HER2-overexpressing Breast Cancer Research Articles

Retraction Note: A83-01 inhibits TGF-β-induced upregulation of Wnt3 and epithelial to mesenchymal transition in HER2-overexpressing breast cancer cells.

Retraction Note: A83-01 inhibits TGF-β-induced upregulation of Wnt3 and epithelial to mesenchymal transition in HER2-overexpressing breast cancer cells.

Abstract PO5-04-02: Combination of trastuzumab competing and non-competing fully human internalizing anti-Her2 monoclonal antibodies drug conjugates increases their inhibitory effect on the growth of HER2 positive metastatic breast cancer cells

Abstract The human epidermal growth factor receptor (HER) family of receptors plays a key role in proliferation stimulator for several human cancers. In particular, HER2 is overexpressed in 15-30% of breast cancers with or without gene amplification with prognostic and predictive implications. HER2 overexpression is associated with shorter disease-free and overall survivals, resistance to hormonal agents and increased risk of brain metastasis. Trastuzumab is a humanized anti-HER2 monoclonal antibody that binds to domain IV of HER2 extracellular domain and blocks its signaling. More recently, two antibody drug conjugates using trastuzumab have been approved: Ado-Trastuzumab-Emtansine (Kadcyla) consisting of trastuzumab conjugated to the drug mertansine DM1 and fam-trastuzumab-deruxtecan-nhki (Enhertu to deliver the topoisomerase inhibitor deruxtecan. We are reporting here the development of fully human internalizing anti-HER2 antibodies with distinct epitopes on the HER2protein which compete or not with trastuzumab for binding to HER2. These monoclonal antibodies have been developed by immunizing fully human (TC-Mab mouse) mice with recombinant HER2 protein. After production of hybridoma secreting fully human immunoglobulins, the screening process included competition with trastuzumab for binding to Her2 by enzyme linked immunoassay and Octet epitope binning and affinity determination as well as internalization assay. Several internalizing antibodies able to compete or not with trastuzumab and with high affinity (Kd ranging from 10−9 M to 10−12 M) were selected. Their ability to deliver a cytotoxic payload in HER2 overexpressing breast cancer cells such as SKBR3, BT474 and AU565 was next investigated. Two groups of antibodies: one competing with trastuzumab and the other one non-competing were further characterized. Data related to these antibodies’ biochemical characteristics as well as their ability to inhibit proliferation in vitro and in vivo in mouse xenografts studies will be presented here. In conclusion, the use of fully human mice to develop monoclonal antibodies provides a powerful and attractive approach to develop fully human monoclonal antibodies against cancer targets by-passing the need for humanization and affinity maturation of antibodies. This work is supported by 5R44CA224718 SBIR grant from the National Cancer Institute. Citation Format: Ginette Serrero, Binbin Yue, Jianping Dong, Jun Hayashi. Combination of trastuzumab competing and non-competing fully human internalizing anti-Her2 monoclonal antibodies drug conjugates increases their inhibitory effect on the growth of HER2 positive metastatic breast cancer cells [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-04-02.

Deep learning-assisted monitoring of trastuzumab efficacy in HER2-Overexpressing breast cancer via SERS immunoassays of tumor-derived urinary exosomal biomarkers

Monitoring drug efficacy is significant in the current concept of companion diagnostics in metastatic breast cancer. Trastuzumab, a drug targeting human epidermal growth factor receptor 2 (HER2), is an effective treatment for metastatic breast cancer. However, some patients develop resistance to this therapy; therefore, monitoring its efficacy is essential. Here, we describe a deep learning-assisted monitoring of trastuzumab efficacy based on a surface-enhanced Raman spectroscopy (SERS) immunoassay against HER2-overexpressing mouse urinary exosomes. Individual Raman reporters bearing the desired SERS tag and exosome capture substrate were prepared for the SERS immunoassay; SERS tag signals were collected to prepare deep learning training data. Using this deep learning algorithm, various complicated mixtures of SERS tags were successfully quantified and classified. Exosomal antigen levels of five types of cell-derived exosomes were determined using SERS-deep learning analysis and compared with those obtained via quantitative reverse transcription polymerase chain reaction and western blot analysis. Finally, drug efficacy was monitored via SERS-deep learning analysis using urinary exosomes from trastuzumab-treated mice. Use of this monitoring system should allow proactive responses to any treatment-resistant issues.

