Erb-b2 Receptor Tyrosine Kinase Research Articles

Novel genes involved in vascular dysfunction of the middle temporal gyrus in Alzheimer's disease: transcriptomics combined with machine learning analysis.

Studies have shown that vascular dysfunction is closely related to the pathogenesis of Alzheimer's disease. The middle temporal gyrus region of the brain is susceptible to pronounced impairment in Alzheimer's disease. Identification of the molecules involved in vascular aberrance of the middle temporal gyrus would support elucidation of the mechanisms underlying Alzheimer's disease and discovery of novel targets for intervention. We carried out single-cell transcriptomic analysis of the middle temporal gyrus in the brains of patients with Alzheimer's disease and healthy controls, revealing obvious changes in vascular function. CellChat analysis of intercellular communication in the middle temporal gyrus showed that the number of cell interactions in this region was decreased in Alzheimer's disease patients, with altered intercellular communication of endothelial cells and pericytes being the most prominent. Differentially expressed genes were also identified. Using the CellChat results, AUCell evaluation of the pathway activity of specific cells showed that the obvious changes in vascular function in the middle temporal gyrus in Alzheimer's disease were directly related to changes in the vascular endothelial growth factor (VEGF)A-VEGF receptor (VEGFR) 2 pathway. AUCell analysis identified subtypes of endothelial cells and pericytes directly related to VEGFA-VEGFR2 pathway activity. Two subtypes of middle temporal gyrus cells showed significant alteration in AD: endothelial cells with high expression of Erb-B2 receptor tyrosine kinase 4 (ERBB4high) and pericytes with high expression of angiopoietin-like 4 (ANGPTL4high). Finally, combining bulk RNA sequencing data and two machine learning algorithms (least absolute shrinkage and selection operator and random forest), four characteristic Alzheimer's disease feature genes were identified: somatostatin (SST), protein tyrosine phosphatase non-receptor type 3 (PTPN3), glutinase (GL3), and tropomyosin 3 (PTM3). These genes were downregulated in the middle temporal gyrus of patients with Alzheimer's disease and may be used to target the VEGF pathway. Alzheimer's disease mouse models demonstrated consistent altered expression of these genes in the middle temporal gyrus. In conclusion, this study detected changes in intercellular communication between endothelial cells and pericytes in the middle temporal gyrus and identified four novel feature genes related to middle temporal gyrus and vascular functioning in patients with Alzheimer's disease. These findings contribute to a deeper understanding of the molecular mechanisms underlying Alzheimer's disease and present novel treatment targets.

ERBB2 mutations define a subgroup of endometrial carcinomas associated with high tumor mutational burden and the microsatellite instability-high (MSI-H) molecular subtype.

Anti-HER2 therapy is indicated for erb-b2 receptor tyrosine kinase 2 (ERBB2)-amplified/overexpressing endometrial carcinoma (EC). Mutations constitute another mode of ERBB2 activation, but only rare ERBB2-mutated ECs have been reported. We sought to characterize the clinicopathologic and genetic features of ERBB2-mutated EC. From an institutional cohort of 2638 ECs subjected to clinical tumor-normal panel sequencing, 69 (2.6%) with pathogenic ERBB2 mutation(s) were identified, of which 11 were also ERBB2-amplified. The most frequent ERBB2 hotspot mutations were V842I (38%) and R678Q (25%). ERBB2 mutations were clonal in 87% of evaluable cases. Immunohistochemistry revealed low HER2 protein expression in most ERBB2-mutated ECs (0/1+ in 66%, 2+ in 27%); all 3+ tumors (7.3%) were also ERBB2-amplified. Compared to ERBB2-wildtype ECs (with or without ERBB2 amplification), ERBB2-mutated/non-amplified ECs were enriched for the microsatellite instability-high (MSI-H) and, to a lesser extent, DNA polymerase epsilon, catalytic subunit (POLE) molecular subtypes, and associated with high tumor mutational burden and low chromosomal instability. Survival outcomes were similar between patients with ERBB2-mutated/non-amplified versus wildtype EC, whereas ERBB2 amplification was associated with worse prognosis on univariate, but not multivariate, analyses. In conclusion, ERBB2 mutation defines a rare subgroup of ECs that is pathogenically distinct from ERBB2-wildtype and ERBB2-amplified ECs.

