Erb-b2 Receptor Tyrosine Kinase Research Articles

Contribution of PGAP3 co-amplified and co-overexpressed with ERBB2 at 17q12 involved poor prognosis in gastric cancer.

The locus at 17q12 erb-b2 receptor tyrosine kinase 2 (ERBB2) has been heavily amplificated and overexpressed in gastric cancer (GC), but it remains to be elucidated about the clinical significance of the co-amplification and co-overexpression of PGAP3 gene located around ERBB2 in GC. The profile of PGAP3 and ERBB2 in four GC cell lines and tissue microarrays containing 418 primary GC tissues was assessed to investigate the co-overexpression and clinical significance of the co-amplified genes, and to evaluate the impact of the co-amplified genes on the malignancy of GC. Co-amplification of PGAP3 and ERBB2 accompanied with co-overexpression was observed in a haploid chromosome 17 of NCI-N87 cells with double minutes (DMs). PGAP3 and ERBB2 were overexpressed and positively correlated in 418 GC patients. Co-overexpression of the PGAP3 and ERBB2 was correlated with T stage, TNM stage, tumour size, intestinal histological type and poor survival proportion in 141 GC patients. In vitro, knockdown of the endogenous PGAP3 or ERBB2 decreased cell proliferation and invasion, increased G1 phase accumulation and induced apoptosis in NCI-N87 cells. Furthermore, combined silencing of PGAP3 and ERBB2 showed an additive effect on resisting proliferation of NCI-N87 cells compared with targeting ERBB2 or PGAP3 alone. Taken together, the co-overexpression of PGAP3 and ERBB2 may be crucial due to its significant correlation with clinicopathological factors of GC. Haploid gain of PGAP3 co-amplified with ERBB2 is sufficient to facilitate the malignancy and progression of GC cells in a synergistic way.

Oncodrivers for Immunotherapies in Triple-Negative Breast Cancer

Breast Cancer: Breast CancerMany advances have been made in therapies for patients having breast cancer driven by the estrogen receptor, the progesterone receptor, or the human epidermal growth factor 2 receptor (HER2). However, for patients with breast cancer not driven by any of these mechanisms, the disease, termed triple-negative, is characterized by an aggressive clinical course with poor patient outcomes. In a recent poster presented at the AACR Annual Meeting 2023, Saurabh K. Garg, PhD, a research scientist in the Czerniecki Lab at Moffitt Cancer Center, presented data from a retrospective study of triple-negative breast cancer patients who had undergone surgery at the Moffitt Cancer Center between January 2010 and February 2019 (Abstract 962). “Our team at the Czerniecki Lab and Moffitt Breast Clinic utilizes the power of dendritic cells, the primary antigen-presenting cells of the body, to present major histocompatibility complex Class II antigens from tumor-associated oncodrivers to prime the immune response against breast cancer,” Garg noted. “In our clinical trials, we are seeing a robust targeted response with dendritic cell-based therapies in HER2-positive breast cancer. This prompted us to identify immunogenic oncodrivers to develop targeted immunotherapies for triple-negative breast cancer, which accounts for 15-20 percent of breast cancer cases and presents as a more aggressive disease, with poor outcomes from current standard-of-care treatment options.” Regarding their study, Garg noted, “This is an institutional review board-approved, single institution retrospective study of 90 patients with triple-negative breast cancer who have undergone standard of care at Moffitt Cancer Center between January 2010 and February 2019. “Surgical biopsy tissue blocks of various stages, along with patient outcome data, were available to perform this downstream analysis,” he stated. “We utilized multiplex tissue microarray analyses, where multiple tissue core biopsies are arranged on a single slide for this immunofluorescence assay,” Garg explained. The tissue microarray analyses were divided into two panels: one for the oncodrivers and the other for tumor-infiltrating lymphocytes. In the first panel, “the expression of three oncodrivers: MET (MET proto-oncogene, receptor tyrosine kinase), EGFR (epidermal growth factor receptor), and HER3 (erb-b2 receptor tyrosine kinase 3) on surgical tissue blocks was scored by tumor microarray analysis,” Garg explained. “We also performed a second tissue microarray analysis to examine tumor-infiltrating lymphocytes expressing CD4, CD8, CD20, CD45, and CD56,” Garg noted about the second panel. “Subsequently, we correlated the expression of oncodrivers with patient outcome data and lymphocyte infiltration to catalog the immunogenicity of MET, EGFR, and HER-3 expression in triple-negative breast cancer settings.” Research Results When queried as to their findings, Dr. Garg answered, “The main finding of this study is that high expression of MET, EGFR, and HER3 correlated with higher occurrence of CD4, CD8, and CD45, respectively. This provided us invaluable information, indicating that these tumor-driving proteins have immunogenic potential to recruit lymphocytes to the tumor site, which could be harnessed to design targeted immunotherapies.” In addition, the elevated expression of HER3 was observed in the samples obtained from chemotherapy-treated patients, possibly implying a role in disease resistance. Interestingly, there was no correlation of prognoses with increased expression levels of the oncodrivers explored in this study. Another relevant observation was that better survival was observed in patients who had intermediate expression levels for EGFR with higher numbers of activated tumor-infiltrating lymphocytes. Future Directions “The present study provided a perfect segue for future targeted therapies that will be further developed and utilized in the clinic for triple-negative breast cancer patients,” Garg noted. “The identification of these immunogenic oncodrivers for triple-negative breast cancer will assist researchers at Moffitt and all over the world to target them with innovative therapies. “The next step in this study will be to identify the immunogenic regions of MET and EGFR proteins using our in-house peptide screening pipeline,” he stated. “This pipeline utilizes pre-clinical investigative tools to screen immunogenic major histocompatibility complex class II peptides to design dendritic cell-based cancer immunotherapies. Once identified and produced, we will test the efficacy of these treatments utilizing murine models of triple-negative breast cancer. “Furthermore, we have already performed peptide screening for the HER3 protein and have validated it in murine models of triple-negative breast cancer,” Garg said. “This HER3-based dendritic cell immunotherapy has been translated to a clinical trial, which is now underway at Moffitt for triple-negative breast cancer patients. Overall, successful completion of the pre-clinical translational research on all three triple-negative breast cancer oncodrivers will open the door for them to be incorporated in future dendritic cell immunotherapy clinical trials at the Moffitt Cancer Center with the potential of making significant improvements to the current triple-negative breast cancer standard of care and patient outcomes.” Richard Simoneaux is a contributing writer.

