Status of Agents Targeting the HGF/c-Met Axis in Lung Cancer

Antitumor activity of gamma-irradiated Rosa canina L. against lung carcinoma in rat model: a proposed mechanism

BACKGROUND

Lung cancer is one of the most prevalent malignancies globally and is the leading cause of cancer-related mortality. Although cisplatin is a widely utilized chemotherapeutic agent, its clinical efficacy is often hampered by significant toxicity and undesirable side effects. Rosa canina, a medicinal plant, has demonstrated a range of beneficial biological activities, including anti-inflammatory, anticancer, immunomodulatory, antioxidant, and genoprotective effects.

METHODS

This study aimed to investigate the potential of Rosa canina to enhance the anticancer efficacy of cisplatin in a dimethyl benz(a)anthracene-induced lung cancer model using female rats. The animals were administered Rosa canina, cisplatin, or a combination of both treatments. The expression levels of critical signaling molecules were evaluated, including phosphoinositide-3-kinase (PI3K), Akt, mammalian target of rapamycin (mTOR), cleaved poly (ADP-ribose) polymerase (PARP-1), myeloid differentiation factor 88 (MyD88), and tumor necrosis factor receptor-associated factor (TRAF), in addition to various autophagic markers. Furthermore, we assessed the levels of toll-like receptor 2 (TLR2), nuclear factor kappa B (NF-κB), and apoptotic markers in lung tissue, complemented by histopathological examinations.

RESULTS

The combined treatment of Rosa canina extract and cisplatin significantly inhibited lung cancer cell proliferation by downregulating PARP-1 and the TLR2/MyD88/TRAF6/NF-κB signaling pathway, as well as the PI3K/Akt/mTOR pathway. Moreover, this combination therapy promoted autophagy and apoptosis, evidenced by elevated levels of autophagic and apoptotic markers.

CONCLUSION

Overall, the findings of this study suggest that Rosa canina enhances the anticancer effects of cisplatin by inhibiting cancer cell proliferation while simultaneously inducing autophagy and apoptosis. Thus, Rosa can be used as adjuvant to cisplatin chemotherapy to overcome its limitations which may be considered a new approach during lung cancer treatment strategy.

Advances in the selective c-MET kinase inhibitors: Application of fused [5,6]-Bicyclic nitrogen-containing cores for anticancer drug design

Over the past two decades, small molecules bearing [5,6]-bicyclic nitrogen-containing cores have emerged as one of the most extensively studied structures for the development of selective c-MET kinase inhibitors. Structure-activity relationship (SAR) studies have demonstrated that modifying these cores can significantly impact the biological properties of c-MET inhibitors, including safety/toxicity, potency, and metabolic stability. For example, although c-MET kinase inhibitors containing the [1,2,4]triazolo[4,3-b][1,2,4]triazine scaffold (core P) exhibit high inhibitory potency, they often face challenges due to metabolic stability defects. Alternatively, compounds containing [1,2,3]triazolo[4,5-b]pyrazine (core K) and [1,2,4]triazolo[4,3-b]pyridazine (core I) scaffolds demonstrate lower potency but improved metabolic stability, allowing some of them to progress into clinical trials and even be approved as novel anticancer drugs. Fortunately, X-ray crystallography studies have well elucidated key interactions between [5,6]-bicyclic nitrogen-containing cores and crucial amino acid residues within the c-MET active site. These insights emphasize the significance of π-π stacking interactions with Tyr1230 and hydrogen bonding with Asp1222, providing valuable guidance for the targeted design and optimization of selective c-MET kinase inhibitors. Following the identification/introduction of sixteen distinct [5,6]-bicyclic nitrogen-containing cores (cores A-P) utilized in the design of selective c-MET kinase inhibitors over the past two decades, this manuscript offers a comprehensive review of their roles in drug development of anticancer agents, and describes the various synthesis methods employed. The insights presented herein can serve as a resource for better structural optimization of c-MET kinase inhibitors in the future research.

Epidermal growth factor receptors unveiled: a comprehensive survey on mutations, clinical insights of global inhibitors, and emergence of heterocyclic derivatives as EGFR inhibitors

Mutations that overexpress the epidermal growth factor receptor (EGFR) are linked to cancers like breast (15-20%), head and neck (10-15%), colorectal (5-8%), and non-small cell lung cancer (10-50%), especially in East Asian populations. EGFR activation stimulates 'RAS/RAF/MEK/ERK, PI3K/Akt, and MAPK' pathways, which enhance cell division, survival, angiogenesis, and tumour growth while inhibiting apoptosis and metastasis. Secondary mutations (e.g. 'T790M', 'C797S'), off-target effects, and resistance due to alternate pathway activation reduce the efficacy of currently available EGFR inhibitors. To address these issues, 'novel heterocyclic inhibitors with structural versatility were developed to improve selectivity and binding affinity for mutant EGFR forms'. These new EGFR reduce side effects, enhance pharmacokinetics, and enhance therapeutic efficacy at low concentrations. This review focuses on 'EGFR mutations in various cancers' detailing the biochemical effects, clinical profiles, and binding interactions of globally approved EGFR inhibitors. Furthermore, it focuses into recent progress in nano-formulations and the development of heterocyclic derivatives that can successfully 'target mutant EGFRs' through varied synthesis methods. These inhibitors have the potential to have better binding affinities, selectivity's, and less side-effect. Further research required to refine the structures and develop nanoformulations of EGFR-targeted therapeutics in order to improve therapeutic efficiency and, provide more effective cancer treatments.

The HGF/Met Receptor Mediates Cytotoxic Effect of Bacterial Cyclodipeptides in Human Cervical Cancer Cells

BACKGROUND

Human cervix adenocarcinoma (CC) caused by papillomavirus is the third most common cancer among female malignant tumors. Bioactive compounds such as cyclodipeptides (CDPs) possess cytotoxic effects in human cervical cancer HeLa cells mainly by blocking the PI3K/Akt/mTOR pathway and subsequently inducing gene expression by countless transcription regulators. However, the upstream elements of signaling pathways have not been well studied.

METHODS

To elucidate the cytotoxic and antiproliferative responses of the HeLa cell line to CDPs by a transcriptomic analysis previously carried out, we identified by immunochemical analyses, differential expression of genes related to the hepatocyte growth factor/mesenchymal-epithelial transition factor (HGF/MET) receptors. Furthermore, molecular docking was carried out to evaluate the interactions of CDPs with the EGF and MET substrate binding sites.

RESULTS

Immunochemical and molecular docking analyses suggest that the HGF/MET receptor participation in CDPs cytotoxic effect was independent of the protein expression levels. However, protein modulation of downstream Met-targets occurred due to the inhibition of phosphorylation of the HGF/MET receptor. Results suggest that the antiproliferative and cytotoxicity of CDPs in HeLa cells involve the HGF/MET receptor upstream of PI3K/Akt/mTOR pathway; assays with the human breast cancer MCF-7 and MDA-MB-231cell lines supported the finding.

CONCLUSION

Data provide new insights into the molecular mechanisms involved in CDPs cytotoxicity and antiproliferative effects, suggesting that the signal transduction mechanism may be related to the inhibition of the phosphorylation of the EGF/MET receptor at the level of substrate binding site by an inhibition mechanism similar to that of Gefitinib and Foretinib anti-neoplastic drugs.

The therapeutic potential of RNA m(6)A in lung cancer

Lung cancer (LC) is a highly malignant and metastatic form of cancer. The global incidence of and mortality from LC is steadily increasing; the mean 5-year overall survival (OS) rate for LC is less than 20%. This frustrating situation may be attributed to the fact that the pathogenesis of LC remains poorly understood and there is still no cure for mid to advanced LC. Methylation at the N6-position of adenosine (N6mA) of RNA (m(6)A) is widely present in human tissues and organs, and has been found to be necessary for cell development and maintenance of homeostasis. However, numerous basic and clinical studies have demonstrated that RNA m(6)A is deregulated in many human malignancies including LC. This can drive LC malignant characteristics such as proliferation, stemness, invasion, epithelial-mesenchymal transition (EMT), metastasis, and therapeutic resistance. Intriguingly, an increasing number of studies have also shown that eliminating RNA m(6)A dysfunction can exert significant anti-cancer effects on LC such as suppression of cell proliferation and viability, induction of cell death, and reversal of treatment insensitivity. The current review comprehensively discusses the therapeutic potential of RNA m(6)A and its underlying molecular mechanisms in LC, providing useful information for the development of novel LC treatment strategies.