Computational and biological approaches in repurposing ribavirin for lung cancer treatment: Unveiling antitumorigenic strategies

Lung cancer is among leading causes of death worldwide. The five-year survival rate of this disease is extremely low (17.8 %), mainly due to difficult early diagnosis and to the limited efficacy of currently available chemotherapeutics. This underlines the necessity to develop innovative therapies for lung cancer. In this context, drug repurposing represents a viable approach, as it reduces the turnaround time of drug development removing costs associated to safety testing of new molecular entities. Ribavirin, an antiviral molecule used to treat hepatitis C virus infections, is particularly promising as repurposed drug for cancer treatment, having shown therapeutic activity against glioblastoma, acute myeloid leukemia, and nasopharyngeal carcinoma. In the present study, we thoroughly investigated the in vitro anticancer activity of ribavirin against A549 human lung adenocarcinoma cells. From a functional standpoint, ribavirin significantly inhibits cancer hallmarks such as cell proliferation, migration, and colony formation. Mechanistically, ribavirin downregulates the expression of numerous proteins and genes regulating cell migration, proliferation, apoptosis, and cancer angiogenesis. The anticancer potential of ribavirin was further investigated in silico through gene ontology pathway enrichment and protein-protein interaction networks, identifying five putative molecular interactors of ribavirin (Erb-B2 Receptor Tyrosine Kinase 4 (Erb-B4); KRAS; Intercellular Adhesion Molecule 1 (ICAM-1); amphiregulin (AREG); and neuregulin-1 (NRG1)). These interactions were characterized via molecular docking and molecular dynamic simulations. The results of this study highlight the potential of ribavirin as a repurposed chemotherapy against lung cancer, warranting further studies to ascertain the in vivo anticancer activity of this molecule.

Analysis of serum proteomic profiles of endangered Siamese and Burmese Eld's deer infected with subclinical Babesia bovis in Thailand

The endangered Eld's deer is a conserved species in Thailand, where tropical parasitic infections are endemic. Although Eld's deer with babesiosis are generally asymptomatic, they can still harbor the parasite and serve as reservoirs for ticks, spreading the infection to healthy animals within the herd. The present study aimed to investigate potential serum proteome biomarkers of Eld's deer with subclinical Babesia bovis infection. A total of 67 blood samples were collected from captive Siamese and Burmese Eld's deer showing no signs of parasitic infection. The nested polymerase chain reaction (nPCR) of a conserved spherical body protein 2 (sbp-2) gene of B. bovis was utilized to classify Eld's deer groups, with 25.37 % (17/67) testing positive for B. bovis. Additionally, the application of proteomic studies showed that six B. bovis proteins, such as Obg-like ATPase 1 (OLA1) and heat shock protein 90 (HSP90), were significantly upregulated by more than a two-fold change compared with the PCR-negative samples. Of the 55 overexpressed serum proteins in the PCR-positives, alpha 2-HS glycoprotein (AHSG) and immunoglobulin lambda variable 2–8 (IGLV2–8) were notably among the top 10 proteins with the highest area under curve (AUC) values. Hence, they were proposed as potential biomarkers for subclinical B. bovis infection in Eld's deer. Analysis of the protein interaction network revealed interactions between Eld's deer AHSG and B. bovis OLA1 and HSP90, alongside associations with other proteins such as erb-b2 receptor tyrosine kinase 2 (ERBB2) and epidermal growth factor receptor (EGFR). These interactions were involved in the immune system pathway and inflammatory responses. Our findings shed light on subclinical infection of B. bovis in Eld's deer and identify potential biomarkers, contributing to the further effective detection and monitoring of B. bovis infection in this endangered species.

Targeting FTO suppresses hepatocellular carcinoma by inhibiting ERBB3 and TUBB4A expression

Fat mass and obesity-associated protein (FTO) is an N6-methyladenosine (m6A) demethylase and plays critical oncogenic roles in multiple cancers. Here we show that FTO is an effective target in hepatocellular carcinoma (HCC). FTO is highly expressed in patients with HCC. Genetic depletion of Fto dramatically attenuated HCC progression in mice. Pharmacological inhibition of FTO by FB23/FB23-2 markedly suppressed the proliferation and migration of HCC cell lines in vitro and inhibited HCC tumorigenicity in xeno-transplanted mice. Mechanistically, FB23-2 suppressed the expression of Erb-b2 receptor tyrosine kinase 3 (ERBB3) and human tubulin beta class Iva (TUBB4A) by increasing the m6A level in these mRNA transcripts. The decrease in ERBB3 expression resulted in the inhibition of Akt-mTOR signaling, which subsequently impaired the proliferation and survival of HCC cells. Moreover, FB23-2 disturbed the stability of the tubulin cytoskeleton, whereas overexpression of TUBB4A rescued the migration of HCC cells. Collectively, our study demonstrates that FTO plays a critical role in HCC by maintaining the proliferation and migration of cells and highlights the potential of FTO inhibitors for targeting HCC.