Augmented antitumor immune responses of HER2-targeted pyroptotic induction by long-lasting recombinant immunopyroptotins

Pyroptosis is a well-documented form of programmed cell death caused by the gasdermin-driven perforation of cell membranes. Selective induction of pyroptosis in tumor cells represents a promising antitumor strategy to enhance the efficacy of immunotherapy. In this study, we established a recombinant protein-based immunopyroptotin strategy that led to the intratumoral induction of pyroptosis for HER2-directed therapy. Long-lasting immunopyroptotins were constructed by sequentially fusing the humanized anti-HER2 single-chain antibody P1h3, albumin-binding peptide (ABD035 or dAb7h8), cathepsin B-cleavable peptide B2, endosome-disruptive peptide E5C3, and active pyroptotic effector gasdermin D-N fragment (GN). After purification, we evaluated the cytotoxicity and antitumor immune responses primarily induced by the immunopyroptotins in HER2-overexpressing breast cancer cells. The resulting ABD035-immunoGN and dAb7h8-immunoGN showed improved in vitro cytotoxicity in HER2-overexpressing cancer cells compared with that in the immunotBid that we previously generated to induce tumor cell apoptosis. The binding of long-lasting immunopyroptotins to albumin increased the half-life by approximately 7-fold in nude mice. The enhanced antitumor efficacy of long-lasting immunopyroptotins was confirmed in both N87 tumor-bearing T cell-deficient mice and 4T1-hHER2 bilateral tumor-bearing immunocompetent mice. Immunopyroptotin treatment elicited systemic antitumor immune responses involving CD8+ T cells and mature dendritic cells and upregulated the expression of proinflammatory cytokines, leading to sustained remission of non-injected distant tumors. This study extends the repertoire of antibody-based therapeutics through the tumor-targeted delivery of a constitutively active pore-forming gasdermin-N fragment, which shows great potential for pyroptosis-based antitumor therapy.

Neratinib could be effective as monotherapy or in combination with trastuzumab in HER2-low breast cancer cells and organoid models.

Previous studies have suggested that patients with HER2-low breast cancers do not benefit from trastuzumab treatment although the reasons remain unclear. We investigated the effect of trastuzumab monotherapy and its combination with different HER2 targeting treatments in a panel of breast cancer cell lines and patient-derived organoids (PDOs) using biochemical methods and cell viability assays. Compared to sensitive HER2 over-expressing (IHC3 + ) breast cancer cells, increasing doses of trastuzumab could not achieve IC50 in MDA-MB-361 (IHC 2 + FISH + ) and MDA-MB-453 (IHC 2 + FISH-) cells which showed an intermediate response to trastuzumab. Trastuzumab treatment induced upregulation of HER ligand release, resulting in the activation of HER receptors in these cells, which could account for their trastuzumab insensitivity. Adding a dual ADAM10/17 inhibitor to inhibit the shedding of HER ligands in combination with trastuzumab only showed a modest decrease in the cell viability of HER2-low breast cancer cells and PDOs. However, the panHER inhibitor neratinib was an effective monotherapy in HER2-low breast cancer cells and PDOs, and showed additive effects when combined with trastuzumab. This study demonstrates that neratinib in combination with trastuzumab may be effective in a subset of HER2-low breast cancers although further validation is required in a larger panel of PDOs and in future clinical studies.

Abstract CT265: Trastuzumab emtansine in patients (pts) with HER2 mutation-positive (HER2mut) tumors: TAPISTRY study

