Novel Third-Generation EGFR Tyrosine Kinase Inhibitors and Strategies to Overcome Therapeutic Resistance in Lung Cancer

Novel EGFR inhibitors against resistant L858R/T790M/C797S mutant for intervention of non-small cell lung cancer

To overcome C797S mutation, the latest and most common resistance mechanism in the clinical treatment of third-generation EGFR inhibitor, a novel series of substituted 6-(2-aminopyrimidine)-indole derivatives were designed and synthesized. Through the structure-activity relationship (SAR) study, compound 11eg was identified as a novel and potent EGFR L858R/T790M/C797S inhibitor (IC50 = 0.053 μM) but had a weak effect on EGFRWT (IC50 = 1.05 μM). 11eg significantly inhibited the proliferation of the non-small cell lung cancer (NSCLC) cells harboring EGFRL858R/T790M/C797S with an IC50 of 0.052 μM. 11eg also showed potent inhibitory activity against other NSCLC cell lines harboring main EGFR mutants. Furthermore, 11eg exhibited much superior activity in arresting cell cycle and inducing apoptosis of NSCLC cells with mutant EGFRC797S. It blocked cellular EGFR signaling. Importantly, 11eg markedly suppressed the tumor growth in in vivo xenograft mouse model with good safety. Additionally, 11eg displayed good microsomal stability. These results demonstrated the potential of 11eg with novel scaffold as a promising lead compound targeting EGFRC797S to guide in-depth structural optimization.

Comparing the toxicity effects of copper oxide nanoparticles conjugated with Lapatinib on breast (MDA-MB-231) and lung (A549) cancer cell lines

In recent years, the increase in cancer morbidity and mortality has presented scientists with a major challenge in developing new therapeutic agents against cancer cells. This study aims to characterize the anticancer effects of copper oxide nanoparticles (NPs) conjugated with Lapatinib (CuO@Lapatinib) on breast and lung cancer cell lines. The physicochemical properties of the NPs were characterized by fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and zeta potential analyses. The antiproliferative potential of the NPs in the breast (MDA-MB-231) and lung (A549) cancer cell lines and a normal cell line (MRC5) was investigated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. Flow cytometry and Hoechst staining were used to evaluate cell apoptosis and cell cycle analysis. The reactive oxygen species (ROS) levels in the treated and control cells were also determined. The NPs were spherical, with a size range of 20-59nm, a DLS size of 338nm, and a zeta potential of -42.9 mV. The half maximal inhibitory concentration (IC50) of CuO@Lapatinib NPs for the normal, breast cancer, and lung cancer cell lines was 105, 98, and 87 µg/ml, respectively. Treatment with CuO@Lapatinib NPs caused considerable apoptosis induction in breast cancer (from 0.65% to 68.96%) and lung cancer cell lines (from 1.11% to 44.11%). Also, an increased level of cell cycle arrest at the S phase was observed in both cancer cell lines. The ROS level in the breast and lung cancer cell lines after treatment with CuO@Lapatinib NPs increased by 3.45 and 21.04 folds, respectively. Nuclear morphological alterations, including chromatin condensation and fragmentation, were observed in both cancer cell lines. This study indicates CuO@Lapatinib is a potent antiproliferative compound with more efficient inhibitory effects on lung cancer than breast cancer cells, which can be related to the higher ROS generation in the A549 cell line.

Mesoporous silica nanoparticles: a versatile carrier platform in lung cancer management

Mesoporous silica nanoparticles (MSNPs) are inorganic nanoparticles that have been comprehensively investigated and are intended to deliver therapeutic agents. MSNPs have revolutionized the therapy for various conditions, especially cancer and infectious diseases. In this article, the viability of MSNPs' administration for lung cancer therapy has been reviewed. However, certain challenges lay ahead in the successful translation such as toxicology, immunology, large-scale production, and regulatory matters have made it extremely difficult to translate such discoveries from the bench to the bedside. This review highlights recent developments, characteristics, mechanism of action and customization for targeted delivery. This review also covers the most recent data that sheds light on MSNPs' extraordinary therapeutic potential in fighting lung cancer as well as future hurdles.

DeKinomics pulse-chases kinase functions in living cells

Cellular context is crucial for understanding the complex and dynamic kinase functions in health and disease. Systematic dissection of kinase-mediated cellular processes requires rapid and precise stimulation ('pulse') of a kinase of interest, as well as global and in-depth characterization ('chase') of the perturbed proteome under living conditions. Here we developed an optogenetic 'pulse-chase' strategy, termed decaging kinase coupled proteomics (DeKinomics), for proteome-wide profiling of kinase-driven phosphorylation at second-timescale in living cells. We took advantage of the 'gain-of-function' feature of DeKinomics to identify direct kinase substrates and further portrayed the global phosphorylation of understudied receptor tyrosine kinases under native cellular settings. DeKinomics offered a general activation-based strategy to study kinase functions with high specificity and temporal resolution under living conditions.

TWIST1 is a critical downstream target of the HGF/MET pathway and is required for MET driven acquired resistance in oncogene driven lung cancer

MET amplification/mutations are important targetable oncogenic drivers in NSCLC, however, acquired resistance is inevitable and the majority of patients with targetable MET alterations fail to respond to MET tyrosine kinase inhibitors (TKIs). Furthermore, MET amplification is among the most common mediators of TKI resistance. As such, novel therapies to target MET pathway and overcome MET TKI resistance are clearly needed. Here we show that the epithelial-mesenchymal transition (EMT) transcription factor, TWIST1 is a key downstream mediator of HGF/MET induced resistance through suppression of p27 and targeting TWIST1 can overcome resistance. We found that TWIST1 is overexpressed at the time of TKI resistance in multiple MET-dependent TKI acquired resistance PDX models. We have shown for the first time that MET directly stabilized the TWIST protein leading to TKI resistance and that TWIST1 was required for MET-driven lung tumorigenesis as well as could induce MET TKI resistance when overexpressed. TWIST1 mediated MET TKI resistance through suppression of p27 expression and genetic or pharmacologic inhibition of TWIST1 overcame TKI resistance in vitro and in vivo. Our findings suggest that targeting TWIST1 may be an effective therapeutic strategy to overcome resistance in MET-driven NSCLC as well as in other oncogene driven subtypes in which MET amplification is the resistance mechanism.