Inhibition of Erb-B2 Receptor Tyrosine Kinase 3 and Associated Regulatory Pathways Potently Impairs Malignant Peripheral Nerve Sheath Tumor Proliferation and Survival

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, currently untreatable Schwann cell-derived neoplasms with hyperactive mitogen-activated protein kinase and mammalian target of rapamycin signaling pathways. To identify potential therapeutic targets, previous studies used genome-scale shRNA screens that implicated the neuregulin-1 receptor erb-B2 receptor tyrosine kinase 3 (erbB3) in MPNST proliferation and/or survival. The current study shows that erbB3 is commonly expressed in MPNSTs and MPNST cell lines and that erbB3 knockdown inhibits MPNST proliferation and survival. Kinomic and microarray analyses of Schwann and MPNST cells implicate Src- and erbB3-mediated calmodulin-regulated signaling as key pathways. Consistent with this, inhibition of upstream (canertinib, sapitinib, saracatinib, and calmodulin) and parallel (AZD1208) signaling pathways involving mitogen-activated protein kinase and mammalian target of rapamycin reduced MPNST proliferation and survival. ErbB inhibitors (canertinib and sapitinib) or erbB3 knockdown in combination with Src (saracatinib), calmodulin [trifluoperazine (TFP)], or proviral integration site of Moloney murine leukemia kinase (AZD1208) inhibition even more effectively reduces proliferation and survival. Drug inhibition enhances an unstudied calmodulin-dependent protein kinase IIα phosphorylation site in an Src-dependent manner. The Src family kinase inhibitor saracatinib reduces both basal and TFP-induced erbB3 and calmodulin-dependent protein kinase IIα phosphorylation. Src inhibition (saracatinib), like erbB3 knockdown, prevents these phosphorylation events; and when combined with TFP, it even more effectively reduces proliferation and survival compared with monotherapy. These findings implicate erbB3, calmodulin, proviral integration site of Moloney murine leukemia kinases, and Src family members as important therapeutic targets in MPNSTs and demonstrate that combinatorial therapies targeting critical MPNST signaling pathways are more effective.

A phase I trial of the pan-ERBB inhibitor neratinib combined with the MEK inhibitor trametinib in patients with advanced cancer with EGFR mutation/amplification, HER2 mutation/amplification, HER3/4 mutation or KRAS mutation

PurposeAberrant alterations of ERBB receptor tyrosine kinases lead to tumorigenesis. Single agent therapy targeting EGFR or HER2 has shown clinical successes, but drug resistance often develops due to aberrant or compensatory mechanisms. Herein, we sought to determine the feasibility and safety of neratinib and trametinib in patients with EGFR mutation/amplification, HER2 mutation/amplification, HER3/4 mutation and KRAS mutation.MethodsPatients with actionable somatic mutations or amplifications in ERBB genes or actionable KRAS mutations were enrolled to receive neratinib and trametinib in this phase I dose escalation trial. The primary endpoint was determination of the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). Secondary endpoints included pharmacokinetic analysis and preliminary anti-tumor efficacy.ResultsTwenty patients were enrolled with a median age of 50.5 years and a median of 3 lines of prior therapy. Grade 3 treatment-related toxicities included: diarrhea (25%), vomiting (10%), nausea (5%), fatigue (5%) and malaise (5%). The MTD was dose level (DL) minus 1 (neratinib 160 mg daily with trametinib 1 mg, 5 days on and 2 days off) given 2 DLTs of grade 3 diarrhea in DL1 (neratinib 160 mg daily with trametinib 1 mg daily). The treatment-related toxicities of DL1 included: diarrhea (100%), nausea (55.6%) and rash (55.6%). Pharmacokinetic data showed trametinib clearance was significantly reduced leading to high drug exposures of trametinib. Two patients achieved stable disease (SD) ≥ 4 months.ConclusionNeratinib and trametinib combination was toxic and had limited clinical efficacy. This may be due to suboptimal drug dosing given drug–drug interactions.Trial registration ID: NCT03065387.