Abstract Background: HER2 point mutations are found in ~1.4% of solid tumors, but prevalence varies across tumor types. Trastuzumab emtansine is an antibody-drug conjugate approved in HER2-overexpressing metastatic breast cancer. Here we present efficacy and safety data of trastuzumab emtansine in pts with HER2mut advanced/metastatic solid tumors (excluding HER2 amplifications) from Cohort F of the TAPISTRY trial (NCT04589845). Methods: TAPISTRY is a phase II, global, open-label, multi-cohort basket trial evaluating the efficacy and safety of multiple therapies in pts with advanced/metastatic solid tumors. Pts in Cohort F were ≥12 years old, with tumors harboring an activating HER2 mutation identified by NGS, and measurable disease by RECIST v1.1. Trastuzumab emtansine 3.6 mg/kg IV was administered every 21 days; tumor assessments were performed at screening, every 6 weeks from day 1/cycle 1 for one year, and every 9 weeks thereafter. Primary endpoint: objective response rate (ORR) by independent review committee (IRC). Key secondary endpoints: ORR by investigator; duration of response; progression-free survival; overall survival; safety. Results: At data cut-off (16 Jul 2023), 35 pts with 10 different tumor types were efficacy evaluable; the most common tumor type was non-small cell lung cancer (NSCLC; 31%). Baseline characteristics and key outcomes are presented in the Table. After a median follow-up of 7 months, ORR by IRC in efficacy-evaluable pts was 14.3% (n/N=5/35; 95% CI 4.8-30.3]). Responses were observed in 3 tumor types: NSCLC (n/N=1/11), breast (n/N=3/5), endometrial (n/N=1/1). The most frequent adverse events were decreased appetite, fatigue, and nausea (25.7% each). No new safety signals were identified. Conclusions: Trastuzumab emtansine in pts with HER2mut tumors (excluding HER2 amplifications) did not meet its primary endpoint. Trastuzumab emtansine was generally well tolerated and the safety profile was consistent with the known profile of the drug. TABLE 1. NAND Baseline characteristics Trastuzumab emtansine N=35 Median age, years (range) 67 (29-83) Female, n (%) 22 (62.9) Prior lines of therapy, n (%) - No prior lines of therapy/1 prior line of therapy/≥2 prior lines of therapy 1 (2.9)/8 (22.9)/26 (74.3) Efficacy N=35 Objective response rate by IRC, n (%) [95% CI] 5 (14.3)* [4.8-30.3] Complete response 0 Partial response 5 (14.3) Stable disease 14 (40.0) Progressive disease 10 (28.6) Missing† 6 (17.1) Clinical benefit rate by IRC, n (%)‡ 8 (22.9) Objective response rate by investigator, n (%) 2 (5.7) Median duration of response, months (95% CI) - By IRC/By investigator 9.4 (2.8-NE)/11.8 (8.3-NE) Median progression-free survival, months (95% CI) - By IRC/By investigator 3.3 (1.4-4.3)/2.7 (1.5-3.9) Median overall survival, months (95% CI) 10.0 (6.2-13.4) Safety, n (%) N=35 ≥1 AE 33 (94.3) Grade 3-5 AEs 19 (54.3) AE-related deaths 4 (11.4) Serious AEs 13 (37.1) AEs leading to withdrawal from study 4 (11.4) Treatment-related AEs 25 (71.4) Treatment-related AEs leading to withdrawal from study 1 (2.9) *By tumor type: non-small cell lung cancer (n=1), breast (n=3), and endometrial (n=1); †Six patients had missing data due to: death (n=4), clinical progression (n=1), or withdrawal of consent (n=1) prior to first scan; ‡Criteria for clinical benefit: either a response (confirmation not required) and/or stable disease or better for at least 24 weeks. AE, adverse event; CI, confidence interval; NE, not estimable. Citation Format: Jeong Eun Kim, David Thomas, Shirish Gadgeel, Marcelo Corassa, Tira J. Tan, Eugenia Girda, Donald Richards, Sabine Tejpar, David Chen, Junhan Fang, Sid Patel, Timothy R. Wilson, Fabrice Barlesi. Trastuzumab emtansine in patients (pts) with HER2 mutation-positive (HER2mut) tumors: TAPISTRY study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT265.

Efficacy and delivery strategies of the dual Rac/Cdc42 inhibitor MBQ-167 in HER2 overexpressing breast cancer

Trastuzumab and trastuzumab-based treatments are the standard of care for breast cancer patients who overexpress the human epidermal growth factor receptor 2 (HER2). However, patients often develop resistance to trastuzumab via signaling from alternative growth factor receptors that converge to activate guanine nucleotide exchange factors (GEFs) that in turn activate the Rho GTPases Rac and Cdc42. Since Rac and Cdc42 have been implicated in high tumor grade and therapy resistance, inhibiting the activity of Rac and Cdc42 is a rational strategy to overcome HER2-targeted therapy resistance. Therefore, our group developed MBQ-167, a dual Rac/Cdc42 inhibitor with IC50s of 103 nM and 78 nM for Rac and Cdc42, respectively, which is highly effective in reducing cell and tumor growth and metastasis in breast cancer cell and mouse models. Herein, we created a trastuzumab resistant variant of the SKBR3 HER2 positive breast cancer cell line and show that Rac activation is a central mechanism in trastuzumab resistance. Next, we tested the potential of targeting MBQ-167 to HER2 overexpressing trastuzumab-resistant cell lines in vitro, and show that MBQ-167, but not trastuzumab, reduces cell viability and induces apoptosis. When MBQ-167 was targeted to mammary fatpad tumors established from HER2 overexpressing cells via immunoliposomes functionalized with trastuzumab, MBQ-167 and MBQ-167-loaded liposomes show equal efficacy in reducing the viability of trastuzumab-resistant cells, inhibiting tumor growth in mouse xenografts, and reducing metastasis to lungs and liver. This study demonstrates the efficacy of MBQ-167 as an alternative therapeutic in HER2 overexpressing cancers, delivered either in free form or in liposomes.