An assessment of EGFR and HER2 inhibitors with structure activity relationship of fused pyrimidine derivatives for breast cancer: a brief review

Epidermal growth factor receptor (EGFR) and its subtype human epidermal growth factor receptor 2 (HER2) gets activated when its endogenous ligand(s) bind to its ATP binding site of target receptors. In breast cancer (BC), EGFR and HER2 are two proteins are overexpressed which leads to overexpression of cells proliferation and decreases cell death/apoptosis. Pyrimidine is one of the most widely studied heterocyclic scaffolds for EGFR as well as HER2 inhibition. We gather some remarkable results for fused-pyrimidine derivatives on various cancerous cell lines (in-vitro) and animal (in-vivo) evaluation to highlight their potency. The heterocyclic (five, six-membered, etc.) moieties which are coupled with pyrimidine moiety are potent against EGFR and HER2 inhibitions. Hence structure-activity relationship (SAR) plays important role in study of heterocyclic moiety along pyrimidine and effects of substituents, groups for increase or decrease in the cancerous activity and toxicity. By thoughtful of fused pyrimidines SAR study, it facilitates in receiving excellent overview of the compounds by concerning of efficacy and potential summary for future EGFR inhibitors. Furthermore, we studied the in-silico interactions of synthesized compounds to evaluate binding affinity towards the key amino acids..Communicated by Ramaswamy H. Sarma.

CDK4/6 inhibitors in lung cancer: current practice and future directions

Lung cancer is the leading cause of cancer-related deaths worldwide, and ∼85% of lung cancers are classified as nonsmall cell lung cancer (NSCLC). These malignancies can proliferate indefinitely, in part due to dysregulation of the cell cycle and the resulting abnormal cell growth. The specific activation of cyclin-dependent kinases 4 and 6 (CDK4/6) is closely linked to tumour proliferation. Approximately 80% of human tumours exhibit abnormalities in the cyclin D-CDK4/6-INK4-RB pathway. Specifically, CDK4/6 inhibitors either as monotherapy or combination therapy have been investigated in pre-clinical and clinical studies for the treatment of NSCLC, and promising results have been achieved. This review article focuses on research regarding the use of CDK4/6 inhibitors in NSCLC, including the characteristics and mechanisms of action of approved drugs and progress of pre-clinical and clinical research.

Recent progress in drug delivery systems for tyrosine kinase inhibitors in the treatment of lung cancer

Lung cancer ranks as the second most commonly diagnosed cancer in both men and women worldwide. Despite the availability of diverse diagnostic and treatment strategies, it remains the leading cause of cancer-related deaths globally. The current treatment approaches for lung cancer involve the utilization of first generation (e.g., erlotinib, gefitinib) and second generation (e.g., afatinib) tyrosine kinase inhibitors (TKIs). These TKIs exert their effects by inhibiting a crucial enzyme called tyrosine kinase, which is responsible for cell survival signaling. However, their clinical effectiveness is hindered by limited solubility and oral bioavailability. Nanotechnology has emerged as a significant application in modern cancer therapy. Nanoparticle-based drug delivery systems, including lipid, polymeric, hybrid, inorganic, dendrimer, and micellar nanoparticles, have been designed to enhance the bioavailability, stability, and retention of these drugs within the targeted lung area. Furthermore, these nanoparticle-based delivery systems offer several advantages, such as increased therapeutic efficacy and reduced side effects and toxicity. This review focuses on the recent advancements in drug delivery systems for some of the most important TKIs, shedding light on their potential in improving lung cancer treatment.

Exploring the inhibitory properties of biflavonoids on α-glucosidase; computational and experimental approaches

Biflavonoids (BFs) are a group of polyphenols that have a unique biochemical structure. One of the key biomedical mechanisms that BFs can have high potential in managing Diabetes mellitus (DM) is α-glucosidase inhibition. Normally, elevated blood glucose levels are caused by high absorption of glucose in the epithelium of the small intestine. Since α-glucosidase helps increase the absorption of glucose in the small intestine in the final stage of glycan catabolism, inhibition of this essential biochemical process in diabetic patients can be considered a suitable approach in the treatment of this disease. The interaction between the BFs and α-glucosidase are still not clear, and need to be deeply investigated. Herein, the aim is to identify BFs with strong α-glucosidase inhibitory activity. Using docking-based virtual screening approach, the potential binding affinity of 18 selected BFs to α-glucosidase was evaluated. The dynamic activity and stability of α-glucosidase-BFs complexes were then measured by molecular dynamics simulation (MDs). "Strychnobiflavone" showed the best score in α-glucosidase inhibition. Arg315 and Phe303 involved in the interactions of α-glucosidase-strychnobiflavone complex through cation-π and π-π stacking, respectively. Based on in vitro kinetic studies, it was determined that the type of inhibition of "strychnobiflavone" corresponds to the pattern of mixed inhibitors. Furthermore, details of the interactions between strychnobiflavone and α-glucosidase were performed by in silico secondary structure content analysis. The findings showed when "strychnobifone" binds to the enzyme, significant alterations occur in the enzyme conformation affecting its catalytic activity. In general, the findings highlighted the potential of "strychnobiflavone" as a promising candidate for the treatment of diabetes mellitus through α-glucosidase inhibition. Further in vitro and in vivo studies have to confirm the therapeutic benefits of "strychnobiflavone" in conformational diseases such as diabetes mellitus.

Recruitment of hexahydroquinoline as anticancer scaffold targeting inhibition of wild and mutants EGFR (EGFRWT, EGFRT790M, and EGFRL858R)

Hexahydroquinoline (HHQ) scaffold was constructed and recruited for development of new series of anticancer agents. Thirty-two new compounds were synthesised where x-ray crystallography was performed to confirm enantiomerism. Thirteen compounds showed moderate to good activity against NCI 60 cancer cell lines, with GI % mean up to 74% for 10c. Expending erlotinib as a reference drug, target compounds were verified for their inhibiting activities against EGFRWT, EGFRT790M, and EGFRL858R where compound 10d was the best inhibitor with IC50 = 0.097, 0.280, and 0.051 µM, respectively, compared to erlotinib (IC50 = 0.082 µM, 0.342 µM, and 0.055 µM, respectively). Safety profile was validated using normal human lung (IMR-90) cells. 10c and 10d disrupted cell cycle at pre-G1 and G2/M phases in lung cancer, HOP-92, and cell line. Molecular docking study was achieved to understand the potential binding interactions and affinities in the active sites of three versions of EGFRs.

