ERβ Expression Research Articles

NRG1/ERBB3/ERBB2 Axis Triggers Anchorage-Independent Growth of Basal-like/Triple-Negative Breast Cancer Cells.

Simple SummaryBreast cancer is a heterogeneous disease, categorized into distinct subgroups with different clinical prognoses and treatment strategies. This study aimed to evaluate the role of ERBB3 in different molecular subtypes of breast cancers. Despite ERBB3/HER3 and its partner ERBB2/HER2 showing low expression levels in basal-like/triple-negative breast cancers, stratification of basal-like patients according to ERBB3 mRNA expression levels highlighted a correlation between higher ERBB3 levels and shorter relapse-free patients’ survival. In vitro analyses unveiled that the activation of the NRG1/ERBB3/ERBB2 axis robustly induces anchorage-independent growth of basal-like/triple-negative breast cancer cellular models, without significant effects on cell proliferation, differentiation, and migration in adhesion. Overall, our data suggest that ERBB2/ERBB3 plays an oncogenic role in basal-like/triple-negative breast cancer patients, suggesting its neutralization as a therapeutic strategy for these breast cancer subtypes, which today have very limited treatment opportunities.ERBB3, also known as HER3, is a tyrosine kinase transmembrane receptor of the ERBB family. Upon binding to neuregulin 1 (NRG1), ERBB3 preferentially dimerizes with HER2 (ERBB2), in turn inducing aggressive features in several cancer types. The analysis of a dataset of breast cancer patients unveiled that higher ERBB3 mRNA expression correlates with shorter relapse-free survival in basal-like breast cancers, despite low ERBB3 expression in this breast cancer subtype. Administration of neuregulin 1 beta (NRG1β) significantly affected neither cellular proliferation nor the basal migratory ability of basal-like/triple-negative quasi-normal MCF10A breast cells, cultured in mono-layer conditions. Furthermore, no significant regulation in cell morphology or in the expression of basal/myoepithelial and luminal markers was observed upon stimulation with NRG1β. In non-adherent conditions, NRG1β administration to MCF10A cells did not significantly influence cell survival; however, it robustly induced cell growth as spheroids (3D growth). Intriguingly, a remarkable upregulation of ERBB3 and ERBB2 protein abundance was observed in 3D compared to 2D cell cultures, and NRG1β-induced 3D cell growth was efficiently prevented by the anti-HER2 monoclonal antibody pertuzumab. Similar results were obtained by the analysis of basal-like/triple-negative breast cancer cellular models, MDA-MB-468 and MDA-MB-231 cells, in which NRG1β induced anchorage-independent cell growth that in turn was prevented or reduced by the simultaneous administration of anti-HER2 neutralizing antibodies. Finally, the ability of pertuzumab in suppressing NRG1β-induced 3D growth was also evaluated and confirmed in MCF10A engineered with HER2-overexpression. We suggest that the NRG1/ERBB3/ERBB2 pathway promotes the anchorage-independent growth of basal-like breast cancer cells. Importantly, we provide evidence that ERBB2 neutralization, in particular by pertuzumab, robustly inhibits this process. Our results pave the way towards the development of novel anticancer strategies for basal-like breast cancer patients based on the interception of the NRG1/ERBB3/ERBB2 signaling axis.

Resveratrol prevents hypoxia-induced retinal ganglion cell death related with ErbB2.

To confirm the changes in proteins related with hypoxia-induced retinal cell death and to assess the effects of resveratrol (Res). The therapeutic effect of Res was verified using an ischemic/reperfusion (I/R) model in vivo and a hypoxia modelin retinal ganglion cells (RGCs) in vitro. Death of RGCs were confirmed by TUNEL assay. Protein expression was confirmed by Western blotting and immunohistochemistry. In addition, flow cytometric analysis was used to confirm the response in the cell unit to obtain more accurate data. ErbB2 expression and apoptosis in the ganglion cell layer (GCL) increased after I/R injury. Treatment of Res rescued I/R-induced ganglion cell death, downregulated apoptosis and ErbB2 protein expression in the retina. In subsequent in vitro models, Res affects apoptosis by regulating the phosphorylation and expression of mouse double minute 2 homolog (MDM2), along with those of ErbB2. These results suggest that Res reverses GCL-specific apoptosis via downregulation of ErbB2 in ischemic injury. In light of Res favorable properties, it should be evaluated in the treatment of RGC death and related retinal disease characterized by ErbB2 and MDM2 expression. Therefore, Res is appropriate therapeutic agent for treating ischemic injury-related eye diseases by targeting the expression of ErbB2 and MDM2.

ARAF suppresses ERBB3 expression and metastasis in a subset of lung cancers

RAF kinases are highly conserved serine/threonine kinases, and among the three RAF isoforms (ARAF, BRAF, and CRAF), the pathophysiological relevance of ARAF is not well defined. Here, we show that patients with lung cancer exhibit low expression of ARAF, which is associated with lymph node metastasis and poor patient survival. We uncover that depletion of ARAF promotes anchorage-independent growth and metastasis through activation of AKT signaling in a subset of lung cancer cells. We identified that loss of ARAF was associated with an increase in ERBB3 expression in a kinase-independent manner. ARAF suppressed the promoter activity of ERBB3, and reconstitution of ARAF in ARAF-depleted cells led to the reversal of enhanced ERBB3-AKT signaling. Furthermore, ARAF inhibited neuregulin 1 (hNRG1)–mediated AKT activation through controlling ERBB3 expression via the transcription factor KLF5. Our results disclose a critical dual role for ARAF kinase in the negative regulation of ERBB3-AKT signaling, thereby suppressing tumor metastasis.