Genomics of ERBB2-Positive Breast Cancer in Young Women Before and After Exposure to Chemotherapy Plus Trastuzumab.

Erb-B2 receptor tyrosine kinase 2 (ERBB2)-positive breast cancer (BC) is particularly common in young women. Genomic features of ERBB2-positive tumors before and after chemotherapy and trastuzumab (chemo + H) have not been described in young women and are important for guiding study of therapeutic resistance in this population. From a large prospective cohort of women age 40 years or younger with BC, we identified patients with ERBB2-positive BC and tumor tissue available before and after chemo + H. Whole-exome sequencing (WES) was performed on each tumor and on germline DNA from blood. Tumor-normal pairs were analyzed for mutations and copy number (CN) changes. Twenty-two women had successful WES on samples from at least one time point; 12 of these had paired sequencing results from before and after chemo + H and 10 had successful sequencing from either time point. TP53 was the only significantly recurrently mutated gene in both pre- and post-treatment samples. MYC gene amplification was observed in four post-treatment tumors. Seven of 12 patients with paired samples showed acquired and/or clonally enriched alterations in cancer-related genes. One patient had an increased clonality putative activating mutation in ERBB2. Another patient acquired a clonal hotspot mutation in TP53. Other genomic changes acquired in post-treatment specimens included alterations in NOTCH2, STIL, PIK3CA, and GATA3. There was no significant change in median ERBB2 CN (20.3 v 22.6; Wilcoxon P = .79) between paired samples. ERBB2-positive BCs in young women displayed substantial genomic evolution after treatment with chemo + H. Approximately half of patients with paired samples demonstrated acquired and/or clonally enriched genomic changes in cancer genes. ERBB2 CN changes were uncommon. We identified several genes warranting exploration as potential mechanisms of resistance to therapy in this population.

The changes of HER3 expression in head and neck cancer patients treated with induction chemotherapy.

e18004 Background: Erb-b2 receptor tyrosine kinase 3 (HER3) is broadly expressed in various types of cancer and is associated with poor prognosis. Recent evidence supports HER3 plays a role in acquired resistance to chemotherapy. The change of HER3 expression by chemotherapy in head and neck squamous cell carcinoma (HNSCC) remains unclear. Methods: We evaluated 95 patients with locally advanced HNSCC who had received induction chemotherapy (ICT) between 2009 and 2019. Immunohistochemical staining for HER3 was performed using formalin-fixed paraffin-embedded surgical specimens and biopsy samples. H-score of membrane staining was evaluated. Results: Median age of patients was 64 years, and 85% were male. Primary locations included oropharynx (54.8%), hypopharynx (21.5%), oral cavity (17.2%), and salivary gland (6.5%). Mean H-score of HER3 in tumor tissues was 77.6 ± 7.9. H-score of HER3 in HPV-positive tumors was higher than HPV-negative tumors (p = 0.019), which was more pronounced in oropharynx and hypopharynx tumors. While, H-score of HER3 in adjacent normal tissues of these tumors did not significantly differ. Compared with the non-smokers, tumor tissues of current or ex-smokers demonstrated higher H-score of HER3 (p = 0.033), independent of tumor location. In contrast, in adjacent normal tissues, no significant differences of H-score of HER3 were observed depending on the smoking status. The H-score higher than 100 was defined as HER3-high group. Among oropharynx and hypopharynx tumors with positive correlation between H-score of HER3 and HPV status (n = 56), HER3-high group was significantly correlated with HPV positivity (p = 0.009) and good response to ICT (p = 0.035). Good clinical response was also strongly related to HPV-positivity (p = 0.001). In addition, there was a tendency for longer overall survival in HER3-high group than low HER3 expression group (93 vs. 70 months, p = 0.053). The paired tumor samples collected at pre- and post-ICT (n = 21) were analyzed. HER3 expressions in adjacent normal tissue were higher at post-ICT compared to pre-ICT (p = 0.003), and these results were more pronounced in the non-smoking group, but no differences were found according to HPV-status. Conclusions: Taken together, our results showed that H-score of HER3 was significantly higher in both HPV-positive and smoking group. Interestingly, high HER3 expression in oropharynx and hypopharynx tumors was associated with HPV positivity and good clinical response to ICT. Additional analysis of tumor immune microenvironment in tumor tissues are underway.

