ErbB2 Overexpression Research Articles

Transcriptome profiling of the nonlactating mammary glands of dairy goats reveals the molecular genetic mechanism of mammary cell remodeling

The mammary gland redevelops to the prepregnancy state during involution, which shows the mammary cells have the characteristics of remodeling. The rapidity and degree of mammary gland involution vary across species (e.g., between model organism mice and dairy livestock). However, the molecular genetic mechanism of involution and remodeling of goat mammary gland has not yet been clarified. This work investigated the structural changes and transcriptome characteristics of the mammary gland tissue of nonlactating dairy goats during the late lactation (LL), the dry period (DP), and late gestation (LG). Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining revealed significant changes in the structure of the nonlactating goat mammary gland, and obvious cell apoptosis occurred at LL and DP. Sequencing identified 1,381 genes that are differentially expressed in mammary gland tissue at the 3 developmental stages. Genes related to cell growth, apoptosis, immunity, nutrient transport, synthesis, and metabolism exhibited adaptive transcriptional changes to meet the needs of a new set of mammary gland lactation functions. The significant enrichment of Gene Ontology terms such as humoral immune response, complement activation, and neutrophil-mediated immunity indicates that the innate immune system plays an important role in maintaining the health of degenerative mammary glands and eliminating apoptotic cells. The peroxisome proliferator-activated receptor signaling pathway plays an important regulatory role in lipid metabolism, especially the adaptive changes in expression of genes encoded lipid transport and enzymes, which promote the formation of milk fat during the lactation. The mammary gland development gene module revealed that pregnancy hormone receptors, cell growth factors and their receptors, and genes encoding insulin-like growth factor binding proteins regulate the physiological process of mammary gland involution through adaptive transcriptional changes. Interestingly, ERBB4 was identified as the hub gene of the network that regulates mammary gland growth and development. Overexpression of ERBB4 in mammary epithelial cells cultured in vitro can reduce cell cycle arrest in G1/S phase and apoptosis by regulating the PI3K/Akt signaling pathway and promote the proliferation of mammary epithelial cells. The gene ERBB4 also affects the expression of genes that initiate mammary gland involution and promote mammary gland remodeling. These findings contribute to an in-depth understanding of the molecular mechanisms involved in mammary gland involution and remodeling.

Loss of MIG-6 results in endometrial progesterone resistance via ERBB2

Female subfertility is highly associated with endometriosis. Endometrial progesterone resistance is suggested as a crucial element in the development of endometrial diseases. We report that MIG-6 is downregulated in the endometrium of infertile women with endometriosis and in a non-human primate model of endometriosis. We find ERBB2 overexpression in the endometrium of uterine-specific Mig-6 knockout mice (Pgrcre/+Mig-6f/f; Mig-6d/d). To investigate the effect of ERBB2 targeting on endometrial progesterone resistance, fertility, and endometriosis, we introduce Erbb2 ablation in Mig-6d/d mice (Mig-6d/dErbb2d/d mice). The additional knockout of Erbb2 rescues all phenotypes seen in Mig-6d/d mice. Transcriptomic analysis shows that genes differentially expressed in Mig-6d/d mice revert to their normal expression in Mig-6d/dErbb2d/d mice. Together, our results demonstrate that ERBB2 overexpression in endometrium with MIG-6 deficiency causes endometrial progesterone resistance and a nonreceptive endometrium in endometriosis-related infertility, and ERBB2 targeting reverses these effects.

Abstract P2-13-35: Pyrotinib combined with fulvestrant in women with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer: A single-arm phase II clinical trial

