scholarly journals The structural basis for distinct binding avidity of Pertuzumab and Trastuzumab IgM towards HER2

2019 ◽  
Author(s):  
Firdaus Samsudin ◽  
Joshua Yi Yeo ◽  
Samuel Ken-En Gan ◽  
Peter J. Bond
Keyword(s):  
Dissociation Constants ◽  
Therapeutic Potential ◽  
Growth Factor Receptor ◽  
Multiscale Simulation ◽  
Immunoglobulin M ◽  
Live Cells ◽  
Structural Basis ◽  
Her2 Positive ◽  
Stable Mode ◽  
Future Design

SUMMARYHarnessing the therapeutic potential of immunoglobulin M (IgM) is of considerable interest in immunotherapy due to its complement-activating and cell-agglutinating abilities. Pertuzumab and Trastuzumab are monoclonal antibody drugs used in therapy for patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer but exhibit significantly different binding affinities as IgM when compared to the original IgG1 form. While the affinity of Pertuzumab IgM to the HER2 extracellular domain is about one order of magnitude higher than IgG1 in experiments, it was recently reported that Trastuzumab IgM and IgG have similar equilibrium dissociation constants to one another. We now perform an integrative multiscale simulation study in order to understand the structural basis for the differences in behavior between the two antibodies, based on complete antibody assemblies. We show that Pertuzumab IgM is able to utilize all of its V-regions to engage HER2 in a more stable mode than Trastuzumab IgM due to steric clashes between the large globular HER2 domains when bound to Trastuzumab. This is subsequently validated by confirming that Pertuzumab IgM inhibits proliferation in HER2 over-expressing live cells more effectively than its IgG1 counterpart. Given the widespread clinical use of Trastuzumab and Pertuzumab, elucidating the molecular details of antibody-antigen interaction may help guide the choice of epitopes for future design and selection of improved therapeutic antibody isotypes.

scholarly journals Structural basis for pharmacological modulation of the TRPC6 channel

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Yonghong Bai ◽  
Xinchao Yu ◽  
Hao Chen ◽  
Daniel Horne ◽  
Ryan White ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Bound States ◽  
Transient Receptor Potential ◽  
Therapeutic Potential ◽  
Receptor Potential ◽  
Structural Basis ◽  
Future Design ◽  
Subunit Interface ◽  
Transient Receptor ◽  
Small Molecule Modulators

Transient receptor potential canonical (TRPC) proteins form nonselective cation channels that play physiological roles in a wide variety of cells. Despite growing evidence supporting the therapeutic potential of TRPC6 inhibition in treating pathological cardiac and renal conditions, mechanistic understanding of TRPC6 function and modulation remains obscure. Here we report cryo-EM structures of TRPC6 in both antagonist-bound and agonist-bound states. The structures reveal two novel recognition sites for the small-molecule modulators corroborated by mutagenesis data. The antagonist binds to a cytoplasm-facing pocket formed by S1-S4 and the TRP helix, whereas the agonist wedges at the subunit interface between S6 and the pore helix. Conformational changes upon ligand binding illuminate a mechanistic rationale for understanding TRPC6 modulation. Furthermore, structural and mutagenesis analyses suggest several disease-related mutations enhance channel activity by disrupting interfacial interactions. Our results provide principles of drug action that may facilitate future design of small molecules to ameliorate TRPC6-mediated diseases.

Co-expression of ER-beta and HER2 associated with poorer prognosis in primary breast cancer

2009 ◽  
Vol 32 (3) ◽  
pp. 250 ◽  
Author(s):  
Wen-sheng Qui ◽  
Lu Yue ◽  
Ai-ping Ding ◽  
Jian Sun ◽  
Yang Yao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Differentiation ◽  
Primary Breast Cancer ◽  
Tumour Size ◽  
Univariate Analysis ◽  
Growth Factor Receptor ◽  
Disease Free Survival ◽  
Breast Cancer Patients ◽  
Her2 Positive ◽  
Er Alpha

Purpose: To assess the prognostic value of co-expression of estrogen receptor (ER)-beta and human epidermal growth factor receptor 2 (HER2) in primary breast cancer patients in China. Methods: Tumour specimens from 308 patients undergoing surgery for primary breast cancer were evaluated. Expression of ER-beta and HER-2 was investigated by the immunohistochemistry. Results: 123 patients (40%) were ER-beta positive and 58 (18.5 %) were HER2 positive. Among the 58 HER2 positive patients, 44 were ER-beta positive and 14 were ER-beta negative. ER-beta positive was associated with HER2 positive (75.9%, P=0.018) as well as ER-alpha positive (79.7%, P=0.023), poor cell differentiation (77.2% grade 2 or 3, P=0.010) and menopause age < 45 yr (55.3%, P=0.031). HER2 positive was associated with poor cell differentiation (93.1%, P=0.001), ?3cm tumour size (67.2%, P=0.011). Conclusion: Both ER-beta positive and HER2 positive status was associated with poorer overall survival (OS) by univariate analysis. In both HER2 positive and HER2 negative subgroups, ER-beta positive was associated with poorer distant disease free survival (DDFS) but not OS, which implied that ER-beta might relate to metastasis in breast cancer.