HER3 expression status following systemic chemotherapy treatment in biliary tract cancers.

e16153 Background: Erb-b2 receptor tyrosine kinase 3 (HER3) is frequently overexpressed in a variety of cancers. Activation of HER3 signaling serves an important role in promoting cell proliferation and is associated with chemoresistance. Thus, there is interest in exploring HER3 status of tumors as a potential prognostic and/or therapeutic target. Prior studies have reported HER3 status in various cancers after treatment with chemotherapy (CT). However, HER3 expression profile in biliary tract cancer (BTC) remains unknown. Here, we evaluated HER3 status of patients with BTC post CT. Methods: The medical records of patients (pts) who had been initially diagnosed with BTC and treated at the National Cancer Center Hospital (Tokyo, Japan), between January 2010 and June 2020, were retrospectively analyzed. Pts whose post CT specimens were available were included in this study. Immunohistochemical staining for HER3 was performed using HER3/ErbB3 (D22C5) XP Rabbit mAb (Cell Signaling Technology) as a primary antibody. IHC scoring (0, 1+, 2+, 3+) of membranous staining intensity was performed according to HER2 IHC gastric scoring guideline. Results: A total of 19 pts with BTC, with a median age of 59 (range 44-79) years, had specimens available after post CT and were evaluated for HER3 expression status. HER3 status was 3+ in 10 pts, 2+ in 3 pts, 1+ in 4 pts, and 0 in 2 pts. The specimens were obtained from liver in 17 pts, bone in 1 pt, and omental lymph node in 1 pt. The histological type was adenocarcinoma in all pts, and HER3 status according to primary tumor type is shown in the table below. Fourteen pts were treated with gemcitabine (GEM) plus cisplatin (CDDP), 1 pt with GEM plus CDDP plus S-1, 1 pt with GEM plus S-1 as first-line CT for advanced BTC, and 3 pts with S-1 as an adjuvant treatment. Fifteen pts were biopsied after CT to participate in clinical trial. The remaining 4 obtained specimens after CT during primary surgery or surgery for metastases or for cholangitis. The median overall survival of pts with advanced BTC was 23.6 months in HER3 3+, 17.1 months in HER3 2+, 27.7 months in HER3 1+, and 24.6 months in HER3 0. Four pts had specimens available from pre and post CT, all of which were intrahepatic cholangiocarcinoma with the treatment of GEM plus CDDP. HER3 status was upregulated in 3 pts (1 pt 1+ to 2+, 2 pts 2+ to 3+) and downregulated in 1 pt (1+ to 0) at post CT. Conclusions: HER3 expression (1+, 2+, 3+) was observed in 89.5% of previously treated pts with BTC, and HER3 status was upregulated after CT in some pts. These results suggest that HER3 might be a potential therapeutic target in BTC post CT. [Table: see text]

Deriving breast cancer chemotherapy patterns from real-world data.

e13586 Background: Real World Data (RWD) collected during routine medical practice can help in clinical trial design, planning and execution. In addition, it can provide a compelling picture of safety of medical products, and account for all potential adverse events that can be encountered in routine clinical practice. However, raw drug information about chemotherapy in cancer care is not readily understandable in the format it is collected. Analytical techniques need to be applied to extract regimen information, which includes drugs, dosage, number of cycles and cycle length. Methods: A retrospective study was performed using data on 7,798 breast cancer patients from the TriNetX Network, a federated network of de-identified, HIPAA-compliant, health data from 21 healthcare organizations across North America as of May 2022. We investigated a method built on rule-based algorithm and clustering analysis to extract regimens and their patterns of administration and align them into lines of treatment (LOT). To derive drug administration patterns, we clustered administration time periods using three features: total number of drug administrations, median number of days between drug administrations, and standard deviation of the days between drug administrations. Results: The patterns of administration that correspond to the two most common regimens for Erb-B2 receptor tyrosine kinase 2 negative group (ERBB2-) stages 1, 2 and 3 are shown. We looked at patients with Hormone Receptor (HR+) positive and Triple Negative (TN) breast cancer. Results of our analysis were in a close agreement with NCCN Guidelines. However, regimen administration patterns varied. This information can be useful to characterize patients based on the adherence to the expected chemotherapy regimens. It can also provide meaningful insight into burden of illness, such that patients who have higher variability of the drug administration might be faced with clinical problems such as drug tolerability or side effects. The variability might also signify access to care challenges. Conclusions: Understanding regimen LOT and administration patterns is central to research based on RWD, but it can also be useful for clinical trial design, execution, as well as site selection and patient recruitment for clinical trials. [Table: see text]

EGFR and ERBB2 exon 20 insertion/duplication in advanced non-small cell lung cancer: genomic profiling and clinicopathologic features.