Pen2/ErbB4 signaling regulates stemness of pancreatic ductal carcinoma

Cancer stem cells (CSCs) are critical for progression, invasion, metastasis, and chemotherapy resistance of pancreatic ductal adenocarcinoma (PDAC). Presenilin enhancer 2 (Pen2), a vital component of the gamma-secretase complex, is overexpressed in various cancers and plays a significant role in carcinogenesis. Here, we investigated the association between Pen2 expression and the stem-like properties of PDAC cells. We analyzed Pen2 and its downstream target, Erb-B2 Receptor Tyrosine Kinase 4 (ErbB4), using public databases. The expression of Pen2 in CSC populations, marked by CD133+, CD44+, or epithelial cell adhesion molecule (EpCAM)+, was evaluated. Pen2-positive cells were sorted from Pen2-negative ones in PDAC cells transduced with a vector designed to express green fluorescent protein (GFP) under the Pen2 promoter. Stemness was examined in vitro and in vivo in Pen2-positive versus Pen2-negative cells. Our results showed that Pen2 was significantly upregulated, while ErbB4 was significantly downregulated in PDAC tissues compared to adjacent non-tumorous tissues, with an inverse relationship between Pen2 and Erbb4 levels. PDACs with high Pen2 expression are associated with considerably poorer patient survival. The CSC populations identified by CD133+, CD44+, and EpCAM+ markers displayed significantly higher Pen2 and lower EpCAM levels. Compared to Pen2-negative PDAC cells, Pen2-positive cells formed more tumor spheres, were more invasive and migratory, and showed significantly increased resistance to chemotherapy-induced apoptosis. Altering Pen2 levels reversed these oncogenic effects. In vivo, Pen2-positive cells formed larger tumors in immunodeficient mice. Overall, our findings suggest that Pen2 is highly expressed in CSCs within PDAC cells, being a novel therapeutic target.

Clinical application of targeted tumour sequencing tests for detecting ERBB2 amplification and optimizing anti-HER2 therapy in gastric cancer

BackgroundEvaluation of human epidermal growth factor receptor 2 (HER2) overexpression caused by erb-b2 receptor tyrosine kinase 2 (ERBB2) amplification (AMP) by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) is essential for treating unresectable metastatic gastric cancer (GC). A targeted tumour sequencing test enables comprehensive assessment of alterations in cancer-related genes, including ERBB2. This study aimed to evaluate the concordance between the targeted tumour sequencing test and IHC/FISH for detecting HER2-positive GC and to clarify the significance of ERBB2 AMP and concomitant genetic alterations in HER2 downstream pathways (DPs) in anti-HER2 therapy for unresectable metastatic GC patients.MethodsERBB2 copy number alteration (CNA) was examined via a targeted tumour sequencing test in 152 formalin-fixed paraffin-embedded (FFPE) GC tissues. ERBB2 CNA was compared to HER2 status evaluated by IHC/FISH in FFPE block sections, which were identical to those subjected to the targeted tumour sequencing test. Treatment outcomes of anti-HER2 therapy in 11 patients with unresectable metastatic GC was evaluated.ResultsERBB2 AMP (≥ 2.5-fold change) was detected by the targeted tumour sequencing test in 15 patients (9.9%), and HER2 positivity (IHC 3 + or IHC 2+/FISH positive) was detected in 21 patients (13.8%). The overall percent agreement, positive percent agreement, negative percent agreement and Cohen’s kappa between ERBB2 CNA and HER2 status were 94.7%, 66.7%, 99.2% and 0.75, respectively. Progression-free survival for trastuzumab therapy in patients with ERBB2 AMP was significantly longer than that in patients with no ERBB2 AMP detected by the targeted tumour sequencing test (median 14 months vs. 4 months, P = 0.007). Treatment response to trastuzumab therapy was reduced in patients with ERBB2 AMP and concomitant CNAs of genes in HER2 DPs. One patient with ERBB2 AMP and concomitant CNAs of genes in HER2 DPs achieved a durable response to trastuzumab deruxtecan as fourth-line therapy.ConclusionsA targeted tumour sequencing test is a reliable modality for identifying HER2-positive GC. ERBB2 AMP and concomitant genetic alterations detected through the targeted tumour sequencing test are potential indicators of treatment response to trastuzumab therapy. The targeted tumour sequencing test has emerged as a plausible candidate for companion diagnostics to determine indications for anti-HER2 therapy in the era of precision medicine for GC.

