Targeting MET amplification in EGFR-mutant non-small-cell lung cancer

Reversing MET-Mediated Resistance in Oncogene-Driven NSCLC by MET-Activated Wnt Condensative Prodrug

The amplification of MET is a major cause of acquired resistance to targeted therapy in EGFR-mutant non-small-cell lung cancer (NSCLC), only to be temporarily restrained by the partial efficacy of MET inhibitors. This study reveals that the MET inhibitor has unexpectedly limited efficacy due to amplified MET triggering a strong positive feedback loop in the Wnt/β-catenin signaling pathway, allowing optimal functionality even when the MET pathway is suppressed again. To test this conjecture and specifically target the Wnt/β-catenin pathway, a cleverly designed Wnt condensative pro drug called WntSI is developed using reversible supramolecular self-assembly driven by liquidliquid phase separation (LLPS). This process involves a MET/pH-responsive peptide (Tyr-Pep) and a potent Wnt inhibitor known as CA. Upon recognition and phosphorylation of Tyr-Pep by over expressed MET in cells, it disrupts LLPS propensity and facilitates the disintegration of WntSI. Consequently,this enables it to suppress the carcinogenic effect mediated by β-catenin,effectively overcoming acquired resistance to EGFR-TKIs caused by MET amplification in both cell line-derived and patient-derived tumor xenograft (PDX) mouse models while maintaining exceptional biosecurity. This effective strategy not only suppresses the Wnt/β-catenin signaling pathway selectively, but also serves as an innovative example for pro-drug development through biologically responsive LLPS.

Recent Advances in Lung Cancer Therapy Based on Nanomaterials: A Review

Lung cancer is one of the commonest cancers with a significant mortality rate for both genders, particularly in men. Lung cancer is recognized as one of the leading causes of death worldwide, which threatens the lives of over 1.6 million people every day. Although cancer is the leading cause of death in industrialized countries, conventional anticancer medications are unlikely to increase patients' life expectancy and quality of life significantly. In recent years, there are significant advances in the development and applications of nanotechnology in cancer treatment. The superiority of nanostructured approaches is that they act more selectively than traditional agents. This progress led to the development of a novel field of cancer treatment known as nanomedicine. Various formulations based on nanocarriers, including lipids, polymers, liposomes, nanoparticles and dendrimers have opened new horizons in lung cancer therapy. The application and expansion of nano-agents lead to an exciting and challenging research era in pharmaceutical science, especially for the delivery of emerging anti-cancer agents. The objective of this review is to discuss the recent advances in three types of nanoparticle formulations for lung cancer treatments modalities, including liposomes, polymeric micelles, and dendrimers for efficient drug delivery. Afterward, we have summarized the promising clinical data on nanomaterials based therapeutic approaches in ongoing clinical studies.

From targeted therapy to a novel way: Immunogenic cell death in lung cancer

Lung cancer (LC) is one of the most incident malignancies and a leading cause of cancer mortality worldwide. Common tumorigenic drivers of LC mainly include genetic alterations of EGFR, ALK, KRAS, BRAF, ROS1, and MET. Small inhibitory molecules and antibodies selectively targeting these alterations or/and their downstream signaling pathways have been approved for treatment of LC. Unfortunately, following initial positive responses to these targeted therapies, a large number of patients show dismal prognosis due to the occurrence of resistance mechanisms, such as novel mutations of these genes and activation of alternative signaling pathways. Over the past decade, it has become clear that there is no possible cure for LC unless potent antitumor immune responses are induced by therapeutic intervention. Immunogenic cell death (ICD) is a newly emerged concept, a form of regulated cell death that is sufficient to activate adaptive immune responses against tumor cells. It transforms dying cancer cells into a therapeutic vaccine and stimulates long-lasting protective antitumor immunity. In this review, we discuss the key targetable genetic aberrations and the underlying mechanism of ICD in LC. Various agents inducing ICD are summarized and the possibility of harnessing ICD in LC immunotherapy is further explored.