Exon 20 (ex20) in-frame insertions or duplications (ins/dup) in epidermal growth factor receptor (EGFR) and its analog erb-b2 receptor tyrosine kinase 2 (ERBB2) are each detected in 1.5% of non-small cell lung cancer (NSCLC). Unlike EGFR p.L858R or ex19 deletions, ex20 ins/dup is associated with de novo resistance to classic EGFR inhibitors, lack of response to immune checkpoint inhibitors, and poor prognosis. US Food and Drug Administration has approved mobocertinib and amivantamab for targeting tumors with this aberration, but the number of comprehensive studies on ex20 ins/dup NSCLC is limited. We identified 18 cases of NSCLCs with EGFR/ERBB2 ex20 ins/dup and correlated the findings with clinical and morphologic information including programed death-ligand 1 (PD-L1) expression. A total of 536 NSCLC cases tested at our institution between 2014 and 2023 were reviewed. A custom-designed 214-gene next-generation sequencing panel was used for detecting DNA variants, and the FusionPlex CTL panel (ArcherDx) was used for the detection of fusion transcripts from formalin-fixed, paraffin-embedded tissue. Immunohistochemistry (IHC)for PD-L1 was performed using 22C3 or E1L3N clones. Nine EGFR and nine ERBB2 ex20 ins/dup variants were identified from an equal number of men and women, 14 were non- or light smokers, and 15 had stage IV disease. All 18 cases were adenocarcinomas. Seven of the 11 cases with available primary tumors had acinar predominant pattern, two had lepidic predominant pattern, and the remainder had papillary (one case) and mucinous (one case) patterns. Ex20 ins/dup variants were heterogenous in-frame one to four amino acids spanning A767-V774 in EGFR and Y772-P780 in ERBB2 and were clustered in the loop following the C-helix and α C-helix. Twelve cases (67%) had co-existing TP53 variants. Copy number variation in CDK4 amplification was identified in one case. No fusion or microsatellite instability was identified in any case. PD-L1 was positive in two cases, low positive in four cases, and negative in 11 cases. NSCLCs harboring EGFR/ERBB2 ex20 ins/dup are rare and tend to be acinar predominant, negative for PD-L1, more frequent in non- or light smokers, and mutually exclusive with other driver mutations in NSCLC. The correlation of different EGFR/ERBB2 ex20 ins/dup variants and co-existing mutations with response to targeted therapy and the possibility of developing resistant mutations after mobocertinib treatment warrants further investigation.

In vivo tissue pharmacokinetics of ERBB2-specific binding oligonucleotide based drugs by PET imaging.

Although aptamers have shown excellent target specificity in preclinical and clinical studies either by themselves or as aptamer-drug conjugates, their in vivo tissue pharmacokinetic (PK) analysis is still problematic. We aimed to examine the utility of image based positron emission tomography (PET) to evaluate in vivo tissue PK, target specificity, and applicability of oligonucleotides. For this, fluorine-18-labeled aptamers with erb-b2 receptor tyrosine kinase 2 (ERBB2)-specific binding were synthesized by base-pair hybridization using a complementary oligonucleotide platform. To investigate the PKs and properties in vivo tissue, usefulness of in vivo PET imaging in the development of oligonucleotide based drug as an assessment tool was evaluated in normal and tumor xenografted mice. ERBB2-cODN-idT-APs-[18 F]F ([18 F]1), injected intravenously showed significant and rapid uptake in most tissues except for the initial brain and muscle; the uptake was highest in the heart, followed by kidneys, liver, lungs, gall bladder, spleen, and stomach. The main route of excretion was through the renal approximately 77.8% while about 8.3% through the biliary tract of the total dose. The estimated effective dose for an adult woman was 0.00189 mGy/MBq, which might be safe. ERBB2-positive tumor could be well visualized in KPL4 xenograft animal model by in vivo PET imaging. Consequently, the distribution in each organ including ERBB2 expression could be well determined and quantified by PET with fluorine-18-labeled aptamers. In vivo PK parameters such as T1/2 , Tmax , AUC, and Cmax , were also successfully estimated. These results suggest that image based PET with radioisotope-labeled aptamers could be provide valuable information on properties of oligonucleotide based drugs in drug discovery of targeted therapeutics against various diseases.

Pattern of MUC6 expression across 119 different tumor types: A tissue microarray study on 15 412 tumors.

Mucin 6 (MUC6) is a secreted gel-forming mucin covering the surfaces of gastrointestinal and other tissues. Published work demonstrates that MUC6 can also be expressed in several cancer types and can aid in the distinction of different tumor entities. To systematically analyze MUC6 expression in normal and cancerous tissues, a tissue microarray containing 15 412 samples from 119 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. At least a weak MUC6 positivity was seen in 50 of 119 (42%) tumor entities. Thirty-three tumor entities included tumors with strong positivity. MUC6 immunostaining was most frequent in mucinous carcinomas of the breast (44%), adenocarcinomas of the stomach (30%-40%) and esophagus (35%), and neuroendocrine carcinomas of the colon. Strong MUC6 staining was linked to advanced pT stage (p = 0.0464), defective mismatch repair status and right-sided tumor location (p < 0.0001 each) in colorectal cancer, as well as to high tumor grade (p = 0.0291), nodal metastasis (p = 0.0485), erb-b2 receptor tyrosine kinase 2 positivity (p < 0.0001) and negative estrogen receptor (p = 0.0332)/progesterone receptor (p = 0.0257) status in breast carcinomas of no special type. The broad range of tumor types with MUC6 expression limits the utility of MUC6 immunohistochemistry for the distinction of different tumor types.