Expressed Barcoding Enables High-Resolution Tracking of the Evolution of Drug Tolerance

For a majority of patients with non-small cell lung cancer with EGFR mutations, treatment with EGFR inhibitors (EGFRi) induces a clinical response. Despite this initial reduction in tumor size, residual disease persists that leads to disease relapse. Elucidating the preexisting biological differences between sensitive cells and surviving drug-tolerant persister cells and deciphering how drug-tolerant cells evolve in response to treatment could help identify strategies to improve the efficacy of EGFRi. In this study, we tracked the origins and clonal evolution of drug-tolerant cells at a high resolution by using an expressed barcoding system coupled with single-cell RNA sequencing. This platform enabled longitudinal profiling of gene expression and drug sensitivity in response to EGFRi across a large number of clones. Drug-tolerant cells had higher expression of key survival pathways such as YAP and EMT at baseline and could also differentially adapt their gene expression following EGFRi treatment compared with sensitive cells. In addition, drug combinations targeting common downstream components (MAPK) or orthogonal factors (chemotherapy) showed greater efficacy than EGFRi alone, which is attributable to broader targeting of the heterogeneous EGFRi-tolerance mechanisms present in tumors. Overall, this approach facilitates thorough examination of clonal evolution in response to therapy that could inform the development of improved diagnostic approaches and treatment strategies for targeting drug-tolerant cells.

SIGNIFICANCE

The evolution and heterogeneity of EGFR inhibitor tolerance are identified in a large number of clones at enhanced cellular and temporal resolution using an expressed barcode technology coupled with single-cell RNA sequencing.

Chromosomal Copy Number Variation Predicts EGFR-TKI Response and Prognosis for Patients with Non-Small Cell Lung Cancer

Purpose

Chromosomal abnormalities represent genomic signatures linked to cancer prognosis and responses to chemotherapy, immunotherapy, and drug resistance. This study aimed to investigate the impact of chromosome copy number variants (CNVs) on the efficacy of tyrosine kinase inhibitors (TKIs) in EGFR-mutated non-small cell lung cancer (NSCLC) patients, as well as its prognostic implications for progression-free survival (PFS) and overall survival (OS) in EGFR wild-type patients.

Methods

A total of 110 patients with advanced NSCLC were enrolled in this study and categorized into EGFR-mutated and wild-type groups. Utilizing next-generation sequencing (NGS) technology, we assessed 24 genes and chromosome CNVs associated with lung cancer pathways in patients' tissue samples.

Results

Within the EGFR-mutated group, patients with a gain in Chr 1p13.3-p13.1 exhibited poor TKI responses, a high relapse rate, and shortened PFS (P = 0.002). Conversely, EGFR-mutated patients with a gain in 14q31.1-q31.3 demonstrated favorable TKI responses and relatively extended PFS (P = 0.005). Among EGFR wild-type patients, the presence of 7q31.1-q31.31 CNV emerged as an independent factor influencing both PFS and OS (P = 0.013, P = 0.004). Notably, patients with a gain in 7q31.1-q31.31 exhibited prolonged PFS and OS. Additionally, independent prognostic significance for OS in EGFR wild-type patients was observed for CNVs in 9q21.31-q22.2 and 11p11.11-q12.1 regions (P = 0.001). Patients with gains in these regions experienced extended OS, while losses were predictive of poorer outcomes.

Conclusion

Our results suggested that chromosomal copy number variation is a practical indicator for predicting the response of EGFR-targeted therapy and prognosis for NSCLC patients.

Recent advances in targeting the "undruggable" proteins: from drug discovery to clinical trials

Undruggable proteins are a class of proteins that are often characterized by large, complex structures or functions that are difficult to interfere with using conventional drug design strategies. Targeting such undruggable targets has been considered also a great opportunity for treatment of human diseases and has attracted substantial efforts in the field of medicine. Therefore, in this review, we focus on the recent development of drug discovery targeting "undruggable" proteins and their application in clinic. To make this review well organized, we discuss the design strategies targeting the undruggable proteins, including covalent regulation, allosteric inhibition, protein-protein/DNA interaction inhibition, targeted proteins regulation, nucleic acid-based approach, immunotherapy and others.

Small molecule protein kinase inhibitors approved by regulatory agencies outside of the United States

Owing to genetic alterations and overexpression, the dysregulation of protein kinases plays a significant role in the pathogenesis of many autoimmune and neoplastic disorders and protein kinase antagonists have become an important drug target. Although the efficacy of imatinib in the treatment of chronic myelogenous leukemia in the United States in 2001 was the main driver of protein kinase inhibitor drug discovery, this was preceded by the approval of fasudil (a ROCK antagonist) in Japan in 1995 for the treatment of cerebral vasospasm. There are 21 small molecule protein kinase inhibitors that are approved in China, Japan, Europe, and South Korea that are not approved in the United Sates and 75 FDA-approved inhibitors in the United States. Of the 21 agents, eleven target receptor protein-tyrosine kinases, eight inhibit nonreceptor protein-tyrosine kinases, and two block protein-serine/threonine kinases. All 21 drugs are orally bioavailable or topically effective. Of the non-FDA approved drugs, sixteen are prescribed for the treatment of neoplastic diseases, three are directed toward inflammatory disorders, one is used for glaucoma, and fasudil is used in the management of vasospasm. The leading targets of kinase inhibitors approved by both international regulatory agencies and by the FDA are members of the EGFR family, the VEGFR family, and the JAK family. One-third of the 21 internationally approved drugs are not compliant with Lipinski's rule of five for orally bioavailable drugs. The rule of five relies on four parameters including molecular weight, number of hydrogen bond donors and acceptors, and the Log of the partition coefficient.

Role of EGFR and FASN in breast cancer progression

Breast cancer (BC) emerged as one of the life-threatening diseases among females. Despite notable improvements made in cancer detection and treatment worldwide, according to GLOBACAN 2020, BC is the fifth leading cancer, with an estimated 1 in 6 cancer deaths, in a majority of countries. However, the exact cause that leads to BC progression still needs to be determined. Here, we reviewed the role of two novel biomarkers responsible for 50-70% of BC progression. The first one is epidermal growth factor receptor (EGFR) which belongs to the ErbB tyrosine kinases family, signalling pathways associated with it play a significant role in regulating cell proliferation and division. Another one is fatty acid synthase (FASN), a key enzyme responsible for the de novo lipid synthesis required for cancer cell development. This review presents a rationale for the EGFR-mediated pathways, their interaction with FASN, communion of these two biomarkers with BC, and improvements to overcome drug resistance caused by them.