Small molecule inhibitors targeting the cancers

Compared with traditional therapies, targeted therapy has merits in selectivity, efficacy, and tolerability. Small molecule inhibitors are one of the primary targeted therapies for cancer. Due to their advantages in a wide range of targets, convenient medication, and the ability to penetrate into the central nervous system, many efforts have been devoted to developing more small molecule inhibitors. To date, 88 small molecule inhibitors have been approved by the United States Food and Drug Administration to treat cancers. Despite remarkable progress, small molecule inhibitors in cancer treatment still face many obstacles, such as low response rate, short duration of response, toxicity, biomarkers, and resistance. To better promote the development of small molecule inhibitors targeting cancers, we comprehensively reviewed small molecule inhibitors involved in all the approved agents and pivotal drug candidates in clinical trials arranged by the signaling pathways and the classification of small molecule inhibitors. We discussed lessons learned from the development of these agents, the proper strategies to overcome resistance arising from different mechanisms, and combination therapies concerned with small molecule inhibitors. Through our review, we hoped to provide insights and perspectives for the research and development of small molecule inhibitors in cancer treatment.

Licochalcone A Promotes the Ubiquitination of c-Met to Abrogate Gefitinib Resistance

Met proto-oncogene (MET) amplification and tyrosine-protein kinase Met (c-Met) overexpression confer gefitinib resistance in non-small cell lung cancer (NSCLC). The natural product Licochalcone A (Lico A) exhibits a broad range of inhibitory effects against various tumors. However, the effects of Lico A on c-Met signaling and gefitinib resistance in NSCLC remain unclear. In the present study, Lico A efficiently overcame gefitinib-acquired resistance in NSCLC cells by suppressing c-Met signaling. Lico A decreased cell viability and colony formation dose-dependently and impaired in vivo tumorigenesis of gefitinib-resistant HCC827 and PC-9 cells. Furthermore, Lico A induced intrinsic apoptosis and upregulated the protein expression levels of cleaved poly (ADP-ribose) polymerase and cleaved caspase 3. Lico A promoted the interaction between c-Met and E3 ligase c-Casitas B-lineage lymphoma (Cbl), which enhanced c-Cbl-mediated c-Met ubiquitination and degradation. Depletion of c-Cbl compromised Lico A-induced c-Met ubiquitination and its inhibitory efficacy in gefitinib-resistant NSCLC cells. Taken together, the results suggest that Lico A is a promising antitumor agent that might be used to overcome c-Met overexpression-mediated gefitinib resistance in NSCLC cells.

Methyltransferase SETD2 Inhibits Tumor Growth and Metastasis via STAT1‐IL‐8 signaling mediated EMT in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a major subtype of non–small‐cell lung cancer, which is the leading cause of cancer death worldwide. The histone H3K36 methyltransferase SETD2 has been reported to be frequently mutated or deleted in types of human cancer. However, the functions of SETD2 in tumor growth and metastasis in LUAD has not been well illustrated. Here, we found that SETD2 was significantly downregulated in human lung cancer and greatly impaired proliferation, migration, and invasion in vitro and in vivo. Furthermore, we found that SETD2 overexpression significantly attenuated the epithelial–mesenchymal transition (EMT) of LUAD cells. RNA‐seq analysis identified differentially expressed transcripts that showed an elevated level of interleukin 8 (IL‐8) in STED2‐knockdown LUAD cells, which was further verified using qPCR, western blot, and promoter luciferase report assay. Mechanically, SETD2‐mediated H3K36me3 prevented assembly of Stat1 on the IL‐8 promoter and contributed to the inhibition of tumorigenesis in LUAD. Our findings highlight the suppressive role of SETD2/H3K36me3 in cell proliferation, migration, invasion, and EMT during LUAD carcinogenesis, via regulation of the STAT1–IL‐8 signaling pathway. Therefore, our studies on the molecular mechanism of SETD2 will advance our understanding of epigenetic dysregulation at LUAD progression.

High Circulating Sonic Hedgehog Protein Is Associated With Poor Outcome in EGFR-Mutated Advanced NSCLC Treated With Tyrosine Kinase Inhibitors

Introduction

Growing preclinical evidence has suggested that the Sonic hedgehog (Shh) pathway is involved in resistance to tyrosine kinase inhibitor (TKI) therapy for EGFR-mutated (EGFRm) non-small cell lung cancer (NSCLC). However, little is known concerning the prognostic value of this pathway in this context.

Materials and Methods

We investigated the relationship between plasma levels of Shh and EGFRm NSCLC patients’ outcome with EGFR TKIs. We included 74 consecutive patients from two institutions with EGFRm advanced NSCLC treated by EGFR TKI as first-line therapy. Plasma samples were collected longitudinally for each patient and were analyzed for the expression of Shh using an ELISA assay. The activation of the Shh–Gli1 pathway was assessed through immunohistochemistry (IHC) of Gli1 and RT-qPCR analysis of the transcripts of Gli1 target genes in 14 available tumor biopsies collected at diagnosis (baseline).