Amivantamab efficacy in wild-type EGFR NSCLC tumors correlates with levels of ligand expression

Amivantamab is an FDA-approved bispecific antibody targeting EGF and Met receptors, with clinical activity against EGFR mutant non-small cell lung cancer (NSCLC). Amivantamab efficacy has been demonstrated to be linked to three mechanisms of action (MOA): immune cell-mediated killing, receptor internalization and degradation, and inhibition of ligand binding to both EGFR and Met receptors. Among the EGFR ligands, we demonstrated that amphiregulin (AREG) is highly expressed in wild-type (WT) EGFR (EGFRWT) NSCLC primary tumors, with significantly higher circulating protein levels in NSCLC patients than in healthy volunteers. Treatment of AREG-stimulated EGFRWT cells/tumors with amivantamab or with an AREG-targeting antibody inhibited ligand-induced signaling and cell/tumor proliferation/growth. Across 11 EGFRWT NSCLC patient-derived xenograft models, amivantamab efficacy correlated with AREG RNA levels. Interestingly, in these models, amivantamab anti-tumor activity was independent of Fc engagement with immune cells, suggesting that, in this context, the ligand-blocking function is sufficient for amivantamab maximal efficacy. Finally, we demonstrated that in lung adenocarcinoma patients, high expression of AREG and EGFR mutations were mutually exclusive. In conclusion, these data 1) highlight EGFR ligand AREG as a driver of tumor growth in some EGFRWT NSCLC models, 2) illustrate the preclinical efficacy of amivantamab in ligand-driven EGFRWT NSCLC, and 3) identify AREG as a potential predictive biomarker for amivantamab activity in EGFRWT NSCLC.

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

Unlocking c-MET: A comprehensive journey into targeted therapies for breast cancer

Breast cancer is the most common malignancy among women, posing a formidable health challenge worldwide. In this complex landscape, the c-MET (cellular-mesenchymal epithelial transition factor) receptor tyrosine kinase (RTK), also recognized as the hepatocyte growth factor (HGF) receptor (HGFR), emerges as a prominent protagonist, displaying overexpression in nearly 50% of breast cancer cases. Activation of c-MET by its ligand, HGF, secreted by neighboring mesenchymal cells, contributes to a cascade of tumorigenic processes, including cell proliferation, metastasis, angiogenesis, and immunosuppression. While c-MET inhibitors such as crizotinib, capmatinib, tepotinib and cabozantinib have garnered FDA approval for non-small cell lung cancer (NSCLC), their potential within breast cancer therapy is still undetermined. This comprehensive review embarks on a journey through structural biology, multifaceted functions, and intricate signaling pathways orchestrated by c-MET across cancer types. Furthermore, we highlight the pivotal role of c-MET-targeted therapies in breast cancer, offering a clinical perspective on this promising avenue of intervention. In this pursuit, we strive to unravel the potential of c-MET as a beacon of hope in the fight against breast cancer, unveiling new horizons for therapeutic innovation.

Biological characteristics and clinical treatment of pulmonary sarcomatoid carcinoma: a narrative review

Background and Objective

Pulmonary sarcomatoid carcinoma (PSC) is a subset of non-small cell lung cancer (NSCLC) with highly malignant, aggressive, and heterogeneous features. Patients with this disease account for approximately 0.1-0.4% of lung cancer cases. The absence of comprehensive summaries on the basic biology and clinical treatments for PSC means there is limited systematic awareness and understanding of this rare disease. This paper provides an overview of the biological characteristics of PSC and systematically summarizes various treatment strategies available for patients with this disease.

Methods

For this narrative review, we have searched literature related to the basic biology and clinical treatment approaches of PSC by searching the PubMed database for articles published from July 16, 1990 to August 29, 2023. The following keywords were used: "pulmonary sarcomatoid carcinoma", "genetic mutations", "immune microenvironment", "hypoxia", "angiogenesis", "overall survival", "surgery", "radiotherapy", "chemotherapy", and "immune checkpoint inhibitors".

Key Content and Findings

Classical PSC comprises epithelial and sarcomatoid components, with most studies suggesting a common origin. PSC exhibits a higher tumor mutational burden (TMB) and mutation frequency than other types of NSCLC. The tumor microenvironment (TME) of PSC is characterized by hypoxia, hypermetabolism, elevated programmed cell death protein 1/programmed cell death-ligand 1 expression, and high immune cell infiltration. Treatment strategies for advanced PSC are mainly based on traditional NSCLC treatments, but PSC exhibits resistance to chemotherapy and radiotherapy. The advancement of genome sequencing has introduced targeted therapies as an option for mutation-positive PSC cases. Moreover, due to the characteristics of the immune microenvironment of PSC, many patients positively respond to immunotherapy, demonstrating its potential for the management of PSC.

Conclusions

Although several studies have examined and assessed the TME of PSC, these are limited in quantity and quality, presenting challenges for research into the clinical treatment strategies for PSC. With the emergence of new technologies and the advancement of clinical research, for example, savolitinib's clinical study for MET exon 14 skipping mutations positive PSC patients have shown promising outcomes, more in-depth studies on PSC are eagerly anticipated.

Recent advances in molecular targeted therapy of lung cancer: Possible application in translation medicine

Lung cancer is one of the leading causes of death among all cancer deaths. This cancer is classified into two different histological subtypes: non-small cell lung cancer (NSCLC), which is the most common subtype, and small cell lung cancer (SCLC), which is the most aggressive subtype. Understanding the molecular characteristics of lung cancer has expanded our knowledge of the cellular origins and molecular pathways affected by each of these subtypes and has contributed to the development of new therapies. Traditional treatments for lung cancer include surgery, chemotherapy, and radiotherapy. Advances in understanding the nature and specificity of lung cancer have led to the development of immunotherapy, which is the newest and most specialized treatment in the treatment of lung cancer. Each of these treatments has advantages and disadvantages and causes side effects. Today, combination therapy for lung cancer reduces side effects and increases the speed of recovery. Despite the significant progress that has been made in the treatment of lung cancer in the last decade, further research into new drugs and combination therapies is needed to extend the clinical benefits and improve outcomes in lung cancer. In this review article, we discussed common lung cancer treatments and their combinations from the most advanced to the newest.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

A novel GSH-activable theranostic probe containing kinase inhibitor for synergistic treatment and selective imaging of tumor cells

Theranostic probe is becoming a powerful tool for diagnosis and treatment of cancer. Although some theranostic probes have been successfully developed, there is still a great room for improvement in sensitive diagnosis and efficient treatment. Herein, we developed a novel GSH-activable theranostic probe NC-G, which uses 1,8-naphthalimide-4-sulfonamide as a fluorescence imaging group and crizotinib as a highly toxic kinase inhibitor to tumor cells. The probe not only has high sensitivity (DL = 74 nM) and specificity, but also can detect GSH sensitively in cells and zebrafish. In addition, probe NC-G can not only show more obvious fluorescence in tumor cells to achieve sensitive diagnosis of tumor cells, but also release the inhibitor crizotinib to achieve high toxicity to tumor cells. It is worth noting that the consumption of GSH can cause oxidative stress response of cells and the release of SO₂ can induce cell apoptosis during the recognition process of the probe and GSH. Thus, the synergistic effect of crizotinib, GSH depletion, and SO₂ release provides a highly effective therapeutic feature for tumor cells. Therefore, probe NC-G can serve as an excellent theranostic probe for sensitive imaging and highly effective treatment of tumor cells.