Prenatal Progestin Exposure-Mediated Oxytocin Suppression Contributes to Social Deficits in Mouse Offspring.

Epidemiological studies have shown that maternal hormone exposure is associated with autism spectrum disorders (ASD). The hormone oxytocin (OXT) is a central nervous neuropeptide that plays an important role in social behaviors as well as ASD etiology, although the detailed mechanism remains largely unknown. In this study, we aim to investigate the potential role and contribution of OXT to prenatal progestin exposure-mediated mouse offspring. Our in vitro study in the hypothalamic neurons that isolated from paraventricular nuclei area of mice showed that transient progestin exposure causes persistent epigenetic changes on the OXT promoter, resulting in dissociation of estrogen receptor β (ERβ) and retinoic acid-related orphan receptor α (RORA) from the OXT promoter with subsequent persistent OXT suppression. Our in vivo study showed that prenatal exposure of medroxyprogesterone acetate (MPA) triggers social deficits in mouse offspring; prenatal OXT deficiency in OXT knockdown mouse partly mimics, while postnatal ERβ expression or postnatal OXT peptide injection partly ameliorates, prenatal MPA exposure-mediated social deficits, which include impaired social interaction and social abilities. On the other hand, OXT had no effect on prenatal MPA exposure-mediated anxiety-like behaviors. We conclude that prenatal MPA exposure-mediated oxytocin suppression contributes to social deficits in mouse offspring.

Combined Estrogen Alpha and Beta Receptor Expression Has a Prognostic Significance for Colorectal Cancer Patients.

We reported that high estrogen receptor beta (ERβ) expression is independently associated with better prognosis in female colorectal cancer (CRC) patients. However, estrogen receptor alpha (ERα) is expressed at very low levels in normal colon mucosa, and its prognostic role in CRC has not been explored. Herein, we investigated the combined role of ERα and ERβ expression in the prognosis of female patients with CRC, which, to the best of our knowledge, is the first study to investigate this topic. A total number of 306 primary CRCs were immunostained for ERα and ERβ expression. A Cox regression model was used to evaluate overall survival (OS) and disease-free survival (DFS). The combined expression of high ERβ + negative ERα correlates with longer OS (HR = 0.23; 95% CI: 0.11–0.45, P <0.0001) and DFS (HR = 0.10; 95% CI: 0.03–0.26, P < 0.0001) and a more favorable tumor outcome, as well as significantly higher expression of antitumorigenic proteins than combined expression of low ERβ + positive ERα. Importantly, we found that low ERβ expression was associated with local recurrence of CRC, whereas ERα expression was correlated with liver metastasis. Overall, our results show that the combined high ERβ + negative ERα expression correlated with a better prognosis for CRC patients. Our results suggest that the combined expression of ERα and ERβ could be used as a predictive combination marker for CRC patients, especially for predicting DFS.

Estrogen receptor beta promotes endometriosis progression by upregulating CD47 expression in ectopic endometrial stromal cells

Endometriosis is a common estrogen-dependent gynecological disorder that is characterized by endometrial-like tissue being found at extrauterine sites. Aberrant expression and activation of estrogen receptor beta (ERβ) in ectopic endometrium are involved in endometriosis development. Here, we used primary tissues and cells from endometriosis patients to investigate the molecular mechanisms involved in ERβ’s contribution to endometriosis progression. Through RNA-seq, quantitative PCR, and immunohistochemistry analysis, we found that ERβ expression is related to the severity of endometriosis; specifically, the ratio of ESR2/ESR1 in ectopic tissues was positively correlated with the severity of endometriosis, which suggests that ERβ has a predominant role in endometriosis progression. Furthermore, we found that ERβ could bind to the CD47 promoter, increasing CD47 expression levels. CD47 is a critical molecule in "don't eat me" signaling. These data highlight the importance of the ERβ-CD47 axis in the pathogenesis of endometriosis. We believe targeting CD47 may be a novel therapeutic approach for treating endometriosis and other ERβ-associated diseases.

Mechanisms of GZ17-6.02 resistance.

The drug GZ17-6.02 is undergoing phase I in solid tumor patients (NCT03775525). The present studies initially determined the impact of prolonged exposure of colorectal tumors to GZ17-6.02, and to determine whether GZ17-6.02 enhanced the efficacy of an anti-PD1 antibody. Subsequently, studies defined the evolutionary resistance mechanisms in tumor cells previously exposed to GZ17-6.02. IACUC-approved animal studies were performed. In cell immunoblotting, cell transfections and trypan blue death assays were performed. Prolonged exposure of colorectal tumors to GZ17-6.02 enhanced the efficacy of 5-fluorouracil and of an anti-PD1 antibody, significantly prolonging animal survival. Tumor cells previously exposed to GZ17-6.02 in vivo had elevated their expression of ERBB2 and ERBB3, and increased phosphorylation of ERBB1, ERBB3, PDGFRβ, AKT T308, ERK1/2, p70 S6K T389, STAT5 Y694 and c-SRC Y416. The phosphorylation of c-SRC Y527 declined. The efficacy of ERBB receptor inhibitors at killing these resistant tumor cells was unaltered by prior GZ17-6.02 exposure whereas the efficacy of multi-kinase/PDGFRβ inhibitors was significantly reduced. Treatment of colon cancer cells with GZ17-6.02 rapidly reduced the levels of multiple HDAC proteins and altered their subcellular localization. Isolates from resistant tumors expressed less CD95 and FAS-L. HDAC inhibitors enhanced CD95 and FAS-L levels in the resistant cells via activation of NFκB and HDAC inhibitors restored the efficacy of GZ17-6.02 to near control levels. Our findings demonstrate that GZ17-6.02 has the potential to be developed as a colon cancer therapeutic and that resistance to the drug can be partially reversed by HDAC inhibitors.