Results

Among the 74 patients, only 61 had baseline (diagnosis) plasma samples, while only 49 patients had plasma samples at the first evaluation. Shh protein was detectable in all samples at diagnosis (n = 61, mean = 1,041.2 ± 252.5 pg/ml). Among the 14 available tumor biopsies, nuclear expression of Gli1 was observed in 57.1% (8/14) of patients’ biopsies. Shh was significantly (p < 0.05) enriched in youth (age < 68), male, nonsmokers, patients with a PS > 1, and patients presenting more than 2 metastatic sites and L858R mutation. Higher levels of Shh correlated with poor objective response to TKI, shorter progression-free survival (PFS), and T790M-independent mechanism of resistance. In addition, the rise of plasma Shh levels along the treatment was associated with the emergence of drug resistance in patients presenting an initial good therapy response.

Conclusion

These data support that higher levels of plasma Shh at diagnosis and increased levels of Shh along the course of the disease are related to the emergence of TKI resistance and poor outcome for EGFR-TKI therapy, suggesting that Shh levels could stand both as a prognostic and as a resistance biomarker for the management of EGFR-mutated NSCLC patients treated with EGFR-TKI.

MET Amplification and Efficacy of Nivolumab in Patients With NSCLC

Introduction

MET amplification is an important genetic alteration in NSCLC. Unlike in patients with EGFR and ALK alterations, the efficacy of immune checkpoint inhibitors in patients with MET-amplified NSCLC remains unknown.

Methods

An exploratory analysis of a prospective, multi-institutional cohort comprising 200 patients with advanced or recurrent NSCLC treated with nivolumab monotherapy was performed, and MET amplification was defined as a MET-to-CEP7 ratio of greater than or equal to 2 using fluorescent in situ hybridization. High-level and low-level MET gains were also defined as MET signals ≥10/nuclei and 10> MET signals ≥5/nuclei, respectively. Overall response rates (ORRs) and survival outcomes were evaluated on the basis of the MET gene copy number status.

Results

Among 175 patients eligible for analysis, MET amplification was detected in 13 tumors (7.4%). Four (2.3%) high-level and 14 (8.0%) low-level MET gains were also detected. There were no considerable differences in ORRs in accordance with the MET gene copy number status. Similarly, no significant differences in both progression-free survival (PFS) and overall survival (OS) were observed between patients with and without MET-amplified NSCLC (log-rank, p = 0.813 for PFS, and p = 0.855 for OS). Among 101 adenocarcinomas, ORRs in patients with high-level and low-level MET gains (50.0% for both, p = 0.049) were significantly higher than those without MET gains (17.6%), yet survival outcomes for both PFS and OS did not improve.

Conclusions

MET amplification was not associated with greater benefit of nivolumab treatment in patients with NSCLC. Further studies are warranted to prioritize immune checkpoint inhibitors in the treatment regimen for patients with MET amplification.

Comparison of MET gene amplification analysis by next-generation sequencing and fluorescence in situ hybridization

MET gene alterations are known to be involved in acquired resistance to epidermal growth factor receptor inhibition. MET amplifications present a potential therapeutic target in non-small cell lung cancer. Although next-generation sequencing (NGS) and fluorescence in situ hybridization (FISH) are conventionally used to assess MET amplifications, there are currently no clinically defined cut-off values for NGS, with FISH still being the gold standard. A collective of 20 formalin-fixed paraffin-embedded lung cancer tissue samples (mean age 64 years) were selected based on increased MET gene copy number (CNV) status or the presence of mutations detected by NGS (GeneReader, QIAGEN) and were further assessed by FISH (MET/CEN7, Zytomed). Of these, 17 tumor samples were MET-amplified and one patient was found to have a MET rearrangement by NGS, while two samples had no MET gene alteration. In contrast to the NGS result, FISH analysis showed only one highly amplified sample and 19 negative samples. The single highly amplified case detected by FISH was also positive by NGS with a fold change (FC) of 3.18 and a mean copy number (CN_{MV 10−100%}) of 20.5. Therefore, for the assessment of MET amplifications using the QIAGEN NGS workflow, we suggest detecting amplified cases with an FC value of ≥ 3.0 and a CN_{MV 10−100%} value of ≥ 20.0 by FISH. In summary, NGS allows for DNA- and RNA-based analysis of specific MET gene amplifications, point mutations or rearrangements.