MET Amplification as a Resistance Driver to TKI Therapies in Lung Cancer: Clinical Challenges and Opportunities

Targeted therapy has emerged as an important pillar for the standard of care in oncogene-driven non-small cell lung cancer (NSCLC), which significantly improved outcomes of patients whose tumors harbor oncogenic driver mutations. However, tumors eventually develop resistance to targeted drugs, and mechanisms of resistance can be diverse. MET amplification has been proven to be a driver of resistance to tyrosine kinase inhibitor (TKI)-treated advanced NSCLC with its activation of EGFR, ALK, RET, and ROS-1 alterations. The combined therapy of MET-TKIs and EGFR-TKIs has shown outstanding clinical efficacy in EGFR-mutated NSCLC with secondary MET amplification-mediated resistance in a series of clinical trials. In this review, we aimed to clarify the underlying mechanisms of MET amplification-mediated resistance to tyrosine kinase inhibitors, discuss the ways and challenges in the detection and diagnosis of MET amplifications in patients with metastatic NSCLC, and summarize the recently published clinical data as well as ongoing trials of new combination strategies to overcome MET amplification-mediated TKI resistance.

To Investigate Growth Factor Receptor Targets and Generate Cancer Targeting Inhibitors

Receptor tyrosine kinase (RTK) regulates multiple pathways, including Mitogenactivated protein kinases (MAPKs), PI3/AKT, JAK/STAT pathway, etc. which has a significant role in the progression and metastasis of tumor. As RTK activation regulates numerous essential bodily processes, including cell proliferation and division, RTK dysregulation has been identified in many types of cancers. Targeting RTK is a significant challenge in cancer due to the abnormal upregulation and downregulation of RTK receptors subfamily EGFR, FGFR, PDGFR, VEGFR, and HGFR in the progression of cancer, which is governed by multiple RTK receptor signalling pathways and impacts treatment response and disease progression. In this review, an extensive focus has been carried out on the normal and abnormal signalling pathways of EGFR, FGFR, PDGFR, VEGFR, and HGFR and their association with cancer initiation and progression. These are explored as potential therapeutic cancer targets and therefore, the inhibitors were evaluated alone and merged with additional therapies in clinical trials aimed at combating global cancer.

Drug Resistance in Cancers: A Free Pass for Bullying

The cancer burden continues to grow globally, and drug resistance remains a substantial challenge in cancer therapy. It is well established that cancerous cells with clonal dysplasia generate the same carcinogenic lesions. Tumor cells pass on genetic templates to subsequent generations in evolutionary terms and exhibit drug resistance simply by accumulating genetic alterations. However, recent evidence has implied that tumor cells accumulate genetic alterations by progressively adapting. As a result, intratumor heterogeneity (ITH) is generated due to genetically distinct subclonal populations of cells coexisting. The genetic adaptive mechanisms of action of ITH include activating "cellular plasticity", through which tumor cells create a tumor-supportive microenvironment in which they can proliferate and cause increased damage. These highly plastic cells are located in the tumor microenvironment (TME) and undergo extreme changes to resist therapeutic drugs. Accordingly, the underlying mechanisms involved in drug resistance have been re-evaluated. Herein, we will reveal new themes emerging from initial studies of drug resistance and outline the findings regarding drug resistance from the perspective of the TME; the themes include exosomes, metabolic reprogramming, protein glycosylation and autophagy, and the relates studies aim to provide new targets and strategies for reversing drug resistance in cancers.

Rectal administration of butyrate ameliorates pulmonary fibrosis in mice through induction of hepatocyte growth factor in the colon via the HDAC-PPARγ pathway

Butyrate, given by oral administration or in drinking water, has been shown to improve experimental pulmonary fibrosis (PF) in mice despite of very low bioavailability. The pharmacokinetic-pharmacodynamics disconnection attracts us to explore its anti-PF mechanism in view of the intestinal expression of anti-PF factors. In bleomycin-induced PF in mice, rectal administration of butyrate (500 mg/kg) exhibited a significant anti-PF effect, with a maximum plasma concentration largely lower than the minimum effective concentration (1 mM) at which butyrate inhibited the expression of pro-inflammatory factors by lung epithelial cells and the production of extracellular matrix by lung fibroblasts. The rectal administration of butyrate significantly upregulated the mRNA expression of hepatocyte growth factor (HGF) in the colons of PF mice, but showed no significant effect on the mRNA expression of HGF in the small intestines, lungs and livers. In colon epithelial cells, the monocarboxylate transporter inhibitor α-cyano-4-hydroxycinnamic acid (CHC) abrogated butyrate-induced expression of HGF, indicating that butyrate functions through entering into cells. Butyrate showed no significant effect on the histone acetylation in the promoter region of HGF, suggesting that it promotes HGF expression not by directly affecting the histone deacetylation of HGF but by other pathways. GW9662, the inhibitor of PPARγ, significantly attenuated the effect of butyrate to promote the mRNA expression of HGF. Butyrate was able to enhance the acetylation of PPARγ, and a targeted mutation of lysine at the position 240 (K240) of PPARγ markedly diminished the induction of butyrate on HGF expression, suggesting that butyrate promoted HGF expression in colon epithelial cells by upregulating PPARγ K240 acetylation. In summary, rectal administration of butyrate promotes the expression of HGF in colonic epithelial cells through upregulating PPARγ acetylation via inhibition of HDAC activity. The findings of the present study provide a reasonable explanation for the anti-PF action mode of butyrate based on the 'lung-gut axis', and found that intestine-derived butyrate and HGF may be involved in the modulation of the occurrence and progression of PF.

Anti-cancer therapeutic strategies based on HGF/MET, EpCAM, and tumor-stromal cross talk

As an intelligent disease, tumors apply several pathways to evade the immune system. It can use alternative routes to bypass intracellular signaling pathways, such as nuclear factor-κB (NF-κB), Wnt, and mitogen-activated protein (MAP)/phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR). Therefore, these mechanisms lead to therapeutic resistance in cancer. Also, these pathways play important roles in the proliferation, survival, migration, and invasion of cells. In most cancers, these signaling pathways are overactivated, caused by mutation, overexpression, etc. Since numerous molecules share these signaling pathways, the identification of key molecules is crucial to achieve favorable consequences in cancer therapy. One of the key molecules is the mesenchymal-epithelial transition factor (MET; c-Met) and its ligand hepatocyte growth factor (HGF). Another molecule is the epithelial cell adhesion molecule (EpCAM), which its binding is hemophilic. Although both of them are involved in many physiologic processes (especially in embryonic stages), in some cancers, they are overexpressed on epithelial cells. Since they share intracellular pathways, targeting them simultaneously may inhibit substitute pathways that tumor uses to evade the immune system and resistant to therapeutic agents.

Recent advances in targeted drug delivery systems for resistant colorectal cancer

Colorectal cancer (CRC) is one of the deadliest cancers in the world, the incidences and morality rate are rising and poses an important threat to the public health. It is known that multiple drug resistance (MDR) is one of the major obstacles in CRC treatment. Tumor microenvironment plus genomic instability, tumor derived exosomes (TDE), cancer stem cells (CSCs), circulating tumor cells (CTCs), cell-free DNA (cfDNA), as well as cellular signaling pathways are important issues regarding resistance. Since non-targeted therapy causes toxicity, diverse side effects, and undesired efficacy, targeted therapy with contribution of various carriers has been developed to address the mentioned shortcomings. In this paper the underlying causes of MDR and then various targeting strategies including exosomes, liposomes, hydrogels, cell-based carriers and theranostics which are utilized to overcome therapeutic resistance will be described. We also discuss implication of emerging approaches involving single cell approaches and computer-aided drug delivery with high potential for meeting CRC medical needs.