Erbb3 regulation of secretory differentiation in the intestinal epithelium

Background: Previous work by our lab showed that intestinal-specific deletion of the ErbB3 receptor tyrosine kinase results in increased ileal Paneth cell numbers. These cells produce host defense peptides and support stem cells with growth factors. The mechanisms by which ErbB3 regulates Paneth cells are not well understood, but a candidate mediator is the polycomb repressor complex 1 component BMI1, which marks secretory progenitor cells. Furthermore, while there are no Paneth cells in the mouse colon, deep crypt secretory (DCS) cells are a distinct Reg4+ population that have some functional overlap with both Paneth and goblet cells; we will also test whether ErbB3 regulates DCS differentiation. Overall we are testing the hypothesis that ErbB3 regulates secretory cell numbers through BMI1. Methods: We bred Villin-Cre;ErbB3flox/flox mice (ErbB3ΔIE) to delete ErbB3 from the intestinal epithelium. Colonic sections from ErbB3ΔIE and ErbB3flox/flox littermates were subjected to RNAscope in situ hybridization for Reg4. RNA from mucosal scrapings (both ileum and colon) was assessed by qPCR for Reg4, Bmi1, and Lgr5. To test signaling mechanisms, we treated HT-29 cells with NRG-1β to activate ErbB3, +/- inhibitors to PI3K (LY294002), MEK/MAPK (U0126), or BMI1 (PTC-209). Colonoids and enteroids from ErbB3ΔIE and ErbB3flox/flox mice were used to confirm responses in a non-transformed system. Results: In ErbB3ΔIE mice, the colonic epithelium showed increased Reg4 levels and more Reg4+ cells compared to littermate controls, similar to our published data for the Paneth cell marker Lyz1 in ileum. BMI1 RNA and protein levels were also increased in both small and large intestinal mucosal scrapings from ErbB3ΔIE mice vs. littermates. ErbB3ΔIE colonoids had increased Reg4 versus control colonoids, and NRG-1β reduced levels in control but not ErbB3ΔIE cultures. Ileal enteroids showed a decrease in Lyz1 expression with Bmi1 inhibition and an increase in Bmi1 expression with PI3K and MAPK blockade. In HT-29 cells, NRG-1β treatment reduced Reg4 and Bmi1 expression. Conversely, Reg4 and Bmi1 were induced by PI3K inhibition with LY294002 (p<0.03) (p<0.0005) or MEK/MAPK inhibition with U0126 (p<0.05) (p<0.0001). Conclusions: NRG1-ErbB3 signaling restricts both ileal Paneth ( Lyz1+) and colonic DCS ( Reg4+) cell numbers. Furthermore, ErbB3 regulates Bmi1 expression through PI3K/Akt and MAPK signaling and BMI1 activity promotes secretory cell development. Since loss of DCS or Paneth cells has been shown to disrupt the intestinal stem cell niche and secretory cell markers are altered in several intestinal disease states, these results may point to potential future therapeutic avenues targeting this regulatory mechanism. NIH/NIDDK award R01DK095004. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Active substance and mechanisms of Actinidia chinensis Planch for the treatment of breast cancer was explored based on network pharmacology and in silico study.

In this paper, our objective was to investigate the potential mechanisms of Actinidia chinensis Planch (ACP) for breast cancer treatment with the application of network pharmacology, molecular docking, and molecular dynamics. "Mihoutaogen" was used as a key word to query the Traditional Chinese Medicine Systems Pharmacology database for putative ingredients of ACP and its related targets. DrugBank, GeneCards, Online Mendelian Inheritance in Man, and therapeutic target databases were used to search for genes associated with "breast cancer." Using Cytoscape 3.9.0 we then constructed the protein-protein interaction and drug-ingredient-target-disease networks. An enrichment analysis of Kyoto encyclopedia of genes and genomes pathway and gene ontology were performed to exploration of the signaling pathways associated with ACP for breast cancer treatment. Discovery Studio software was applied to molecular docking. Finally, the ligand-receptor complex was subjected to a 50-ns molecular dynamics simulation using the Desmond_2020.4 tools. Six main active ingredients and 176 targets of ACP and 2243 targets of breast cancer were screened. There were 118 intersections of targets for both active ingredients and diseases. Tumor protein P53 (TP53), AKT serine/threonine kinase 1 (AKT1), estrogen receptor 1 (ESR1), Erb-B2 receptor tyrosine kinase 2 (ERBB2), epidermal growth factor receptor (EGFR), Jun Proto-Oncogene (JUN), and Heat Shock Protein 90 Alpha Family Class A Member 1 (HSP90AA1) selected as the most important genes were used for verification by molecular docking and molecular dynamics simulation. The primary active compounds of ACP against breast cancer were predicted preliminarily, and its mechanism was studied, thereby providing a theoretical basis for future clinical studies.

Multiple receptor tyrosine kinases regulate dengue infection of hepatocytes.