The potential therapeutic regimen for overcoming resistance to osimertinib due to rare mutations in NSCLC

The mechanisms of osimertinib resistance have not been well characterized. We conducted next-generation sequencing to recognize novel resistance mechanism and used cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models to evaluate the anti-proliferative effects of aspirin in vivo and in vitro. We observed that PIK3CG mutations led to acquired resistance to osimertinib in a patient and further confirmed that both PIK3CG and PIK3CA mutations caused osimertinib resistance. Mechanistically, the expression of PI3Kγ or PI3Kα was up-regulated after PIK3CG or PIK3CA lentivirus transfection, respectively, and which can be effectively suppressed by aspirin. Lastly, our results from in vivo studies indicate that aspirin can reverse osimertinib resistance caused by PIK3CG or PIK3CA mutations in both CDX and PDX models. Herein, we first confirmed that mutations in PIK3CG can lead to resistance to osimertinib, and the combined therapy may be a strategy to reverse PIK3CG/PIK3CA mutation-induced osimertinib resistance.

Enhancement of TKI sensitivity in lung adenocarcinoma through m6A-dependent translational repression of Wnt signaling by circ-FBXW7

BACKGROUND

Tyrosine kinase inhibitors (TKIs) that specifically target mutational points in the EGFR gene have significantly reduced suffering and provided greater relief to patients with lung adenocarcinoma (LUAD). The third-generation EGFR-TKI, Osimertinib, has been successfully employed in clinical treatments to overcome resistance to both original and acquired T790M and L858R mutational points. Nevertheless, the issue of treatment failure response has emerged as an insurmountable problem.

METHODS

By employing a combination of multiple and integrated approaches, we successfully identified a distinct population within the tumor group that plays a significant role in carcinogenesis, resistance, and recurrence. Our research suggests that addressing TKI resistance may involve targeting the renewal and repopulation of stem-like cells. To investigate the underlying mechanisms, we conducted RNA Microarray and m6A Epi-Transcriptomic Microarray analyses, followed by assessment of transcription factors. Additionally, we specifically designed a tag to detect the polypeptide circRNA-AA, and its expression was confirmed through m6A regulations.

RESULTS

We initially identified unique molecular signatures present in cancer stem cells that contributed to poor therapeutic responses. Activation of the alternative Wnt pathway was found to sustain the renewal and resistant status of these cells. Through bioinformatics analysis and array studies, we observed a significant decrease in the expression of circFBXW7 in Osimertinib-resistant cell lines. Notably, the abnormal expression pattern of circFBXW7 determined the cellular response to Osimertinib. Functional investigations revealed that circFBXW7 inhibits the renewal of cancer stem cells and resensitizes both resistant LUAD cells and stem cells to Osimertinib. In terms of the underlying mechanism, we discovered that circFBXW7 can be translated into short polypeptides known as circFBXW7-185AA. These polypeptides interact with β-catenin in an m6A-dependent manner. This interaction leads to reduced stability of β-catenin by inducing subsequent ubiquitination, thereby suppressing the activation of canonical Wnt signaling. Additionally, we predicted that the m6A reader, YTHDF3, shares common binding sites with hsa-Let-7d-5p. Enforced expression of Let-7d post-transcriptionally decreases the levels of YTHDF3. The repression of Let-7d by Wnt signaling releases the stimulation of m6A modification by YTHDF3, promoting the translation of circFBXW7-185AA. This creates a positive feedback loop contributing to the cascade of cancer initiation and promotion.

CONCLUSIONS

Our bench study, in vivo experiments, and clinical validation have unequivocally shown that circFBXW7 effectively inhibits the abilities of LUAD stem cells and reverses resistance to TKIs by modulating Wnt pathway functions through the action of circFBXW7-185AA on β-catenin ubiquitination and inhibition. The regulatory role of circRNA in Osimertinib treatment has been rarely reported, and our findings reveal that this process operates under the influence of m6A modification. These results highlight the tremendous potential of this approach in enhancing therapeutic strategies and overcoming resistance to multiple TKI treatments.

Acquired resistance mechanisms to osimertinib: The constant battle

Lung cancer is the leading cause of cancer-related mortality worldwide. Detectable driver mutations have now changed the course of lung cancer treatment with the emergence of targeted therapy as a novel strategy that widely improved lung cancer prognosis, especially in metastatic patients. Osimertinib (AZD9291) is an irreversible third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) used to treat stage IV EGFR-mutated non-small-cell lung cancer. It was initially designed to target both EGFR-activating mutations and the EGFR T790M mutation as well, which is the most common resistance mechanism to first- and second-generation EGFR-TKIs. Following the FLAURA trial, osimertinib is now widely used in the first-line setting. However, resistance to osimertinib inevitably develops, with numerous mechanisms leading to its resistance, classified into two main categories: EGFR-dependent and EGFR-independent mechanisms. While EGFR-dependent mechanisms consist mainly of the C797S EGFR mutation, EGFR-independent mechanisms include bypass pathways, oncogenic fusions, and phenotypic transformation, among others. This review summarizes the molecular resistance mechanisms to osimertinib, with the aim of identifying novel therapeutic approaches to overcome osimertinib resistance and improve patient outcome.

Structure-Activity Relationship Studies Based on Quinazoline Derivatives as EGFR Kinase Inhibitors (2017-Present)

The epidermal growth factor receptor (EGFR) plays a critical role in the tumorigenesis of various forms of cancer. Targeting the mutant forms of EGFR has been identified as an attractive therapeutic approach and led to the approval of three generations of inhibitors. The quinazoline core has emerged as a favorable scaffold for the development of novel EGFR inhibitors due to increased affinity for the active site of EGFR kinase. Currently, there are five first-generation (gefitinib, erlotinib, lapatinib, vandetanib, and icotinib) and two second-generation (afatinib and dacomitinib) quinazoline-based EGFR inhibitors approved for the treatment of various types of cancers. The aim of this review is to outline the structural modulations favorable for the inhibitory activity toward both common mutant (del19 and L858R) and resistance-conferring mutant (T790M and C797S) EGFR forms, and provide an overview of the newly synthesized quinazoline derivatives as potentially competitive, covalent or allosteric inhibitors of EGFR.

Taking early preventive interventions to manage the challenging issue of acquired resistance to third-generation EGFR inhibitors

Although the clinical efficacies of third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) such as osimertinib in the treatment of non-small cell lung cancer (NSCLC) with EGFR-activating mutations are promising, drug-acquired resistance inevitably occurs whether they are used as first-line or second-line treatment. Therefore, managing the acquired resistance to third-generation EGFR-TKIs is crucial in the clinic for improving patient survival. Great efforts have been made to develop potentially effective strategies or regimens for the treatment of EGFR-mutant NSCLC patients after relapse following these TKIs therapies with the hope that patients will continue to benefit from treatment through overcoming acquired resistance. Although this approach, which aims to overcome drug-acquired resistance, is necessary and important, it is a passive practice. Taking preventive action early before disease progression to manage the unavoidable development of acquired resistance offers an equally important and efficient approach. We strongly believe that early preventive interventions using effective and tolerable combination regimens that interfere with the process of developing acquired resistance may substantially improve the outcomes of EGFR-mutant NSCLC treatment with third-generation EGFR-TKIs. Thus, this review focuses on discussing the scientific rationale and mechanism-driven strategies for delaying and even preventing the emergence of acquired resistance to third-generation EGFR-TKIs, particularly osimertinib.