β-Estradiol inhibits melatonin synthesis and melatonin receptor expression in sheep granulosa cells.

Melatonin, an important regulator of mammalian reproduction, is mainly produced in the pineal gland, and granulosa cells (GCs), the main mammalian ovarian secretory cells, synthesize melatonin and express melatonin receptors (MRs) MT1 and MT2. However, studies on melatonin regulation in GCs are lacking in sheep. In this study, we explored the effects of β-estradiol (E2) on melatonin production and MR expression in GCs. We cultured sheep GCs to analyze the expression of the melatonin rate-limiting enzymes AANAT and HIOMT and the effects of E2 on AANAT, HIOMT, and MR expression and melatonin synthesis. To determine whether estrogen receptors (ERs) mediated E2 action on melatonin secretion and MR expression, we assessed ERA and ERB expression in GCs and observed whether ER antagonists counterbalanced the effects of E2. GCs expressed AANAT and HIOMT mRNA, indicating that they transformed exogenous serotonin into melatonin. E2 inhibited melatonin production by downregulating AANAT, HIOMT, and MRs. GCs expressed ERA and ERB; ERA/ERB inhibitors abolished E2-mediated inhibition of melatonin secretion and MR expression. PHTPP upregulated melatonin secretion and MT1 expression in E2-treated GCs, but did not significantly affect AANAT and MT2 expression. In conclusion, melatonin secretion in GCs was inhibited by E2 through an ERA- and ERB-mediated process.

Premarin Reduces Neurodegeneration and Promotes Improvement of Function in an Animal Model of Spinal Cord Injury.

Spinal cord injury (SCI) causes significant mortality and morbidity. Currently, no FDA-approved pharmacotherapy is available for treating SCI. Previously, low doses of estrogen (17β-estradiol, E2) were shown to improve the post-injury outcome in a rat SCI model. However, the range of associated side effects makes advocating its therapeutic use difficult. Therefore, this study aimed at investigating the therapeutic efficacy of Premarin (PRM) in SCI. PRM is an FDA-approved E2 (10%) formulation, which is used for hormone replacement therapy with minimal risk of serious side effects. The effects of PRM on SCI were examined by magnetic resonance imaging, immunofluorescent staining, and western blot analysis in a rat model. SCI animals treated with vehicle alone, PRM, E2 receptor antagonist (ICI), or PRM + ICI were graded in a blinded way for locomotor function by using the Basso–Beattie–Bresnahan (BBB) locomotor scale. PRM treatment for 7 days decreased post-SCI lesion volume and attenuated neuronal cell death, inflammation, and axonal damage. PRM also altered the balance of pro- and anti-apoptotic proteins in favor of cell survival and improved angiogenesis and microvascular growth. Increased expression of estrogen receptors (ERs) ERα and ERβ following PRM treatment and their inhibition by ER inhibitor indicated that the neuroprotection associated with PRM treatment might be E2-receptor mediated. The attenuation of glial activation with decreased inflammation and cell death, and increased angiogenesis by PRM led to improved functional outcome as determined by the BBB locomotor scale. These results suggest that PRM treatment has significant therapeutic implications for the improvement of post-SCI outcome.

Altered endometrial oestrogen-responsiveness and recurrent reproductive failure.

Graphical abstract Recurrent reproductive failure (RRF) encompasses recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL). These highly prevalent, distressing conditions have many unanswered questions regarding aetiology and management. Oestrogen receptor beta (ERβ) is the predominant oestrogen receptor expressed in the vascular endothelium of the endometrium during the window of implantation (WOI). The establishment of normal endometrial receptivity is integrally associated with progesterone receptor (PR). Therefore, we aimed to investigate whether women with RRF have clinical, type-specific endometrial aberrations of ERβ, PR and Ki-67 expression during the WOI. Thirty-eight endometrial biopsies were collected; 29 RRF (10 RIF, 9 recurrent loss of early pregnancy (RLEP) and 10 recurrent fetal loss (RFL)) and 9 fertile controls (FC). Within RIF, RLEP and RFL groups, the perivascular compartment showed significantly lower levels of ERβ vs FC (P = 0.02, P = 0.03 and P = 0.01, respectively). Vascular endothelium also displayed significantly lower levels of ERβ within RIF and RFL cohorts vs FC (P = 0.03 and P = 0.003). The expression of Ki-67 was significantly lower within vascular endothelium of all RRF; RIF (P = 0.02), RLEP (P = 0.02) and RFL (P <0.01). PR was significantly reduced (P <0.001) in the perivascular area of women with RIF. These findings provide novel insights into biological correlates of clinical subtypes of RRF. The endometrium of women with RRF display significantly altered levels of ERβ, PR and Ki-67 during the WOI, furthering our understanding of the defective endometrial phenotype of women suffering from RRF, with possible impaired glandular function, angiogenesis and decidualisation.Lay summaryRecurrent reproductive failure (RRF) refers to a group of devastating conditions with many unanswered questions regarding their causes and treatment options. The lining of the womb, the endometrium, is primed and suitable for successful embryo implantation for a short time during the menstrual cycle; the window of implantation (WOI). Oestrogen is a key hormone that plays an important role in regulating the endometrium and its effects are exerted via two oestrogen receptor subtypes. Oestrogen receptor beta (ERβ) is the main oestrogen receptor present during the WOI. Progesterone receptor allows the other main hormone, progesterone, to influence the endometrial activity and Ki-67 reflects the proliferative activity of the cells within the endometrium. We investigated the expression of these markers in endometrial samples collected from women with RRF and proven fertility. We found that the endometrium of women with RRF has significantly lower levels of ERβ and Ki-67 during the WOI, possibly leading to unsuccessful pregnancies.