A narrative review of MET inhibitors in non-small cell lung cancer with MET exon 14 skipping mutations

Treatment of advanced non-small cell lung cancer (NSCLC) has radically improved in the last years due to development and clinical approval of highly effective agents including immune checkpoint inhibitors (ICIs) and oncogene-directed therapies. Molecular profiling of lung cancer samples for activated oncogenes, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1) and BRAF, is routinely performed to select the most appropriate up-front treatment. However, the identification of new therapeutic targets remains a high priority. Recently, MET exon 14 skipping mutations have emerged as novel actionable oncogenic alterations in NSCLC, sensitive to MET inhibition. In this review we discuss: (I) MET gene and MET receptor structure and signaling pathway; (II) MET exon 14 alterations; (III) current data on MET inhibitors, mainly focusing on selective MET tyrosine kinase inhibitors (TKIs), in the treatment of NSCLC with MET exon 14 skipping mutations. We identified the references for this review through a literature search of papers about MET, MET exon 14 skipping mutations, and MET inhibitors, published up to September 2020, by using PubMed, Scopus and Web of Science databases. We also searched on websites of main international cancer congresses (ASCO, ESMO, IASLC) for ongoing studies presented as abstracts. MET exon 14 skipping mutations have been associated with clinical activity of selective MET inhibitors, including capmatinib, that has recently received approval by FDA for clinical use in this subgroup of NSCLC patients. A large number of trials are testing MET inhibitors, also in combinatorial therapeutic strategies, in MET exon 14-altered NSCLC. Results from these trials are eagerly awaited to definitively establish the role and setting for use of these agents in NSCLC patients.

EphA2 and EGFR: Friends in Life, Partners in Crime. Can EphA2 Be a Predictive Biomarker of Response to Anti-EGFR Agents?

The Eph receptors represent the largest group among Receptor Tyrosine kinase (RTK) families. The Eph/ephrin signaling axis plays center stage during development, and the deep perturbation of signaling consequent to its dysregulation in cancer reveals the multiplicity and complexity underlying its function. In the last decades, they have emerged as key players in solid tumors, including colorectal cancer (CRC); however, what causes EphA2 to switch between tumor-suppressive and tumor-promoting function is still an active theater of investigation. This review summarizes the recent advances in understanding EphA2 function in cancer, with detail on the molecular determinants of the oncogene-tumor suppressor switch function of EphA2. We describe tumor context-specific examples of EphA2 signaling and the emerging role EphA2 plays in supporting cancer-stem-cell-like populations and overcoming therapy-induced stress. In such a frame, we detail the interaction of the EphA2 and EGFR pathway in solid tumors, including colorectal cancer. We discuss the contribution of the EphA2 oncogenic signaling to the resistance to EGFR blocking agents, including cetuximab and TKIs.

Prognostic impacts of extracranial metastasis on non-small cell lung cancer with brain metastasis: A retrospective study based on surveillance, epidemiology, and end results database

This study was designed to investigate the prognostic value of the number and sites of extracranial metastasis (ECM) in NSCLC patients with BM. NSCLC patients with BM from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015 were enrolled in analysis. Patients from 2010 to 2013 were included in the training set and those from 2014 to 2015 in the validation set. ECM sites among different subtypes of NSCLC were compared by Chi-square tests. Kaplan-Meier methods and Cox regression models were performed to analyze survival data. Competing-risks analysis was used to predict cumulative incidence rates for CSS and non-CSS cause. We included 5974 patients in the training cohort and 3561 patients in the validation cohort. Most (nearly 80%) NSCLC patients with BM showed 0-1 involved extracranial organ, with the most and least common ECM organ being bone and distant lymph nodes (DLNs) among all subtypes of NSCLC, respectively. The number of involved extracranial organs was an independent prognostic factor for patients with BM from NSCLC (p < 0.001). Patients with 0-1 ECM had better survival than those with larger number of involved extracranial organs (p < 0.001). Cumulative incidence rates for CSS were increased with the number of ECM raising (p < 0.001). All involved extracranial organs were associated with worse survival (p < 0.05). In patients with single-organ ECM, we observed a better prognosis in lung and bone metastasis, while liver metastasis showed worst survival. But the difference in survival in these patient groups was relatively small. Patients with liver metastasis had higher cumulative incidence rates for CSS than that in patients with lung and bone metastasis (p < 0.05). More extracranial metastases were associated with poor prognosis in NSCLC patients with BM and ECM sites showed limited effect on survival. Tailored treatments would be reasonable for BM patients from NSCLC with different metastasis patterns.