OSppc: A web server for online survival analysis using proteome of pan-cancers

Prognostic biomarker, as a feasible and objective indicator, is valuable in the assessment of cancer risk. With the development of high-throughput sequencing technology, the screening of prognostic biomarkers has become easy, but it is difficult to screen prognostic markers based on proteomic data. In this study we developed a tool named Online consensus Survival analysis web server based on Proteome of Pan-cancers, abbreviated as OSppc, to evaluate the prognostic values of protein biomarkers. >8000 cancer cases with proteomic data, transcriptomic data and clinical follow-up information were collected from TCGA and CPTAC. 14,038 proteins (including proteins and their phosphorylated forms) analyzed by reverse-phase protein arrays and mass spectrometry in 33 types of cancers were collected. In OSppc, three analysis modules are provided, including Survival Analysis, Differential Analysis and Correlation Analysis. Survival analysis module exhibits HR with 95% CI and KM curves with log-rank p value of protein and mRNA levels of input genes. Differential analysis module shows the box plots of protein expression levels in different tissues. Correlation analysis module provides scatter plot with pearson's and spearman's correlation coefficient of the protein and its corresponding mRNA. OSppc can be accessed at http://bioinfo.henu.edu.cn/Protein/OSppc.html. SIGNIFICANCE: OSppc can analyze the association between protein, mRNA and prognosis, the correlation between proteome data and gene expression profiles, the differential expression of proteome data between subgroups such as normal and cancer as well. OSppc is registration-free and very valuable to evaluate the prognostic potency of protein of interests. OSppc is very valuable for researchers and clinicians to screen, develop and validate potential protein prognostic biomarkers in pan-cancers, and offers the opportunities to investigate the clinical important functional genes and therapeutic targets of cancers.

Crizotinib-based proteolysis targeting chimera suppresses gastric cancer by promoting MET degradation

As one of the common malignant cancer types, gastric cancer (GC) is known for late-stage diagnosis and poor prognosis. Overexpression of the receptor tyrosine kinase MET is associated with poor prognosis among patients with advanced stage GC. However, no MET inhibitor has been used for GC treatment. Like other tyrosine kinase inhibitors that fit the "occupancy-driven" model, current MET inhibitors are prone to acquired resistance. The emerging proteolysis targeting chimera (PROTAC) strategy could overcome such limitations through direct degradation of the target proteins. In this study, we successfully transformed the MET-targeted inhibitor crizotinib into a series of PROTACs, recruiting cereblon/cullin 4A E3 ubiquitin ligase to degrade the MET proteins. The optimized lead PROTAC (PRO-6 E) effectively eliminated MET proteins in vitro and in vivo, inhibiting proliferation and motility of MET-positive GC cells. In the MKN-45 xenograft model, PRO-6 E showed pronounced antitumor efficacy with a well-tolerated dosage regimen. These results validated PRO-6 E as the first oral PROTAC for MET-dependent GC.

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.

Pharmacological Modulation of the Crosstalk between Aberrant Janus Kinase Signaling and Epigenetic Modifiers of the Histone Deacetylase Family to Treat Cancer

Hyperactivated Janus kinase (JAK) signaling is an appreciated drug target in human cancers. Numerous mutant JAK molecules as well as inherent and acquired drug resistance mechanisms limit the efficacy of JAK inhibitors (JAKi). There is accumulating evidence that epigenetic mechanisms control JAK-dependent signaling cascades. Like JAKs, epigenetic modifiers of the histone deacetylase (HDAC) family regulate the growth and development of cells and are often dysregulated in cancer cells. The notion that inhibitors of histone deacetylases (HDACi) abrogate oncogenic JAK-dependent signaling cascades illustrates an intricate crosstalk between JAKs and HDACs. Here, we summarize how structurally divergent, broad-acting as well as isoenzyme-specific HDACi, hybrid fusion pharmacophores containing JAKi and HDACi, and proteolysis targeting chimeras for JAKs inactivate the four JAK proteins JAK1, JAK2, JAK3, and tyrosine kinase-2. These agents suppress aberrant JAK activity through specific transcription-dependent processes and mechanisms that alter the phosphorylation and stability of JAKs. Pharmacological inhibition of HDACs abrogates allosteric activation of JAKs, overcomes limitations of ATP-competitive type 1 and type 2 JAKi, and interacts favorably with JAKi. Since such findings were collected in cultured cells, experimental animals, and cancer patients, we condense preclinical and translational relevance. We also discuss how future research on acetylation-dependent mechanisms that regulate JAKs might allow the rational design of improved treatments for cancer patients. SIGNIFICANCE STATEMENT: Reversible lysine-ɛ-N acetylation and deacetylation cycles control phosphorylation-dependent Janus kinase-signal transducer and activator of transcription signaling. The intricate crosstalk between these fundamental molecular mechanisms provides opportunities for pharmacological intervention strategies with modern small molecule inhibitors. This could help patients suffering from cancer.

The landscape of therapeutic vulnerabilities in EGFR inhibitor osimertinib drug tolerant persister cells

Third-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs), including osimertinib, an irreversible EGFR-TKI, are important treatments for non-small cell lung cancer with EGFR-TKI sensitizing or EGFR T790M resistance mutations. While patients treated with osimertinib show clinical benefit, disease progression and drug resistance are common. Emergence of de novo acquired resistance from a drug tolerant persister (DTP) cell population is one mechanism proposed to explain progression on osimertinib and other targeted cancer therapies. Here we profiled osimertinib DTPs using RNA-seq and ATAC-seq to characterize the features of these cells and performed drug screens to identify therapeutic vulnerabilities. We identified several vulnerabilities in osimertinib DTPs that were common across models, including sensitivity to MEK, AURKB, BRD4, and TEAD inhibition. We linked several of these vulnerabilities to gene regulatory changes, for example, TEAD vulnerability was consistent with evidence of Hippo pathway turning off in osimertinib DTPs. Last, we used genetic approaches using siRNA knockdown or CRISPR knockout to validate AURKB, BRD4, and TEAD as the direct targets responsible for the vulnerabilities observed in the drug screen.