Evidence for cytoprotective autophagy in response to HER2-targeted monoclonal antibodies.

The advent of HER2-targeted monoclonal antibodies such as trastuzumab has significantly improved the clinical outcomes for patients with breast cancer overexpressing HER2, and more recently also for gastric cancers. However, the development of resistance, as is frequently the case for other antineoplastic modalities, constrains clinical efficacy. Multiple molecular mechanisms and signaling pathways have been investigated for their potential involvement in the development of resistance to HER2-targeted therapies, among which is autophagy. Autophagy is an inherent cellular mechanism whereby cytoplasmic components are selectively degraded to maintain cellular homeostasis via the generation of energy and metabolic intermediates. Although the cytoprotective form of autophagy is thought to predominate, other forms of autophagy have also been identified in response to chemotherapeutic agents in various tumor models; these include cytotoxic, cytostatic, and non-protective functional forms of autophagy. In this review, we provide an overview of the autophagic machinery induced in response to HER2-targeted monoclonal antibodies, with a focus on trastuzumab and trastuzumab-emtansine, in an effort to determine whether autophagy targeting or modulation could be translated clinically to increase their effectiveness and/or overcome resistance development. Significance Statement This manuscript is one in a series of papers that investigate the different roles of the autophagic machinery induced in response to versatile anti-neoplastic agents in various cancer models. This series designed in an attempt to build a conclusion whether autophagy targeting or modulation is an effective adjuvant strategy to increase the efficacy of chemotherapeutic agents. In this review, we shed the light on the relationship between the autophagic machinery and HER2 targeted therapies.

HER2-Targeted Therapy-From Pathophysiology to Clinical Manifestation: A Narrative Review.

Trastuzumab is the primary treatment for all stages of HER2-overexpressing breast cancer in patients. Though discovered over 20 years ago, trastuzumab-induced cardiotoxicity (TIC) remains a research topic in cardio-oncology. This review explores the pathophysiological basis of TIC and its clinical manifestations. Their understanding is paramount for early detection and cardioprotective treatment. Trastuzumab renders cardiomyocytes susceptible by inhibiting the cardioprotective NRG-1/HER2/HER4 signaling pathway. The drug acts on HER2-receptor-expressing cardiomyocytes, endothelium, and cardiac progenitor cells (see the Graphical Abstract). The activation of immune cells, fibroblasts, inflammation, and neurohormonal systems all contribute to the evolution of TIC. A substantial amount of research demonstrates that trastuzumab induces overt and subclinical left ventricular (LV) systolic failure. Data suggest the development of right ventricular damage, LV diastolic dysfunction, and heart failure with preserved ejection fraction. Further research is needed to define a chronological sequence of cardiac impairments to guide the proper timing of cardioprotection implementation.

Alcohol, Smoking, and Risks of Breast Cancer Recurrence and Mortality among Women with Luminal, Triple-Negative, and HER2-Overexpressing Breast Cancer.

This study evaluates the relationship between smoking, alcohol, and breast cancer outcomes according to molecular subtype. This population-based prospective cohort consisted of 3,876 women ages 20 to 69 diagnosed with a first primary invasive breast cancer from 2004 to 2015 in the Seattle-Puget Sound region. Breast cancer was categorized into three subtypes based on estrogen receptor (ER), progesterone receptor (PR), and HER2 expressions: luminal (ER+), triple-negative (TN; ER-/PR-/HER2-), and HER2-overexpressing (H2E; ER-/HER2+). We fit Cox proportional hazards models to assess the association between alcohol consumption and smoking status at diagnosis and risks of recurrence, breast cancer-specific mortality, and all-cause mortality. Histories of ever smoking [HR, 1.33; 95% confidence interval (CI), 1.01-1.74] and current smoking (HR, 1.59; 95% CI, 1.07-2.35) were associated with greater risk of breast cancer recurrence among TN cases. Smoking was also associated with greater risk of recurrence to bone among all cases and among luminal cases. Elevated risks of breast cancer-specific and all-cause mortality were observed among current smokers across all subtypes. Alcohol use was not positively associated with risk of recurrence or mortality overall; however, TN patients who drank four or more drinks per week had a decreased risk of recurrence (HR, 0.71; 95% CI, 0.51-0.98) and breast cancer-specific mortality (HR, 0.73; 95% CI, 0.55-0.97) compared with non-current drinkers. Patients with breast cancer with a history of smoking at diagnosis have elevated risks of recurrence and mortality. These findings underscore the need to prioritize smoking cessation among women diagnosed with breast cancer.

