PCC0208027, a novel tyrosine kinase inhibitor, inhibits tumor growth of NSCLC by targeting EGFR and HER2 aberrations

Profiling of ERBB receptors and downstream pathways reveals selectivity and hidden properties of ERBB4 antagonists

ERBB receptor tyrosine kinases are involved in development and diseases like cancer, cardiovascular, neurodevelopmental, and mental disorders. Although existing drugs target ERBB receptors, the next generation of drugs requires enhanced selectivity and understanding of physiological pathway responses to improve efficiency and reduce side effects. To address this, we developed a multilevel barcoded reporter profiling assay, termed 'ERBBprofiler', in living cells to monitor the activity of all ERBB targets and key physiological pathways simultaneously. This assay helps differentiate on-target therapeutic effects from off-target and off-pathway side effects of ERBB antagonists. To challenge the assay, eight established ERBB antagonists were profiled. Known effects were confirmed, and previously uncharacterized properties were discovered, such as pyrotinib's preference for ERBB4 over EGFR. Additionally, two lead compounds selectively targeting ERBB4 were profiled, showing promise for clinical trials. Taken together, this multiparametric profiling approach can guide early-stage drug development and lead to improved future therapeutic interventions.

Dual kinase inhibitor for EGFR mutants and ErbB2 limit breast cancer

Mutations in the epidermal growth factor receptor (EGFR) have been found in more than 10% of non-small cell lung cancer (NSCLC) patients in North America. The vast majority of these differences are L858R point mutations in Exon 21. Currently, monoclonal antibodies directed against the extracellular domain of EGFR or small molecule/tyrosine kinase inhibitors (TKI) are the stalwarts of NSCLC therapy. Resistance, however, gradually develops because of the T790 mutation towards first and second generation TKIs. The third generation TKI AZD9291 (Osimertinib) has a high affinity for both activating and the acquired resistant mutation (T790 M) in EGFR, with a low affinity towards wild-type EGFR. Recent research, however, suggests that the EGFR (C797S) mutation in the tyrosine kinase domain is a likely cause of resistance to AZD9291. Another significant transformation mechanism associated with this resistance is erbB2 amplification. Our laboratory has developed a small kinase inhibitor, ER121 (MW: ∼500), that inhibits the erbB2/HER2 tyrosine kinases in addition to the EGFR C797S mutations. We have identified a TKI, ER121 targeting the mutant EGFR(T790 M). Using in vitro and in vivo models, examined the efficacy of ER121 on mutant EGFR cell lines. This has enabled us to establish that ER121 is well tolerated when administered orally and produces significant inhibitory activity against human cancers generated by mutant EGFR and amplified ErbB2.

Reverse predictive analysis of Rhizoma Pinelliae and Rhizoma Coptidis on differential miRNA target genes in lung adenocarcinoma

To use bioinformatics and network analysis to reveal the mechanism of "Rhizoma Pinelliae-Rhizoma Coptidis" herb pair in the treatment of lung adenocarcinoma. The target and pathway of "Rhizoma Pinelliae-Rhizoma Coptidis" herb pair in the treatment of lung adenocarcinoma were explored by online databases and network analysis tools, and the potential biomarkers of "Rhizoma Pinelliae-Rhizoma Coptidis" herb pair in the treatment of lung adenocarcinoma were predicted in reverse. A total of 59 traditional Chinese medicine compounds and 510 drug targets were screened in this study. A total of 25 micro-RNAs and 15,323 disease targets were obtained through GEO2R software analysis. In the end, 294 therapeutic targets and 47 core targets were obtained. A total of 186 gene ontology enrichment assays were obtained, and core therapeutic targets play multiple roles in biological processes, molecular functions, and cellular composition. Kyoto encyclopedia of genes and genomes pathway enrichment analysis showed that the core targets were mainly enriched in cancer-related pathways, immune-related pathways, endocrine-related pathways, etc, among which the non-small cell lung cancer pathway was the most significant core pathway. Molecular docking shows that the compound and the target have good binding ability. "Rhizoma Pinelliae-Rhizoma Coptidis" herb pair plays a mechanism of action in the treatment of lung adenocarcinoma through multiple targets and pathways. miR-5703, miR-3125, miR-652-5P, and miR-513c-5p may be new biomarkers for the treatment of lung adenocarcinoma.