Abstract Background: HR+/HER2+ breast cancer is a unique molecular subtype of HER2+ breast cancer, which is characterized by mild biological behavior and is sensitive to endocrine therapy. Although the standard treatment for HR+/HER2+ metastatic breast cancer is chemotherapy combined with anti-HER2 therapy, this combination is not ideal for patients because of the heavy side effects of chemotherapy. Previous studies have shown that endocrine therapy combined with anti-HER2 therapy can also bring survival benefits to these patients. However, due to the limitations of previous treatment, the optimal combination mode of endocrine and anti-HER2 therapies has not been found. Pyrotinib is the most efficient pan-HER tyrosine kinase inhibitor (TKI) with irreversible blocking of HER2, while fulvestrant is the most potent estrogen receptor (ER) inhibitor. Previous cell experiments showed the cross-talk between ER and HER2 receptor pathways, indicating that the two signal pathways were important mechanisms of drug resistance for each other. Further research showed that ER inhibitor fulvestrant had synergistic effect with HER2 inhibitor pyrotinib. Therefore, we firstly explored the efficacy and safety of pyrotinib combined with fulvestrant in the treatment of HR+/HER2+ metastatic breast cancer.Methods: Eligible patients had histologically confirmed HR+/HER2+ metastatic breast cancer with no more than one line of prior treatment for metastatic disease. Those with central nervous system metastases or any prior HER2 TKI were excluded. Patients were treated with oral pyrotinib 400 mg once daily plus intramuscular injection of fulvestrant 500 mg on days 1, 15, and 29, and once every 28 days thereafter. The primary endpoint was progression-free survival (PFS), as assessed by the data and safety monitoring committee. Secondary endpoints included objective response rate, disease control rate (DCR), overall survival and safety. We also explored the efficacy of subgroups defined by different gene signatures, which were identified using comprehensive genomic variation profiling (FoundationOne CDx). This study is registered with ClinicalTrials.gov, NCT04034589.Results: From July 9, 2019 to June 20, 2021, 34 patients were enrolled; 19 (55.8%) patients had visceral metastases. Of 14 patients with measurable disease according to RECIST 1.1, seven (50%) achieved objective response. The DCR was 84.6%. Nine of the 34 included patients discontinued treatment because of disease progression, and PFS was immature. Twelve patients had available data of comprehensive genomic variation profiling, and the results showed that six patients had PIK3CA mutation, ten had TP53 mutation, and 11 had ErbB2 overexpression. The most common treatment-related adverse events were diarrhea and fatigue. The incidence of grade 3 or greater diarrhea was 12.1% (4/33) in patients with available safety data. No patient discontinued treatment because of adverse events. Conclusions: The combination of pyrotinib and fulvestrant was convenient and effective with manageable toxicity, which may offer a chemotherapy-free alternative treatment option for patients with HR+/HER2+ metastatic breast cancer. Citation Format: Ying Wang, Jianli Zhao, Zhongyu Yuan, Guorong Zou, Haiyan Li, Linxiaoxiao Ding, Yaping Yang, Jie Chai, Donggeng Liu, Herui Yao. Pyrotinib combined with fulvestrant in women with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer: A single-arm phase II clinical trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-13-35.

MiR-551b is Associated with the Poor Prognosis and Malignant Development of Papillary Thyroid Cancer Through Regulating ERBB4.

The function of miR-551b has been widely reported in various human cancers, and its dysregulation in papillary thyroid cancer (PTC) has also been disclosed, implying its potential regulator role in PTC. The aim of the study was to evaluate the function of miR-551b in PTC development and its potential mechanism. miR-551b was evaluated in PTC tissues and cells by RT-qPCR and associated with the clinicopathological features of patients. The biological effect of miR-551b on cellular processes of PTC was assessed with the CCK8 proliferation assay and the Transwell migration and invasion assay. The potential molecular mechanism was estimated with the dual-luciferase reporter assay. miR-551b was significantly upregulated in PTC, which showed a close relationship with the malignancy and development of PTC patients. miR-551b served as a prognostic biomarker negatively related to patients' survival together with the TNM stage. The overexpression of miR-551b exerted promoted effect on the development-related cellular processes of PTC, which was reversed by the overexpression of ERBB4. In conclusion, miR-551b could predict the poor prognosis of PTC patients and serve as a tumor promoter via suppressing ERBB4.

Integrated Transcriptome and Multiple Activated Pathways in Endometrial Cancer

Because the incidence of endometrial cancer is notably increasing worldwide, it has become the leading gynecologic cancer in the United States. Standard treatment results in the loss of reproductive function in women of childbearing age. Furthermore, advanced cancer stages are associated with poor overall survival. The aim of this study was to explore the abnormal expression profile of genes during the development of endometrial cancer, which is essential to provide a better understanding of the mechanisms involved. Five pairs of endometrial cancer tissues and normal endometrial tissues were subjected to next-generation transcriptome sequencing technology. Quantitative real-time PCR (RT-qPCR) was performed to validate the expression profile of key differentially expressed genes (2.0-fold change, adj. p < 0.05) (DEGs) identified in the RNA-seq result. GO and KEGG pathways were used for bioinformatic analyses. The transcriptomic sequencing results showed 1153 DEGs, including 673 upregulated and 480 downregulated genes, in the EC specimens. Decreased expression of ID1, IGF1, GDF7, SMAD9, TGF-beta and WNT4, as well as GDF5, INHBA and ERBB4 overexpression, were confirmed in EC using RT-qPCR. Additionally, EC tissue exhibited marked enrichment in genes promoting cellular adhesion, proliferation, migration and plasma membrane. KEGG analysis revealed changes in various pathways, such as the TGF-beta, PI3K-Akt, Wnt, and estrogen pathways. Our data describe the molecular events involved in the pathogenesis of EC, which may be potential diagnostic markers and targets of therapeutic interventions.