Response to Treatment, Racial and Ethnic Disparity, and Survival in Patients With Breast Cancer Undergoing Neoadjuvant Chemotherapy in the US

With the increasing delivery of neoadjuvant chemotherapy (NACT) for patients with breast cancer in the US, it is important to know whether there is differential response to NACT by race and ethnicity and the potential long-term outcomes. To examine whether there were any racial and ethnic differences in pathologic complete response (pCR) rate following NACT and, if so, whether they varied by molecular subtype and were associated with survival. A retrospective cohort study was conducted including patients with stage I to III breast cancer diagnosed between January 2010 and December 2017 who underwent surgery and received NACT; median follow-up was 5.8 years, and data analysis was conducted from August 2021 to January 2023. Data were obtained from the National Cancer Data Base, a nationwide, facility-based, oncology data set that captures approximately 70% of all newly diagnosed cases of breast cancer in the US. Pathologic complete response, defined as ypT0/Tis ypN0, was modeled using logistic regression. Racial and ethnic differences in survival were analyzed using a Weibull accelerated failure time model. Mediation analysis was conducted to measure whether racial and ethnic differences in the pCR rate affect survival. The study included 107 207 patients (106 587 [99.4%] women), with a mean (SD) age of 53.4 (12.1) years. A total of 5009 patients were Asian or Pacific Islander, 18 417 were non-Hispanic Black, 9724 were Hispanic, and 74 057 were non-Hispanic White. There were significant racial and ethnic differences in pCR rates, but the differences were subtype-specific. In hormone receptor-negative (HR-)/erb-b2 receptor tyrosine kinase 2 (ERBB2; formerly HER2 or HER2/neu)-positive (ERBB2+) subtype, Asian and Pacific Islander patients achieved the highest pCR rate (56.8%), followed by Hispanic (55.2%) and non-Hispanic White (52.3%) patients with the lowest pCR rate seen in Black patients (44.8%). In triple-negative breast cancer, Black patients had a lower pCR rate (27.3%) than other racial and ethnic groups (all >30%). In HR+/ERBB2- subtype, Black patients had a higher pCR rate (11.3%) than other racial/ethnic groups (all ≤10%). In mediation analysis, racial and ethnic differences in achieving pCR after NACT could explain approximately 20% to 53% of the subtype-specific survival differences across racial and ethnic groups. In this cohort study of patients with breast cancer receiving NACT, Black patients had a lower pCR rate for triple-negative and HR-/ERBB2+ breast cancer but a higher pCR rate for HR+/ERBB2- diseases, whereas Asian and Pacific Islander patients had a higher pCR rate for HR-/ERBB2+ diseases. Tumor grade and ERBB2 copy number could account for some of these within-subtype disparities, but further studies are warranted. Inability to achieve a pCR can mediate in part, but not entirely, the worse survival outcomes experienced by Black patients.

Effect of Silibinin on the Expression of Mir-20b, Bcl2L11, and Erbb2 in Breast Cancer Cell Lines.

This study aimed to evaluate the comparative effect of silibinin (SB) on the expression of MiR‑20b and BCL2L11 in T47D and MCF-7 cell lines. Molecular simulation studies were carried out to analyze Erbb2, as a potential target of SB, to direct the breast cancer cells toward apoptosis. At first, cell viability, apoptosis, and cell cycle arrest-inducing capacity of SB were examined using MTT and flow cytometry analysis, respectively. Real-time PCR (RT-PCR) was employed to assess the effect of SB on BCL2L11, Phosphatase and tensin homolog (PTEN), and Caspase 9 mRNarrest-indu. Moreover, alterations in Caspase 9 protein expression were determined using Western blot analysis. Finally, AutoDockVina software was used to dock the SB/ MiR‑20b and SB/ erb-b2 receptor tyrosine kinase 2 (Erbb2) interaction. The obtained data revealed the potent cytotoxicity of SB in both T47D and MCF-7 cells through apoptosis induction and cell cycle arrest. SB-treated cells also showed downregulation of MiR‑20b and high expression of BCL2L11, PTEN, and Caspase 9 mRNA compared to non-treated cancer cells. Computational docking showed a strong interaction between SB/ MiR‑20b and SB/Erbb2. It can be concluded that SB had a strong anti-tumorigenic activity through BCL2L11upregulation and MiR‑20b down expression, maybe through targeting the PTEN and interacting with Erbb2, which resulted in apoptotic induction and cell cycle arrest.

Mutations in Classical Signaling Pathways and Their Functional Impact in Microsatellite Instability High Colorectal Cancer.

Aims: Colorectal carcinomas with microsatellite instability high (MSI-H) are a distinctive group among colorectal cancers (CRCs). This study investigated the mutations of genes in the common signaling pathways and their potential clinical implications in MSI-H CRC. Materials and Methods: Twenty-five MSI-H tumors were selected from 384 primary CRCs, and the related clinical and pathological information were also collected from medical records. A commercial kit was used to detect the mutational status of crucial oncogenes within these tumors using next generation sequencing (NGS). Fluorescence in situ hybridization and immunohistochemistry were used to validate the NGS findings. Result: In the present study, MSI-H cases accounted for 6.51% of primary CRCs, with special clinicopathological features. NGS showed that the average number of mutations per tumor in the target genes evaluated was 3.36 and ranged from 1 to 9. In total, there were 17 cases (68%) with mutations in the RAS-RAF pathway and 18 cases (72%) with mutations in the PI3K pathway among the MSI-H CRCs. The remaining two cases included an EMAP Like 4-ALK Receptor Tyrosine Kinase (EML4-ALK) fusion and one with a Erb-B2 Receptor Tyrosine Kinase 2 (ERBB2) missense mutation. Conclusion: This study found multiple variants within different signaling pathways that were mutually present in MSI-H CRCs, suggesting that such a heterogeneous group of tumors requires complex treatment responses. Thus, additional clinical molecular testing is recommended for such patients, such as NGS, to inform the appropriate treatment strategies.

