Kinase ErbB2 Research Articles

One-Pot multicomponent synthesis of novel pyrazole-linked thiazolyl-pyrazolines: Molecular docking and cytotoxicity assessment on breast and lung cancer cell-lines

Cancer remains a foremost cause of mortality globally, with approximately 20 million new cases and nearly 10 million deaths reported in 2022. Lung and breast cancers are particularly prevalent and deadly, underscoring the critical need for novel therapeutic strategies. This study utilized a one-pot, multicomponent reaction (MCR) approach to synthesize a novel series of pyrazole-linked thiazolyl-pyrazolines. The optimal reaction conditions were determined by systematically varying bases, temperatures, reaction times, and solvents. The best yield was achieved using NaOH as the base at 50 °C with 2 h of stirring in ethanol. The synthesized compounds underwent thorough characterization through IR, mass spectrometry, and NMR spectroscopy. Molecular docking studies indicated strong binding affinities to the ErbB4 kinase, suggesting potential utility as kinase inhibitors. Compounds 5E, 5F, and 5G exhibited significant cytotoxicity against breast cancer cell lines, with IC50 values ranging from 15.79±1.272 to 28.38±1.520 µM. Meanwhile, compounds 5A, 5B, 5D, and 5G demonstrated potent effects against lung cancer cell lines, with IC50 values between 7.945±0.99 and 9.295±1.074 µM. Remarkably, compound 5G showed potent efficacy against both breast and lung cancers, with IC50 values of 28.38±1.520 µM and 9.02±1.07 µM, respectively. This study illuminates the critical role of pyrazole-linked thiazolyl-pyrazoline scaffolds in crafting powerful cancer therapeutics targeting ErbB4 (HER4) kinase. Unique in its dual functionality, ErbB4 can act as either an oncogene or a tumor suppressor in lung and breast cancers, contingent on specific cellular contexts and isoform variations. The dynamic expression of ErbB4 intricately modulates tumor growth and patient outcomes, marking it as a compelling therapeutic target for innovative treatments in both breast and lung cancer.

CDX2-Suppressed Colorectal Cancers Possess Potentially Targetable Alterations in Receptor Tyrosine Kinases and Other Colorectal-Cancer-Associated Pathways.

Colorectal cancer, a prevalent gastrointestinal carcinoma, has a high risk for recurrence when locally advanced and remains lethal when in an advanced stage. Prognostic biomarkers may help in better delineating the aggressiveness of this disease in individual patients and help to tailor appropriate therapies. CDX2, a transcription factor of gastrointestinal differentiation, has been proposed as a biomarker for good outcomes and could also be a marker of specific sub-types amenable to targeted therapies. Colorectal cancers from The Cancer Genome Atlas (TCGA) colorectal cohort and colon cancers from the Sidra-LUMC AC-ICAM cohort were categorized according to their expressions of CDX2 mRNA. Groups with CDX2 suppression were compared with cancers showing no suppression regarding their clinical and genomic characteristics. CDX2-suppressed colorectal cancers showed a high prevalence of Microsatellite Instability (MSI) and a lower prevalence of chromosomal Instability (CIN) compared to non-CDX2-suppressed cancers. In addition, CDX2-suppressed cancers had a higher prevalence of mutations in several receptor tyrosine kinase genes, including EGFR, ERBB3, ERBB4, RET, and ROS1. In contrast, CDX2-suppressed cancers displayed lower mutation frequencies than non-CDX2-suppressed cancers in the genes encoding for the two most frequently mutated tumor suppressors, APC and TP53, and the most frequently mutated colorectal cancer oncogene, KRAS. However, CDX2-suppressed colorectal cancers had a higher prevalence of mutations in alternative genes of the WNT/APC/β-catenin and KRAS/BRAF/MEK pathways. In addition, they showed frequent mutations in DNA damage response (DDR) genes, such as BRCA2 and ATM. CDX2-suppressed colorectal cancers constitute a genomically distinct subset of colon and rectal cancers that have a lower prevalence of KRAS, APC, and TP53 mutations, but a high prevalence of mutations in less commonly mutated colorectal cancer genes. These alterations could serve as targets for personalized therapeutics in this subset.

Integrative Modeling of Signaling Network Dynamics Identifies Cell Type-Selective Therapeutic Strategies for FGFR4-Driven Cancers.

Oncogenic FGFR4 signaling represents a potential therapeutic target in various cancer types, including triple-negative breast cancer and hepatocellular carcinoma. However, resistance to FGFR4 single-agent therapy remains a major challenge, emphasizing the need for effective combinatorial treatments. Our study sought to develop a comprehensive computational model of FGFR4 signaling and to provide network-level insights into resistance mechanisms driven by signaling dynamics. An integrated approach, combining computational network modeling with experimental validation, uncovered potent AKT reactivation following FGFR4 targeting in triple-negative breast cancer cells. Analyzing the effects of cotargeting specific network nodes by systematically simulating the model predicted synergy of cotargeting FGFR4 and AKT or specific ErbB kinases, which was subsequently confirmed through experimental validation; however, cotargeting FGFR4 and PI3K was not synergistic. Protein expression data from hundreds of cancer cell lines was incorporated to adapt the model to diverse cellular contexts. This revealed that although AKT rebound was common, it was not a general phenomenon. For example, ERK reactivation occurred in certain cell types, including an FGFR4-driven hepatocellular carcinoma cell line, in which there is a synergistic effect of cotargeting FGFR4 and MEK but not AKT. In summary, this study offers key insights into drug-induced network remodeling and the role of protein expression heterogeneity in targeted therapy responses. These findings underscore the utility of computational network modeling for designing cell type-selective combination therapies and enhancing precision cancer treatment. Significance: Computational predictive modeling of signaling networks can decipher mechanisms of cancer cell resistance to targeted therapies and enable identification of more effective cancer type-specific combination treatment strategies.