Endocrine disruptor hexachlorobenzene induces cell migration and invasion, and enhances aromatase expression levels in human endometrial stromal cells

Endometriosis is the presence and growth of endometrial tissue outside of the uterus. Previous studies have suggested that endocrine disrupting chemicals such as organochlorine pesticides could be a risk factor for endometriosis. Hexachlorobenzene (HCB) is a weak ligand of the aryl hydrocarbon receptor (AhR) and promotes metalloproteinase and cyclooxygenase-2 (COX-2) expression, as well as, c-Src activation in human endometrial stromal cells (T-HESC) and in rat endometriosis model. Our aim was to evaluate the effect of HCB exposure on oestrogen receptor (ER) ɑ and β, progesterone receptor (PR) and aromatase expression, as well as, on cell migration and invasion in T-HESC and primary cultures of endometrial stromal cells from eutopic endometria of control subjects (ESC). Results show that HCB increases ERɑ and aromatase protein levels and reduces PR content in both T-HESC and ESC. However, the pesticide only increases ERβ expression in ESC, without changes in T-HESC. Moreover, cell migration and invasion are promoted by pesticide exposure involving the AhR, c-Src, COX-2 and ER pathways in T-HESC. HCB also triggers ERɑ activation via phosphorylation in Y537 through AhR/c-Src pathway. Our results provide experimental evidence that HCB induces alterations associated with endometriosis, suggesting that these mechanisms could contribute to pesticide exposure-induced endometriosis development.

Abstract P4-02-09: The lncRNA XIST mediates sensitivity to ERβ targeted therapies in triple negative breast cancer

Abstract Background:. Poor patient outcomes in triple negative breast cancer (TNBC) largely stem from a lack of understanding of therapeutic vulnerabilities and an insufficient armamentarium of effective drugs. The standard of care for most early stage TNBC patients continues to be (neo)adjuvant chemotherapy and radiation. Identifying additional therapeutic options for this subset of patients represents a major unmet need. We and others demonstrated that estrogen receptor beta (ERβ) is expressed in about 20% of TN tumors. Prior research has shown that ligand-mediated activation of ERβ decreases proliferation, invasion, and migration in TNBC cell lines. In vivo, ERβ suppresses the growth of cell line xenograft models and prevents the development of metastatic lesions in a ligand dependent manner. Mechanistically, we found that ERβ repurposes EZH2 to suppress oncogenic NFκB signaling and that pharmacologic inhibition of EZH2 diminishes ERβ function and its anti-cancer effects. This research has led to an ongoing clinical trial (NCT03941730) assessing the efficacy of estradiol in ERβ+ TNBC patients with chemorefractory disease. As with all therapies, patients will exhibit de novo and acquired resistance and therefore we sought to understand the mechanisms of resistance to ERβ targeted therapies. Methods:. Using multiple models of ERβ positive TNBC, we developed ERβ resistant cell lines through chronic exposure to estradiol and the ERβ specific agonist LY500307 over a period of 8 months. We employed RNA sequencing to characterize the transcriptomic changes which occurred following ERβ resistance. We profiled XIST expression across multiple publicly available datasets, including TCGA, Metabric, BEAUTY, and GTEx. XIST expression was also modulated using CRISPR/Cas9 to assess subsequent effects on TNBC cell biology, ERβ function, and response to ERβ targeted therapies. Results:. Our resistant cell line models of ERβ positive TNBC maintained ERβ expression, but were no longer growth inhibited by ERβ agonists. RNAseq revealed substantial differences comparing the transcriptome of resistant versus sensitive cell lines, of which the most increased transcript in the resistant setting was the lncRNA XIST. XIST is best known for its role in X-chromosome inactivation through recruitment and association with the PRC2 complex, and thus EZH2. However, little is known about its functions in breast cancer. We therefore assessed the expression levels of XIST in breast tumors and cell lines. XIST expression was highly variable in breast cancer, was found in a proportion of all breast cancer sub-types and did not correlate with ERβ status. However, XIST expression was up-regulated in ERβ expressing cell lines following long term estrogen treatment. No effects on XIST expression were identified in multiple ERα positive models following estrogen, SERM/SERD treatment, or estrogen deprivation. Furthermore, upregulation of XIST was not associated with resistance to Paclitaxel or Doxorubicin, suggesting XIST is not a part of a broad resistance phenotype. Strikingly, CRISPR mediated knockout of XIST in ERβ resistant cells completely re-sensitized cells to ERβ targeted therapies suggesting that XIST expression is a critical component of ERβ resistance. Conclusions:. ERβ represents a relevant therapeutic target that is being tested in clinical trials. Using multiple in vitro models, we provide evidence that XIST expression is sufficient to induce resistance to. ERβ targeted therapies in TNBC and may therefore represent a relevant biomarker for patient stratification. Further strategies to suppress XIST expression may elicit anti-cancer effects on their own and may resensitize a sub-set of ERβ resistant tumors to ERβ agonists. Citation Format: Michael J Emch, Kirsten GM Aspros, Elizabeth S Bruinsma, Krishna R Kalari, Calley J Jones, Brandon W Simone, Matthew P Goetz, John R Hawse. The lncRNA XIST mediates sensitivity to ERβ targeted therapies in triple negative breast cancer [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 P4-02-09.