scholarly journals Emerging Targeted Therapies for HER2 Positive Gastric Cancer That Can Overcome Trastuzumab Resistance

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 400 ◽  
Author(s):  
Seiichiro Mitani ◽  
Hisato Kawakami
Keyword(s):  
Gastroesophageal Junction ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Trastuzumab Resistance ◽  
Her2 Positive ◽  
Drug Conjugates ◽  
Gastroesophageal Junction Cancer ◽  
Development Of Resistance ◽  
Epidermal Growth ◽  
Antibody Drug

Trastuzumab, a monoclonal antibody to human epidermal growth factor receptor 2 (HER2), has improved survival in patients with HER2-positive advanced gastric or gastroesophageal junction cancer (AGC). The inevitable development of resistance to trastuzumab remains a problem, however, with several treatment strategies that have proven effective in breast cancer having failed to show clinical benefit in AGC. In this review, we summarize the mechanisms underlying resistance to HER2-targeted therapy and outline past and current challenges in the treatment of HER2-positive AGC refractory to trastuzumab. We further describe novel agents such as HER2 antibody–drug conjugates that are under development and have shown promising antitumor activity in early studies.

scholarly journals HER2-positive breast cancer and tyrosine kinase inhibitors: the time is now

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ilana Schlam ◽  
Sandra M. Swain
Keyword(s):  
Breast Cancer ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinase ◽  
Kinase Inhibitors ◽  
Growth Factor Receptor ◽  
Her2 Positive ◽  
Epidermal Growth ◽  
Positive Breast Cancer

AbstractHuman epidermal growth factor receptor 2 (HER2) positive breast cancer accounts for 20–25% of all breast cancers. Multiple HER2-targeted therapies have been developed over the last few years, including the tyrosine kinase inhibitors (TKI) lapatinib, neratinib, tucatinib, and pyrotinib. These drugs target HER2 and other receptors of the epidermal growth factor receptor family, therefore each has unique efficacy and adverse event profile. HER2-directed TKIs have been studied in the early stage and advanced settings and have shown promising responses. There is increasing interest in utilizing these drugs in combination with chemotherapy and /or other HER2-directed agents in patients with central nervous system involvement, TKIs have shown to be effective in this setting for which treatment options have been previously limited and the prognosis remains poor. The aim of this review is to summarize currently approved TKIs for HER2+ breast, key clinical trials, and their use in current clinical practice.

scholarly journals Anthracycline-containing versus carboplatin-containing neoadjuvant chemotherapy in combination with trastuzumab for HER2-positive breast cancer: the neoCARH phase II randomized clinical trial

2021 ◽  
Vol 13 ◽  
pp. 175883592110090
Author(s):  
Hong-Fei Gao ◽  
Zhiyong Wu ◽  
Ying Lin ◽  
Xiang-Yang Song ◽  
Yin Cao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Neoadjuvant Chemotherapy ◽  
Primary Endpoint ◽  
Growth Factor Receptor ◽  
Group Versus ◽  
Complete Response ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Epidermal Growth ◽  
Positive Breast Cancer

Background: Although dual blockade HER2-based neoadjuvant chemotherapy is associated with excellent outcomes for human epidermal growth factor receptor 2 (HER2)-positive breast cancer, pertuzumab is not available to all patients due to cost. The optimal neoadjuvant chemotherapy for HER2-positive breast cancer in the presence of a single HER2 blockade is unknown. This study aimed to compare the efficacy and safety of epirubicin/cyclophosphamide followed by docetaxel/trastuzumab (EC-TH) with docetaxel/carboplatin/trastuzumab (TCH) neoadjuvant setting for HER2-positive breast cancer under the single HER2 blockade. Methods: Patients with stage II-IIIC HER2-positive breast cancer were randomly assigned to either eight cycles of EC-TH every 3 weeks during all chemotherapy cycles, or six cycles of TCH every 3 weeks. The primary endpoint was pathological complete response (pCR) (defined as the absence of invasive tumor cells in breast and axilla, ypT0/is ypN0). Results: From May 2017 to November 2019, 140 patients were randomly assigned, and 135 patients were ultimately found evaluable for the primary endpoint. The pCR was recorded in 25 of 67 patients [37.3%; 95% confidence interval (CI), 25.8–50.0] in the EC-TH group and in 38 of 68 patients (55.9%, 95% CI, 43.3–67.9) in the TCH group ( p = 0.032). The most common adverse events (AEs) were neutropenia in 24 of 67 (35.8%) patients in the EC-TH group versus 27 of 68 (39.7%) in the TCH group ( p = 0.642), anemia in 33 of 67 (49.3%) patients in the EC-TH group versus 34 of 68 (50.0%) in the TCH group ( p = 0.931), and thrombocytopenia in five of 67 (7.5%) patients in the EC-TH group versus 17 of 68 (25.0%) in the TCH group ( p = 0.006). Conclusion: For patients receiving the single HER2 blockade trastuzumab for HER2-positive breast cancer, TCH regimen might be a preferred neoadjuvant therapy. Trial registration: This trial was registered with ClinicalTrials.gov identifier: NCT03140553) on 2 May 2017.