Targeting erbB Pathways in Breast Cancer: Dual Kinase Inhibition for Brain Metastasis and Prevention of p185HER2/Neu Tumor Development.

Breast cancer predominantly affects women and poses challenges in the treatment of both local and advanced diseases. In a previous study, we reported the effectiveness of ER121, a structurally resolved small compound specifically designed to target human cancers expressing or overexpressing mutant EGFR and HER2. The objective of this study is to assess the efficacy and toxicity of ER121 in metastatic and triple negative breast cancer (TNBC, HER2+) cells and tumor models. The Herceptin-resistant breast cancer cell line JIMT-1 was used in an in vivo tumor model, and MMTV-erbB2 (Fo5) transgenic mice models were used to evaluate the efficacy and safety of ER121 as neoadjuvant. ER121 treatment focusing on experimental brain metastasis in TNBC, HER2+ model, was quantified by total flux employing the In Vivo Imaging System (IVIS). We also compared the brain tissue from the treated and the controls groups. Additionally, ER121 was evaluated in JIMT-1, a Herceptin-resistant breast cancer cell line, both in vitro and in vivo tumor model. We also administered ER121 orally in neoadjuvant model with the MMTV-erbB2 (Fo5) transgenic mice, the survival rates were compared with the control group. Tumor-free survival of multiple treated groups were analyzed by Kaplan-Meier analysis employing the log-rank test with the Bonferroni correction using R Statistical Software. In this study, we present findings indicating that ER121 treatment significantly attenuated breast tumor growth using a TNBC, HER2+ model, focusing on experimental brain metastasis, as quantified by total flux employing IVIS. These observations were further corroborated by analysis of brain tissue from the treatment group compared to controls. Data is presented as Mean ± S.D. statistical significance was calculated using Student t test (*p < 0.05). Additionally, ER121 significantly inhibited JIMT-1, a Herceptin-resistant breast cancer cell line was used in vivo xenograft model. Additionally, we used a neoadjuvant model with the MMTV-erbB2 (Fo5) transgenics and the tumor-free survival rates exhibited a remarkable difference between the control and treated groups when ER121 was administered orally. We found statistically significant p values of 0.048 employing log-rank test with Bonferroni Correction for comparing ER121high, ER121 Low, Herceptin and PBS groups. All analyses were performed using R Statistical Software. ER121 is a non-toxic small-molecule erbB kinase inhibitor and holds promise as an oral and systemic therapeutic agent for treating progressive erbB-driven tumors in therapeutic settings. Moreover, ER121 shows potential as a preventive therapy in neoadjuvant settings for erbB2-associated tumors and when administered systemically can dramatically limit erbB2 brain metastases in animal models.

Isothiocyanates attenuate heparin-induced proliferation of colon cancer cells invitro.

Isothiocyanates (ITCs), prevalent in cruciferous vegetables, are known for their anticarcinogenic properties. Prior research has indicated that heparin can stimulate the growth of colon cancer cells. However, the implications of ITCs in the diet of cancer patients receiving heparin-based therapies have yet to be fully understood. This exploratory invitro study examines the proliferative effects of low-molecular-weight heparin (LMWH) on human colon cancer cells and assesses the antiproliferative potential of four ITC compounds, exploring possible epidermal growth factor family of receptor tyrosine kinases (Erb-B) related mechanisms. We evaluated cell viability in HCT-116 and HT-29 cell lines following treatment with ITCs alone or combined with LMWH (20 μg/mL) at various concentrations (1-100 μM). Clonogenic and wound-healing assays were performed after 24 h of treatment with 5 μM ITCs. Additionally, messenger RNA (mRNA) and protein expression of Erb-B family genes was measured using quantitative polymerase chain reaction (qPCR) and Western blotting. Statistical analysis was conducted using analysis of variance (ANOVA) with Dunnett's post hoc test. Results indicated that the half-maximal inhibitory concentration (IC50) values for Phenylethyl isothiocyanate (PEITC), Benzyl isothiocyanate (BITC), and Sulforaphane (SFN) were lower than those of Allyl isothiocyanate (AITC) in LMWH-stimulated HCT-116 (20.77, 19.10, and 44.05 μM, respectively) and HT-29 (74.94, 26.77, and 43.49 μM, respectively). PEITC and SFN significantly reduced ErbB1 (epidermal growth factor receptor (EGFR)) and ErbB4 (receptor tyrosine-protein kinase erbB-4) expression, while BITC decreased ErbB2 (receptor tyrosine-protein kinase erbB-2) and transforming growth factor beta (TGF-β) expression in HCT-116 cells (all, p < .05). PEITC, BITC, and SFN also increased proapoptotic Bax expression and decreased the antiapoptotic B-cell lymphoma 2 (Bcl-2) expression (all, p < .05). These findings suggest that specific ITCs may mitigate cancer cell proliferation induced by LMWH in cancer therapies, highlighting their potential therapeutic efficacy.