Abstract PD13-04: Activity of patritumab deruxtecan, a HER3-directed antibody drug conjugate, in early breast cancer according to ERBB3 expression: Interim analysis results of a window-of-opportunity study (SOLTI-1805 TOT-HER3)

Abstract Introduction Patritumab deruxtecan (U3-1402; HER3-DXd) is a HER3-directed antibody drug conjugate with demonstrated clinically meaningful antitumor activity and acceptable safety profile in heavily pre-treated metastatic breast cancer (BC) with high or low HER3 expression levels (Masuda et al. Cancer Res. 2019; Krop et al. SABCS 2020). Here, we report the interim efficacy and safety data of the TOT-HER3 trial (NCT04610528), the first window-of-opportunity study designed to assess whether a single dose of HER3-DXd may increase immune infiltration during short-term preoperative treatment in early BC. Methods This is a prospective, phase 0, multicenter, single arm trial planned to enroll 80 patients with treatment naïve hormone receptor positive, HER2 negative primary operable BC ≥1 cm by ultrasound. Patients are allocated to one of 4 cohorts based on centrally assessed levels of ERBB3 mRNA by the nCounter platform in a pre-treatment biopsy and receive HER3-DXd administered as a single dose of 6.4 mg/kg. Post-treatment biopsy at C1D21 is obtained to explore primary and correlative endpoints. The primary objective is to evaluate the median change in the CelTIL score (-0.8*tumor cellularity% + 1.3*tumor-infiltrating lymphocytes%) (Nuciforo et al. Ann Oncol. 2018) in paired pre- and post-treatment samples in the overall cohort. Change in CelTIL score and the expression of 67 genes across ERBB3 cohorts and PAM50 subtypes is also explored. Adverse events (AEs) are graded according to CTCAE v 5.0. Results As of April 21 2021, 30 patients (all women) received the study treatment and were evaluable for the primary endpoint. Mean age was 52 years (range 35-77 years); 19 patients were pre- and 11 were post-menopausal. Median tumor size was 20 mm (range 10-60 mm); cN0 70%; mean Ki67 35% (range 10-90%); grade 1-2 67%. According to ERBB3 expression, 6 (20%), 13 (43%), 5 (17%) and 6 (20%) patients were categorized as high, medium, low and ultra-low, respectively. CelTIL score increased, was stable and decreased in 17 (57%), 3 (10%) and 10 (33%) patients, respectively. Overall, a statistically significant increase in CelTIL was observed between paired samples (p=0.028). At C1D21, a total of 12 (44%) patients experienced a response (7 complete and 5 partial response) by clinical palpation. CelTIL significantly changed in responders (p=0.006) but not in patients with stable disease (p=0.61). Baseline ERBB3 levels did not correlate with CelTIL change or clinical response. Moreover, PAM50 subtype distribution was as follows: Luminal A 15 (50%), Luminal B 13 (43%), HER2-Enriched 1 (3.5%), Basal-like 1 (3.5%). CelTIL score did not change significantly between Luminal A and Luminal B tumors. Five (38.5%) Luminal B tumors switched to Luminal A at C1D21. Interestingly, baseline high PAM50 risk-of-recurrence was associated with higher CelTIL score at C1D21 (p=0.002). Patritumab deruxtecan induced high expression of immune-related genes including PD1, CD8a and CD19 and Luminal A signature and suppressed proliferation-related genes. Overall, 29 (97%) patients reported at least one AE and 98% of AEs were grade 1 or 2. The most common AEs were nausea, asthenia, abdominal pain, alopecia, vomiting, diarrhea, neutropenia, increased liver enzymes. A grade 3 treatment-related reversible AST increase occurred in 1 patient. Conclusion In this interim trial analysis, a single dose of patritumab deruxtecan was associated with clinical response and important biological changes irrespective of baseline ERBB3 expression. The safety profile was consistent with that previously reported for the drug. Citation Format: Aleix Prat, Juan M. Cejalvo, Laia Pare, Olga Martínez-Sáez, Mireia Margelí Vila, Claudette Falato, Josefina Cruz, Miriam Arumí de Dios, Maria J Vidal, Juan Antonio Guerra, Ana Maria Luna Barrera, Pablo Tolosa, Francisco Javier Salvador-Bofill, Sonia Pernas, Blanca Gonzáles-Farré, Esther Sanfeliu, Eva Ciruelos, Violeta Serra, Martin Espinosa-Bravo, Yann Izarzugaza, Stephen Esker, Pang-Dian Fan, Guillermo Villacampa, Juan M Ferrero-Cafiero, Tomás Pascual, Mafalda Oliveira. Activity of patritumab deruxtecan, a HER3-directed antibody drug conjugate, in early breast cancer according to ERBB3 expression: Interim analysis results of a window-of-opportunity study (SOLTI-1805 TOT-HER3) [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 PD13-04.