Analysis of clinicopathological features and prognostic factors of breast cancer brain metastasis.

Breast cancer (BC) has become the most common malignancy in women. The incidence and detection rates of BC brain metastasis (BCBM) have increased with the progress of imaging, multidisciplinary treatment techniques and the extension of survival time of BC patients. BM seriously affects the quality of life and sur-vival prognosis of BC patients. Therefore, clinical research on the clinicopathological features and prognostic factors of BCBM is valuable. By analyzing the clinicopathological parameters of BCBM patients, and assessing the risk factors and prognostic indicators, we can perform hierarchical diagnosis and treatment on the high-risk population of BCBM, and achieve clinical benefits of early diagnosis and treatment. To explore the clinicopathological features and prognostic factors of BCBM, and provide references for diagnosis, treatment and management of BCBM. The clinicopathological data of 68 BCBM patients admitted to the Air Force Medical Center, Chinese People's Liberation Army (formerly Air Force General Hospital) from 2000 to 2022 were collected. Another 136 BC patients without BM were matched at a ratio of 1:2 based on the age and site of onset for retrospective analysis. Categorical data were subjected to χ2 test or Fisher's exact probability test, and the variables with P < 0.05 in the univariate Cox proportional hazards model were incorporated into the multivariate model to identify high-risk factors and independent prognostic factors of BCBM, with a hazard ratio (HR) > 1 suggesting poor prognostic factors. The survival time of patients was estimated by the Kaplan-Meier method, and overall survival was compared between groups by log-rank test. Multivariate Cox regression analysis showed that patients with stage III/IV tumor at initial diagnosis [HR: 5.58, 95% confidence interval (CI): 1.99-15.68], lung metastasis (HR: 24.18, 95%CI: 6.40-91.43), human epidermal growth factor receptor 2 (HER2)-overexpressing BC and triple-negative BC were more prone to BM. As can be seen from the prognostic data, 52 of the 68 BCBM patients had died by the end of follow-up, and the median time from diagnosis of BC to the occurrence of BM and from the occurrence of BM to death or last follow-up was 33.5 and 14 mo, respectively. It was confirmed by multivariate Cox regression analysis that patients with neurological symptoms (HR: 1.923, 95%CI: 1.005-3.680), with bone metastasis (HR: 2.011, 95%CI: 1.056-3.831), and BM of HER2-overexpressing and triple-negative BC had shorter survival time. HER2-overexpressing, triple-negative BC, late tumor stage and lung metastasis are risk factors of BM. The presence of neurological symptoms, bone metastasis, and molecular type are influencing prognosis factors of BCBM.

De-escalated radiotherapy for HER2-overexpressing breast cancer patients with 1-3 positive lymph nodes undergoing anti-HER2 targeted therapy.

In the era of anti-HER2 targeted therapy, the potential clinical feasibility of considering HER2-overexpressing breast cancer cases presenting with 1-3 positive axillary lymph nodes as low-risk, and thereby contemplating postoperative radiotherapy reduction, remains an important subject for in-depth examination. The aim of this retrospective study was to evaluate the effectiveness of de-escalated radiotherapy in T1-2N1M0 HER2-overexpressing breast cancer patients receiving anti-HER2 targeted therapy. Specifically, omitting regional lymph node irradiation (RNI) after breast-conserving surgery and only performing whole-breast irradiation or omitting postmastectomy radiation therapy. A retrospective analysis was conducted on 429 patients with stage T1-2N1M0 primary invasive HER2-overexpressing breast cancer from our center between 2004 and 2018. Patients who received anti-HER2 targeted therapy were divided into an RNI group and a no RNI group to assess the role of RNI. The prognostic role of RNI was investigated via the Kaplan-Meier method and Cox proportional hazards modeling. The median follow-up time was 46.8 months (range 7.1-225.8 months). In the anti-HER2 targeted therapy group RNI yielded no significant improvements in invasive disease-free survival (IDFS) (p = 0.940), local-regional recurrence-free survival (p = 0.380), distant metastases-free survival (p = 0.698), or overall survival (p = 0.403). Estrogen receptor (ER) status (hazard ratio [HR] 0.105, 95% confidence interval [CI] 0.023-0.749, p = 0.004) and lymph vascular invasion status (LVI) (HR 5.721, 95% CI 1.586-20.633, p = 0.008) were identified as independent prognostic factors for IDFS, and ER-positive and LVI-negative patients exhibited better prognoses. Omitting RNI may be a safe option in T1-2N1 HER2-overexpressing breast cancer patients receiving standardized anti-HER2 targeted therapy; particularly in ER-positive or LVI-negative subgroups.