Advanced approaches of developing targeted covalent drugs

In recent years, the development of targeted covalent inhibitors has gained popularity around the world. Specific groups (electrophilic warheads) form irreversible bonds with the side chain of nucleophilic amino acid residues, thus changing the function of biological targets such as proteins. Since the first targeted covalent inhibitor was disclosed in the 1990s, great efforts have been made to develop covalent ligands from known reversible leads or drugs by addition of tolerated electrophilic warheads. However, high reactivity and "off-target" toxicity remain challenging issues. This review covers the concept of targeted covalent inhibition to diseases, discusses traditional and interdisciplinary strategies of cysteine-focused covalent drug discovery, and exhibits newly disclosed electrophilic warheads majorly targeting the cysteine residue. Successful applications to address the challenges of designing effective covalent drugs are also introduced.

Discovery of novel thiazolyl-pyrazolines as dual EGFR and VEGFR-2 inhibitors endowed with in vitro antitumor activity towards non-small lung cancer

New series of thiazolyl-pyrazoline derivatives (7a–7d, 10a–10d and 13a–13f) have been synthesised and assessed for their potential EGFR and VEGFR-2 inhibitory activities. Compounds 10b and 10d exerted potent and selective inhibitory activity towards the two receptor tyrosine kinases; EGFR (IC₅₀ = 40.7 ± 1.0 and 32.5 ± 2.2 nM, respectively) and VEGFR-2 (IC₅₀ = 78.4 ± 1.5 and 43.0 ± 2.4 nM, respectively). The best anti-proliferative activity for the examined thiazolyl-pyrazolines was observed against the non-small lung cancer cells (NSCLC). Compounds 10b and 10d displayed pronounced efficacy against A549 (IC₅₀ = 4.2 and 2.9 µM, respectively) and H441 cell lines (IC₅₀ = 4.8 and 3.8 µM, respectively). Moreover, our results indicated that 10b and 10d were much more effective towards EGFR-mutated NSCLC cell lines (NCI-H1650 and NCI-H1975 cells) than gefitinib. Finally, compounds 10b and 10d induce G2/M cell cycle arrest and apoptosis and inhibit migration in A549 cancerous cells.

Real-world efficacy of osimertinib in previously EGFR-TKI treated NSCLC patients without identification of T790M mutation

BACKGROUND

The efficacy of osimertinib in previously EGFR-TKI-treated NSCLC without identification of T790M mutational status remains unclear in real-world practice.

PATIENTS AND METHODS

417 patients had stage III-IV NSCLC harboring EGFR mutation and 154 out of 417 patients receiving osimertinib as ≥ second-line EGFR-TKI were identified. The time to treatment failure and risk of death were analyzed.

RESULTS

Higher risk of death was found in EGFR-mutant patients with age ≥ 65 years, non-adenocarcinoma, no surgery or radiation, non-exon 19 deletion/exon 21 L858R, higher ECOG PS (2-4), PD-L1 expression ≥ 50%, and bone/liver/adrenal metastasis (all p < 0.05). Osimertinib as ≥ second-line TKI in patients with/without identification of T790M revealed lower risk of death compared to first-line first/second generation TKI without subsequent osimertinib (p = 0.0002; 0.0232, respectively). However, osimertinib-treated patients with T790M did not have superior survival than those without (p = 0.2803). A higher risk of treatment failure for osimertinib was found in males, patients with first-line TKI duration ≤ 12 months, BMI drop > 10%, and PD-L1 expression ≥ 50% (All p < 0.05). Nonetheless, osimertinib as ≥ second-line TKI in patients without identification of 790 M did not have higher risk of treatment failure than those with T790M (p = 0.1236).

CONCLUSIONS

This study demonstrates that osimertinib as second line or subsequent TKI in EGFR-TKI-treated patients without identification of T790M revealed lower risk of death compared to first-line first/second generation TKI without subsequent osimertinib, in real-world practice. Additionally, EGFR-mutant patients with PD-L1 expression ≥ 50% had a higher risk of treatment failure for osimertinib and worse overall survival than those with PD-L1 expression < 50%. These results suggest that osimertinib as second line or subsequent TKI may be a potential alternative option for the treatment of patients without identification of T790M and PD-L1 expression ≥ 50% is associated with a significantly poor outcome in patients receiving osimertinib.

The story of EGFR: from signaling pathways to a potent anticancer target

EGFR is a member of the ERBB family. It plays a significant role in cellular processes such as growth, survival and differentiation via the activation of various signaling pathways. EGFR deregulation is implicated in various human malignancies, and therefore EGFR has emerged as an attractive anticancer target. EGFR inhibition using strategies such as tyrosine kinase inhibitors and monoclonal antibodies hinders cellular proliferation and promotes apoptosis in cancer cells in vitro and in vivo. EGFR inhibition by tyrosine kinase inhibitors has been shown to be a better treatment option than chemotherapy for advanced-stage EGFR-driven non-small-cell lung cancer, yet de novo and acquired resistance limits the clinical benefit of these therapeutic molecules. This review discusses the cellular signaling pathways activated by EGFR. Further, current therapeutic strategies to target aberrant EGFR signaling in cancer and mechanisms of resistance to them are highlighted.

A pharmacological exploration of targeted drug therapy in non-small cell lung cancer

Lung cancer is the prime cause of cancer-related deaths globally, with a contribution of 85% from non-small cell lung cancer. Before a few decades back, conventional chemotherapy was the most chosen treatment option for NSCLC but with side effects. Now, the treatment approaches have shifted to a new trend, targeted therapy, and a better treatment strategy with minimal side effects compared to chemotherapy. Advances in technologies and understanding the pathways lead to the discovery of new targets and through which it is possible to improve treatment outcomes and patient compliance. Unlike chemotherapy, targeted therapy focuses on the tumor cells and does not produce toxicity to healthy cells. The last two decades were very crucial in the development of many small molecules with the capability to target-specific proteins or genes in the disease progression pathway. Although the targeted therapy approach was a gemstone with many successful drugs for the treatment of NSCLC, various resistance mechanisms and activation of bypass signaling pathways put many of these drugs in the trash. In this review, we will discuss the major targeted proteins involved in NSCLC as well as the inhibitor drugs developed to target them for now and along with the future directions.