Abstract PD15-02: HER2-enriched subtype and novel molecular subgroups drive aromatase inhibitor resistance and an increased risk of relapse in early ER+/HER2+ breast cancer

Abstract Background: Approximately 10% of estrogen receptor positive (ER+) early breast cancers (EBC) are human epidermal growth factor positive/overexpressed (HER2+). Resistance to aromatase inhibitors (AIs) is poorly understood among ER+HER2+ BC. We aimed to identify biomarkers of response and resistance using the HER2+ tumours in the POETIC trial. Methods: POETIC was a phase III trial of post-menopausal women with ER+ EBC randomized 2:1 to 2-weeks of peri-surgical AI vs control, followed by standard-of-care. Baseline formalin-fixed paraffin-embedded samples from 342 ER+HER2+ BC (237 treated/105 controls) were gene expression profiled using Breast cancer 360™ panel (NanoString) covering intrinsic subtypes and 40 key biological signatures. New molecular subgroups were identified using consensus clustering (CC).Proliferation rate was estimated as percentage of cancer-cells staining for Ki67. Ki67 response was defined by percentage-changes from baseline to surgery: poor (PR; reduction &amp;lt;50%), intermediate (IR; 50-75%) and good (GR; &amp;gt;75%). Residual Ki67 at 2 weeks timepoint (Ki672w) was defined as High (H) (≥ 10%) vs Low (L) (&amp;lt;10%). Association of molecular features with Ki67 response was assessed using logistic regression models and with time to recurrence (TTR) using multivariable Cox regression models adjusted for post-surgery clinicopathological variables: grade, tumour size, nodal status and age. Results: Ki672w was measured for all treated samples (n = 227, 48% H, 52% L) and a fraction of controls (n = 50, 96% H, 4% L). At baseline, 45% of tumours were HER2-enriched (HER2-E), 53% Luminal A/B and 2% Basal-Like. HER2-E associated with high Ki672W (84% H, 16% L) compared to non-HER2-E (29% H, 71% L, p&amp;lt;0.001). Amongst the 40 BC360 signatures, 9 were significantly associated with Ki67 response (Table). High expression of endocrine-related and apoptosis signatures associated with GR while HRD and TP53 with PR. These features were also related to Ki672W, with additional signatures involved in immune-checkpoint component and immune-enrichment (IM) (IDO1, PD-L1, IFN-gamma and T-reg) associated with high Ki672W.. Using CC, 4 molecular subgroups predicting differential response to AI were identified. Cluster (C) 1 was characterized by overexpression of IM features and low ER signaling (42%); C2 low IM but highest ERBB2 expression (15%); C3 ESR1 high and PgR low (4%) and C4 high endocrine signaling and lowest ERBB2 expression (39%). Distribution of Intrinsic subtypes varied across these molecular subgroups with the majority of C1 being HER2-E (62%) and Luminal B (27%); C2 HER2-E (74%); C3 Luminal B (64%) and C4 Luminal B (55%) and Luminal A (30%). HER2-E had significantly poorer TTR (HR 2.14; 95%CI1.11-4.17; p=0.0224) compared to Luminal tumours, remaining significant (HR 2.55, 95%CI1.14-5.69; p=0.0222) in the multivariable analysis. C2 (HR 4.67, 95%CI 1.90-11.51; p&amp;lt;0.001) and C4 (HR 2.42, 95%CI1.05-4.5.58; p=0.0385) were independent predictors of shorter TTR compared to C1, adding significant value beyond intrinsic subtypes (Likelihood ratio test, p=0.00429). Conclusions: Our results confirm that HER2-E, TP53 mutation, HRD and IM features are the main components driving poor early response to AI in ER+/HER2+ EBC. Novel molecular subgroups identify additional non-HER-E tumours not responding to AI with an increased risk of relapse. The appropriate additional treatment warrants further investigation. List of significant gene expression signatures associated with response as defined by reduction of Ki67. Odds ratio (OR) were determined by ordinal logistic regression analyses. OR: &amp;lt;1 indicating associated with good response and &amp;gt; 1.0 associated with worse response.Odds Ratiop-valuep-adjusted (False Discovery Rate)ESR10.65&amp;lt; 0.001&amp;lt; 0.001Estrogen Receptor Signaling0.44&amp;lt; 0.001&amp;lt; 0.001ERBB21.52&amp;lt; 0.001&amp;lt; 0.001TP53 mutant signature2.65&amp;lt; 0.001&amp;lt; 0.001FOXA10.42&amp;lt; 0.001&amp;lt; 0.001Apoptosis0.26&amp;lt; 0.0010.00228Homologous Recombination Deficiency (HRD)2.33&amp;lt; 0.0010.00349PgR0.820.001480.00737Hypoxia2.180.001660.00737 Citation Format: Milana A Bergamino Sirvén, Elena López-Knowles, Gabriele Morani, Holly Tovey, Lucy Kilburn, Chris Holcombe, Anthony Skene, Ian Smith, John Robertson, Gene Schuster, Judith M Bliss, Mitch Dowsett, Maggie CU Cheang, POETIC investigators. HER2-enriched subtype and novel molecular subgroups drive aromatase inhibitor resistance and an increased risk of relapse in early ER+/HER2+ breast cancer [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 PD15-02.