FOXP3 Is an X-Linked Breast Cancer Suppressor Gene and an Important Repressor of the HER-2/ErbB2 Oncogene

(Cell 129, 1275–1286; June 29, 2007) We, the editors of Cell, were contacted by the authors of this article regarding a duplication in Figure 7 that was not identified in the previous 2008 correction. Dr. Yang Liu, the corresponding author, has determined that the error was introduced during revision of the manuscript. In preparing the final figure, three images from the experiment showing that Foxp3 expression inhibits the growth of drug-resistant clones in breast cancer cell lines shown in Figure 7A—SKBR3 cells transfected with Otc cDNA, SKBR3 cells with vector, and MCF-7 cells with Foxp3—were mistakenly inserted into Figure 7D showing that ectopic expression of ErbB2 abrogated Foxp3-mediated repression. These images were incorrectly presented as TSA cells transfected with ErbB2 + pEF1 vector, ErbB2 + Foxp3, and pcDNA6 vector + Foxp3, respectively. The authors no longer have access to the original data, and consequently, a correction is not possible. Given the age of the paper and that the duplication does not compromise the conclusions of the paper, based on the information available to us at this time, we believe that no further action is warranted. FOXP3 Is an X-Linked Breast Cancer Suppressor Gene and an Important Repressor of the HER-2/ErbB2 OncogeneZuo et al.CellJune 29, 2007In BriefThe X-linked Foxp3 is a member of the forkhead/winged helix transcription factor family. Germline mutations cause lethal autoimmune diseases in males. Serendipitously, we observed that female mice heterozygous for the “scurfin” mutation of the Foxp3 gene (Foxp3sf/+) developed cancer at a high rate. The majority of the cancers were mammary carcinomas in which the wild-type Foxp3 allele was inactivated and HER-2/ErbB2 was overexpressed. Foxp3 bound and repressed the HER-2/ErbB2 promoter. Deletion, functionally significant somatic mutations, and downregulation of the FOXP3 gene were commonly found in human breast cancer samples and correlated significantly with HER-2/ErbB2 overexpression, regardless of the status of HER-2 amplification. Full-Text PDF Open Archive

Rationale and design of the CRAFT (Continuous ReAssessment with Flexible ExTension in Rare Malignancies) multicenter phase II trial

BackgroundApprovals of cancer therapeutics are primarily disease entity specific. Current molecular diagnostic approaches frequently identify actionable alterations in rare cancers or rare subtypes of common cancers for which the corresponding treatments are not approved and unavailable within clinical trials due to entity-related eligibility criteria. Access may be negotiated with health insurances. However, approval rates vary, and critical information required for a scientific evaluation of treatment-associated risks and benefits is not systematically collected. Thus clinical trials with optimized patient selection and comprehensive molecular characterization are essential for translating experimental treatments into standard care.Patients and methodsContinuous ReAssessment with Flexible ExTension in Rare Malignancies (CRAFT) is an open-label phase II trial for adults with pretreated, locally advanced, or metastatic solid tumors. Based on the evaluation by a molecular tumor board, patients are assigned to combinations of six molecularly targeted agents and a programmed death-ligand 1 (PD-L1) antagonist within seven study arms focusing on (i) BRAF V600 mutations; (ii) ERBB2 amplification and/or overexpression, activating ERBB2 mutations; (iii) ALK rearrangements, activating ALK mutations; (iv and v) activating PIK3CA and AKT mutations, other aberrations predicting increased PI3K–AKT pathway activity; (vi) aberrations predicting increased RAF–MEK–ERK pathway activity; (vii) high tumor mutational burden and other alterations predicting sensitivity to PD-L1 inhibition. The primary endpoint is the disease control rate (DCR) at week 16; secondary and exploratory endpoints include the progression-free survival ratio, overall survival, and patient-reported outcomes. Using Simon’s optimal two-stage design, 14 patients are accrued for each study arm. If three or fewer patients achieve disease control, the study arm is stopped. Otherwise, 11 additional patients are accrued. If the DCR exceeds 7 of 25 patients, the null hypothesis is rejected for the respective study arm.ConclusionsCRAFT was activated in October 2021 and will recruit at 10 centers in Germany.Trial registration numbersEudraCT: 2019-003192-18; ClinicalTrials.gov: NCT04551521.

Thin Layer-Protected Gold Nanoparticles for Targeted Multimodal Imaging with Photoacoustic and CT.

The large size of nanoparticles prevents rapid extravasation from blood vessels and diffusion into tumors. Multimodal imaging uses the physical properties of one modality to validate the results of another. We aim to demonstrate the use of a targeted thin layer-protected ultra-small gold nanoparticles (Au-NPs) to detect cancer in vivo using multimodal imaging with photoacoustic and computed tomography (CT). The thin layer was produced using a mixed thiol-containing short ligands, including MUA, CVVVT-ol, and HS-(CH2)11-PEG4-OH. The gold nanoparticle was labeled with a heterobivalent (HB) peptide ligand that targets overexpression of epidermal growth factor receptors (EGFR) and ErbB2, hereafter HB-Au-NPs. A human xenograft model of esophageal cancer was used for imaging. HB-Au-NPs show spherical morphology, a core diameter of 4.47 ± 0.8 nm on transmission electron microscopy, and a hydrodynamic diameter of 6.41 ± 0.73 nm on dynamic light scattering. Uptake of HB-Au-NPs was observed only in cancer cells that overexpressed EGFR and ErbB2 using photoacoustic microscopy. Photoacoustic images of tumors in vivo showed peak HB-Au-NPs uptake at 8 h post-injection with systemic clearance by ~48 h. Whole-body images using CT validated specific tumor uptake of HB-Au-NPs in vivo. HB-Au-NPs showed good stability and biocompatibility with fast clearance and contrast-enhancing capability for both photoacoustic and CT imaging. A targeted thin layer-protected gold nanoprobe represents a new platform for molecular imaging and shows promise for early detection and staging of cancer.