scholarly journals Curcumin: Modulator of Key Molecular Signaling Pathways in Hormone-Independent Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3427
Author(s):  
Reyhaneh Farghadani ◽  
Rakesh Naidu
Keyword(s):  
Breast Cancer ◽  
Signaling Pathways ◽  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Progesterone Receptors ◽  
Drug Candidate ◽  
Molecular Signaling ◽  
Her2 Positive ◽  
Therapeutic Implications ◽  
Epidermal Growth

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among women worldwide. Despite the overall successes in breast cancer therapy, hormone-independent HER2 negative breast cancer, also known as triple negative breast cancer (TNBC), lacking estrogens and progesterone receptors and with an excessive expression of human epidermal growth factor receptor 2 (HER2), along with the hormone-independent HER2 positive subtype, still remain major challenges in breast cancer treatment. Due to their poor prognoses, aggressive phenotype, and highly metastasis features, new alternative therapies have become an urgent clinical need. One of the most noteworthy phytochemicals, curcumin, has attracted enormous attention as a promising drug candidate in breast cancer prevention and treatment due to its multi-targeting effect. Curcumin interrupts major stages of tumorigenesis including cell proliferation, survival, angiogenesis, and metastasis in hormone-independent breast cancer through the modulation of multiple signaling pathways. The current review has highlighted the anticancer activity of curcumin in hormone-independent breast cancer via focusing on its impact on key signaling pathways including the PI3K/Akt/mTOR pathway, JAK/STAT pathway, MAPK pathway, NF-ĸB pathway, p53 pathway, and Wnt/β-catenin, as well as apoptotic and cell cycle pathways. Besides, its therapeutic implications in clinical trials are here presented.

scholarly journals A paradigm shift in cell-free approach: the emerging role of MSCs-derived exosomes in regenerative medicine

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Soudeh Moghadasi ◽  
Marischa Elveny ◽  
Heshu Sulaiman Rahman ◽  
Wanich Suksatan ◽  
Abduladheem Turki Jalil ◽  
...  
Keyword(s):  
Regenerative Medicine ◽  
Ethical Issues ◽  
Therapeutic Potential ◽  
Kidney Diseases ◽  
Experimental Models ◽  
Live Cells ◽  
Target Cells ◽  
Intercellular Interaction ◽  
Micro Rnas

AbstractRecently, mesenchymal stem/stromal cells (MSCs) due to their pro-angiogenic, anti-apoptotic, and immunoregulatory competencies along with fewer ethical issues are presented as a rational strategy for regenerative medicine. Current reports have signified that the pleiotropic effects of MSCs are not related to their differentiation potentials, but rather are exerted through the release of soluble paracrine molecules. Being nano-sized, non-toxic, biocompatible, barely immunogenic, and owning targeting capability and organotropism, exosomes are considered nanocarriers for their possible use in diagnosis and therapy. Exosomes convey functional molecules such as long non-coding RNAs (lncRNAs) and micro-RNAs (miRNAs), proteins (e.g., chemokine and cytokine), and lipids from MSCs to the target cells. They participate in intercellular interaction procedures and enable the repair of damaged or diseased tissues and organs. Findings have evidenced that exosomes alone are liable for the beneficial influences of MSCs in a myriad of experimental models, suggesting that MSC- exosomes can be utilized to establish a novel cell-free therapeutic strategy for the treatment of varied human disorders, encompassing myocardial infarction (MI), CNS-related disorders, musculoskeletal disorders (e.g. arthritis), kidney diseases, liver diseases, lung diseases, as well as cutaneous wounds. Importantly, compared with MSCs, MSC- exosomes serve more steady entities and reduced safety risks concerning the injection of live cells, such as microvasculature occlusion risk. In the current review, we will discuss the therapeutic potential of MSC- exosomes as an innovative approach in the context of regenerative medicine and highlight the recent knowledge on MSC- exosomes in translational medicine, focusing on in vivo researches.