Dengue is an arboviral disease causing severe illness in over 500,000 people each year. Currently, there is no way to constrain dengue in the clinic. Host kinase regulators of dengue virus (DENV) infection have the potential to be disrupted by existing therapeutics to prevent infection and/or disease progression. To evaluate kinase regulation of DENV infection, we performed kinase regression (KiR), a machine learning approach that predicts kinase regulators of infection using existing drug-target information and a small drug screen. We infected hepatocytes with DENV in vitro in the presence of a panel of 38 kinase inhibitors then quantified the effect of each inhibitor on infection rate. We employed elastic net regularization on these data to obtain predictions of which of 291 kinases are regulating DENV infection. Thirty-six kinases were predicted to have a functional role. Intriguingly, seven of the predicted kinases - EPH receptor A4 (EPHA4), EPH receptor B3 (EPHB3), EPH receptor B4 (EPHB4), erb-b2 receptor tyrosine kinase 2 (ERBB2), fibroblast growth factor receptor 2 (FGFR2), Insulin like growth factor 1 receptor (IGF1R), and ret proto-oncogene (RET) - belong to the receptor tyrosine kinase (RTK) family, which are already therapeutic targets in the clinic. We demonstrate that predicted RTKs are expressed at higher levels in DENV infected cells. Knockdown of EPHB4, ERBB2, FGFR2, or IGF1R reduces DENV infection in hepatocytes. Finally, we observe differential temporal induction of ERBB2 and IGF1R following DENV infection, highlighting their unique roles in regulating DENV. Collectively, our findings underscore the significance of multiple RTKs in DENV infection and advocate further exploration of RTK-oriented interventions against dengue.

NNOS in Erbb4-positive neurons regulates GABAergic transmission in mouse hippocampus

Neuronal nitric oxide synthase (nNOS, gene name Nos1) orchestrates the synthesis of nitric oxide (NO) within neurons, pivotal for diverse neural processes encompassing synaptic transmission, plasticity, neuronal excitability, learning, memory, and neurogenesis. Despite its significance, the precise regulation of nNOS activity across distinct neuronal types remains incompletely understood. Erb-b2 receptor tyrosine kinase 4 (ErbB4), selectively expressed in GABAergic interneurons and activated by its ligand neuregulin 1 (NRG1), modulates GABA release in the brain. Our investigation reveals the presence of nNOS in a subset of GABAergic interneurons expressing ErbB4. Notably, NRG1 activates nNOS via ErbB4 and its downstream phosphatidylinositol 3-kinase (PI3K), critical for NRG1-induced GABA release. Genetic removal of nNos from Erbb4-positive neurons impairs GABAergic transmission, partially rescued by the NO donor sodium nitroprusside (SNP). Intriguingly, the genetic deletion of nNos from Erbb4-positive neurons induces schizophrenia-relevant behavioral deficits, including hyperactivity, impaired sensorimotor gating, and deficient working memory and social interaction. These deficits are ameliorated by the atypical antipsychotic clozapine. This study underscores the role and regulation of nNOS within a specific subset of GABAergic interneurons, offering insights into the pathophysiological mechanisms of schizophrenia, given the association of Nrg1, Erbb4, Pi3k, and Nos1 genes with this mental disorder.

Recurrence/prognosis estimation using a molecularly positive surgical margin-based model calls for alternative curative strategies in pIIIA/N2 NSCLC.

Stage pIIIA/N2 non-small cell lung cancer (NSCLC) is primarily treated by complete surgical resection combined with neoadjuvant/adjuvant therapies. However, up to 40% of patients experience tumor recurrence. Here, we studied 119 stage pIIIA/N2 NSCLC patients who received complete surgery plus adjuvant chemotherapy (CT) or chemoradiotherapy (CRT). The paired tumor and resection margin samples were analyzed using next-generation sequencing (NGS). Although all patients were classified as negative resection margins by histologic methods, NGS revealed that 47.1% of them had molecularly positive surgical margins. Patients who tested positive for NGS-detected residual tumors had significantly shorter disease-free survival (DFS) (P = 0.002). Additionally, metastatic lymph node ratio, erb-b2 receptor tyrosine kinase 2 (ERBB2) mutations, and SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4) mutations were also independently associated with DFS. We used these four features to construct a COX model that could effectively estimate recurrence risk and prognosis. Notably, mutational profiling through broad-panel NGS could more sensitively detect residual tumors than the conventional histologic methods. Adjuvant CT and adjuvant CRT exhibited no significant difference in eliminating locoregional recurrence risk for stage pIIIA/N2 NSCLC patients with molecularly positive surgical margins.

ErbB2/HER2 receptor tyrosine kinase regulates human papillomavirus promoter activity.