Pan-cancer proteogenomic investigations identify post-transcriptional kinase targets

Identifying genomic alterations of cancer proteins has guided the development of targeted therapies, but proteomic analyses are required to validate and reveal new treatment opportunities. Herein, we develop a new algorithm, OPPTI, to discover overexpressed kinase proteins across 10 cancer types using global mass spectrometry proteomics data of 1,071 cases. OPPTI outperforms existing methods by leveraging multiple co-expressed markers to identify targets overexpressed in a subset of tumors. OPPTI-identified overexpression of ERBB2 and EGFR proteins correlates with genomic amplifications, while CDK4/6, PDK1, and MET protein overexpression frequently occur without corresponding DNA- and RNA-level alterations. Analyzing CRISPR screen data, we confirm expression-driven dependencies of multiple currently-druggable and new target kinases whose expressions are validated by immunochemistry. Identified kinases are further associated with up-regulated phosphorylation levels of corresponding signaling pathways. Collectively, our results reveal protein-level aberrations—sometimes not observed by genomics—represent cancer vulnerabilities that may be targeted in precision oncology.

Breast cancer immunophenotype and its relationship with haematopoiesis

Background. The applying of immunotherapeutic approaches in cancer treatment requires a deep and comprehensive understanding of the tumor biological characteristics. In this regard, the study of the tumor immunophenotype is one of the leading scientific directions. The major histocompatibility complex molecules are considered to be the promising markers of the immunotherapy effectiveness prediciton. Aim. To research tumor immunophenotype in different molecular subtypes of breast cancer (BC). Materials and methods. The study included 99 patients with BC. Luminal cancer 84.8% (n=83), Erb-B2 overexpressing (HER2+) subtype 5.0% of cases (n=5), triple-negative BC 10.2% (n=10). Stages: T1 (51.5%), T2 (44.4%), T3 (2.0%). Lymph node metastases (N+) were present in 39.4% (n=39) of cases. Grade of malignancy: 80.8% (G2). Samples of tumor tissue and bone marrow were examined. Immunophenotyping of the tumor was carried out on cryostat sections by the method of immunofluorescense. Antibodies to HLA-I, HLA-DR, CD71 were used and were directly conjugated to fluorochromes PE, FITC, PE-Cy5. The bone marrow was examined by a morphological method using light microscopy. Statistical data processing was performed using the IBM-SPSS statistics v2.1. Results. In 50.8% (31/61) cases of luminal BC (LBC), the HLA-I molecule is absent on the membrane or is expressed by single tumor cells. A decrease in HLA-I expression levels in the luminal subtype was combined with the absence of HLA-DR antigens, which was found in 63.1% of cases. A higher frequency of HLA-I expression is observed in the Erb-B2 overexpressing BC, the differences are insignificant. Expression of CD71 was defected in 67.8% (40/59) of the studied samples of LBC. CD71 was expressed on the surface of most tumor cells (70%) in triple-negative BC. There were no statistically significant differences between the studied molecular subtypes of BC. Analysis of the luminal subtypes revealed that CD71 expression was observed much more often in luminal B subtype: 76.5% (n=26) and 75% (n=3) versus 52.4% (n=11). HLA-I expressing luminal cancer were characterized by higher levels of erythroid precursors (polychromatophilic normoblasts 9.00.9 and 5.80.8%, p=0.0017; oxyphilic normoblasts (7.90.7 and 5.30.6%, p=0.008), an increase in the amount of erythroid germ cells (17.71.5 and 11.61.5%, р=0.009) and an increased content of myelokaryocytes (93.117.1 thousand/l versus 57.39.0 thousand/l, p=0.083). Conclusion. In LBC a decrease in the expression levels of HLA-I class molecules was noted in combination with the absence of HLA-DR antigens on the membrane of tumor cells, which was observed in more than half of the analyzed samples. The frequency of expression in triple-negative cancer is higher than in the luminal subtype. There were no statistically significant differences between molecular subtypes by the level of expression of HLA-I and II class molecules. Transferrin receptor expression has been reported in most cases of triple-negative BC subtype. The interconnection between the expression of HLA-I histocompatibility molecules and hematopoetic parameters in LBC has been established.

Haploinsufficiency Interactions between RALBP1 and p53 in ERBB2 and PyVT Models of Mouse Mammary Carcinogenesis.