Immune microenvironment dynamics of HER2 overexpressing breast cancer under dual anti-HER2 blockade.

The clinical prognosis of the HER2-overexpressing (HER2-OE) subtype of breast cancer (BC) is influenced by the immune infiltrate of the tumor. Specifically, monocytic cells, which are promoters of pro-tumoral immunosuppression, and NK cells, whose basal cytotoxic function may be enhanced with therapeutic antibodies. One of the standards of care for HER2+ BC patients includes the combination of the anti-HER2 antibodies trastuzumab and pertuzumab. This dual combination was a breakthrough against trastuzumab resistance; however, this regimen does not yield complete clinical benefit for a large fraction of patients. Further therapy refinement is still hampered by the lack of knowledge on the immune mechanism of action of this antibody-based dual HER2 blockade. To explore how the dual antibody challenge influences the phenotype and function of immune cells infiltrating the HER2-OE BC microenvironment, we developed in vitro 3D heterotypic cell models of this subtype. The models comprised aggregates of HER2+ BC cell lines and human peripheral blood mononuclear cells. Cells were co-encapsulated in a chemically inert alginate hydrogel and maintained in agitation-based culture system for up to 7 days. The 3D models of the HER2-OE immune microenvironment retained original BC molecular features; the preservation of the NK cell compartment was achieved upon optimization of culture time and cytokine supplementation. Challenging the models with the standard-of-care combination of trastuzumab and pertuzumab resulted in enhanced immune cytotoxicity compared with trastuzumab alone. Features of the response to therapy within the immune tumor microenvironment were recapitulated, including induction of an immune effector state with NK cell activation, enhanced cell apoptosis and decline of immunosuppressive PD-L1+ immune cells. This work presents a unique human 3D model for the study of immune effects of anti-HER2 biologicals, which can be used to test novel therapy regimens and improve anti-tumor immune function.

Dual-Targeted Therapy in HER2-Overexpressing Breast Cancer with Trastuzumab and Novel Cholesterol-Based Nioplexes Silencing Mcl-1.

The challenge in HER2-overexpressing breast cancer therapy lies in creating an effective target therapy to overcome treatment resistance. Monoclonal antibodies and target gene silencing by siRNA are two potential strategies that have been widely developed for treating HER2-positive breast cancer. The siRNA delivery system is a crucial factor that influences siRNA therapy's success. In this study, lipid-based nanoparticles (cationic niosomes) composed of different cholesterol-based cationic lipids were formulated and characterized for delivering siRNA into HER2-overexpressing breast cancer cells. Niosomes containing a trimethylammonium headgroup showed the highest siRNA delivery efficiency with low toxicity. The myeloid cell leukemia-1 (Mcl-1) siRNA nioplex treatment significantly decreased mRNA expression and breast cancer cell growth. Dual-targeted therapy, consisting of treatment with an Mcl-1 siRNA nioplex and trastuzumab (TZ) solution, noticeably promoted cell-growth inhibition and apoptosis. The synergistic effect of dual therapy was also demonstrated by computer modeling software (CompuSyn version 1.0). These findings suggest that the developed cationic niosomes were effective nanocarriers for siRNA delivery in breast cancer cells. Furthermore, the Mcl-1 nioplex/TZ dual treatment establishes a synergistic outcome that may have the potential to treat HER2-overexpressing breast cancer.

Deep (phospho)proteomics profiling of pre- treatment needle biopsies identifies signatures of treatment resistance in HER2+ breast cancer

Patients with early-stage HER2-overexpressing breast cancer struggle with treatment resistance in 20%-40% of cases. More information is needed to predict HER2 therapy response and resistance invivo. In this study, we perform (phospho)proteomics analysis of pre-treatment HER2+ needle biopsies of early-stage invasive breast cancer to identify molecular signatures predictive of treatment response to trastuzumab, pertuzumab, and chemotherapy. Our data show that accurate quantification of the estrogen receptor (ER) and HER2 biomarkers, combined with the assessment of associated biological features, has the potential to enable better treatment outcome prediction. In addition, we identify cellular mechanisms that potentially precondition tumors to resist therapy. We find proteins with expression changes that correlate with resistance and constitute to a strong predictive signature for treatment success in our patient cohort. Our results highlight the multifactorial nature of drug resistance invivo and demonstrate the necessity of deep tumor profiling.