Investigation of molecular mechanism leading to gefitinib and osimertinib resistance against EGFR tyrosine kinase: molecular dynamics and binding free energy calculation

Tyrosine kinase (TK) is an important protein responsible for phosphorylation of variety of proteins that helps in signal transduction process in transferring signal to regulate various physiological and biochemical processes. Drugs inhibiting signal transduction pathways can be a very rational approach to inhibit cellular physiological and biochemical process. Tyrosine kinase inhibitors are a wide family of drugs that have been used successfully in cancer chemotherapy. Certain mutations around the catalytic cleft may cause conformational changes at binding site and leads to decrease in inhibitor sensitivity to TK mutants. EGFR^T790M mutation is the first recognized acquired resistance after tyrosine kinase inhibitor therapy that leads to resistant to first generation TKI in about 50% of non-small cell lung carcinoma patients. Third generation EGFR-TKIs bind irreversibly to the C797, which is present in the ATP-binding pocket. The present work provides a molecular mechanism for understanding the Gefitinib and Osimertinib sensitivities with the EGFR^WILD, EGFR^L858R, EGFR^T790M, EGFR^T790M+C797S mutants using molecular modelling techniques. Changes in response against Gefitinib and Osimertinib were observed with the change of amino acids at the tyrosine kinase domain of EGFR^WILD and its mutants (EGFR^L858R, EGFR^T790M, EGFR^T790M+C797S). RMSD, RMSF and binding energies calculation well correlates with the change in clinical observation.Communicated by Ramaswamy H. Sarma.

The Development of Positron Emission Tomography Tracers for In Vivo Targeting the Kinase Domain of the Epidermal Growth Factor Receptor

Multiple small molecule PET tracers have been developed for the imaging of the epidermal growth factor receptor (EGFR). These tracers target the tyrosine kinase (TK) domain of the receptor and have been used for both quantifying EGFR expression and to differentiate between EGFR mutational statuses. However, the approaches for in vivo evaluation of these tracers are diverse and have resulted in data that are hard to compare. In this review, we analyze the historical development of the in vivo evaluation approaches, starting from the first EGFR TK PET tracer [11C]PD153035 to tracers developed based on TK inhibitors used for the clinical treatment of mutated EGFR expressing non-small cell lung cancer like [11C]erlotinib and [18F]afatinib. The evaluation of each tracer has been compiled to allow for a comparison between studies and ultimately between tracers. The main challenges for each group of tracers are thereafter discussed. Finally, this review addresses the challenges that need to be overcome to be able to efficiently drive EGFR PET imaging forward.

Discovery of potent antiproliferative agents from selected oxygen heterocycles as EGFR tyrosine kinase inhibitors from the U.S. National Cancer Institute database by in silico screening and bioactivity evaluation

A similarity search was conducted on the U.S. Enhanced National Cancer Institute Database Browser 2.2 to find structures related to 1,5-dihydroxy-9H-xanthen-9-one, a previously established EGFR-TK inhibitor. Compounds were virtually screened and selected for bioactivity testing revealed 5 candidates, mostly displayed stronger antiproliferative activities than erlotinib with IC₅₀ values between 0.95 and 17.71 μM against overexpressed EGFR-TK cancer cell lines: A431 and HeLa. NSC107228 displayed the strongest antiproliferative effects with IC₅₀ values of 2.84 and 0.95 μM against A431 and HeLa cancer cell lines, respectively. Three compounds, NSC81111, NSC381467 and NSC114126 inhibited EGFR-TK with IC₅₀ values between 0.15 and 30.18 nM. NSC81111 was the best inhibitor with IC₅₀ = 0.15 nM. Molecular docking analysis of the 3 compounds predicted hydrogen bonding and hydrophobic interactions with key residues were important for the bioactivities observed. Furthermore, calculations of the physicochemical properties suggest the compounds are drug-like and are potentially active orally.