Ginsenoside Rd enhances blood-brain barrier integrity after cerebral ischemia/reperfusion by alleviating endothelial cells ferroptosis via activation of NRG1/ErbB4-mediated PI3K/Akt/mTOR signaling pathway

The incidence of ischemic stroke is increasing year by year and showing a younger trend. Impaired blood-brain barrier (BBB) is one of the pathological manifestations caused by cerebral ischemia, leading to poor prognosis of patients. Accumulating evidence indicates that ferroptosis is involved in cerebral ischemia/reperfusion injury (CIRI). We have previously demonstrated that Ginsenoside Rd (G-Rd) protects against CIRI-induced neuronal injury. However, whether G-Rd can attenuate CIRI-induced disruption of the BBB remains unclear. In this study, we found that G-Rd could upregulate the levels of ZO-1, occludin, and claudin-5 in ipsilateral cerebral microvessels and bEnd.3 cells, reduce endothelial cells (ECs) loss and Evans blue (EB) leakage, and ultimately improve BBB integrity after CIRI. Interestingly, the expressions of ACSL4 and COX2 were upregulated, the expressions of GPX4 and xCT were downregulated, the levels of GSH was decreased, and the levels of MDA and Fe2+ were increased in ischemic tissues and bEnd.3 cells after CIRI, suggesting that ECs ferroptosis occurred after CIRI. However, G-Rd can alleviate CIRI-induced BBB disruption by inhibiting ECs ferroptosis. Mechanistically, G-Rd prevented tight junction loss and BBB leakage by upregulating NRG1, activating its tyrosine kinase ErbB4 receptor, and then activating downstream PI3K/Akt/mTOR signaling, thereby inhibiting CIRI-induced ferroptosis in ECs. Taken together, these data provides data support for G-Rd as a promising therapeutic drug for cerebral ischemia.

Dynamic effects of ventral hippocampal NRG3/ERBB4 signaling on nicotine withdrawal-induced responses

Tobacco smoking remains a leading cause of preventable death in the United States, with approximately a 5% success rate for smokers attempting to quit. High relapse rates have been linked to several genetic factors, indicating that the mechanistic relationship between genes and drugs of abuse is a valuable avenue for the development of novel smoking cessation therapies. For example, various single nucleotide polymorphisms (SNPs) in the gene for neuregulin 3 (NRG3) and its cognate receptor, the receptor tyrosine-protein kinase erbB-4 (ERBB4), have been linked to nicotine addiction. Our lab has previously shown that ERBB4 plays a role in anxiety-like behavior during nicotine withdrawal (WD); however, the neuronal mechanisms and circuit-specific effects of NRG3-ERBB4 signaling during nicotine and WD are unknown. The present study utilizes genetic, biochemical, and functional approaches to examine the anxiety-related behavioral and functional role of NRG3-ERBB4 signaling, specifically in the ventral hippocampus (VH) of male and female mice. We report that 24hWD from nicotine is associated with altered synaptic expression of VH NRG3 and ERBB4, and genetic disruption of VH ErbB4 leads to an elimination of anxiety-like behaviors induced during 24hWD. Moreover, we observed attenuation of GABAergic transmission as well as alterations in Ca2+-dependent network activity in the ventral CA1 area of VH ErbB4 knock-down mice during 24hWD. Our findings further highlight contributions of the NRG3-ERBB4 signaling pathway to anxiety-related behaviors seen during nicotine WD.

Lipid environment modulates processivity and kinetics of a presenilin homolog acting on multiple substrates in vitro

Intramembrane proteases (IPs) hydrolyze peptides in the lipid membrane where they participate in a number of cellular pathways including immune response and surveillance, cholesterol biosynthesis, and they are exploited by viruses for replication. Despite their broad importance across biology, how activity is regulated in the cell to control protein maturation and release of specific bioactive peptides at the right place and right time remains largely unanswered, particularly for the intramembrane aspartyl protease (IAP) subtype. At a molecular biochemical level, different IAP homologs can cleave non-biological substrates and there is no sequence recognition motif among the nearly 150 substrates identified for just one IAP, presenilin-1, the catalytic component of γ-secretase known for its involvement in production of amyloid-β plaques associated with Alzheimer disease. Here we used gel-based assays combined with quantitative mass spectrometry and FRET-based kinetics assays to probe the cleavage profile of the presenilin homolog from the methanogen Methanoculleus marisnigri JR1 as a function of the surrounding lipid-mimicking environment, either detergent micelles or bicelles. We selected four biological IAP substrates that have not undergone extensive cleavage profiling previously, namely, the viral core protein of Hepatitis C virus, the viral core protein of Classical Swine Fever virus, the transmembrane segment of Notch-1, and the tyrosine receptor kinase ErbB4. Our study demonstrates a proclivity toward cleavage of substrates at positions of low average hydrophobicity and a consistent role for the lipid environment in modulating kinetic properties.

Energy Expenditure Homeostasis Requires ErbB4, an Obesity Risk Gene, in the Paraventricular Nucleus.