Investigation of Tumor Heterogeneity Using Integrated Single-Cell RNA Sequence Analysis to Focus on Genes Related to Breast Cancer-, EMT-, CSC-, and Metastasis-Related Markers in Patients with HER2-Positive Breast Cancer.

Human epidermal growth factor receptor 2 (HER2) protein, which is characterized by the amplification of ERBB2, is a molecular target for HER2-overexpressing breast cancer. Many targeted HER2 strategies have been well developed thus far. Furthermore, intratumoral heterogeneity in HER2 cases has been observed with immunohistochemical staining and has been considered one of the reasons for drug resistance. Therefore, we conducted an integrated analysis of the breast cancer single-cell gene expression data for HER2-positive breast cancer cases from both scRNA-seq data from public datasets and data from our cohort and compared them with those for luminal breast cancer datasets. In our results, heterogeneous distribution of the expression of breast cancer-related genes (ESR1, PGR, ERBB2, and MKI67) was observed. Various gene expression levels differed at the single-cell level between the ERBB2-high group and ERBB2-low group. Moreover, molecular functions and ERBB2 expression levels differed between estrogen receptor (ER)-positive and ER-negative HER2 cases. Additionally, the gene expression levels of typical breast cancer-, CSC-, EMT-, and metastasis-related markers were also different across each patient. These results suggest that diversity in gene expression could occur not only in the presence of ERBB2 expression and ER status but also in the molecular characteristics of each patient.

Discrimination between human epidermal growth factor receptor 2 (HER2)-low-expressing and HER2-overexpressing breast cancers: a comparative study of four MRI diffusion models.

To determine the value of conventional DWI, continuous-time random walk (CTRW), fractional order calculus (FROC), and stretched exponential model (SEM) in discriminating human epidermal growth factor receptor 2 (HER2) status of breast cancer (BC). This prospective study included 158 women who underwent DWI, CTRW, FROC, and SEM and were pathologically categorized into the HER2-zero-expressing group (n = 10), HER2-low-expressing group (n = 86), and HER2-overexpressing group (n = 62). Nine diffusion parameters, namely ADC, αCTRW, βCTRW, DCTRW, βFROC, DFROC, μFROC, αSEM, and DDCSEM of the primary tumor, were derived from four diffusion models. These diffusion metrics and clinicopathologic features were compared between groups. Logistic regression was used to determine the optimal diffusion metrics and clinicopathologic variables for classifying the HER2-expressing statuses. Receiver operating characteristic(ROC) curves were used to evaluate their discriminative ability. The estrogen receptor (ER) status, progesterone receptor (PR) status, and tumor size differed between HER2-low-expressing and HER2-overexpressing groups (p < 0.001 to p = 0.009). The αCTRW, DCTRW, βFROC, DFROC, μFROC, αSEM, and DDCSEM were significantly lower in HER2-low-expressing BCs than those in HER2-overexpressing BCs (p < 0.001 to p = 0.01). Further multivariable logistic regression analysis showed that the αCTRW was the single best discriminative metric, with an area under the curve (AUC) being higher than that of ADC (0.802 vs. 0.610, p < 0.05); the addition of ER status, PR status, and tumor size to the αCTRW improved the AUC to 0.877. The αCTRW could help discriminate the HER2-low-expressing and HER2-overexpressing BCs. Human epidermal growth factorreceptor 2 (HER2)-low-expressing breast cancer (BC) might also benefit from the HER2-targeted therapy. Prediction of HER2-low-expressing BC or HER2-overexpressing BC is crucial for appropriate management. Advanced continuous-time random walk diffusion MRI offers a solution to this clinical issue. • Human epidermal receptor 2 (HER2)-low-expressing BC had lower αCTRW, DCTRW, βFROC, DFROC, μFROC, αSEM, and DDCSEM values compared with HER2-overexpressing breast cancer. • The αCTRW was the single best diffusion metric (AUC = 0.802) for discrimination between the HER2-low-expressing and HER2-overexpressing breast cancers. • The addition of αCTRW to the clinicopathologic features (estrogen receptor status, progesterone receptor status, and tumor size) further improved the discriminative ability.

Inhibiting HER3 Hyperphosphorylation in HER2-Overexpressing Breast Cancer through Multimodal Therapy with Branched Gold Nanoshells.