scholarly journals Imaging-Guided Therapy Simultaneously Targeting HER2 and EpCAM with Trastuzumab and EpCAM-Directed Toxin Provides Additive Effect in Ovarian Cancer Model

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3939
Author(s):  
Tianqi Xu ◽  
Anzhelika Vorobyeva ◽  
Alexey Schulga ◽  
Elena Konovalova ◽  
Olga Vorontsova ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Growth Factor Receptor ◽  
Repeated Administration ◽  
Ovarian Cancer Cells ◽  
Her2 Positive ◽  
Efficient Treatment ◽  
Pseudomonas Exotoxin A ◽  
Epidermal Growth

Efficient treatment of disseminated ovarian cancer (OC) is challenging due to its heterogeneity and chemoresistance. Overexpression of human epidermal growth factor receptor 2 (HER2) and epithelial cell adhesion molecule (EpCAM) in approx. 30% and 70% of ovarian cancers, respectively, allows for co-targeted treatment. The clinical efficacy of the monoclonal antibody trastuzumab in patients with HER2-positive breast, gastric and gastroesophageal cancers makes it readily available as the HER2-targeting component. As the EpCAM-targeting component, we investigated the designed ankyrin repeat protein (DARPin) Ec1 fused to a truncated variant of Pseudomonas exotoxin A with reduced immunogenicity and low general toxicity (LoPE). Ec1-LoPE was radiolabeled, evaluated in ovarian cancer cells in vitro and its biodistribution and tumor-targeting properties were studied in vivo. The therapeutic efficacy of Ec1-LoPE alone and in combination with trastuzumab was studied in mice bearing EpCAM- and HER2-expressing SKOV3 xenografts. SPECT/CT imaging enabled visualization of EpCAM and HER2 expression in the tumors. Co-treatment using Ec1-LoPE and trastuzumab was more effective at reducing tumor growth and prolonged the median survival of mice compared with mice in the control and monotherapy groups. Repeated administration of Ec1-LoPE was well tolerated without signs of hepatic or kidney toxicity. Co-treatment with trastuzumab and Ec1-LoPE might be a potential therapeutic strategy for HER2- and EpCAM-positive OC.

Amplification and expression of c-MET correlate with poor prognosis of patients with gastric cancer and upregulate the expression of PDL1

2021 ◽  
Vol 53 (5) ◽  
pp. 547-557
Author(s):  
Ya’nan Yang ◽  
Chenchen Wang ◽  
Congqi Dai ◽  
Xinyang Liu ◽  
Wenhua Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Prognostic Significance ◽  
Growth Factor Receptor ◽  
Disease Free Survival ◽  
Positive Association ◽  
Her2 Positive ◽  
Kaplan Meier ◽  
Met Amplification ◽  
Amplification Rate ◽  
Cox Proportional Hazard Regression

Abstract The prognostic significance of c-MET in gastric cancer (GC) remains uncertain. In the present study, we examined the amplification, expression, and the prognostic value of c-MET, human epidermal growth factor receptor 2 (HER2), and programmed cell death 1 ligand 1 (PDL1), together with the correlations among them in a large cohort of Chinese samples. A total of 444 patients were included. The immunohistochemistry (IHC) and the dual-color silver in situ hybridization (SISH) were performed to examine their expression and amplification. Univariate and multivariate analyses were performed by the Cox proportional hazard regression model, and survival curves were estimated by the Kaplan–Meier method. The positivity determined by IHC of c-MET was 24.8%, and the MET amplification rate was 2.3%. The positivity rates of HER2 and PDL1 were 8% and 34.7%, respectively. PDL1 expression had a significantly positive association with c-MET expression. c-MET positivity played a significant prognostic role in disease-free survival (DFS) (P = 0.032). Patients with mesenchymal-epithelial transition (MET) amplification had significantly poorer prognosis on both DFS and overall survival (OS). Subgroup analysis showed that in HER2-negative patients, but not in HER2-positive patients, MET-positive patients had significantly worse DFS (P = 0.000) and OS (P = 0.006). c-MET regulated the expression of PDL1 through an AKT-dependent pathway. c-MET inhibitor enhanced the T-cell killing ability and increased the efficacy of PD1 antibody. c-MET was found to be an independent prognostic factor for DFS of GC patients. A combination of c-MET inhibitors and PD1 antibodies could enhance the killing capacity of T cells, providing a preliminary basis for the clinical research on the same combination in GC treatment.

Sign in / Sign up

Export Citation Format

Share Document