Nazartinib for treatment-naive EGFR-mutant non-small cell lung cancer: Results of a phase 2, single-arm, open-label study

INTRODUCTION

Nazartinib, a novel third-generation EGFR-tyrosine kinase inhibitor, previously demonstrated antitumor activity and manageable safety in patients with EGFR-mutant advanced non-small cell lung cancer (NSCLC) who received ≤ 3 prior lines of systemic therapy. Herein, we report phase 2 efficacy and safety of first-line nazartinib.

METHODS

This single-arm, open-label, global study enrolled treatment-naive adult patients with stage IIIB/IV NSCLC harboring EGFR-activating mutations (eg, L858R and/or ex19del). Patients with neurologically stable and controlled brain metastases were also eligible. Patients received oral nazartinib 150 mg once daily. The primary endpoint was Blinded Independent Review Committee (BIRC)-assessed overall response rate (ORR) per RECIST v1.1.

RESULTS

Forty-five patients received ≥ 1 dose of nazartinib. The median follow-up time from enrollment to data cutoff (November 1, 2019) was 30 months (range: 25-34). The BIRC-assessed ORR was 69% (95% CI, 53-82). The median progression-free survival (PFS) was 18 months (95% CI, 15-not estimable [NE]). The median overall survival was NE. In patients with baseline brain metastases (n = 18), the ORR and median PFS (95% CIs) were 67% (41-87) and 17 months (11-21). Seventeen of 18 patients had brain metastases as non-target lesions; the CNS lesions were absent/normalized in 9 of 17 (53%). Only 2 of 27 patients without baseline brain metastases developed new brain metastases postbaseline. Most frequent adverse events (≥ 25%, any grade, all-causality) were diarrhea (47%), maculopapular rash (38%), pyrexia (29%), cough, and stomatitis (27% each).

CONCLUSIONS

First-line nazartinib demonstrated promising efficacy, including clinically meaningful antitumor activity in the brain, and manageable safety in patients with EGFR-mutant NSCLC.

TRIAL REGISTRATION

ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT02108964.

Effect of autoinduction and food on the pharmacokinetics of furmonertinib and its active metabolite characterized by a population pharmacokinetic model

Furmonertinib (AST2818) is a novel third-generation irreversible EGFR TKI and recently has been approved in China for the treatment of non-small cell lung cancer (NSCLC) with EGFR-sensitizing and T790M resistance mutations. In the current study, we developed a semi-mechanistic population pharmacokinetic model to characterize the nonstationary pharmacokinetics (PK) of the furmonertinib and its active metabolite AST5902 simultaneously. The PK data of furmonertinib and AST5902 were obtained from 38 NSCLC patients and 16 healthy volunteers receiving 20-240 mg furmonertinib in three clinical trials. A nonlinear mixed-effects modeling approach was used to describe the PK data. The absorption process of furmonertinib was described by a transit compartment model. The disposition of both furmonertinib and AST5902 was described by a two-compartment model. An indirect response model accounted for the autoinduction of furmonertinib metabolism mediated by CYP3A4. The model-based simulation suggested that furmonertinib clearance was increased in one cycle of treatment (orally once daily for 21 days) compared to baseline, ranging from 1.1 to 1.8 fold corresponding to the dose range of 20-240 mg. The concentration of furmonertinib was decreased over time whereas that of AST5902 was increased. Interestingly, the concentration of the total active compounds (furmonertinib and AST5902) appeared to be stable. The food intake, serum alkaline phosphatase and body weight were identified as statistically significant covariates. The mechanism of food effect on PK was investigated, where the food intake might increase the bioavailability of furmonertinib via increasing the splanchnic blood flow. Overall, a population PK model was successfully developed to characterize the nonstationary PK of furmonertinib and AST5902 simultaneously. The concentrations of total active compounds were less affected by the autoinduction of furmonertinib metabolism.

LY2874455 and Abemaciclib Reverse FGF3/4/19/CCND1 Amplification Mediated Gefitinib Resistance in NSCLC

Non-small cell lung carcinoma (NSCLC) patients who initially received tyrosine kinase inhibitor (TKI) therapy often acquired resistance via multiple complex mechanisms. The amplification of FGF3/4/19/CCND1 on chromosome 11q13 was found in many cancers with TKI resistance. However, the role of these amplifications in TKI-resistant NSCLC remains uncovered. Here, we generated the FGF3/4/19/CCND1 amplification model in the NSCLC cell lines PC-9 and HCC827. Upregulation of FGF3/4/19/CCND1 strongly promoted cell proliferation and gefitinib resistance in NSCLC cells. To find out the potential therapeutic strategies, we screened the combination of inhibitors against the FGF/FGFR signaling pathway and the CCND1/CDK4 complex and revealed that gefitinib combined with LY2874455 and abemaciclib exhibited the most effective inhibition of resistance in vitro and in vivo. Mechanistically, FGFs/CCND1 activated the MAPK pathway, which was abolished by the combination drugs. Our study provides a rationale for clinical testing of dual targeting FGFR and CCND1 with LY2874455 and abemaciclib in NSCLC patients who harbored FGF3/4/19/CCND1 amplification.

YES1: a novel therapeutic target and biomarker in cancer

YES1 is a non-receptor tyrosine kinase that belongs to the SRC family of kinases (SFKs) and controls multiple cancer signaling pathways. YES1 is amplified and overexpressed in many tumor types, where it promotes cell proliferation, survival and invasiveness. Therefore, YES1 has been proposed as an emerging target in solid tumors. In addition, studies have shown that YES1 is a prognostic biomarker and a predictor of dasatinib activity. Several SFKs-targeting drugs have been developed and some of them have reached clinical trials. However, these drugs have encountered challenges to their utilization in the clinical practice in unselected patients due to toxicity and lack of efficacy. In the case of YES1, novel specific inhibitors have been developed and tested in preclinical models, with impressive antitumor effects. In this review, we summarize the structure and activation of YES1 and describe its role in cancer as a target and prognostic and companion biomarker. We also address the efficacy of SFKs inhibitors that are currently in clinical trials, highlighting the main hindrances for their clinical use. Current available information strongly suggests that inhibiting YES1 in tumors with high expression of this protein is a promising strategy against cancer.