Clinicopathologic Characteristics and Prognosis of ERBB2-Low Breast Cancer Among Patients in the National Cancer Database

Given conflicting results regarding the prognosis of erb-b2 receptor tyrosine kinase 2 (ERBB2; formerly HER2 or HER2/neu)-low breast cancer, a large-scale, nationally applicable comparison of ERBB2-low vs ERBB2-negative breast cancer is needed. To investigate whether ERBB2-low breast cancer is a clinically distinct subtype in terms of epidemiological characteristics, prognosis, and response to neoadjuvant chemotherapy. This retrospective cohort study was conducted using the National Cancer Database, including 1 136 016 patients in the US diagnosed with invasive breast cancer from January 1, 2010, to December 31, 2019, who had ERBB2-negative disease and had immunohistochemistry results available. ERBB2-low tumors were classified as having an immunohistochemistry score of 1+, or 2+ with a negative in situ hybridization test. Data were analyzed from November 1, 2021, through November 30, 2022. Standard therapy according to routine clinical practice. The primary outcomes were overall survival (OS), reported as adjusted hazard ratios (aHRs), and pathologic complete response, reported as adjusted odds ratios (aORs), for ERBB2-negative vs ERBB2-low breast cancer, controlling for age, sex, race and ethnicity, Charlson-Deyo Comorbidity Index score, treatment facility type, tumor grade, tumor histology, hormone receptor status, and cancer stage. The study identified 1 136 016 patients (mean [SD] age, 62.4 [13.1] years; 99.1% female; 78.6% non-Hispanic White), of whom 392 246 (34.5%) were diagnosed with ERBB2-negative and 743 770 (65.5%) with ERBB2-low breast cancer. The mean (SD) age of the ERBB2-negative group was 62.1 (13.2) years and 62.5 (13.0) years for the ERBB2-low group. Higher estrogen receptor expression was associated with increased rates of ERBB2-low disease (aOR, 1.15 per 10% increase). Compared with non-Hispanic White patients, of whom 66.1% were diagnosed with ERBB2-low breast cancer, fewer non-Hispanic Black (62.8%) and Hispanic (61.0%) patients had ERBB2-low disease, although in non-Hispanic Black patients this was mediated by differences in rates of triple-negative disease and other confounders. A slightly lower rate of pathologic complete response was seen in patients with ERBB2-low disease vs patients with ERBB2-negative disease on multivariable analysis (aOR, 0.89; 95% CI, 0.86-0.92; P < .001). ERBB2-low status was also associated with small improvements in OS for stage III (aHR, 0.92; 95% CI, 0.89-0.96; P < .001) and stage IV (aHR, 0.91; 95% CI, 0.87-0.96; P < .001) triple-negative breast cancer, although this amounted to only a 2.0% (stage III) and 0.4% (stage IV) increase in 5-year OS. This large-scale retrospective cohort analysis found minimal prognostic differences between ERBB2-low and ERBB2-negative breast cancer. These findings suggest that, moving forward, outcomes in ERBB2-low breast cancer will be driven by ERBB2-directed antibody-drug conjugates, rather than intrinsic differences in biological characteristics associated with low-level ERBB2 expression. These findings do not support the classification of ERBB2-low breast cancer as a unique disease entity.

Irreversible tyrosine kinase inhibitors induce the endocytosis and downregulation of ErbB2

Erb-b2 receptor tyrosine kinase 2 (ErbB2) is an oncogene that frequently overexpressed in a subset of cancers. Anti-ErbB2 therapies have been developed to treat these types of cancers. However, less is known about how anti-ErbB2 drugs affect the trafficking and degradation of ErbB2. We demonstrate that the reversible and irreversible tyrosine kinase inhibitors (TKIs) differentially modulate the subcellular trafficking and downregulation of ErbB2. Only the irreversible TKIs can induce the loss of ErbB2 expression, which is not dependent on proteasome or lysosome. The irreversible TKIs promote ErbB2 endocytosis from plasma membrane and enhance the ErbB2 accumulation at endosomes. The endocytosis of ErbB2 is mediated by a dynamin-dependent but clathrin-independent mechanism. Blocking of ErbB2 endocytosis can impair the TKI-induced ErbB2 downregulation.

Whispering gallery mode resonant microspheres as labels for biological imaging.

Optical whispering gallery modes (WGMs) arise from total internal reflection of light from an optical cavity, such as microspheres. Whispering gallery mode phenomena produce resonant frequencies at the reflected wavelengths that appear as peaks in spectrographic data. In microspheres, whispering gallery mode spectra vary by the size and material used. These differences allow for distinct labeling of many targets using only a single fluorescent input and output. In this work we use resonant microspheres that, conjugated to antibodies, label bacterial and mammalian cell populations in vitro. We use 5 µm resonant microspheres of polystyrene and polystyrene-divinylbenzene conjugated with antibodies against biological targets of interest including Epidermal Growth Factor Receptor (EGFR) and Erb-B2 Receptor Tyrosine Kinase 2 (ErbB2) to label human cells and lipopolysaccharide to detect Gram-negative bacterial infection. Beads are distinguished using their whispering gallery mode spectra. This work presents an early step towards labeling and biodetection of many biological targets using a single fluorescent input and output.