EGFR tyrosine kinase inhibitor Almonertinib induces apoptosis and autophagy mediated by reactive oxygen species in non-small cell lung cancer cells

Almonertinib, a new third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is highly selective to EGFR T790M-mutant non-small cell lung cancer (NSCLC). However, there is no available information on the form and molecular mechanism of Almonertinib-induced death in NSCLC cells. Herein, CCK-8 and colony formation assays, flow cytometry, electron microscopy, and western blots assay showed that Almonertinib inhibited NSCLC cells growth and proliferation by inducing apoptosis and autophagy which can be inhibited by a broad spectrum of caspase inhibitor Z-VAD-fmk or autophagy inhibitor chloroquine. Importantly, Almonertinib-induced autophagy was cytoprotective in NSCLC cells, and the blockade of autophagy improved cell apoptosis. In addition, Almonertinib increased reactive oxygen species (ROS) generation and clearance of ROS through pretreatment with N-acetyl-L-cysteine (NAC) inhibited the decrease of cell viability, apoptosis and increase of LC3-II induced by Almonertinib. The results of Western blot showed that both EGFR activity and downstream signaling pathways were inhibited by Almonertinib. Taken together, these findings indicated that Almonertinib induced apoptosis and autophagy by promoting ROS production in NSCLC cells.

[EGFR tyrosine kinase inhibitor HS-10296 induces autophagy and apoptosis in triplenegative breast cancer MDA-MB-231 cells]

OBJECTIVE

To investigate the inhibitory effect of epidermal growth factor receptor tyrosine kinase inhibitor (EGFRTKI) HS-10296 on the proliferation of triple-negative breast cancer (TNBC) MDA-MB-231 cells and explore the possible molecular mechanism.

METHODS

MDA-MB-231 cells were treated with HS-10296 for 24, 48, or 72 h, and CCK-8 assay was used to assess the changes in the cell viability. The inhibitory effect of HS-10296 on cell proliferation was determined by clonogenic assay. JC-1 and flow cytometry were employed for analyzing the cell apoptosis, and the ultrastructure of the cells was observed under electron microscope. After pretreatment with autophagy inhibitor chloroquine (CQ), MDA-MB-231 cells were divided into control group, CQ treatment group, HS-10296 (4 and 6 μmol/L) treatment groups and combined treatment groups, and the sensitivity of the treated cells to HS-10296 was determined using CCK-8 assay. The effects of HS-10296 on EGFR pathway and apoptosis- and autophagy-related proteins in MDA-MB-231 cells were investigated using Western blotting.

RESULTS

HS-10296 significantly inhibited the proliferation of MDA-MB-231 cells with IC₅₀ values at 24, 48 and 72 h of 8.393, 2.777 and 2.016 μmol/L, respectively. JC-1 and flow cytometry showed that HS-10296 induced obvious apoptosis of MDA-MB-231 cells, which showed an apoptosis rate of (21.63 ± 2.97)% following treatment with 8 μmol/L HS-10296. Autophagy vesicles were observed in the cells treated with HS-10296 under electron microscope. In MDA-MB-231 cells pretreated with CQ, inhibition of autophagy significantly enhanced HS-10296-induced cell death. Western blotting showed that the apoptosis-related protein caspase-3 was activated after HS-10296 treatment to cut its substrate PARP. The expression of autophagy-related protein light chain 3B (LC3B) was significantly enhanced after HS-10296 treatment (P < 0.01), which also resulted in inhibited phosphorylation of EGFR and AKT proteins in the cells.

CONCLUSIONS

HS-10296 can inhibit the proliferation and induce autophagy and apoptosis of MDA-MB-231 cells by inhibiting the EGFR/PI3K/AKT signaling pathway.