Human papillomaviruses (HPVs) are a major cause of cancer. While surgical intervention remains effective for a majority of HPV-caused cancers, the urgent need for medical treatments targeting HPV-infected cells persists. The pivotal early genes E6 and E7, which are under the control of the viral genome's long control region (LCR), play a crucial role in infection and HPV-induced oncogenesis, as well as immune evasion. In this study, proteomic analysis of endosomes uncovered the co-internalization of ErbB2 receptor tyrosine kinase, also called HER2/neu, with HPV16 particles from the plasma membrane. Although ErbB2 overexpression has been associated with cervical cancer, its influence on HPV infection stages was previously unknown. Therefore, we investigated the role of ErbB2 in HPV infection, focusing on HPV16. Through siRNA-mediated knockdown and pharmacological inhibition studies, we found that HPV16 entry is independent of ErbB2. Instead, our signal transduction and promoter assays unveiled a concentration- and activation-dependent regulatory role of ErbB2 on the HPV16 LCR by supporting viral promoter activity. We also found that ErbB2's nuclear localization signal was not essential for LCR activity, but rather the cellular ErbB2 protein level and activation status that were inhibited by tucatinib and CP-724714. These ErbB2-specific tyrosine kinase inhibitors as well as ErbB2 depletion significantly influenced the downstream Akt and ERK signaling pathways and LCR activity. Experiments encompassing low-risk HPV11 and high-risk HPV18 LCRs uncovered, beyond HPV16, the importance of ErbB2 in the general regulation of the HPV early promoter. Expanding our investigation to directly assess the impact of ErbB2 on viral gene expression, quantitative analysis of E6 and E7 transcript levels in HPV16 and HPV18 transformed cell lines unveiled a noteworthy decrease in oncogene expression following ErbB2 depletion, concomitant with the downregulation of Akt and ERK signaling pathways. In light of these findings, we propose that ErbB2 holds promise as potential target for treating HPV infections and HPV-associated malignancies by silencing viral gene expression.

Plasma-based analysis of ERBB2 mutational status by multiplex digital PCR in a large series of patients with metastatic breast cancer.

Erb-b2 receptor tyrosine kinase 2 (ERBB2)-activating mutations are therapeutically actionable alterations found in various cancers, including metastatic breast cancer (MBC). We developed multiplex digital PCR assays to detect and quantify ERBB2 mutations in circulating tumor DNA from liquid biopsies. We studied the plasma from 272 patients with hormone-receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) MBC to detect 17 ERBB2 mutations using a screening assay. The assay was developed on the three-color Crystal dPCR™ naica® platform with a two-step strategy for precise mutation identification. We found that nine patients (3.3%) harbored at least one ERBB2 mutation. The mutation rate was higher in patients with lobular histology (5.9%) compared to invasive breast carcinoma of no special type (2.6%). A total of 12 mutations were found with the following frequencies: L755S (25.00%), V777L (25.00%), S310Y (16.67%), L869R (16.67%), S310F (8.33%), and D769H (8.33%). Matched tumor samples from six patients identified the same mutations with an 83% concordance rate. In summary, our highly sensitive multiplex digital PCR assays are well suited for plasma-based monitoring of ERBB2 mutational status in patients with MBC.

Abstract IA20: Stromal-derived NRG1 enables oncogenic KRAS bypass in pancreas cancer

Abstract Oncogenic KRAS (KRAS*) is a signature mutation in pancreatic ductal adenocarcinoma (PDAC). While genetic extinction or pharmacological inhibition of KRAS* elicits anti-tumor responses in preclinical models and patients, we and others have identified cancer cell intrinsic (YAP, RTKs) and paracrine immune-mediated (TGFb) mechanisms enabling KRAS* bypass and tumor recurrence. Here, we explored the potential role of cancer associated fibroblasts (CAFs) as contributors to mechanisms driving KRAS* bypass and identified CAF-derived NRG1 activation of cancer cell ERBB2 and ERBB3 receptor tyrosine kinases as a mechanism by which KRAS* independent tumor regrowth is supported. We showed that genetic extinction or pharmacological inhibition of KRAS* results in upregulation of ERBB2 and ERBB3 expression in human and murine cancer cell models. We demonstrated that CAF-derived NRG1 supports KRAS*-dependent tumor growth. These insights prompted genetic depletion or pharmacological inhibitions studies targeting ERBB2/3 or NRG1, which showed abolition of KRAS* bypass and synergy with KRASG12D inhibitor in mouse and human PDAC models. Thus, CAFs via the NRG-ERBB2/3 paracrine axis provide yet another mechanism enabling KRAS* inhibitor therapy resistance, providing a highly actionable combination therapeutic strategy to improve the effectiveness of KRAS* inhibitors in PDAC patients. Citation Format: Jincheng Han, Jiaqian Xu, Yonghong Liu, Shaoheng Liang, Kyle A. LaBella, Deepavali Chakravarti, Denise J. Spring, Yan Xia, Ronald A. DePinho. Stromal-derived NRG1 enables oncogenic KRAS bypass in pancreas cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr IA20.