Obesity affects more than a third adult population in the United States; the prevalence is even higher in patients with major depression disorders. GWAS studies identify the receptor tyrosine kinase ErbB4 as a risk gene for obesity and for major depression disorders. We found that ErbB4 was enriched in the paraventricular nucleus of the hypothalamus (PVH). To investigate its role in metabolism, we deleted ErbB4 by injecting a Cre-expressing virus into the PVH of ErbB4-floxed male mice and found that PVH ErbB4 deletion increased weight gain without altering food intake. ErbB4 PVH deletion also reduced nighttime activity and decreased intrascapular brown adipose tissue (iBAT) thermogenesis. Analysis of covariance (ANCOVA) revealed that ErbB4 PVH deletion reduced O2 consumption, CO2 production and heat generation in a manner independent of body weight. Immunostaining experiments show that ErbB4+ neurons in the PVH were positive for oxytocin (OXT); ErbB4 PVH deletion reduces serum levels of OXT. We characterized mice where ErbB4 was specifically mutated in OXT+ neurons and found reduction in energy expenditure, phenotypes similar to PVH ErbB4 deletion. Taken together, our data indicate that ErbB4 in the PVH regulates metabolism likely through regulation of OXT expressing neurons, reveal a novel function of ErbB4 and provide insight into pathophysiological mechanisms of depression-associated obesity.

Nitrogen Mustard-Induced Ex Vivo Human Cornea Injury Model and Therapeutic Intervention by Dexamethasone.

Sulfur mustard (SM), a vesicating agent first used during World War I, remains a potent threat as a chemical weapon to cause intentional/accidental chemical emergencies. Eyes are extremely susceptible to SM toxicity. Nitrogen mustard (NM), a bifunctional alkylating agent and potent analog of SM, is used in laboratories to study mustard vesicant-induced ocular toxicity. Previously, we showed that SM-/NM-induced injuries (in vivo and ex vivo rabbit corneas) are reversed upon treatment with dexamethasone (DEX), a US Food and Drug Administration-approved, steroidal anti-inflammatory drug. Here, we optimized NM injuries in ex vivo human corneas and assessed DEX efficacy. For injury optimization, one cornea (randomly selected from paired eyes) was exposed to NM: 100 nmoles for 2 hours or 4 hours, and 200 nmoles for 2 hours, and the other cornea served as a control. Injuries were assessed 24 hours post NM-exposure. NM 100 nmoles exposure for 2 hours was found to cause optimal corneal injury (epithelial thinning [∼69%]; epithelial-stromal separation [6-fold increase]). In protein arrays studies, 24 proteins displayed ≥40% change in their expression in NM exposed corneas compared with controls. DEX administration initiated 2 hours post NM exposure and every 8 hours thereafter until 24 hours post-exposure reversed NM-induced corneal epithelial-stromal separation [2-fold decrease]). Of the 24 proteins dysregulated upon NM exposure, six proteins (delta-like canonical Notch ligand 1, FGFbasic, CD54, CCL7, endostatin, receptor tyrosine-protein kinase erbB-4) associated with angiogenesis, immune/inflammatory responses, and cell differentiation/proliferation, showed significant reversal upon DEX treatment (Student's t test; P ≤ 0.05). Complementing our animal model studies, DEX was shown to mitigate vesicant-induced toxicities in ex vivo human corneas. SIGNIFICANCE STATEMENT: Nitrogen mustard (NM) exposure-induced injuries were optimized in an ex vivo human cornea culture model and studies were carried out at 24 h post 100 nmoles NM exposure. Dexamethasone (DEX) administration (started 2 h post NM exposure and every 8 h thereafter) reversed NM-induced corneal injuries. Molecular mediators of DEX action were associated with angiogenesis, immune/inflammatory responses, and cell differentiation/proliferation, indicating DEX aids wound healing via reversing vesicant-induced neovascularization (delta-like canonical Notch ligand 1 and FGF basic) and leukocyte infiltration (CD54 and CCL7).

ErbBs in Lens Cell Fibrosis and Secondary Cataract.

TGFβ-induced epithelial-to-myofibroblast transition (EMyT) of lens cells has been linked to the most common vision-disrupting complication of cataract surgery-namely, posterior capsule opacification (PCO; secondary cataract). Although inhibitors of the ErbB family of receptor tyrosine kinases have been shown to block some PCO-associated processes in model systems, our knowledge of ErbB signaling in the lens is very limited. Here, we investigate the expression of ErbBs and their ligands in primary cultures of chick lens epithelial cells (dissociated cell-derived monolayer cultures [DCDMLs]) and how TGFβ affects ErbB function. DCDMLs were analyzed by immunofluorescence microscopy and Western blotting under basal and profibrotic conditions. Small-molecule ErbB kinase blockers, including the human therapeutic lapatinib, selectively inhibit TGFβ-induced EMyT of DCDMLs. Lens cells constitutively express ErbB1 (EGFR), ErbB2, and ErbB4 protein on the plasma membrane and release into the medium ErbB-activating ligand. Culturing DCDMLs with TGFβ increases soluble bioactive ErbB ligand and markedly alters ErbBs, reducing total and cell surface ErbB2 and ErbB4 while increasing ErbB1 expression and homodimer formation. Similar, TGFβ-dependent changes in relative ErbB expression are induced when lens cells are exposed to the profibrotic substrate fibronectin. A single, 1-hour treatment with lapatinib inhibits EMyT in DCDMLs assessed 6 days later. Short-term exposure to lower doses of lapatinib is also capable of eliciting a durable response when combined with suboptimal levels of a mechanistically distinct multikinase inhibitor. Our findings support ErbB1 as a therapeutic target for fibrotic PCO, which could be leveraged to pharmaceutically preserve the vision of millions of patients with cataracts.