Simple SummaryRlip knockout has been reported to prevent cancer in highly cancer-susceptible mice lacking p53, and Rlip knockdown kills many types of cancer cells. In humans, breast cancer shows diverse characteristics, including HER2-driven subtypes and viral-driven subtypes. HER2 can be targeted; however, escape of the cancer from targeted therapies remains a problem. In this work we evaluated the capacity of Rlip knockout to prevent breast cancer in genetically engineered mouse models of HER2-driven breast cancer (Erbb2 model) and polyomavirus-driven breast cancer (PyVT model). We found that in Erbb2 mice, Rlip knockout significantly delayed oncogenesis and reduced the expression of genes associated with poor prognosis in patients. In PyVT mice, Rlip knockout did not delay oncogenesis or tumor growth, but Rlip knockdown reduced tumor metastasis to the lung. We conclude that Rlip inhibitors may significantly improve survival in HER2-positive patients, but are unlikely to offer benefits to patients with polyomavirus-associated tumors.We recently reported that loss of one or both alleles of Ralbp1, which encodes the stress-protective protein RLIP76 (Rlip), exerts a strong dominant negative effect on both the inherent cancer susceptibility and the chemically inducible cancer susceptibility of mice lacking one or both alleles of the tumor suppressor p53. In this paper, we examined whether congenital Rlip deficiency could prevent genetically-driven breast cancer in two transgenic mouse models: the MMTV-PyVT model, which expresses the polyomavirus middle T antigen (PyVT) under control of the mouse mammary tumor virus promoter (MMTV) and the MMTV-Erbb2 model which expresses MMTV-driven erythroblastic leukemia viral oncogene homolog 2 (Erbb2, HER2/Neu) and frequently acquires p53 mutations. We found that loss of either one or two Rlip alleles had a suppressive effect on carcinogenesis in Erbb2 over-expressing mice. Interestingly, Rlip deficiency did not affect tumor growth but significantly reduced the lung metastatic burden of breast cancer in the viral PyVT model, which does not depend on either Ras or loss of p53. Furthermore, spontaneous tumors of MMTV-PyVT/Rlip+/+ mice showed no regression following Rlip knockdown. Finally, mice lacking one or both Rlip alleles differentially expressed markers for apoptotic signaling, proliferation, angiogenesis, and cell cycling in PyVT and Erbb2 breast tumors. Our results support the efficacy of Rlip depletion in suppressing p53 inactivated cancers, and our findings may yield novel methods for prevention or treatment of cancer in patients with HER2 mutations or tumor HER2 expression.

ERBB3 overexpression due to miR-205 inactivation confers sensitivity to FGF, metabolic activation, and liability to ERBB3 targeting in glioblastoma.

In glioblastoma (GBM), the most frequent and lethal brain tumor, therapies suppressing recurrently altered signaling pathways failed to extend survival. However, in patient subsets, specific genetic lesions can confer sensitivity to targeted agents. By exploiting an integrated model based on patient-derived stem-like cells, faithfully recapitulating the original GBMs invitro and invivo, here, we identify a human GBM subset (∼9% of all GBMs) characterized by ERBB3 overexpression and nuclear accumulation. ERBB3 overexpression is driven by inheritable promoter methylation or post-transcriptional silencing of the oncosuppressor miR-205 and sustains the malignant phenotype. Overexpressed ERBB3 behaves as a specific signaling platform for fibroblast growth factor receptor (FGFR), driving PI3K/AKT/mTOR pathway hyperactivation, and overall metabolic upregulation. As a result, ERBB3 inhibition by specific antibodies is lethal for GBM stem-like cells and xenotransplants. These findings highlight a subset of patients eligible for ERBB3-targeted therapy.

Abstract 942: ErbB3 overexpression unleashed by miR-205 epigenetic silencing is a therapeutic target in glioblastoma

Abstract In glioblastoma (GBM), the most frequent and lethal brain tumor, targeted therapies suppressing commonly altered signaling pathways has remained so far disappointing. However, in selected patient subsets, specific genetic alterations can confer sensitivity to targeted agents. In this study, by generating an integrated model based on patient-derived stem-like cells, faithfully recapitulating the original GBMs in vitro and in vivo, we identified a human GBM subset (around 9% of all GBMs) characterized by ERBB3 overexpression and nuclear accumulation. This was driven by inheritable epigenetic or post-transcriptional silencing of the oncosuppressor miR-205 and sustained the malignant phenotype. Unexpectedly, ERBB3, known to be devoid of autonomous signaling properties, was overexpressed in the absence of the other members of the EGFR family, but behaved as a specific signaling platform for FGFRs. ERBB3/FGFR dimerization led to hyperactivation of the PI3K/AKT/mTOR pathway and consequent upregulation of glycolysis, oxidative metabolism and de novo fatty acid biosynthesis. Treatment with a specific antibody (MM121) preventing ERBB3 association with FGFR caused metabolic shutdown and consequent proliferative arrest and apoptosis induction in vitro. Moreover, experimental tumors regenerated through ERBB3 overexpressing stem-like cell transplantation reproduced the features of the original GBMs and, upon treatment with the anti-ERBB3 antibody, significantly regressed. These findings identify a subset of GBM patients where exploitation of an ERBB3-targeted therapy could be effective. Citation Format: Francesca De Bacco, Francesca Orzan, Jessica Erriquez, Elena Casanova, Ludovic Barault, Raffaella Albano, Antonio D'Ambrosio, Viola Bigatto, Gigliola Reato, Monica Patané, Bianca Pollo, Geoffrey Kuesters, Carmine Dell'Aglio, Laura Casorzo, Serena Pellegatta, Gaetano Finocchiaro, Paolo M. Comoglio, Carla Boccaccio. ErbB3 overexpression unleashed by miR-205 epigenetic silencing is a therapeutic target in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 942.