Repurposing the Kinase Inhibitor Mavelertinib for Giardiasis Therapy

A phenotypic screen of the ReFRAME compound library was performed to identify cell-active inhibitors that could be developed as therapeutics for giardiasis. A primary screen against Giardia lamblia GS clone H7 identified 85 cell-active compounds at a hit rate of 0.72%. A cytotoxicity counterscreen against HEK293T cells was carried out to assess hit compound selectivity for further prioritization. Mavelertinib (PF-06747775), a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), was identified as a potential new therapeutic based on indication, activity, and availability after reconfirmation. Mavelertinib has in vitro efficacy against metronidazole-resistant 713-M3 strains. Other EGFR-TKIs screened in follow-up assays exhibited insignificant inhibition of G. lamblia at 5 μM, suggesting that the primary molecular target of mavelertinib may have a different mechanistic binding mode from human EGFR-tyrosine kinase. Mavelertinib, dosed as low as 5 mg/kg of body weight or as high as 50 mg/kg, was efficacious in the acute murine Giardia infection model. These results suggest that mavelertinib merits consideration for repurposing and advancement to giardiasis clinical trials while its analogues are further developed.

A Review on Fused Pyrimidine Systems as EGFR Inhibitors and Their Structure–Activity Relationship

Epidermal growth factor receptor (EGFR) belongs to the family of tyrosine kinase that is activated when a specific ligand binds to it. The EGFR plays a vital role in the cellular proliferation process, differentiation, and apoptosis. In the case of cancer, EGFR undergoes uncontrolled auto-phosphorylation that results in increased cellular proliferation and decreased apoptosis, causing cancer promotion. From the literature, it shows that pyrimidine is one of the most commonly studied heterocycles for its antiproliferative activity against EGFR inhibition. The authors have collated some interesting results in the heterocycle-fused pyrimidines that have been studied using different cell lines (sensitive and mutational) and in animal models to determine their activity and potency. It is quite clear that the fused systems are highly effective in inhibiting EGFR activity in cancer cells. Therefore, the structure–activity relationship (SAR) comes into play in determining the nature of the heterocycle and the substituents that are responsible for the increased activity and toxicity. Understanding the SAR of heterocycle-fused pyrimidines will help in getting a better overview of the molecules concerning their activity and potency profile as future EGFR inhibitors.

Semaphorin 4B promotes tumor progression and associates with immune infiltrates in lung adenocarcinoma

BACKGROUND

Semaphorins have been found to play important roles in multiple malignancy-related processes. However, the role of Semaphorin 4B (SEMA4B) in lung cancer remains unclear. Here, we aimed to explore the biological functions of SEMA4B in through bioinformatic analysis, in vitro and in vivo assays. In the present study, the possible mechanism by which SEMA4B affected the tumor growth and microenvironment of lung adenocarcinoma (LUAD) were investigated.

METHODS

The expression of SEMA4B in LUAD was analyzed by bioinformatic analysis and verified by the immunohistochemistry staining. The prognostic value of SEMA4B in LUAD was investigated using the Kaplan-Meier survival and Cox's regression model. After silencing SEMA4B expression, the functions of SEMA4B in LUAD cells were investigated by in vitro experiments, including CCK-8 and plate clone formation. And the effect of SEMA4B on tumor growth and immune infiltration was explored in C57BL/6 mice tumor-bearing models.

RESULTS

SEMA4B expression was upregulated in LUAD tissues and correlated with later pathological stages and poor prognosis of LUAD patients. Further study found that SEMA4B silencing suppressed the proliferation of lung cancer cells both in vitro and in vivo. Bioinformatic analysis showed that SEMA4B expression was correlated with the increased infiltration of myeloid-derived suppressor cells (MDSCs), T-regs and the decreased infiltration of CD8⁺ T cell in LUAD. Importantly, in vivo study verified that the infiltration of T-regs and MDSCs in tumor microenvironment (TME) of Xenograft tissues was decreased after SEMA4B silencing.

CONCLUSIONS

These findings demonstrated SEMA4B might play an oncogenic role in LUAD progression, and be a promising therapeutic target for lung cancer.

Detection of MET amplification by droplet digital PCR in peripheral blood samples of non-small cell lung cancer

PURPOSE

Mesenchymal-epithelial transition (MET) amplification is one of the mechanisms accounting for the resistance of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in lung cancer patients, as well as the poor prognosis. Fluorescence in situ hybridization (FISH) is the most widely used method for MET amplification detection. However, it is inapplicable when tissue samples were unavailable. Herein, we assessed the value of droplet digital PCR (ddPCR) in MET copy number gain (CNG) detection in non-small cell lung cancer (NSCLC) patients treated with EGFR-TKIs.

MATERIALS AND METHODS

A total of 103 cancer tissues and the paired peripheral blood samples from NSCLC patients were collected for MET CNG detection using ddPCR. In parallel, MET amplification in tissue samples was verified by FISH. Also, the relationships between MET CNG and EGFR T790M, as well as the EGFR-TKI resistance were also evaluated using Chi-square or Fisher's exact tests.

RESULT

The concordance rate of ddPCR and FISH in detecting MET CNG in tissue samples was 100% (102/102), and it was 94.17% (97/103) for ddPCR method in detecting the MET CNG among peripheral blood and tissue samples. No statistical difference was observed between MET amplification and EGFR T790M (p = 0.65), while MET amplification rate was significantly increased in patients with resistance to third generations of EGFR-TKIs as compared with patients with resistance to first/second EGFR-TKIs (p < 0.05).

CONCLUSIONS

ddPCR is an alternative method to detect MET CNG in both tissues and peripheral blood samples, which is of worthy in clinical promotion.

Design, Synthesis, and Antitumor Activity of Erlotinib Derivatives

Nineteen erlotinib derivatives bearing different 1,2,3-triazole moieties were designed, synthesized, and evaluated for their potential against different cancer cell lines. The structures of the synthesized compounds were confirmed via 1H NMR, 13C NMR, and HR MS. Preliminary antitumor activity assay results suggested that some compounds showed remarkable inhibitory activity against different cancer cell lines including the corresponding drug-resistant ones. Among these compounds, 3d was the most promising one with an IC50 of 7.17 ± 0.73 μM (KYSE70TR), 7.91 ± 0.61 μM (KYSE410TR), 10.02 ± 0.75 μM (KYSE450TR), 5.76 ± 0.3 3 μM (H1650TR), and 2.38 ± 0.17 μM (HCC827GR). A preliminary mechanism study suggested that compound 3d suppressed cancer cell proliferation through the EGFR-TK pathway.

Analysis to determine the effect of mutations on binding to small chemical molecules

In this paper, the authors present and describe, in detail, an original software-implemented numerical methodology used to determine the effect of mutations on binding to small chemical molecules, on the example of gefitinib, AMPPNP, CO-1686, ASP8273, erlotinib binding with EGFR protein, and imatinib binding with PPARgamma. Furthermore, the developed numerical approach makes it possible to determine the stability of a molecular complex, which consists of a protein and a small chemical molecule. The description of the software package that implements the presented algorithm is given in the website: https://binomlabs.com/ .