Androgen receptor transcriptional activity is required for heregulin-1β–mediated nuclear localization of the HER3/ErbB3 receptor tyrosine kinase

Prostate cancer is initially regulated by the androgen receptor (AR), a ligand-activated, transcription factor, and is in a hormone-dependent state (hormone-sensitive prostate cancer (HSPC)), but eventually becomes androgen-refractory (castration-resistant prostate cancer (CRPC)) because of mechanisms that bypass the AR, including by activation of ErbB3, a member of the epidermal growth factor receptor family. ErbB3 is synthesized in the cytoplasm and transported to the plasma membrane for ligand binding and dimerization, where it regulates downstream signaling, but nuclear forms are reported. Here, we demonstrate in prostatectomy samples that ErbB3 nuclear localization is observed in malignant, but not benign prostate, and that cytoplasmic (but not nuclear) ErbB3 correlated positively with AR expression but negatively with AR transcriptional activity. In support of the latter, androgen depletion upregulated cytoplasmic, but not nuclear ErbB3, while invivo studies showed that castration suppressed ErbB3 nuclear localization in HSPC, but not CRPC tumors. Invitro treatment with the ErbB3 ligand heregulin-1β (HRG) induced ErbB3 nuclear localization, which was androgen-regulated in HSPC but not in CRPC. In turn, HRG upregulated AR transcriptional activity in CRPC but not in HSPC cells. Positive correlation between ErbB3 and AR expression was demonstrated in AR-null PC-3cells where stable transfection of AR restored HRG-induced ErbB3 nuclear transport, while AR knockdown in LNCaP reduced cytoplasmic ErbB3. Mutations of ErbB3's kinase domain did not affect its localization but was responsible for cell viability in CRPC cells. Taken together, we conclude that AR expression regulated ErbB3 expression, its transcriptional activity suppressed ErbB3 nuclear translocation, and HRG binding to ErbB3 promoted it.

Abstract 540: c-MET mutations sensitize to antibody-drug conjugate telisotuzumab vedotin through efficient internalization and rapid intracellular drug delivery

Abstract Background: Telisotuzumab vedotin (Teliso-V) is an antibody-drug conjugate (ADC) composed of the c-MET antibody ABT-700 and the microtubule inhibitor monomethyl auristatin E (MMAE). Patients with EGFR wildtype (WT) nonsquamous non-small cell lung cancer with high c-MET expression had an overall response rate of 54% with Teliso-V. In addition to overexpression and amplification, genetic alterations in c-MET, such as exon 14 deletion (ex14del) and missense mutations in the tyrosine kinase domain (TKD), contribute to its constitutive activation. The efficacy of Teliso-V in context of these genomic backgrounds is currently unknown. Methods: Recombinant retroviruses were used to express WT-c-MET, c-MET-TKD (D1228H/V/N and Y1230C/H mutations), c-MET-Y1003F/N (CBL E3 ubiquitin ligase binding site mutation), and c-MET-ex14del (47 aa juxtamembrane deletion) mutants in NIH3T3 and Ba/F3 cells. c-MET surface expression, intracellular signaling, ADC internalization and endolysosomal (EL) trafficking (using pHrodo Red-labeled Teliso-V), intracellular MMAE by LC/MS, and Teliso-V sensitivity were studied in 2D/3D cell cultures. Full-length c-MET protein structures were created with the ColabFold program and molecular dynamics simulation software (with/without artificial lipid bilayer) was used to predict the mechanistic basis for differential function. Results: c-MET expression was required for Teliso-V cytotoxicity and intracellular payload delivery in all cell lines. Compared with WT-c-MET, various mutants showed oncogene-driven transformation evident by elevated levels of phosphorylated c-MET/AKT, cytokine-independent colony formation, oncogene-driven proliferation, and tyrosine kinase inhibitor (TKI) resistance. Interestingly, c-MET-TKD-expressing cells were the most sensitive to Teliso-V, which was associated with faster ADC internalization and EL trafficking. An AI-generated protein model and associated molecular dynamics simulation demonstrated that all oncogenic TKD variants tested stabilized the c-MET-plexin-semaphorin-integrin domain (R592-L614), known for its ability to position the extracellular ligand-binding (ELB) site for optimal activation. Conclusions: c-MET-TKD mutations induced TKI resistance and enhanced MMAE delivery in association with robust ADC internalization and EL trafficking. Previous studies have shown that the HER2 ADC fam-trastuzumab deruxtecan-nxki was highly effective in cell lines and patients with ERBB2 kinase domain-mutant lung cancer via a similar mechanism, raising the possibility that this may be a general phenomenon across receptor tyrosine kinase-targeting ADCs. c-MET-TKD mutations are predicted to stabilize the ELB conformation to activate enhanced oncogenic signaling that may contribute to rapid endocytosis-mediated drug delivery. Citation Format: Izhar S. Batth, Bijay S. Jaiswal, Dolonchampa Maji, Robert Sparks, William Glauser, Tamar Uziel, D. Ross Camidge, Athan Vasilopoulos, Peter Ansell, PK Epling-Burnette. c-MET mutations sensitize to antibody-drug conjugate telisotuzumab vedotin through efficient internalization and rapid intracellular drug delivery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 540.