Abstract LB106: The EGF domains of MUC4 oncomucin interact with ErbB2 and mediate tumorigenic activity of cancer cells represent new potential therapeutic targets

Abstract The MUC4 mucin and its membrane partner ErbB2 form an oncogenic complex at the surface of epithelial cancer cells that promotes tumor progression. They directly physically interact via an extracellular region of MUC4 encompassing three EGF domains opening the route to therapeutic targeting of ErbB2 over-expressing cancers in which MUC4-ErbB2 is present. However, before small inhibitory molecules may be designed, it is mandatory (i) to decipher at the molecular level which amino acid regions are involved in the interaction and (ii) show that they mediate cancer cell tumorigenicity. By using in vitro (2D cell culture, Micro Scale Thermophoresis, PLA assay, Co-IP, GST pull down, Molecular Dynamics simulations) and in vivo (xenograft model of pancreatic cancer) approaches, we show that the EGF1 domain of MUC4 is central both in the interaction with ErbB2 and in the activation of cell proliferation and migration and tumor growth via activation of key oncogenic pathways (Src, Ras, p70S6K/AKT/mTOR, β-catenin, FAK). Finally, we have identified hotspots of interaction paving the way to the design of therapeutic inhibitory molecules targeting the EGF domains of MUC4 which may represent a new alternative strategy to overcome ErbB2 therapeutic failure in cancer. Citation Format: Nicolas STOUP, Maxime LIBERELLE, Céline SCHULZ, Romain VASSEUR, Romain MAGNEZ, Xavier THURU, Patricia MELNYK, Nicolas RENAULT, Nicolas JONCKHEERE, Nicolas LEBEGUE, Isabelle VAN SEUNINGEN. The EGF domains of MUC4 oncomucin interact with ErbB2 and mediate tumorigenic activity of cancer cells represent new potential therapeutic targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB106.

Pertuzumab plus trastuzumab (P+T) in patients (Pts) with uterine cancer (UC) with ERBB2 or ERBB3 amplification, overexpression or mutation: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) study.

5508 Background: TAPUR is a phase II basket study evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of UC pts with ERBB2 or ERBB3 amplification , overexpression or mutation treated with P+T are reported. Methods: Eligible pts had advanced UC, no standard treatment options, measurable disease, ECOG PS 0-2, and adequate organ function. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Pts matched to P+T had UC with ERBB2 or ERBB3 amplification or overexpression or a pre-specified ERBB2 mutation. Recommended dosing was P at an initial dose of 840 mg intravenously (IV) over 60 minutes (m), then 420 mg IV over 30-60 m every 3 weeks (wks), and T at an initial dose of 8 mg/kg IV over 90 m, then 6 mg/kg IV over 30-60 m every 3 wks until disease progression. Simon 2-stage design tested the null disease control (DC) - defined as partial (PR), complete response (CR) or stable disease at 16+ weeks (SD 16+) - rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 have DC, 18 more pts are enrolled. If ≥7 of 28 pts have DC, the null DC rate is rejected. Secondary endpoints are progression-free survival (PFS), overall survival (OS) and safety. Results: Twenty-eight female pts were enrolled from August 2017 to November 2019; all pts were evaluable for efficacy and toxicity. Demographics and outcomes are summarized in Table. Twenty-two pts had tumors with ERBB2 amplification (21) or overexpression (1); 4 tumors had ERBB2 mutations; 1 tumor had ERBB3 amplification; 1 tumor had both an ERBB2 amplification and mutation. Two PR and 7 SD16+ were observed in pts with ERBB2 amplification, and 1 SD16+ was observed in a pt with ERBB2 V8421 mutation only (no amplification) for DC and objective response (OR) rates of 37% (95% CI, 21% to 50%) and 7.1% (95% CI, 0.8% to 24%), respectively. One pt experienced grade 3 muscle weakness at least possibly related to P+T. Conclusions: P+T demonstrated evidence of anti-tumor activity in heavily pre-treated UC pts with ERBB2 amplification or certain mutations. Additional study is warranted to confirm the efficacy of P+T in this pt population. Clinical trial information: NCT02693535. [Table: see text]

Molecular profiling and targeted agents in recurrent, metastatic salivary gland tumor (R/M SGT) patients (pts) treated at two academic centers.