Intercellular Communication-Related Molecular Subtypes and a Gene Signature Identified by the Single-Cell RNA Sequencing Combined with a Transcriptomic Analysis

Background. The tumor microenvironment (TME) of lung adenocarcinoma (LUAD) comprise various cell types that communicate with each other through ligand-receptor interactions. This study focused on the identification of cell types in LUAD by single-cell RNA sequencing (scRNA-seq) data and screening of intercellular communication-related genes. Methods. The Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/geo) provided the RNA-seq data of LUAD patients in the GSE149655, GSE31210, and GSE72094 datasets. Quality control of the scRNA-seq data in GSE149655 was performed by the Seurat package (http://seurat.r-forge.r-project.org) for identifying highly variable genes for principal component analysis (PCA) and cell clustering. The CellPhoneDB (http://www.cellphonedb.org) was used for filtering intercellular communication-related ligand-receptor pairs. According to ligand and receptor expressions, LUAD samples were clustered using ConsensusClusterPlus (https://www.bioconductor.org/packages/release/bioc/html/ConsensusClusterPlus). Additionally, the identification of prognosis-related ligand and receptor genes was conducted along with the development of a risk prediction model by the least absolute shrinkage and selection operator (LASSO) Cox regression analysis. Results. This study identified twelve cell types in 8170 cells of LUAD tissues along with 219 ligand and receptor genes. LUAD was classified into three different molecular subtypes, among which cluster 3 (C3) had the longest overall survival (OS) time and cluster (C1) had the shortest OS time. In comparison with the other two molecular subtypes, it was observed that C1 had a higher rate of somatic mutations and lower levels of infiltrating immune cells and immune scores. Ten genes were screened from the total ligand and receptor genes to construct a risk model, which showed a strong prediction power in the prognosis of patients with LUAD. Conclusion. The results of this study revealed cell types specific to LUAD, which were classified into different molecular subtypes according to intercellular communication-related genes. A novel prognostic risk model was developed in this study, providing new insights into prognostic assessment models for LUAD.

c-Met specific CAR-T cells as a targeted therapy for non-small cell lung cancer cell A549

Non-small cell lung cancer (NSCLC) is considered to be one of the most prevalent and fatal malignancies, with a poor survival rate. Chimeric antigen receptor T cell (CAR-T) cell therapy is one of the most exciting directions in the field of Cellular immunotherapy. Therefore, CAR-T cells that target c-Met have been developed for use in NSCLC therapy and might be a potential therapeutic strategy. The anti c-Met ScFv structure was fused with the transmembrane and intracellular domains. Using a lentiviral vector to load the c-Met CAR gene, then transfected the c-Met CAR lentiviral into human T cells to obtain the second generation c-Met CAR-T expressing CARs stably. In vitro co-culture, experiments revealed that CAR-T cells have high proliferative activity and the potential to secrete cytokines (IL-2, TNF-α, and IFN-γ). c-Met CAR-T cells showed special cellular cytotoxicity in LDH release assay. A subcutaneous tumor model in nude mice was used to test the anticancer effectiveness of c-Met CAR-T cells in vivo. For c-Met positive NSCLC tissue, according to tumor volume, weight, fluorescence intensity, and immunohistochemical detection, c-Met CAR-T cells had stronger tumor growth suppression compared to untransduced T cells. HE staining revealed that c-Met CAR-T cells did not produced side effects in nude mice. Taken together, we provided useful method to generate c-Met CAR- T cells, which exhibit enhanced cytotoxicity against NSCLC cells in vitro and in vivo. Thus, providing a new therapeutic avenue for treating NSCLC clinically.

Highlights

(1) c-Met CAR-T capable of stably expressing c-Met CARs were constructed.

(2) c-Met CAR-T have strong anti-tumor ability and proliferation ability in vitro.

(3) c-Met CAR-T can effectively inhibit the growth of A549 cells subcutaneous xenografts.

Mesenchymal Epithelial Transition Factor (MET): A Key Player in Chemotherapy Resistance and an Emerging Target for Potentiating Cancer Immunotherapy

The MET protein is a cell surface receptor tyrosine kinase predominately expressed in epithelial cells. Upon binding of its only known ligand, hepatocyte growth factor (HGF), MET homodimerizes, phosphorylates, and stimulates intracellular signalling to drive cell proliferation. Amplification or hyperactivation of MET is frequently observed in various cancer types and it is associated with poor response to conventional and targeted chemotherapy. More recently, emerging evidence also suggests that MET/HGF signalling may play an immunosuppressive role and it could confer resistance to cancer immunotherapy. In this review, we summarized the preclinical and clinical evidence of MET's role in drug resistance to conventional chemotherapy, targeted therapy, and immunotherapy. Previous clinical trials investigating MET-targeted therapy in unselected or MET-overexpressing cancers yielded mostly unfavourable results. More recent clinical studies focusing on MET exon 14 alterations and MET amplification have produced encouraging treatment responses to MET inhibitor therapy. The translational relevance of MET inhibitor therapy to overcome drug resistance in cancer patients is discussed.

Multifaceted Interplay between Hormones, Growth Factors and Hypoxia in the Tumor Microenvironment

Hormones and growth factors (GFs) are signaling molecules implicated in the regulation of a variety of cellular processes. They play important roles in both healthy and tumor cells, where they function by binding to specific receptors on target cells and activating downstream signaling cascades. The stages of tumor progression are influenced by hormones and GF signaling. Hypoxia, a hallmark of cancer progression, contributes to tumor plasticity and heterogeneity. Most solid tumors contain a hypoxic core due to rapid cellular proliferation that outgrows the blood supply. In these circumstances, hypoxia-inducible factors (HIFs) play a central role in the adaptation of tumor cells to their new environment, dramatically reshaping their transcriptional profile. HIF signaling is modulated by a variety of factors including hormones and GFs, which activate signaling pathways that enhance tumor growth and metastatic potential and impair responses to therapy. In this review, we summarize the role of hormones and GFs during cancer onset and progression with a particular focus on hypoxia and the interplay with HIF proteins. We also discuss how hypoxia influences the efficacy of cancer immunotherapy, considering that a hypoxic environment may act as a determinant of the immune-excluded phenotype and a major hindrance to the success of adoptive cell therapies.

Dictamnine, a novel c-Met inhibitor, suppresses the proliferation of lung cancer cells by downregulating the PI3K/AKT/mTOR and MAPK signaling pathways

Dictamnine (Dic), a naturally occurring small-molecule furoquinoline alkaloid isolated from the root bark of Dictamnus dasycarpus Turcz., is reported to display anticancer properties. However, little is known about the direct target proteins and anticancer mechanisms of Dic. In the current study, Dic was found to suppress the growth of lung cancer cells in vitro and in vivo, and to attenuate the activation of PI3K/AKT/mTOR and mitogen-activated protein kinase (MAPK) signaling pathways by inhibiting the phosphorylation and activation of receptor tyrosine kinase c-Met. Moreover, the binding of Dic to c-Met was confirmed by using cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) assay. Among all cancer cell lines tested, Dic inhibited the proliferation of c-Met-dependent EBC-1 cells with the greatest potency (IC50 = 2.811 μM). Notably, Dic was shown to synergistically improve the chemo-sensitivity of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-resistant lung cancer cells to gefitinib and osimertinib. These results suggest that Dic is a c-Met inhibitor that can serve as a potential therapeutic agent in the treatment of lung cancer, especially against EGFR TKI-resistant and c-Met-dependent lung cancer.

Roles of MET in human cancer

The MET proto-oncogene was first identified in osteosarcoma cells exposed to carcinogens. Although expressed in many normal cells, MET is overexpressed in many human cancers. MET is involved in the initiation and development of various human cancers and mediates proliferation, migration and invasion. Accordingly, MET has been successfully used as a biomarker for diagnosis and prognosis, survival, post-operative recurrence, risk assessment and pathologic grading, as well as a therapeutic target. In addition, recent work indicates that inhibition of MET expression and function has potential clinical benefit. This review summarizes the role, mechanism, and clinical significance of MET in the formation and development of human cancer.