In vitro effects of heparin-binding epidermal growth factor on adhesion stage of implantation.

A member of the epidermal growth factor (EGF) family, the heparin-binding EGF (HB-EGF) is expressed in the uteri of both humans and mice during the implantation process. To study the effects of HB-EGF on adhesion stage, we developed an in vitro implantation model employing Ishikawa cell line and JAR cell line, which may attach to Ishikawa cells. For 1, 6, 12, and 24 hours, co-cultures of JAR spheroids grown on Ishikawa monolayers were treated with 1, 10, and 100 ng∕mL doses of HB-EGF. Using immunocytochemistry and Western blot analysis, the effects of HB-EGF on the protein expressions of E-cadherin, Erb-B2 receptor tyrosine kinase 4 (ErbB4), and integrin ανβ3 in Ishikawa and JAR cells were examined semi-quantitatively and quantitatively. Ultrastructural changes of in vitro implantation model were investigated by transmission electron microscopy. We revealed that HB-EGF influenced trophoblast cell adhesion to endometrial cells by upregulating the expression of the proteins ErbB4 and trophoblastic integrin ανβ3. Decrease in trophoblastic E-cadherin expression and increase in endometrial E-cadherin expression were demonstrated accompanying morphological variations in cells required for the invasion. We discovered ultrastructurally that Ishikawa cells acquired uterodome-like appearance, including the organelles, when 10 and 100 ng∕mL dosages of HB-EGF were administered for 12 and 24 hours. However, following additional hours of adhesion and invasion, their intercellular spaces enlarged. The trafficking of vesicular transport was enhanced by JAR spheroids. We therefore discovered that in this implantation paradigm, HB-EGF may enhance the receptivity of Ishikawa cells and the adherence of JAR cells.

Racial/Ethnic Differences in Pathologic Complete Response to Neoadjuvant Chemotherapy and Survival Among Early-Stage, Erb-B2 Receptor Tyrosine Kinase 2-Low Breast Cancer Patients.

Racial/ethnic differences in pathologic complete response (pCR), and in overall survival (OS) by pCR status, among early-stage, erb-b2 receptor tyrosine kinase 2 (ERBB2)-low breast cancer patients after neoadjuvant chemotherapy (NACT) are unknown. Data were from the 2010-2020 National Cancer Database that included Asian/Pacific Islander (API), American Indian/Alaska Native/Other (AIANO), Black, Hispanic, and White patients. pCR and OS were modeled using logistic regression and Cox regression, respectively. Of 25,577 patients, Black patients achieved a 17.4% pCR rate, Hispanic 16.0%, White 14.7%, API 13.5%, and AIANO 10.9%. AIANO patients had lower odds of pCR than White patients (adjusted odds ratio, 0.66; 95% confidence interval [CI], 0.48-0.91). Among patients without pCR, API (adjusted hazard ratio [aHR], 0.62; 95% CI, 0.51-0.76) and Hispanic (aHR, 0.77; 95% CI, 0.67-0.89) patients had lower mortality risks than White patients. Among patients with pCR, similar OS rates were observed between Hispanic (aHR, 1.08; 95% CI, 0.66-1.78), Black (aHR, 0.77; 95% CI, 0.55-1.09), API (aHR, 0.41; 95% CI, 0.15-1.12), or AIANO (aHR, 0.35; 95% CI, 0.05-2.50) and White patients. Post-NACT pCR rates were similar across racial/ethnic groups of early-stage, ERBB2-low breast cancer patients. Among patients without pCR, API and Hispanic patients had better OS; among patients with pCR, there was no differential OS by race/ethnicity. Our findings suggest the need for longitudinal studies of OS differences in this patient population.

Genetic variants of ERBB4 gene and risk of gestational diabetes mellitus: a susceptibility and diagnostic nomogram study.