Treatment failure in breast cancers overexpressing human epidermal growth factor receptor 2 (HER2) is associated mainly to the upregulation of human epidermal growth factor receptor 3 (HER3) oncoprotein linked to chemoresitence. Therefore, to increase patient survival, here a multimodaltheranostic nanoplatform targeting both HER2 and HER3 is developed. This consists of doxorubicin-loaded branched gold nanoshells functionalized with the near-infrared (NIR) fluorescent dye indocyanine green, a small interfering RNA (siRNA) against HER3, and the HER2-specific antibody Transtuzumab, able to provide a combined therapeutic outcome (chemo- and photothermal activities, RNA silencing, and immune response). In vitro assays in HER2+ /HER3+ SKBR-3 breast cancer cells have shown an effective silencing of HER3 by the released siRNA and an inhibition of HER2 oncoproteins provided by Trastuzumab, along with a decrease of the serine/threonine protein kinase Akt (p-AKT) typically associated with cell survival and proliferation, which helps to overcome doxorubicin chemoresistance. Conversely, adding the NIR light therapy, an increment in p-AKT concentration is observed, although HER2/HER3 inhibitions are maintained for 72h. Finally, in vivo studies in a tumor-bearing mice model display a significant progressively decrease of the tumor volume after nanoparticle administration and subsequent NIR light irradiation, confirming the potential efficacy of the hybrid nanocarrier.

Photodynamic Therapy of Cancer: Quality and Prospective of Therapy based on Photosensitizer

Abstract: To kill cancer cells, photodynamic therapy (PDT) utilizes a light-sensitive medication and light. Light-sensitive drugs are absorbed by cancerous cells. The cells are then illuminated with a specific light or laser by a specialist and oxygen that destroys cancer cells is released. The present study aims to discuss the roles, advancements, and limitations of photodynamic therapy in cancer treatment. Photosensitizers and photosensitizing agents are used in photodynamic treatment to destroy cancer cells. Lasers or other light sources, such as LEDs, may provide illumination. There are reports of a novel nanoplatform for the treatment of HER2-overexpressed breast cancer, as well as other primary and metastatic cancers, using fluorescent electron microscopy PDT/photothermal therapy (PTT) dualtherapy. PDT has a significant benefit over conventional cancer therapies because it may cause fewer adverse effects. PDT-induced immunostimulatory cell death and the production of a robust local inflammatory response might lead to effective local anticancer therapy. PDT has a lower long-term morbidity and recovery time than surgery, chemotherapy, or radiation.

Combined doxorubicin and arctigenin treatment induce cell cycle arrest-associated cell death by promoting doxorubicin uptake in doxorubicin-resistant breast cancer cells.

Chemotherapy failure is often caused by drug resistance, for which no effective treatment strategy has been established. Many studies have been undertaken with the aim of overcoming drug resistance using natural products. Arctigenin (ATG), a natural product, has been investigated for its anti-cancer effects in HER2-overexpressing, ER-positive, and triple-negative breast cancer cells. We investigated the efficacy of ATG against self-established doxorubicin (DOX)-resistant breast cancer cells (MCF-DR and MDA-DR cells) derived from MCF-7 and MDA-MB-231 cells, respectively. ATG was found to increase DOX intracellular levels by downregulating multidrug Resistance 1 (MDR1) mRNA expression in DOX-resistant cells. In addition, combined treatment with DOX and ATG (DOX/ATG) reduced the viability of and colony formation by DOX-resistant cells. DOX/ATG also significantly induced G2/M cell cycle arrest by suppressing the Cyclin D1/CDK4/RB pathways and suppressed the expressions of MDR1 and Cyclin D1 by inhibiting the Mitogen-activated protein kinase (MAPK)/Activating protein-1 (AP-1) signaling pathways. Furthermore, DOX/ATG induced DNA damage and attenuated the expressions of RAD51 and Ku80. However, PARP1 (Poly [ADP-ribose] polymerase1) cleavage and AIF (Apoptosis-inducing factor) induced apoptosis did not occur despite DNA damage-induced cell death. Rather, flow cytometry showed that DOX/ATG caused necrosis. In summary, DOX/ATG increased intracellular DOX levels by inhibiting MDR1 and inducing G2/M arrest by inhibiting the Cyclin D1/CDK4/RB pathways and causing necrosis by damaging DNA. Our results suggest that ATG might be used as an adjuvant to enhance the efficacy of DOX in DOX-resistant breast cancer.