Correlation of MET-Receptor Overexpression with MET Gene Amplification and Patient Outcome in Malignant Mesothelioma

Thanks to clinically newly introduced inhibitors of the mesenchymal–epithelial transition (MET) receptor tyrosine-kinase, MET-gene copy number gain/amplification (MET-GCNG/GA) and increased expression of the MET protein are considered very promising therapeutic targets in lung cancer and other malignancies. However, to which extent these MET alterations occur in malignant mesothelioma (MM) remains unclear. Thus, we investigated by well-established immunohistochemistry and fluorescence in situ hybridization methods, the frequency of these alterations in specimens from 155 consecutive MMs of different subtypes obtained from pleural or peritoneal biopsies and pleurectomies. Thirty-three benign reactive mesothelial proliferations (RMPs) were used as controls. MET-protein upregulation was observed in 35% of all MM-cases, though restricted to predominantly epithelioid MMs. We detected low-/intermediate-level MET-GCNG/GA in 22.2% of MET-overexpressing MMs (7.8% of whole MM-cohort) and no MET-GCNG/GA in the other 77.8%, suggesting other upregulating mechanisms. In contrast, 100% of RMPs exhibited no MET-upregulation or MET-GCNG/-GA. Neither MET exon 14 skipping mutations nor MET-fusions were detected as mechanisms of MET overexpression in MM using RNA next-generation sequencing. Finally, in two cohorts of 30 MM patients with or without MET overexpression (MET-positive/-negative) that were matched for several variables and received the same standard chemotherapy, the MET-positive cases showed a significantly lower response rate, but no significant difference in progression-free or overall survival. Our results imply that MET overexpression occurs in a substantial fraction of predominantly epithelioid MMs, but correlates poorly with MET-amplification status, and may impact the likelihood of response to mesothelioma standard chemotherapy. The predictive significance of MET-IHC and -FISH for possible MET-targeted therapy of MM remains to be elucidated.

The Role of HGF/MET Signaling in Metastatic Uveal Melanoma

Simple Summary

Hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) signaling plays an important role in the metastatic formation and therapeutic resistance to uveal melanoma. Here, we review the various functions of MET signaling contributing to metastatic formation, as well as review resistance to treatments in metastatic uveal melanoma.

Abstract

Hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) signaling promotes tumorigenesis and tumor progression in various types of cancer, including uveal melanoma (UM). The roles of HGF/MET signaling have been studied in cell survival, proliferation, cell motility, and migration. Furthermore, HGF/MET signaling has emerged as a critical player not only in the tumor itself but also in the tumor microenvironment. Expression of MET is frequently observed in metastatic uveal melanoma and is associated with poor prognosis. It has been reported that HGF/MET signaling pathway activation is the major mechanism of treatment resistance in metastatic UM (MUM). To achieve maximal therapeutic benefit in MUM patients, it is important to understand how MET signaling drives cellular functions in uveal melanoma cells. Here, we review the HGF/MET signaling biology and the role of HGF/MET blockades in uveal melanoma.

Upregulation of Linc00284 Promotes Lung Cancer Progression by Regulating the miR-205-3p/c-Met Axis

Lung cancer (LC) is a malignant tumor with the highest incidence and mortality rates worldwide. Linc00284, a long non-coding RNA, is a newly discovered regulator of LC. This study aimed to explore the role of Linc00284 in LC progression. Gene expression levels were detected by RT-qPCR and/or western blot analysis. Cell migratory and invasive capabilities were measured by wound healing and transwell assays. Subcutaneous xenograft models were constructed to examine tumor growth of LC cells. Data showed that Linc00284 was significantly upregulated in LC tissues compared to adjacent normal lung tissues and predicted poor prognosis in patients with LC. In vitro, Linc00284 was highly expressed in LC cells and was mainly localized in the cytoplasm. Mechanistically, Linc00284 directly bound to miR-205-3p, leading to the upregulation of c-Met expression. A significant negative correlation was observed between Linc00284 and miR-205-3p expression levels, and the Linc00284 level was positively correlated with the c-Met expression. Linc00284/miR-205-3p/c-Met regulatory axis promotes LC cell proliferation, migration, and invasion. Furthermore, the in vivo results indicated that Linc00284 knockdown markedly suppressed tumor growth. Taken together, these data suggest that Linc00284 facilitates LC progression by targeting the miR-205-3p/c-Met axis, which may be a potential target for LC treatment.

Computational study on novel natural inhibitors targeting c-MET

This study was designed to select ideal lead compounds and preclinical drug candidates http://dict.youdao.com/w/eng/preclinical_drug_candidate/javascript:void (0); with inhibitory effect on c-MET from the drug library (ZINC database).A battery of computer-aided virtual techniques was used to identify possible inhibitors of c-MET. A total of 17,931 ligands were screened from the ZINC15 database. LibDock is applied for structure-based screening followed by absorption, distribution, metabolic, and excretion, and toxicity prediction. Molecular docking was conducted to confirm the binding affinity mechanism between the ligand and c-MET. Molecular dynamics simulations were used to assess the stability of ligand-c-MET complexes.Two new natural compounds ZINC000005879645 and ZINC000002528509 were found to bind to c-MET in the ZINC database, showing higher binding affinity. In addition, they were predicted to have lower rodent carcinogenicity, Ames mutagenicity, developmental toxicity potential, and high tolerance to cytochrome P4502D6. Molecular dynamics simulation shows that ZINC000005879645 and ZINC000002528509 have more favorable potential energies with c-MET, which could exist stably in the natural environment.This study suggests that ZINC000005879645 and ZINC000002528509 are ideal latent inhibitors of c-MET targeting. As drug candidates, these 2 compounds have low cytotoxicity and hepatotoxicity as well as important implications for the design and improvement of c-MET target drugs.

Once-daily savolitinib in Chinese patients with pulmonary sarcomatoid carcinomas and other non-small-cell lung cancers harbouring MET exon 14 skipping alterations: a multicentre, single-arm, open-label, phase 2 study

BACKGROUND

Savolitinib is a selective MET tyrosine-kinase inhibitor. We investigated the activity and safety of savolitinib in patients with pulmonary sarcomatoid carcinoma and other non-small-cell lung cancer (NSCLC) subtypes positive for MET exon 14 skipping alterations (METex14-positive).

METHODS

We did a multicentre, single-arm, open-label, phase 2 study across 32 hospitals in China. Eligible patients were 18 years or older with locally advanced or metastatic METex14-positive pulmonary sarcomatoid carcinoma or other NSCLC subtypes, had either presented with disease progression or toxicity intolerance towards one or more standard treatments or were deemed clinically unsuitable for standard treatment, were MET inhibitor-naive, and had measurable disease. Patients received either 600 mg (bodyweight ≥50 kg) or 400 mg (bodyweight <50 kg) of oral savolitinib once daily until disease progression, death, intolerable toxicity, initiation of other anti-tumour therapy, non-compliance, patient withdrawal, or patient discontinuation. Radiographic tumour evaluation was done at baseline, every 6 weeks within 1 year of the first dose, and every 12 weeks thereafter. The primary endpoint was objective response rate, defined as the proportion of patients with confirmed complete or partial responses by independent review committee (IRC) assessment. The primary endpoint was assessed in the tumour response evaluable set, which comprised all treated patients with a measurable lesion at baseline and at least one adequate scheduled post-baseline tumour assessment or the presence of radiological disease progression, with a sensitivity analysis done in the full analysis set, which comprised all patients who received at least one dose of savolitinib. Safety was also evaluated in the full analysis set. This study is registered with ClinicalTrials.gov, NCT02897479, and recruitment is complete, with treatment and follow-up ongoing.