6081 Background: Treatment selection based on actionable alterations (AAs) is an appealing strategy for pts with R/M SGT. The GEMS-001 study (NCT02069730) at Princess Margaret Cancer Centre (PM) and the Vall D´Hebron Institute of Oncology (VHIO) pre-screening program facilitate the identification of AAs for R/M SGT pts and treatment selection. Methods: We analyzed R/M SGT treated at PM and VHIO from 2015 to 2020. Clinicopathological features, molecular alterations and treatment modalities were correlated with outcomes. The primary endpoint was overall response rate (ORR) by RECIST 1.1. Clinical benefit rate (CBR) was defined by pts with partial response or stable disease ≥4 months. Clinical actionability of multigene panel testing (NGS) and immunohistochemistry (IHC) were assessed as per institutional molecular tumor boards or investigators. Pts were opportunistically matched to available therapies from each center. Results: In total 206 pts were enrolled. On IHC, HER2 overexpression was present in 9%, Androgen Receptor (AR) 33%, Estrogen/Progesterone Receptor (ER/PR) 11% and ALK overexpression 0%. On NGS, PIK3CA mutation (mut) was in 9%, NTRK fusion 6%, NOTCH1-3 mut 5%, HRAS mut 6%, ERBB2/3 alterations (alt) 4% and FGFR1-4 alt 3%. Up to 92 pts (45%) displayed at least 1 AA and 36 pts (18%) had ≥2 AAs. A total of 60 pts (29%) were matched to AAs. Of those matched, median age was 60 years (range 33-84), M:F 21:39, 95% ECOG≤1 with a median number of prior treatment lines 0 (range 0-3), and their AAs included 26 AR, 9 HER2 or ERBB2 overexpression, 9 PIK3CA mut, 3 NTRK fusion, 3 FGFR1-3 alt and 10 other AAs (2 ER/PR overexpression, 2 EGFR mut, 1 c-kit mut, 1 BAP1 mut, 1 Non-V600 BRAF mut, 1 CDKN2A mut, 1 CHEK2 mut and 1 PTCH1 mut). Overall, ORR was 27% for the matched population. See table for outcomes. Conclusions: In our cohort, almost one third of the population received therapies matched to AAs. Our results suggest that targeted therapies have promising activity in pts with R/M SGT supporting comprehensive molecular and IHC profiling in treatment determination.[Table: see text]

Halting Retrograde Transport Excludes ErbB-2 From the Nucleus Abrogating Tumor Growth in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) refers to a subtype of tumors with poor prognosis, devoid of hormone receptors and of membrane overexpression or gene amplification of ErbB-2. Due to its molecular heterogeneity, TNBC represents a major clinical challenge. In this regard, clinical biomarkers and targeted therapies remain elusive, and chemotherapy has been the standard of care for early and metastatic TNBC. ErbB-2, a member of the ErbB family of tyrosine kinase receptors, is a major player in the BC scenario. While it is a cell membrane-bound receptor, it migrates to the nucleus (NErbB-2) where it acts as a transcription factor or coactivator. We recently found that both the canonical (wild-type, WT) ErbB-2 and the alternative isoform c are located in the nucleus of TNBC, a scenario with an aggressive oncogenic potential. The route of intracellular transport from the plasma membrane to the trans Golgi network (TGN) and the endoplasmic reticulum (ER) is termed retrograde trafficking, and constitutes the pathway by which ErbB-2 migrates to the nucleus. The retrograde transport route is also hijacked by toxins and viruses to access the ER and exert their deleterious effects. Retro-2, a small molecule inhibitor, was shown to protect cells from toxin and virus effects by blocking their retrograde trafficking. Given the high levels of NErbB-2 in TNBC cells, we explored whether treatment with Retro-2 modulates localization of ErbB-2 and proliferation in TNBC.We found that Retro-2 treatment decreased the levels of both WT ErbB-2 and isoform c in the nucleus of TNBC cells demonstrating that Retro-2 effects are not limited to a particular ErbB-2 isoform. Indeed, immunofluorescence assays revealed accumulation of ErbB-2 in the Golgi after Retro-2 treatment further preventing its sorting to the ER. We previously demonstrated that growth factors induce ErbB-2 migration into the nucleus in ErbB-2-positive BC cells. Consistently, we observed that Retro-2 prevents growth factor-induced NErbB-2 in ErbB-2-positive BC cells. Retro-2 treatment resulted in a dose-dependent decrease in cell proliferation in a panel of TNBC cells, whilst did not inhibit cell proliferation in the ErbB-2-negative MCF10A normal breast cell line. Moreover, disruption of retrograde transport by Retro-2 decreased the expression of cell cycle related NErbB-2 target genes (i.e. Erk5 and cyclin D1) therefore inducing cell cycle arrest at the G0/G1 phase. Most importantly, Retro-2 excluded ErbB-2 from the nucleus and abrogated tumor growth in preclinical models of TNBC.Collectively, our findings reveal Retro-2, a non-toxic inhibitor of the retrograde transport route, as a candidate novel therapeutic agent for TNBC based on its ability to evict ErbB-2 from the nucleus and to abrogate TNBC growth.