The lonidamine derivative H2-gamendazole reduces cyst formation in polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is a debilitating renal neoplastic disorder with limited treatment options. It is characterized by the formation of large fluid-filled cysts that develop from kidney tubules through abnormal cell proliferation and cyst-filling fluid secretion driven by cAMP-dependent Cl- secretion. We tested the effectiveness of the indazole carboxylic acid H2-gamendazole (H2-GMZ), a derivative of lonidamine, to inhibit these processes using in vitro and in vivo models of ADPKD. H2-GMZ was effective in rapidly blocking forskolin-induced, Cl--mediated short-circuit currents in human ADPKD cells, and it significantly inhibited both cAMP- and epidermal growth factor-induced proliferation of ADPKD cells. Western blot analysis of H2-GMZ-treated ADPKD cells showed decreased phosphorylated ERK and decreased hyperphosphorylated retinoblastoma levels. H2-GMZ treatment also decreased ErbB2, Akt, and cyclin-dependent kinase 4, consistent with inhibition of heat shock protein 90, and it decreased levels of the cystic fibrosis transmembrane conductance regulator Cl- channel protein. H2-GMZ-treated ADPKD cultures contained a higher proportion of smaller cells with fewer and smaller lamellipodia and decreased cytoplasmic actin staining, and they were unable to accomplish wound closure even at low H2-GMZ concentrations, consistent with an alteration in the actin cytoskeleton and decreased cell motility. Experiments using mouse metanephric organ cultures showed that H2-GMZ inhibited cAMP-stimulated cyst growth and enlargement. In vivo, H2-GMZ was effective in slowing postnatal cyst formation and kidney enlargement in the Pkd1flox/flox: Pkhd1-Cre mouse model. Thus, H2-GMZ treatment decreases Cl- secretion, cell proliferation, cell motility, and cyst growth. These properties, along with its reported low toxicity, suggest that H2-GMZ might be an attractive candidate for treatment of ADPKD.NEW & NOTEWORTHY Autosomal dominant polycystic kidney disease (ADPKD) is a renal neoplastic disorder characterized by the formation of large fluid-filled cysts that develop from kidney tubules through abnormal cell proliferation and cyst-filling fluid secretion driven by cAMP-dependent Cl- secretion. This study shows that the lonidamine derivative H2-GMZ inhibits Cl- secretion, cell proliferation, and cyst growth, suggesting that it might have therapeutic value for the treatment of ADPKD.

Gene Identification and Potential Drug Therapy for Drug-Resistant Melanoma with Bioinformatics and Deep Learning Technology.

Background Melanomas are skin malignant tumors that arise from melanocytes which are primarily treated with surgery, chemotherapy, targeted therapy, immunotherapy, radiation therapy, etc. Targeted therapy is a promising approach to treating advanced melanomas, but resistance always occurs. This study is aimed at identifying the potential target genes and candidate drugs for drug-resistant melanoma effectively with computational methods. Methods Identification of genes associated with drug-resistant melanomas was conducted using the text mining tool pubmed2ensembl. Further gene screening was carried out by GO and KEGG pathway enrichment analyses. The PPI network was constructed using STRING database and Cytoscape. GEPIA was used to perform the survival analysis and conduct the Kaplan-Meier curve. Drugs targeted at these genes were selected in Pharmaprojects. The binding affinity scores of drug-target interactions were predicted by DeepPurpose. Results A total of 433 genes were found associated with drug-resistant melanomas by text mining. The most statistically differential functional enriched pathways of GO and KEGG analyses contained 348 genes, and 27 hub genes were further screened out by MCODE in Cytoscape. Six genes were identified with statistical differences after survival analysis and literature review. 16 candidate drugs targeted at hub genes were found by Pharmaprojects under our restrictions. Finally, 11 ERBB2-targeted drugs with top affinity scores were predicted by DeepPurpose, including 10 ERBB2 kinase inhibitors and 1 antibody-drug conjugate. Conclusion Text mining and bioinformatics are valuable methods for gene identification in drug discovery. DeepPurpose is an efficient and operative deep learning tool for predicting the DTI and selecting the candidate drugs.

An ErbB4-Positive Neuronal Network in the Olfactory Bulb for Olfaction.