FINDINGS

From Nov 8, 2016, to Aug 3, 2020, 84 patients with METex14 skipping alterations were screened for eligibility, of whom 70 were enrolled, received savolitinib, and comprised the full analysis set. The IRC-assessed tumour response evaluable set comprised 61 patients. At a median follow-up of 17·6 months (IQR 14·2-24·4), the IRC-assessed objective response rate was 49·2% (36·1-62·3; 30 of 61 patients) in the tumour response evaluable set and 42·9% (95% CI 31·1-55·3; 30 of 70 patients) in the full analysis set. All 70 patients reported at least one treatment-related adverse event. Treatment-related adverse events of grade 3 or more occurred in 32 (46%) patients, the most frequent of which were increased aspartate aminotransferase (n=9), increased alanine aminotransferase (n=7), and peripheral oedema (n=6). Treatment-related serious adverse events occurred in 17 (24%) patients, the most common being abnormal hepatic function (n=3) and hypersensitivity (n=2). One death due to tumour lysis syndrome in a patient with pulmonary sarcomatoid carcinoma was assessed to be probably related to savolitinib by the investigator.

INTERPRETATION

Savolitinib yielded promising activity and had an acceptable safety profile in patients with pulmonary sarcomatoid carcinoma and other NSCLC subtypes positive for METex14 skipping alterations. Savolitinib could therefore be a novel treatment option in this population.

FUNDING

Hutchison MediPharma and AstraZeneca.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

[Progress on Mechanism of MET Gene Mutation and Targeted Drugs in Non-small Cell Lung Cancer]

间质-上皮细胞转化因子（mesenchymal-epithelial transition factor, MET）基因是非小细胞肺癌（non-small cell lung cancer, NSCLC）的一种重要肿瘤驱动基因，针对MET 14外显子的跳跃突变的靶向治疗药物给患者带来新的希望。目前已经上市或者即将上市的MET抑制剂包括：克唑替尼、卡博替尼、沃利替尼和Tepotinib等。MET抑制剂的客观缓解率较高，并且安全性良好。但是，MET抑制剂的耐药不可避免，因此需要重视对于耐药机制的研究。肝细胞生长因子（hepatocyte growth factor, HGF）/MET信号通路抑制剂与其他药物的联合应用，对于抑制和逆转耐药可能发挥重要作用。

Pharmacological Activities and Mechanisms of Hirudin and Its Derivatives - A Review

Hirudin, an acidic polypeptide secreted by the salivary glands of Hirudo medicinalis (also known as "Shuizhi" in traditional Chinese medicine), is the strongest natural specific inhibitor of thrombin found so far. Hirudin has been demonstrated to possess potent anti-thrombotic effect in previous studies. Recently, increasing researches have focused on the anti-thrombotic activity of the derivatives of hirudin, mainly because these derivatives have stronger antithrombotic activity and lower bleeding risk. Additionally, various bioactivities of hirudin have been reported as well, including wound repair effect, anti-fibrosis effect, effect on diabetic complications, anti-tumor effect, anti-hyperuricemia effect, effect on cerebral hemorrhage, and others. Therefore, by collecting and summarizing publications from the recent two decades, the pharmacological activities, pharmacokinetics, novel preparations and derivatives, as well as toxicity of hirudin were systematically reviewed in this paper. In addition, the clinical application, the underlying mechanisms of pharmacological effects, the dose-effect relationship, and the development potential in new drug research of hirudin were discussed on the purpose of providing new ideas for application of hirudin in treating related diseases.

Combined Treatment of Cinobufotalin and Gefitinib Exhibits Potent Efficacy against Lung Cancer

This study aimed to evaluate the efficacy of cinobufotalin combined with gefitinib in the treatment of lung cancer. A549 cells were treated with gefitinib, cinobufotalin, or cinobufotalin plus gefitinib. MTT assay, annexin-V/PI staining and flow cytometry, TUNEL staining, DCFH-DA staining, Western blot, and real-time RT-PCR were performed to investigate the synergistic inhibitory effect of cinobufotalin combined with gefitinib on the growth of A549 cells. Results showed that cinobufotalin synergized with gefitinib displayed inhibited cell viability and enhanced apoptosis in the combination group. Cinobufotalin combined with gefitinib induced a significant enhancement in reactive oxygen species (ROS) production accompanied by cell cycle arrest in the S phase arrest, characterized by upregulation of p21 and downregulation of cyclin A, cyclin E, and CDK2. Besides, cinobufotalin plus gefitinib downregulated the levels of HGF and c-Met. In summary, cinobufotalin combined with gefitinib impedes viability and facilitates apoptosis of A549 cells, indicating that the combined therapy might be a new promising treatment for lung cancer patients who are resistant to gefitinib.

Phase I results of S49076 plus gefitinib in patients with EGFR TKI-resistant non-small cell lung cancer harbouring MET/AXL dysregulation

BACKGROUND

MET and AXL dysregulation is reported as a bypass mechanism driving tumour progression in non-small cell lung cancer (NSCLC) with acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). This non-comparative phase I study investigated the combination of gefitinib with S49076, a MET/AXL inhibitor, in advanced EGFR TKI-resistant NSCLC patients with MET and/or AXL dysregulation.

METHODS

Patients received S49076 at escalating doses of 500 or 600 mg with a fixed dose of 250 mg gefitinib orally once daily in continuous 28day cycles. MET and AXL dysregulation and EGFR/T790M mutation status were centrally assessed in tumour biopsies at screening. Tumour response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST). EGFR TKI resistance mechanisms were analysed by next-generation sequencing. The clonal evolution of tumours was monitored with the analysis of circulating tumour DNA.

RESULTS

Of 92 pre-screened patients, 22 met the molecular inclusion criteria and 14 were included. The recommended dose was 600 mg daily S49076. Best overall responses were 2 partial responses (1 patient with MET dysregulation only, 1 MET and AXL co-dysregulation) and 8 patients with stable disease. Other potential concomitant mechanisms of resistance to EGFR TKI were identified in more than half of the included patients.

CONCLUSIONS

S49076 plus gefitinib demonstrated a good tolerability with limited anti-tumour activity. Due to the low number of eligible patients, no tendency in term of activity appeared in any specific molecular subset and the data did not allow for identification of AXL overexpression as an oncogenic driver.

Imidazopyridine hydrazone derivatives exert antiproliferative effect on lung and pancreatic cancer cells and potentially inhibit receptor tyrosine kinases including c-Met

Aberrant activation of c-Met signalling plays a prominent role in cancer development and progression. A series of 12 imidazo [1,2-α] pyridine derivatives bearing 1,2,3-triazole moiety were designed, synthesized and evaluated for c-Met inhibitory potential and anticancer effect. The inhibitory activity of all synthesized compounds against c-Met kinase was evaluated by a homogeneous time-resolved fluorescence (HTRF) assay at the concentration range of 5-25 µM. Derivatives 6d, 6e and 6f bearing methyl, tertiary butyl and dichloro-phenyl moieties on the triazole ring, respectively, were the compounds with the highest potential. They significantly inhibited c-Met by 55.3, 53.0 and 51.3%, respectively, at the concentration of 25 µM. Synthetic compounds showed antiproliferative effects against lung (EBC-1) and pancreatic cancer cells (AsPc-1, Suit-2 and Mia-PaCa-2) expressing different levels of c-Met, with IC₅₀ values as low as 3.0 µM measured by sulforhodamine B assay. Active derivatives significantly blocked c-Met phosphorylation, inhibited cell growth in three-dimensional spheroid cultures and also induced apoptosis as revealed by Annexin V/propidium iodide flow cytometric assay in AsPc-1 cells. They also inhibited PDGFRA and FLT3 at 25 µM among a panel of 16 kinases. Molecular docking and dynamics simulation studies corroborated the experimental findings and revealed possible binding modes of the select derivatives with target receptor tyrosine kinases. The results of this study show that some imidazopyridine derivatives bearing 1,2,3-triazole moiety could be promising molecularly targeted anticancer agents against lung and pancreatic cancers.