Abstract P2-07-08: Identification of UGT2B15 as a potential biomarker in response to neoadjuvant therapy in HER2+ breast cancer

Abstract INTRODUCTION. In response to neoadjuvant therapy, pathological complete response (pCR; lack of residual disease in breast and lymph nodes), has been proposed as a prognostic marker for long-term clinical outcomes, such as disease-free (DFS) and overall survival (OS), in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancer. In clinical practice, recognizing those patients likely to achieve such responses proves challenging to the oncologist, making the identification of new useful biomarkers vital. Here, we searched for potential biomarkers that anticipate pCR to neoadjuvant therapy in HER2-positive, hormone receptor-negative breast cancer tissue samples. METHODS. Patients with early and locally advanced breast cancer, diagnose as HER2-positive, hormone receptor-negative by immunohistochemistry (IHC) at the time of neoadjuvant treatment were included. All samples were collected from biobank at Hospital Universitario Virgen del Rocio. We defined two groups: responder (R) and non-responder (nR) and analyzed 18 samples in the discovery cohort (10 R vs 8 nR) and 12 samples in the validation cohort (6 R vs 6 nR).The RNA for the study was extracted from tissue fixed in formaldehyde and paraffin embedded. The extraction of the RNA was carried out using the commercial kit RecoverAll Total Nucleic Acid Isolation Kit from Ambion (Applied Biosystems). RNA was quantified by Qubit RNA HS Assay Kit (Molecular Probes). Before hybridization, RNA for the discovery cohort was amplified using GeneChip WT Pico Kit (Applied Biosystems).We analyzed transcript expression using ClariomD array. Differential expression between the two groups was analyzed using in-house R scripts (version 3.5.1). Data were corrected and normalized using Robust Multi-array Average method. Expression was summarized at gene level using the corresponding annotation for ClariomD BrainArray. Gene validation was performed by qPCR using TaqMan Gene Expression Assay (Applied Biosystem). RESULTS. Considering a fold change ≥ 2 and an adjusted p-value &amp;lt;0.05 as statistically significant, we found 53 differentially expressed transcripts: 51 downregulated transcripts (lower expression in R) and 2 upregulated transcripts (higher expression in R). The RNA was annotated as non-coding RNAs in over 25% of the cases. The distribution of such molecules was as followed: 8 long non-coding RNAs (56%); 3 non-coding RNAs (22%) and 3 pseudo-genes (22%). Regarding protein coding transcripts, gene ontology analysis revealed an enrichment of terms associated to metabolic processes and response to toxic substance.As expected, ERBB2, which encodes for HER2, appeared at the top of the list with a patent upregulation of expression in the responder group when compared with non-responder patients. To validate the data, we used qPCR and ERBB2 expression as a positive control of the results (p-value=0.0380). Our data showed a significant downregulation of UDP-glucuronosyltransferase 2B15 (UGT2B15; p-value= 0.0173), which encodes a glycosyltransferase, involved in the metabolism and elimination of toxic compounds. CONCLUSIONS. The ability to predict which patients will benefit from neoadjuvant therapy and achieve a pCR would allow for improved patient stratification and more personalized medicine. Here, we identified a set of transcript differentially expressed (FC&amp;gt;2; adjusted p-value&amp;lt;0.05) in patients that achieve pCR (R) when compared with tissue samples with residual disease (nR). We usedERBB2 expression as a positive control to validate the data and show that UGT2B15 is consistently upregulated in non-responder patients. Further work is needed to elucidate UGT2B15 role, but it is worth mentioning that an increased rate of glucuronidation has been associated with a loss of potency for the target drugs. Citation Format: Ana Gil-Torralvo, Marta Benavent, Maria A Dominguez-Cejudo, Alejandro Falcon, Begoña Vieites, Sonia Molina-Pinela, Manuel Ruiz, Álvaro Montaño, Rosario Gónzalez, Julia Martínez, Juan de la Haba, Antonio Rodríguez, Maria I Queipo, Begoña Jímenez, Javier Salvador-Bofill. Identification of UGT2B15 as a potential biomarker in response to neoadjuvant therapy in HER2+ breast cancer [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 P2-07-08.

Neuregulin-1 regulates the conversion of M1/M2 microglia phenotype via ErbB4-dependent inhibition of the NF-κB pathway.

The inflammatory response caused by microglia in the central nervous system plays an important role in Alzheimer's disease. Neuregulin-1 (NRG1) is a member of the neuregulin family and has been demonstrated to have anti-inflammatory properties. The relationship between NRG1, microglia phenotype and neuroinflammation remains unclear. BV2 cells were used to examine the mechanism of NRG1 in regulating microglia polarization. Neuronal apoptosis, inflammatory factors TNF-α and iNOS, microglia polarization, ErbB4 and NF-κB p65 expression were assessed. We found that exogenous NRG1 treatment or overexpression improved microglial activity and reduced the secretion of the inflammatory factors TNF-α and iNOS in vitro. The expression of Bax in SH-SY5Y neuron cells incubated with medium collected from the NRG1 treatment group decreased. Additionally, our study showed that NRG1 treatment reduced the levels of the M1 microglia markers CD120 and iNOS and increased the levels of the M2 microglia markers CD206 and Arg-1. Furthermore, we observed that NRG1 treatment attenuated Aβ-induced NF-κB activation and promoted the expression of p-ErbB4 and that knockdown of ErbB4 abrogated the effects of NRG1 on NF-κB, Bax levels and M2 microglial polarization. NRG1 inhibits the release of inflammatory factors in microglia and regulates the switching of the M1/M2 microglia phenotype, most likely via ErbB4-dependent inhibition of the NF-κB pathway.