Olfactory information is relayed and processed in the olfactory bulb (OB). Mitral cells, the principal output excitatory neurons of the OB, are controlled by multiple types of interneurons. However, mechanisms that regulate the activity of OB interneurons are not well understood. We provide evidence that the transmembrane tyrosine kinase ErbB4 is selectively expressed in subsets of OB inhibitory neurons in both male and female mice. ErbB4-positive (ErbB4+) neurons are mainly located in the glomerular layer (GL) and granule cell layer (GCL) and do not express previously defined markers. Optogenetic activation of GL-ErbB4+ neurons promotes theta oscillation, whereas activation of those in the GCL generates γ oscillations. Stimulation of OB slices with NRG1, a ligand that activates ErbB4, increases GABA transmission onto mitral cells, suggesting a role of OB NRG1-ErbB4 signaling in olfaction. In accord, ErbB4 mutant mice or acute inhibition of ErbB4 by a chemical genetic approach diminishes GABA transmission, reduces bulbar local field potential power, increases the threshold of olfactory sensitivity, and impairs odor discrimination. Together, these results identified a bulbar inhibitory network of ErbB4+ neurons for olfaction. Considering that both Nrg1 and Erbb4 are susceptibility genes for neuropsychiatric disorders, our study provides insight into pathologic mechanisms of olfactory malfunctions in these disorders.SIGNIFICANCE STATEMENT This study demonstrates that ErbB4+ neurons are a new subset of olfactory bulb inhibitory neurons in the glomerular layer and granule cell layer that innervate mitral cells and ErbB4- cells. They regulate olfaction by controlling local synchrony and distinct oscillations. ErbB4 inhibition diminishes GABA transmission, reduces bulbar local field potential power, increases the threshold of olfactory sensitivity, and impairs odor discrimination. Our results provide insight into pathophysiological mechanism of olfaction deficits in brain disorders associated with Nrg1 or Erbb4 mutations.

Abstract 2418: Markers for metastasis evaluation of the ErbB family and GDF15 inratosteosarcoma

Abstract The most recent advance in the treatment of osteosarcoma (OS) occurred in the 1980s when multi-agent chemotherapy was shown to improve overall survival compared to surgery alone. Animal model investigations can accelerate the understanding of human diseases and since few models are available for OS, we refined a rat model to ask questions regarding pathways of metastasis and metastasis biomarker predictiveness. The outbred Sprague-Dawley (SD) rat model is an immunocompetent, syngeneic model, as we implant UMR106 OS cells (ATCC), which were originally isolated from a SD OS. We developed a reproducible method to orthotopically implant cells into the tibia microenvironment and to amputate the limb for longitudinal studies. Using young rats, we also modeled pediatric OS. We found that rats develop reproducible primary and metastatic pulmonary tumors which histologically resemble human primary and metastatic osteosarcoma. Using immunohistochemistry methods, we found that primary OS is infiltrated with numerous macrophages with relatively fewer CD3+ T cells. A protein expression survey of these OS cells revealed significant expression of ErbB family receptor tyrosine kinases (ErbB2, ErbB4), which have recently been shown to be anti-inflammatory against macrophages. We also discovered that rats with osteosarcoma have markedly high serum levels of Growth Differentiation Factor 15 (GDF15), also called Macrophage Inhibitory Cytokine 1, a member of the TGF beta family of proteins, which is also frequently expressed with ErbB2 in cancers. GDF15 was measured by ELISA. Western blot analysis showed that GDF15 precursor (pro-peptide) was expressed in primary and metastases. This model will enable studies with anti-ErbB2 or GDF15 pathway inhibition to assess the role of macrophage activation in the setting of pathway inhibition and chemotherapy, as well as how pathway inhibition modulates metastasis incidence. In vivo and invitro, systems will enable the assessment of the role of GDF15 as a potential biomarker of metastasis, compared to tibial radiographic patterns, serum alkaline phosphatase, and lung histopathology. In conclusion, we have an immunocompetent, syngeneic orthotopic osteosarcoma rat model which affectively resembles human osteosarcoma, and can be used for better understanding metastasis mechanisms and metastasis biomarkers. Citation Format: Shun Ishiyama, Bailey West, Hyo-Jeong Han, Xin Guo, Tomoaki Ito, Harumi Saeki, Malcolm V. Brock, Kathleen Gabrielson. Markers for metastasis evaluation of the ErbB family and GDF15 inratosteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2418.

Abstract 1102: Fyn and Src cooperate with ERBB family to drive resistance to crizotinib in ROS1+ and ALK+ NSCLC

Abstract ALK/ROS1 TKIs have significantly improved outcomes for patients with ALK/ROS1+ lung adenocarcinoma. However, drug resistance inevitably develops, leading to disease progression. Approximately 1/3 of patients resistant to ROS1 TKIs demonstrate on-target ROS1 kinase domain (KD) mutations (Dziadziuszko et al. ESMO 2019), but the mechanism of resistance in most patients remains unknown/poorly characterized. To model and characterize acquired resistance to crizotinib, we used ROS1+ and ALK+ primary, patient tumor-derived non-small cell lung cancer (NSCLC) cell lines to generate acquired resistance models to the ALK/ROS1 inhibitor crizotinib. We used several techniques to probe the mechanisms driving resistance: DNA and RNA sequencing (seq), fluorescence in-situ hybridization (FISH), cell proliferation assays, and western blotting. The crizotinib-resistant line initially driven by a TPM3-ROS1 fusion (CUTO28-CR) displayed exquisite sensitivity to Src family kinase (SFK) TKIs in proliferation assays, which was modestly improved by addition of ERBB TKI afatinib. Bulk RNA seq revealed upregulation of SFKs Fyn and Src transcripts (141- and 2.31-fold, respectively). Interphase FISH revealed modest EGFR gene amplification in CUTO28-CR cells vs parental (EGFR:CEP7 ratio 2.1 vs 1.0), and RNA seq revealed upregulation of EGFR and HER2 transcripts (1.79- and 2.45-fold, respectively). Western blot analysis confirmed upregulation of Fyn at the protein level. CUTO28-CR cells treated with a SFK TKI revealed dose-dependent deactivation of Akt signaling, and addition of afatinib caused inhibition of MAPK signaling. Stimulation with epidermal growth factor (EGF) enhanced MAPK signaling in CUTO28-CR cells more than in parental cells, consistent with EGFR/HER2 dependence. Because of a noted propensity for the EML4-ALK line (H3122) to upregulate ERBB kinase activity under sustained ALK TKI treatment, we maintained these cells in low dose (25nM) afatinib while driving crizotinib resistance to identify additional bypass signaling pathways. These H3122-CAR cells were partially resensitized to crizotinib with the addition of SFK TKIs, and the addition of afatinib with SFK TKIs further resensitized these resistant cells to crizotinib. Bulk RNA seq of H3122-CAR cells revealed upregulation of Fyn and Src (2.64- and 3.63-fold, respectively), and western blot analysis confirmed upregulation at the protein level. In conclusion, we demonstrated increased SFK (particularly Fyn and/or Src) expression and/or activation is a mechanism utilized to drive bypass signaling, in cooperation with ERBB family kinases, to circumvent treatment with ALK/ROS1 TKI crizotinib. To our knowledge, this is the first report of SFK-driven bypass signaling as a mechanism of acquired resistance to an ALK/ROS1 TKI in NSCLC. The upregulation of Src and/or Fyn in NSCLC biopsies may guide the exploration of combination SFK TKIs with ALK/ROS1 TKIs. Citation Format: Logan C. Tyler, Nan Chen, Anh T. Le, Hala Nijmeh, Liming Bao, Robert C. Doebele. Fyn and Src cooperate with ERBB family to drive resistance to crizotinib in ROS1+ and ALK+ NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1102.