Ursodesoxycholic acid alleviates liver fibrosis via proregeneration by activation of the ID1-WNT2/HGF signaling pathway

BACKGROUND

The human liver possesses a remarkable capacity for self-repair. However, liver fibrosis remains a serious medical concern, potentially progressing to end-stage liver cirrhosis and even death. Liver fibrosis is characterized by excess accumulation of extracellular matrix in response to chronic injury. Liver regenerative ability, a strong indicator of liver health, is important in resisting fibrosis. In this study, we provide evidence that ursodesoxycholic acid (UDCA) can alleviate liver fibrosis by promoting liver regeneration via activation of the ID1-WNT2/hepatocyte growth factor (HGF) pathway.

METHODS

Bile duct ligation (BDL) and partial hepatectomy (PH) mouse models were used to verify the effects of UDCA on liver fibrosis, regeneration, and the ID1-WNT2/HGF pathway. An Id1 knockdown mouse model was also used to assess the role of Id1 in UDCA alleviation of liver fibrosis.

RESULTS

Our results demonstrate that UDCA can alleviate liver fibrosis in the BDL mice and promote liver regeneration via the ID1-WNT2/HGF pathway in PH mice. In addition, Id1 knockdown abolished the protection afforded by UDCA in BDL mice.

CONCLUSIONS

We conclude that UDCA protects against liver fibrosis by proregeneration via activation of the ID1-WNT2/HGF pathway.

Discovery of 4-((4-(4-(3-(2-(2,6-difluorophenyl)-4-oxothiazolidin-3-yl)ureido)-2-fluorophenoxy)-6-methoxyquinolin-7-yl)oxy)-N,N-diethylpiperidine-1-carboxamide as kinase inhibitor for the treatment of colorectal cancer

In this study, a novel series of 4,6,7-trisubstituted quinoline analogues bearing thiazolidinones were designed and synthesized based on our previous study. Among them, the most potent compound 15i, 4-((4-(4-(3-(2-(2,6-difluorophenyl)-4-oxothiazolidin-3-yl)ureido)-2-fluorophenoxy)-6-methoxyquinolin-7-yl)oxy)-N,N-diethylpiperidine-1-carboxamide was identified as a multi-kinase inhibitor. The results of MTT assay revealed in vitro antitumor activities against HT-29 cells of compound 15i with an IC₅₀ value of 0.19 μM which was 14.5-fold more potent than that of Regorafenib. In the cellular context, significant antiproliferation, cytotoxicity and induction of apoptosis on HT-29 cells in a dose- and time-dependent manner were confirmed by IncuCyte live-cell imaging assays. Moreover, compound 15i strongly induced apoptosis by arresting cell cycle into the G2/M phase. No antiproliferation and cytotoxicity against human normal colorectal mucosa epithelial cell FHC was observed at 10.0 μg/mL or lower concentrations which indicated that the toxicity to normal cells of compound 15i was much lower than that of Regorafenib. Based on the above findings, further structural modification will be conducted for the development of more potent kinase inhibitors as anticancer agents.

HDAC1-Smad3-mSin3A complex is required for Smad3-induced transcriptional inhibition of hepatocyte growth factor receptor in human lung cancers

c-Met hyperactivity has been observed in numerous neoplasms. Several researchers have shown that the abnormal activation of c-Met is mainly caused by transcriptional activation. However, the molecular mechanism behind this transcriptional regulation is poorly understood. Here, we suggest that Smad3 negatively regulates the expression and activation of c-Met via a transcriptional mechanism. We explore the molecular mechanisms that underlie Smad3-induced c-Met transcription inhibition. We found in contrast to the high expression of c-Met, Smad3 showed low protein and mRNA levels. Smad3 and c-Met expressions were inconsistent between lung cancer tissues and cell lines. We also found that Smad3 overexpression suppresses whereas Smad3 knockdown significantly promotes Epithelial-Mesenchymal Transition and production of the angiogenic factors VEGF, CTGF and COX-2 through the ERK1/2 pathway. In addition, Smad3 overexpression decreases whereas Smad3 knockdown significantly increases protein and mRNA levels of invasion-related β-catenin and FAK through the PI3K/Akt pathway. Furthermore, using the chromatin immunoprecipitation analysis method, we demonstrate that a transcriptional regulatory complex consisting of HDAC1, Smad3 and mSin3A binds to the promoter of the c-Met gene. By either silencing endogenous mSin3A expression with siRNA or by pretreating cells with a specific HDAC1 inhibitor (MS-275), Smad3-induced transcriptional suppression of c-Met could be effectively attenuated. These results demonstrate that Smad3-induced inhibition of c-Met transcription depends on of a functional transcriptional regulatory complex that includes Smad3, mSin3A and HDAC1 at the c-Met promoter. Collectively, our findings reveal a new regulatory mechanism of c-Met signaling, and suggest a potential molecular target for the development of anticancer drugs.

HGF/c-Met Axis: The Advanced Development in Digestive System Cancer

Numerous studies have indicated that abnormal activation of the HGF/c-Met signaling pathway can lead to cell proliferation, invasiveness, and metastasis of cancers of the digestive system. Moreover, overexpression of c-Met has been implicated in poor prognosis of patients with these forms of cancer, suggesting the possibility for HGF/c-Met axis as a potential therapeutic target. Despite the large number of clinical and preclinical trials worldwide, no significant positive success in the use of anti-HGF/c-Met treatments on cancers of the digestive system has been achieved. In this review, we summarize advanced development of clinical research on HGF/c-Met antibody and small-molecule c-Met inhibitors of cancers of the digestive system and provide a possible direction for future research.

CREB5 promotes invasiveness and metastasis in colorectal cancer by directly activating MET

BACKGROUND

cAMP responsive element binding protein 5 (CREB5) is a transcriptional activator in eukaryotic cells that can regulate gene expression. Previously, we found that CREB5 was involved in the occurrence and development of colorectal cancer (CRC) using bioinformatics analysis. However, the biological roles and underlying regulatory mechanism of CREB5 in CRC remain unclear.

METHODS

Real-time PCR, western blotting, and immunohistochemistry were used to examine CREB5 expression. In vitro experiments including migration assay, wound-healing assay, chicken chorioallantoic membrane assay, and human umbilical vein endothelial cells tube formation assay were used to investigate the effects of CREB5 on CRC cell migration and tumor angiogenesis ability. Additionally, an orthotopic implantation assay was performed in nude mice to confirm the effects of CREB5 in vivo. Furthermore, gene set enrichment analysis was performed to explore the potential mechanism of CREB5 in CRC.

RESULTS

We found that CREB5 expression was highly upregulated in CRC. CREB5 overexpression was positively correlated with advanced WHO stages and TNM stages and shorter survival in CRC patients. Moreover, CREB5 overexpression promoted while CREB5 silencing reduced the invasiveness and metastatic capacity of CRC cells both in vitro and in vivo. Furthermore, CREB5 directly interacted with the MET promoter and activated the hepatocyte growth factor-MET signalling pathway. Importantly, inhibition of MET reduced the invasion and metastasis of CREB5-overexpressing CRC cells, suggesting that CREB5 promotes metastasis mainly through activation of MET signalling.

CONCLUSION

Our study demonstrates a crucial role for CREB5 in CRC metastasis by directly upregulating MET expression. CREB5 may be both a potential prognostic marker and a therapeutic target to effectively overcome metastasis in CRC.

The prognostic value of HGF-c-MET signaling pathway in Gastric Cancer: a study based on TCGA and GEO databases

Gastric cancer is a heterogeneous tumor that underlying molecular mechanisms are largely unclear. This study aimed to elucidate the expression level of HGF-c-MET in gastric cancer patients and to investigate the prognostic and diagnostic value of HGF-c-MET. In silico analysis of the TCGA and GEO database found that HGF and c-MET mRNA expression are significantly higher in gastric cancer tissues than those in peritumor tissues. Both higher mRNA expression of HGF and c-MET were associated with a poorer prognosis. c-MET expression was modulated by methylation in the promoter regions. HGF was positively correlated with CD8+ T cell, CD4+ T cell, macrophage, neutrophil and dendritic cell. Furthermore, functional enrichment analysis and protein-protein interaction networks further shown that HGF-c-MET and related proteins mainly participated in growth factor receptor binding, protein tyrosine kinase activity and signaling receptor binding. Finally, outcome of GSEA analysis showed 13 shared KEGG pathways enriched in high expressed group of HGF and c-MET.