Zebrafish patient-derived xenograft models predict lymph node involvement and treatment outcome in non-small cell lung cancer

BackgroundAccurate predictions of tumor dissemination risks and medical treatment outcomes are critical to personalize therapy. Patient-derived xenograft (PDX) models in mice have demonstrated high accuracy in predicting therapeutic outcomes, but methods for predicting tumor invasiveness and early stages of vascular/lymphatic dissemination are still lacking. Here we show that a zebrafish tumor xenograft (ZTX) platform based on implantation of PDX tissue fragments recapitulate both treatment outcome and tumor invasiveness/dissemination in patients, within an assay time of only 3 days.MethodsUsing a panel of 39 non-small cell lung cancer PDX models, we developed a combined mouse-zebrafish PDX platform based on direct implantation of cryopreserved PDX tissue fragments into zebrafish embryos, without the need for pre-culturing or expansion. Clinical proof-of-principle was established by direct implantation of tumor samples from four patients.ResultsThe resulting ZTX models responded to Erlotinib and Paclitaxel, with similar potency as in mouse-PDX models and the patients themselves, and resistant tumors similarly failed to respond to these drugs in the ZTX system. Drug response was coupled to elevated expression of EGFR, Mdm2, Ptch1 and Tsc1 (Erlotinib), or Nras and Ptch1 (Paclitaxel) and reduced expression of Egfr, Erbb2 and Foxa (Paclitaxel). Importantly, ZTX models retained the invasive phenotypes of the tumors and predicted lymph node involvement of the patients with 91% sensitivity and 62% specificity, which was superior to clinically used tests. The biopsies from all four patient tested implanted successfully, and treatment outcome and dissemination were quantified for all patients in only 3 days.ConclusionsWe conclude that the ZTX platform provide a fast, accurate, and clinically relevant system for evaluation of treatment outcome and invasion/dissemination of PDX models, providing an attractive platform for combined mouse-zebrafish PDX trials and personalized medicine.

Maternal exercise during pregnancy increases neuregulin-1 and ErbB4 expression in the newborn offspring of Wistar rats

Maternal exercise during pregnancy increases neuregulin-1 and ErbB4 expression in the newborn offspring of Wistar rats

Preparation, Characterization, Evaluation of Neuroprotective Effect, and Related Mechanisms of Phosphatidylserine Emulsion in 5- and 12-Week Old Mice.

Phosphatidylserine (PS) improves learning and memory capacity. In this study, PS formulation was optimized by a response surface methodology. Moreover, we found that PS not only functions as a biologically active component in food preparations but also improves the emulsion's physical stability. Our results showed that the PS emulsions are characterized by a smaller particle size, higher ζ-potential (negative), higher viscosity, and lower surface tension and centrifugal stability constants than the emulsion without PS. Furthermore, we explored the neuroprotective effects of PS emulsion and its underlying mechanisms. Treatment with 2% (w/w) PS emulsion for three months enhanced spatial learning and memory in 5- and 12-week old mice in the Morris water maze test. Western-blotting analysis displayed that the 2% (w/w) PS emulsion treated group upregulated BDNF, TrkB, PSD95, mTOR, MBP, and ErbB4 expression in the hippocampus of 5- and 12-week old mice. Reverse transcription polymerase chain reaction (RT-PCR) analysis revealed elevated Nrg-1 and ErbB4 mRNA expression in the 2% (w/w) PS emulsion treated groups, and high Nrg-1 and ErbB4 expression levels were associated with better myelination. In conclusion, we reported PS emulsions with high stability and high bioavailability. Meanwhile, 2% (w/w) PS emulsion enhances learning, memory, and myelination in mice by activating the BDNF/TrkB and Nrg-1/ErbB4 signaling.

High expression of ERBB2 is an independent risk factor for reduced recurrence-free survival in patients with stage T1 non-muscle-invasive bladder cancer.

Molecular markers associated with breast cancer are assumed to be associated with outcome in non-muscle-invasive bladder cancer (NMIBC). We retrospectively investigated the association of the mRNA expression of estrogen receptor 1 (ESR1) and 2 (ESR2), progesterone receptor (PGR), MKI67, and HER2 (ERBB2) with recurrence-free (RFS), cancer-specific (CSS), and overall survival (OS) in 80 patients with stage T1 NMIBC. High expression of ESR2 (P = 0.003), ERBB2 (P < 0.001), and MKI67 (P = 0.029) was associated with shorter RFS. Only high ERBB2 was an independent prognostic factor for reduced RFS (HR = 2.98; P = 0.009). When sub stratifying the cohort, high ESR2 was associated with reduced RFS (P < 0.001), CSS (P = 0.037) and OS (P = 0.006) in patients without instillation therapy. High ESR2 was associated with reduced CSS (P = 0.018) and OS (P = 0.029) in females and with shorter RFS in both sexes (males: P = 0.035; females: P = 0.010). Patients with high ERBB2 showed reduced CSS (P = 0.011) and OS (P = 0.042) in females and reduced CSS (P = 0.012) in those without instillation, while RFS was significantly reduced irrespective of sex or instillation. High mRNA expression of ERBB2 is an independent predictor of reduced RFS in patients with stage T1 NMIBC. High ERBB2 and ESR2 are associated with reduced outcomes, especially in females and patients without instillation therapy.