The EGF domains of MUC4 oncomucin interact with ErbB2 and mediate tumorigenic activity of cancer cells represent new potential therapeutic targets

The MUC4 mucin and its membrane partner ErbB2 form an oncogenic complex at the surface of epithelial cancer cells that promotes tumor progression. They directly physically interact via an extracellular region of MUC4 encompassing three EGF domains opening the route to therapeutic targeting of ErbB2 over-expressing cancers in which MUC4-ErbB2 is present. However, before small inhibitory molecules may be designed, it is mandatory (i) to decipher at the molecular level which amino acid regions are involved in the interaction and (ii) show that they mediate cancer cell tumorigenicity. By using in vitro (2D cell culture, Micro Scale Thermophoresis, PLA assay, Co-IP, GST pull down, Molecular Dynamics simulations) and in vivo (xenograft model of pancreatic cancer) approaches, we show that the EGF1 domain of MUC4 is central both in the interaction with ErbB2 and in the activation of cell proliferation and migration and tumor growth via activation of key oncogenic pathways (Src, Ras, p70S6K/AKT/mTOR, beta-catenin, FAK). Finally, we have identified hotspots of interaction paving the way to the design of therapeutic inhibitory molecules targeting the EGF domains of MUC4 which may represent a new alternative strategy to overcome ErbB2 therapeutic failure in cancer.

MicroRNA-133a-3p suppresses malignant behavior of non-small cell lung cancer cells by negatively regulating ERBB2.

Non-small cell lung cancer (NSCLC) has high morbidity and mortality rates worldwide, and tumor metastasis is generally associated with poor prognosis. Chemotherapy resistance aggravates the challenges associated with treating NSCLC. Therefore, identifying effective targets and developing therapies based on these findings could bring novel perspectives for patients with metastatic NSCLC. The expression levels of receptor tyrosine-protein kinase erbB-2 (ERBB2) are associated with NSCLC progression. Differential microRNA (miR) expression profiles have been identified in tumors and can be used to identify multiple malignant phenotypes. miR-133a-3p expression is dysregulated in a variety of tumors. However, to the best of our knowledge, the association between miR-133a-3p and the NSCLC pathogenesis process has not been demonstrated yet. The present study revealed a decrease in miR-133a-3p expression in both tissues and cell lines, which was detected using reverse transcription-quantitative (RT-q)PCR, and western blotting and RT-qPCR demonstrated ERBB2 levels were increased at both protein and mRNA levels. Bioinformatics analysis and dual-luciferase reporter assays demonstrated that ERBB2 was a direct target of miR-133a-3p. Furthermore, MTT, wound healing and Transwell assays revealed that overexpression of miR-133a-3p suppressed proliferation, invasion and migration of NSCLC cells, respectively, effects that were inhibited following ERBB2 overexpression. In addition, immunofluorescence assays demonstrated that overexpression of ERBB2 upregulated N-cadherin expression, while E-cadherin expression was downregulated. In conclusion, the present data demonstrated that miR-133a-3p acted as a tumor suppressor by negatively regulating ERBB2 expression. The miR-133a-3p/ERBB2 axis may be a potential target for the diagnosis and treatment of NSCLC in the future.

Selective ERBB2 and BCL2 Inhibition Is Synergistic for Mitochondrial-Mediated Apoptosis in MDS and AML Cells.

The ERBB2 proto-oncogene is associated with an aggressive phenotype in breast cancer. Its role in hematologic malignancies is incompletely defined, in part because ERBB2 is not readily detected on the surface of cancer cells. We demonstrate that truncated ERBB2, which lacks the extracellular domain, is overexpressed on primary CD34+ myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) cells compared with healthy hematopoietic cells. This overexpression of ERBB2 is associated with aberrant, oncogenic signaling with autophosphorylation of multiple tyrosine sites. Like in breast cancers, ERBB2 can exist as truncated isoforms p95ERBB2 and p110ERBB2 in MDS and AML. Neutralization of ERBB2 signaling with ERBB2 tyrosine kinase inhibitors (i.e., lapatinib, afatinib, and neratinib) increases apoptotic cell death and reduces human engraftment of MDS cells in mice at 21 weeks posttransplantation. Inhibition of ERBB2 modulates the expression of multiple pro- and anti-apoptotic mitochondrial proteins, including B-cell lymphoma 2 (BCL2). Dual blockade with ERBB2 and BCL2 inhibitors triggers additional reductions of BCL2 phosphorylation and myeloid cell leukemia-1 (MCL1) expression compared with single drug treatment. Dual therapy was synergistic at all tested doses, with a dose reduction index of up to 29 for lapatinib + venetoclax compared with venetoclax alone. Notably, these agents operated together and shifted cancer cells to a pro-apoptotic phenotype, resulting in increased mitochondrial cytochrome c release and activated caspase-3-mediated cell death. IMPLICATIONS: These findings warrant study of ERBB2 and BCL2 combination therapy in patients with MDS and AML. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/5/886/F1.large.jpg.