Gestational diabetes (GDM) is one of the common complications of female pregnancy, which seriously affects the health of mothers and their offspring. So far, the etiology has not been fully clarified. A case-control study was conducted to clarify the relationship between Erb-b2 receptor tyrosine kinase 4 (ERBB4) functional tag genetic variants (rs1595064, rs1595065, rs1595066 and rs6719645) and the risk of GDM. Associations between variants and GDM risk were evaluated with the odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Subsequently, the false-positive reporting probability (FPRP), multi-factor dimension reduction (MDR) and bioinformatics analysis were adopted to confirm the significant associations. A nomogram model was constructed to predict the risk of GDM. Association analysis demonstrated that rs1595066 TT genotype performed a protective effect on GDM risk among all subjects (TT vs. CC: adjusted OR = 0.60, 95% CI = 0.38 - 0.94, P = 0.026; TT vs. CC/CT: adjusted OR = 0.61, 95% CI = 0.40 - 0.95, P = 0.027). Meanwhile, stratified analysis showed that rs1595066 TT can also reduce the GDM risk in age > 30.09 years old, pre-pregnancy BMI > 22.23 Kg/m2, SBP ≤ 110.08 mmHg, etc subgroups. Interactions between rs1595066 and DBP (P interaction = 0.01), FPG (P interaction < 0.001) and HbA1c (P interaction < 0.001) were detected. The FPRP analysis confirmed that association between rs1595066 and GDM risk in subjects of FPG < 4.79 mmol/L (P = 0.199) is true. The MDR analysis showed that rs1595066 was the best single locus model while the 4-loci model was the best multiple factors model to predict GDM risk. Functional prediction revealed that rs1595066 may disturb the stability of miRNA-mRNA binding. The predictive nomogram model has a well consistence and acceptable discriminative ability with a diagnosed AUC of 0.813. ERBB4 variants can change an individual's susceptibility to GDM via the interaction of gene-gene, gene-environment and changes in the regulatory effects of miRNAs on ERBB4 expression.

Long noncoding RNA NONHSAT160169.1 promotes resistance via hsa-let-7c-3p/SOX2 axis in gastric cancer

In clinical trials involving patients with HER2 (ERBB2 receptor tyrosine kinase 2) positive gastric cancer, the efficacy of the HER2-targeted drug lapatinib has proven to be disappointingly poor. Under the persistent pressure exerted by targeted drug therapy, a subset of tumor cells exhibit acquired drug resistance through the activation of novel survival signaling cascades, alongside the proliferation of tumor cells that previously harbored mutations conferring resistance to the drug. This study was undertaken with the aim of elucidating in comprehensive detail the intricate mechanisms behind adaptive resistance and identifying novel therapeutic targets that hold promise in the development of effective lapatinib-based therapies for the specific subset of patients afflicted with gastric cancer. We have successfully established a gastric cancer cell line with acquired lapatinib resistance, designated as HGC-27-LR cells. Utilizing comprehensive coding and noncoding transcriptome sequencing analysis, we have identified key factors that regulate lapatinib resistance in HGC-27 cells. We have compellingly validated that among all the lncRNAs identified in HGC-27-LR cells, a novel lncRNA (long noncoding RNA) named NONHSAT160169.1 was found to be most notably upregulated following exposure to lapatinib treatment. The upregulation of NONHSAT160169.1 significantly augmented the migratory, invasive, and stemness capabilities of HGC-27-LR cells. Furthermore, we have delved into the mechanism by which NONHSAT160169.1 regulates lapatinib resistance. The findings have revealed that NONHSAT160169.1, which is induced by the p-STAT3 (signal transducer and activator of transcription 3) nuclear transport pathway, functions as a decoy that competitively interacts with hsa-let-7c-3p and thereby abrogates the inhibitory effect of hsa-let-7c-3p on SOX2 (SRY-box transcription factor 2) expression. Hence, our study has unveiled the NONHSAT160169.1/hsa-let-7c-3p/SOX2 signaling pathway as a novel and pivotal axis for comprehending and surmounting lapatinib resistance in the treatment of HER2-positive gastric cancer.

Screening for a practical method to monitor the status of patients with metastatic bladder cancer at the circulating cell-gene level

Identifying a novel method to monitor metastatic bladder cancer status at the cell-gene level could lead to earlier appropriate therapeutic intervention and better outcomes. In this study, we evaluated a practical method to monitor the cancer status at the circulating cell-gene level before and after treatment in fourteen patients with metastatic bladder cancer who were indicated for systemic drug therapy. Patients were assessed via imaging before and after drug treatment, and cell-free DNA (cfDNA) analysis was performed to detect three parameters: cfDNA level, ERRB2 gene copy numbers, and telomerase reverse transcriptase (TERT) gene mutations. We hypothesized that decreased cfDNA levels, a normal copy number of ERB-B2 receptor tyrosine kinase 2 (ERBB2), and the absence of the TERT C228T mutation indicate cancer suppression. We found that a > 1.8-fold increase in cfDNA levels, increased copy number of ERBB2, or the existence of the TERT C228T mutation indicated disease progression. Stable cfDNA levels, normal ERBB2 copy number, and the absence of TERT C228T mutations indicate a stable cancer status. Collectively, our results show that the combination of cfDNA concentration, TERT mutation, and ERBB2 copy number may be useful for determining the efficacy of drug therapy in patients with metastatic bladder cancer.