Abstract 828: Screen for actionable ERBB3 mutations

Abstract Activating mutations and copy number variations in ERBB genes have been shown to serve as oncogenic driver mutations and predictive biomarkers for ERBB inhibitor drugs. To address whether mutations in ERBB3 can affect the potential of ERBB3 to promote growth or affect sensitivity to ERBB inhibitors, we set up an unbiased functional screen for ERBB3 missense or nonsense mutations in the context of ERBB2/ERBB3 heterodimers. To this end, the iSCREAM (in vitro screen of activating mutations) pipeline, recently developed in our laboratory, was chosen. This platform exploits randomly mutated cDNA libraries of the gene of interest created with error-prone PCR and allows an unbiased assessment of growth-advantage conferred by thousands of mutations in parallel. To set up the model for screening actionable ERBB3 mutations, interleukin-3 (IL-3)-dependent Ba/F3 cells were engineered to express a homodimerization-incompetent ERBB2 V956R mutant together with ERBB3 constructs. The model was validated to serve as a readout for ERBB3's ability in activating ERBB2 kinase by demonstrating that cells expressing known transforming ERBB3 mutations, together with ERBB2 V956R, survived and expanded in the absence of IL-3. In contrast, control cells expressing ERBB2 V956R together with wild-type ERBB3 rapidly died in the absence of IL-3. The cell background with ERBB2 V956R expression was subsequently used as a target for retroviral expression of a cDNA library of randomly mutated ERBB3 constructs. The cells harboring activating ERBB3 mutations were allowed to evolve for 15-48 days. The identity of the mutations was determined from the surviving cell population by ERBB3-targeted next generation sequencing. The discovered activating mutations were validated by cloning them into expression vectors and addressing their activity by Western analyses and growth assays in Ba/F3, NIH-3T3, and MCF10A cell backgrounds. As a demonstration of the validity of the protocol, the well-characterized activating ERBB3 mutation ERBB3 E928G was identified as one of the major hits. These analyses are expected to identify activating ERBB3 mutations that are directly actionable or that provide predictive value for the use of drugs targeting ERBB signaling. Citation Format: Marika K. Koivu, Deepankar Chakroborty, Kari J. Kurppa, Klaus Elenius. Screen for actionable ERBB3 mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 828.

Simultaneously targeting ErbB family kinases and PI3K in HPV-positive head and neck squamous cell carcinoma

ObjectivesTo identify the most effective PI3K and EGFR inhibitors in HPV-positive head and neck squamous cell carcinoma (HNSCC) and investigate the efficacy of a combination of an ErbB family kinase inhibitor and a PI3K inhibitor to inhibit cell proliferation of HPV-positive HNSCC. Materials and methodHPV-positive HNSCC cell lines were treated with the FDA approved ErbB kinase inhibitor, Afatinib or FDA-approved PI3K inhibitor, Copanlisib, alone or in combination, and phosphorylation and total protein levels of cells were assessed by Western blot analysis.Cell proliferation and apoptosis were examined by MTS assay, flow cytometry, and Western blots, respectively. ResultsCopanlisib more effectively inhibited cell proliferation in comparison to other PI3K inhibitors tested. HPV-positive HNSCC cells differentially responded to cisplatin, Afatinib, or Copanlisib. The combination of Afatinib and Copanlisib more effectively suppressed cell proliferation and induced apoptosis compared to either treatment alone. Mechanistically, the combination of Afatinib and Copanlisib completely blocked phosphorylation of EGFR, HER2, HER3, and Akt as well as significantly decreased the HPV E7 expression compared to either treatment alone. ConclusionAfatinib and Copanlisib more effectively suppress cell proliferation and survival of HPV-positive HNSCC in comparison to either treatment alone.