Current Strategies for Treating NSCLC: From Biological Mechanisms to Clinical Treatment

The identification of specific epidermal growth factor receptor (EGFR)-activating mutations heralded a breakthrough in non-small-cell lung cancer (NSCLC) treatments, with the subsequent development of EGFR-tyrosine kinase inhibitor (TKIs) becoming the first-line therapy for patients harboring EGFR mutations. However, acquired resistance to EGFR-TKIs inevitably occurs in patients following initial TKI treatment, leading to disease progression. Various mechanisms are behind the acquired resistance, and mainly include (1) target gene modification, (2) alternative parallel pathway activation, (3) downstream pathway activation, and (4) histological/phenotypic transformation. Approaches to combat the acquired resistance have been investigated according to these mechanisms. Newer generations of TKIs have been developed to target the secondary/tertiary EGFR mutations in patients with acquired resistance. In addition, combination therapies have been developed as another promising strategy to overcome acquired resistance through the activation of other signaling pathways. Thus, in this review, we summarize the mechanisms for acquired resistance and focus on the potential corresponding therapeutic strategies for acquired resistance.

Conformational Insight on WT- and Mutated-EGFR Receptor Activation and Inhibition by Epigallocatechin-3-Gallate: Over a Rational Basis for the Design of Selective Non-Small-Cell Lung Anticancer Agents

Non-small cell lung cancer (NSCLC) represents a difficult condition to treat, due to epidermal growth factor receptor (EGFR) kinase domain mutations, which lead to ligand-independent phosphorylation. Deletion of five amino acids (ELREA) in exon 19 and mutational change from leucine to arginine at position 858 (L858R) are responsible for tyrosine kinase domain aberrant activation. These two common types of EGFR-mutated forms are clinically associated with high response with Tyrosine Kinase Inhibitors (TKI); however, the secondary T790M mutation within the Tyrosine Kinase Domain (TKD) determines a resistance to these EGFR-TKIs. Using molecular dynamic simulation (MD), the present study investigated the architectural changes of wild-type and mutants EGFR's kinase domains in order to detect any conformational differences that could be associated with a constitutively activated state and thus to evaluate the differences between the wild-type and its mutated forms. In addition, in order to evaluate to which extent the EGFR mutations affect its inhibition, Epigallocatechin 3-Gallate (EGCG) and Erlotinib (Erl), known EGFR-TKI, were included in our study. Their binding modes with the EGFR-TK domain were elucidated and the binding differences between EGFR wild-type and the mutated forms were evidenced. The aminoacids mutations directly influence the binding affinity of these two inhibitors, resulting in a different efficacy of Erl and EGCG inhibition. In particular, for the T790M/L858R EGFR, the binding modes of studied inhibitors were compromised by aminoacidic substitution confirming the experimental findings. These results may be useful for novel drug design strategies targeting the dimerization domain of the EGFR mutated forms, thus preventing receptor activation.

Targeting Autophagy for Overcoming Resistance to Anti-EGFR Treatments

Epidermal growth factor receptor (EGFR) plays critical roles in cell proliferation, tumorigenesis, and anti-cancer drug resistance. Overexpression and somatic mutations of EGFR result in enhanced cancer cell survival. Therefore, EGFR can be a target for the development of anti-cancer therapy. Patients with cancers, including non-small cell lung cancers (NSCLC), have been shown to response to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) and anti-EGFR antibodies. However, resistance to these anti-EGFR treatments has developed. Autophagy has emerged as a potential mechanism involved in the acquired resistance to anti-EGFR treatments. Anti-EGFR treatments can induce autophagy and result in resistance to anti-EGFR treatments. Autophagy is a programmed catabolic process stimulated by various stimuli. It promotes cellular survival under these stress conditions. Under normal conditions, EGFR-activated phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase (AKT)/mammalian target of rapamycin (mTOR) signaling inhibits autophagy while EGFR/rat sarcoma viral oncogene homolog (RAS)/mitogen-activated protein kinase kinase (MEK)/mitogen-activated protein kinase (MAPK) signaling promotes autophagy. Thus, targeting autophagy may overcome resistance to anti-EGFR treatments. Inhibitors targeting autophagy and EGFR signaling have been under development. In this review, we discuss crosstalk between EGFR signaling and autophagy. We also assess whether autophagy inhibition, along with anti-EGFR treatments, might represent a promising approach to overcome resistance to anti-EGFR treatments in various cancers. In addition, we discuss new developments concerning anti-autophagy therapeutics for overcoming resistance to anti-EGFR treatments in various cancers.