Ab locks for improving the selectivity and safety of antibody drugs

Monoclonal antibodies (mAbs) are a major targeted therapy for malignancies, infectious diseases, autoimmune diseases, transplant rejection and chronic inflammatory diseases due to their antigen specificity and longer half-life than conventional drugs. However, long-term systemic antigen neutralization by mAbs may cause severe adverse events. Improving the selectivity of mAbs to distinguish target antigens at the disease site from normal healthy tissue and reducing severe adverse events caused by the mechanisms-of-action of mAbs is still a pressing need. Development of pro-antibodies (pro-Abs) by installing a protease-cleavable Ab lock is a novel and advanced recombinant Ab-based strategy that efficiently masks the antigen binding ability of mAbs in the normal state and selectively "turns on" the mAb activity when the pro-Ab reaches the proteolytic protease-overexpressed diseased tissue. In this review, we discuss the design and advantages/disadvantages of different Ab lock strategies, focusing particularly on spatial-hindrance-based and affinity peptide-based approaches. We expect that the development of different masking strategies for mAbs will benefit the local reactivity of mAbs at the disease site, increase the therapeutic efficacy and safety of long-term treatment with mAbs in chronic diseases and even permit scientists to develop Ab drugs for formerly undruggable targets and satisfy the unmet medical needs of mAb therapy.

Structural and Functional Insight Into the Glycosylation Impact Upon the HGF/c-Met Signaling Pathway

Upon interactions with its specific ligand hepatocyte growth factor (HGF), the c-Met signal is relayed to series of downstream pathways, exerting essential biological roles. Dysregulation of the HGF-c-Met signaling pathway has been implicated in the onset, progression and metastasis of various cancers, making the HGF-c-Met axis a promising therapeutic target. Both c-Met and HGF undergo glycosylation, which appears to be biologically relevant to their function and structural integrity. Different types of glycoconjugates in the local cellular environment can also regulate HGF/c-Met signaling by distinct mechanisms. However, detailed knowledge pertaining to the glycosylation machinery of the HGF-c-Met axis as well as its potential applications in oncology research is yet to be established. This mini review highlights the significance of the HGF-c-Met signaling pathway in physiological and pathological context, and discusses the molecular mechanisms by which affect the glycosylation of the HGF-c-Met axis. Owing to the crucial role played by glycosylation in the regulation of HGF/c-Met activity, better understanding of this less exploited field may contribute to the development of novel therapeutics targeting glycoepitopes.

(-)-Oleocanthal as a Dual c-MET-COX2 Inhibitor for the Control of Lung Cancer

Lung cancer (LC) represents the topmost mortality-causing cancer in the U.S. LC patients have overall poor survival rate with limited available treatment options. Dysregulation of the mesenchymal epithelial transition factor (c-MET) and cyclooxygenase 2 (COX2) initiates aggressive LC profile in a subset of patients. The Mediterranean extra-virgin olive oil (EVOO)-rich diet already documented to reduce multiple malignancies incidence. (-)-Oleocanthal (OC) is a naturally occurring phenolic secoiridoid exclusively occurring in EVOO and showed documented anti-breast and other cancer activities via targeting c-MET. This study shows the novel ability of OC to suppress LC progression and metastasis through dual targeting of c-MET and COX-2. Western blot analysis and COX enzymatic assay showed significant reduction in the total and activated c-MET levels and inhibition of COX1/2 activity in the lung adenocarcinoma cells A549 and NCI-H322M, in vitro. In addition, OC treatment caused a dose-dependent inhibition of the HGF-induced LC cells migration. Daily oral treatment with 10 mg/kg OC for 8 weeks significantly suppressed the LC A549-Luc progression and prevented metastasis to brain and other organs in a nude mouse tail vein injection model. Further, microarray data of OC-treated lung tumors showed a distinct gene signature that confirmed the dual targeting of c-MET and COX2. Thus, the EVOO-based OC is an effective lead with translational potential for use as a prospective nutraceutical to control LC progression and metastasis.

Open-label, single-center, phase I trial to investigate the mass balance and absolute bioavailability of the highly selective oral MET inhibitor tepotinib in healthy volunteers

Tepotinib (MSC2156119J) is an oral, potent, highly selective MET inhibitor. This open-label, phase I study in healthy volunteers (EudraCT 2013-003226-86) investigated its mass balance (part A) and absolute bioavailability (part B). In part A, six participants received tepotinib orally (498 mg spiked with 2.67 MBq [¹⁴C]-tepotinib). Blood, plasma, urine, and feces were collected up to day 25 or until excretion of radioactivity was <1% of the administered dose. In part B, six participants received 500 mg tepotinib orally as a film-coated tablet, followed by an intravenous [¹⁴C]-tepotinib tracer dose (53–54 kBq) 4 h later. Blood samples were collected until day 14. In part A, a median of 92.5% (range, 87.1–96.9%) of the [¹⁴C]-tepotinib dose was recovered in excreta. Radioactivity was mainly excreted via feces (median, 78.7%; range, 69.4–82.5%). Urinary excretion was a minor route of elimination (median, 14.4% [8.8–17.7%]). Parent compound was the main constituent in excreta (45% [feces] and 7% [urine] of the radioactive dose). M506 was the only major metabolite. In part B, absolute bioavailability was 72% (range, 62–81%) after oral administration of 500 mg tablets (the dose and formulation used in phase II trials). In conclusion, tepotinib and its metabolites are mainly excreted via feces; parent drug is the major eliminated constituent. Oral bioavailability of tepotinib is high, supporting the use of the current tablet formulation in clinical trials. Tepotinib was well tolerated in this study with healthy volunteers.

Acquired resistance to targeted therapies in NSCLC: Updates and evolving insights

While significant advancements have been made in the available therapies for metastatic non-small cell lung cancer (NSCLC), acquired resistance remains a major barrier to treatment. We have not yet achieved the ability to cure advanced NSCLC with systemic therapy, despite our growing understanding of many of the oncogenic drivers of this disease. Rather, the emergence of drug-tolerant and drug-resistant cells remains the rule, even in the face of increasingly potent targeted therapies. In this review, we provide a broad overview of the mechanisms of resistance to targeted therapy that have been demonstrated across molecular subtypes of NSCLC, highlighting the dynamic interplay between driver oncogene, bypass signaling pathways, shifting cellular phenotypes, and surrounding tumor microenvironment.

Large-Scale Virtual Screening Against the MET Kinase Domain Identifies a New Putative Inhibitor Type

By using an ensemble-docking strategy, we undertook a large-scale virtual screening campaign in order to identify new putative hits against the MET kinase target. Following a large molecular dynamics sampling of its conformational space, a set of 45 conformers of the kinase was retained as docking targets to take into account the flexibility of the binding site moieties. Our screening funnel started from about 80,000 chemical compounds to be tested in silico for their potential affinities towards the kinase binding site. The top 100 molecules selected—thanks to the molecular docking results—were further analyzed for their interactions, and 25 of the most promising ligands were tested for their ability to inhibit MET activity in cells. F0514-4011 compound was the most efficient and impaired this scattering response to HGF (Hepatocyte Growth Factor) with an IC50 of 7.2 μM. Interestingly, careful docking analysis of this molecule with MET suggests a possible conformation halfway between classical type-I and type-II MET inhibitors, with an additional region of interaction. This compound could therefore be an innovative seed to be repositioned from its initial antiviral purpose towards the field of MET inhibitors. Altogether, these results validate our ensemble docking strategy as a cost-effective functional method for drug development.