: CONFLICTS OF INTEREST The authors declare that there is no conflicts of interests.

Introduction: The role of the c-mesenchymal-epithelial transition factor (c-MET) signaling pathway in tumor progression and invasion has been extensively studied. C-MET inhibitors have shown anti-tumor activity in NSCLC both in preclinical and in clinical trials. However, given the molecular heterogeneity of NSCLC, it is likely that only a specific subset of NSCLC patients will benefit from c-MET inhibitors. Emerging data also suggest that MET inhibitors in combination with EGFR-TKIs (epidermal growth factor receptor tyrosine kinase inhibitors) may have a role in therapy for both EGFR-TKI resistant and EGFR-TKI naïve patients. The challenges ahead are in the identification of the molecular subtypes that benefit most., Areas Covered: This review summarizes the current understanding of c-MET biology in relation to studies evaluating c-MET inhibitors in the treatment of NSCLC., Expert Opinion: MET inhibitors have the potential to benefit subsets of NSCLC patients with specific genetic alterations. Exon-14 skipping mutations appear so far to be the most promising molecular subset that is sensitive to MET inhibitors, whereas overexpression, amplification and point mutations of MET seem more challenging subgroups to target. Combination with other target agents, such as EGFR inhibitors, may represent a promising therapeutic strategy in specific areas (e.g. EGFR-TKI resistance).

Introduction: Hepatocellular carcinoma (HCC) is the fifth most diagnosed cancer in the world and the third leading cause of death. Unfortunately, when diagnosed two thirds of patients have an advanced disease for which only palliative treatment can be proposed and most likely systemic therapy. Areas covered: As of today only one systemic therapy is validated in the treatment of advanced HCC, a tyrosine kinase inhibitor (TKI): Sorafenib. Treatment options are therefore lacking. With the advent of Sorafenib other TKIs have been studied with some disappointing results. Many explanations can be found to the failure of these tested TKIs such as the underlying cirrhosis leading to rapidly serious adverse events, or trial design imperfections. Expert opinion: Taking into account these failures, new trials with more appropriate designs have led to recent success with multi-target TKIs (Regorafenib and Lenvatinib). This multi-target approach allows to overcome the molecular heterogeneity of advanced HCC which is associated with multiple simultaneously dysregulated signaling pathways. On the contrary, another lead is to study target a specific TKI such as c-MET inhibitors or TGFβR inhibitors in HCC sub-populations with promising results in early phase trials. These results will have to be validated in the ongoing phase III trials.

A series of novel 6,7-disubstituted-4-phenoxyquinoline derivatives bearing (E)-3-hydrosulfonylacrylamido or 1H-imidazole-4-carboxamido moieties were designed, synthesized and evaluated for their cytotoxicity against A549, MKN-45, and HT-29 cancer cell lines in vitro. All the target compounds showed moderate to significant cytotoxic activity against the tested cells with IC 50 values ranging from 0.13 to 2.65 µM. Five of them were further examined for their inhibitory activity against c-Met kinase, which identified compound 30 as a promising agent (c-Met IC 50  = 1.52 nM) with IC 50 values of 0.24, 0.45, and 0.13 µM against HT-29, MKN-45, and A549 cells, respectively., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

c-Met, also known as the surface receptor of hepatocyte growth factor receptor (HGFR), is a receptor tyrosine kinase with heterodimer transmembrane. c-Met involves in the activation of several signaling pathways, most of them are implicated in aggressive cancer phenotypes. In a variety of human malignances, c-Met/HGF signaling has been found aberrant, and in many instances, has been correlated with advanced disease stage and poor prognosis. Thus, the c-Met has identified as an emerging and interesting target for cancer chemotherapy. In this review, we briefly summarize signaling pathways of c-Met, and discuss the crystal structures of representative c-Met and the binding modes with their ligands. We also present updates on the design, synthesis and structure-activity relationship analysis of c-Met inhibitors developed from 2014 till now. At last, we review the c-Met inhibitors that are in clinical development and highlight the future prospects., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)