Oncogenic ERRB2 signals through the AP-1 transcription factor to control mesenchymal-like properties of oesophageal adenocarcinoma.

Oesophageal adenocarcinoma (OAC) is a deadly disease with poor survival statistics and few targeted therapies available. One of the most common molecular aberrations in OAC is amplification or activation of the gene encoding the receptor tyrosine kinase ERBB2, and ERBB2 is targeted in the clinic for this subset of patients. However, the downstream consequences of these ERBB2 activating events are not well understood. Here we used a combination of phosphoproteomics, open chromatin profiling and transcriptome analysis on cell line models and patient-derived datasets to interrogate the molecular pathways operating downstream from ERBB2. Integrated analysis of these data sets converge on a model where dysregulated ERBB2 signalling is mediated at the transcriptional level by the transcription factor AP-1. AP-1 in turn controls cell behaviour by acting on cohorts of genes that regulate cell migration and adhesion, features often associated with EMT. Our study therefore provides a valuable resource for the cancer cell signalling community and reveals novel molecular determinants underlying the dysregulated behaviour of OAC cells.

Erb-b2 receptor tyrosine kinase 2 interaction with growth factor receptor bound protein 7 acts as a molecular switch to activate non-small cell lung cancer: An in silico prediction

Background: The progression and metastasis of non small cell lung cancer (NSCLC) are considered a very complex process as it involves aberrations of multiple genes and cellular pathways. Genes which are differentially expressed in NSCLC have multi interactions with other genes, which can promote the carcinogenesis. To improve diagnosis and treatment of NSCLC, it is vitally important to study these interactions and understand their roles in the molecular mechanism of NSCLC. As the need to find more potential targets for NSCLC is very paramount we have predicted very important interactions for NSCLC. Methods: In our study, some NSCLC specific genes were differentially identified from microarray datasets and text mining of SCLC and NSCLC abstracts. The expression of these genes has been seen in 8 different cancer types and NSCLC stages. A network of genes specific to NSCLC has been identified and interactions of these NSCLC specific genes have been studied. Results: We found two network modules joined through erb b2 receptor tyrosine kinase 2 (ERBB2) in NSCLC i.e. network of genes growth factor receptor bound protein 7 (GRB7), StAR related lipid transfer domain containing 3, post GPI attachment to proteins 3 and migration and invasion enhancer 1 ERBB2 interacting with GRB7 and PAK1 using GIANT. In normal lungs, ERBB2 is strongly interacting with PAK1 and in NSCLC it has strong interaction with GRB7. Conclusion: We have found that ERBB2 and GRB7 interaction is a transforming connection between normal lung and NSCLC.

Characterization of Expression and Function of the Formins FHOD1, INF2, and DAAM1 in HER2-Positive Breast Cancer.

Human epidermal growth factor receptor 2 (HER2)-targeted therapies, such as trastuzumab, benefit patients with HER2-positive metastatic breast cancer; however, owing to traditional pathway activation or alternative signaling, resistance persists. Given the crucial role of the formin family in shaping the actin cytoskeleton during cancer progression, these proteins may function downstream of the HER2 signaling pathway. Our aim was to uncover the potential correlations between formins and HER2 expression using a combination of public databases, immunohistochemistry, and functional in vitro assays. Using online databases, we identified a negative prognostic correlation between specific formins mRNA expression in HER2-positive cancers. To validate these findings at the protein level, immunohistochemistry was performed on HER2 subtype breast cancer tumors to establish the links between staining patterns and clinical characteristics. We then knocked down individual or combined formins in MDA-MB-453 and SK-BR-3 cells and investigated their effects on wound healing, transwell migration, and proliferation. Furthermore, we investigated the effects of erb-b2 receptor tyrosine kinase 2 (ERBB2)/HER2 small interfering RNA (siRNA)-mediated knockdown on the PI3K/Akt and MEK/ERK1 pathways as well as on selected formins. Our results revealed that correlations between INF2, FHOD1, and DAAM1 mRNA expression and ERBB2 in HER2-subtype breast cancer were associated with worse outcomes. Using immunohistochemistry, we found that high FHOD1 protein expression was linked to higher histological grades and was negatively correlated with estrogen and progesterone receptor positivity. Upon formins knockdown, we observed effects on wound healing and transwell migration, with a minimal impact on proliferation, which was evident through single and combined knockdowns in both cell lines. Notably, siRNA-mediated knockdown of HER2 affected FHOD1 and INF2 expression, along with the phosphorylated Akt/MAPK states. Our study highlights the roles of FHOD1 and INF2 as downstream effectors of the HER2/Akt and HER2/MAPK pathways, suggesting that they are potential therapeutic targets in HER2-positive breast cancer.