HER2-overexpressing Breast Cancer Research Articles

Antitumor Activities of a Humanized Cancer-Specific Anti-HER2 Monoclonal Antibody, humH2Mab-250 in Human Breast Cancer Xenografts

Monoclonal antibody (mAb) and cell-based immunotherapies represent cutting-edge strategies for cancer treatment. However, safety concerns persist due to the potential targeting of normal cells that express reactive antigens. Therefore, it is crucial to develop cancer-specific mAbs (CasMabs) that can bind to cancer-specific antigens and exhibit antitumor activity in vivo, thereby reducing the risk of adverse effects. We previously screened mAbs targeting human epidermal growth factor receptor 2 (HER2) and successfully developed a cancer-specific anti-HER2 mAb, H2Mab-250/H2CasMab-2 (mouse IgG1, kappa). In this study, we assessed both the in vitro and in vivo antitumor efficacy of the humanized H2Mab-250 (humH2Mab-250). Although humH2Mab-250 showed lower reactivity to HER2-overexpressed Chinese hamster ovary-K1 (CHO/HER2) and breast cancer cell lines (BT-474 and SK-BR-3) than trastuzumab in flow cytometry, both humH2Mab-250 and trastuzumab showed similar antibody-dependent cellular cytotoxicity (ADCC) against CHO/HER2 and the breast cancer cell lines in the presence of effector splenocytes. In addition, humH2Mab-250 exhibited significant complement-dependent cellular cytotoxicity (CDC) in CHO/HER2 and the breast cancer cell lines compared to trastuzumab. Furthermore, humH2Mab-250 possesses compatible in vivo antitumor effects against CHO/HER2 and breast cancer xenografts with trastuzumab. These findings highlight the distinct roles of ADCC and CDC in the antitumor effects of humH2Mab-250 and trastuzumab and suggest a potential direction for the clinical development of humH2Mab-250 for HER2-positive tumors.

Omission of Axillary Dissection After Neoadjuvant Systemic Treatment In Initially Node-Positive HER2-Overexpressed and Triple-Negative Breast Cancer Patients: SENATURK OTHER-NAC Study

Omission of Axillary Dissection After Neoadjuvant Systemic Treatment In Initially Node-Positive HER2-Overexpressed and Triple-Negative Breast Cancer Patients: SENATURK OTHER-NAC Study

Recent advances of antibody-drug conjugates in treating breast cancer with different HER2 status.

Despite the availability of multiple treatment options for breast cancer, challenges such as adverse events, drug resistance, and disease progression persist for patients. The identification of human epidermal growth factor receptor 2 (HER2) as an oncogenic driver in a subset of breast cancers, alongside the development of HER2-targeted therapies, has significantly improved the prognosis of HER2-amplified breast cancers. However, therapeutic options remain limited for HER2-overexpressing or HER2-negative breast cancers. In response to this gap, antibody-drug conjugates (ADCs) have emerged as a promising approach. ADCs combine the specificity of monoclonal antibodies with the cytotoxic effects of chemotherapy, which allows for the targeted delivery of a cytotoxic payload to cancer cells. ADCs have been used as adjuvant chemotherapeutic treatments and salvage therapies across various breast cancer subtypes, which have greatly improved the prognosis of breast cancer patients. Numerous ongoing clinical trials seek to optimize dosing strategies and identify patient populations that would benefit most from ADCs. This review presents an updated and comprehensive overview of emerging investigational ADCs for treating breast cancer patients with various HER2 subtypes. These ADCs are spearheading a new era in targeted cancer therapy, promising to innovate treatment paradigms for both HER2-positive and HER2-low breast cancers.

The association of BMI and subclinical myocardial dysfunction in breast cancer patients after single or dual anti-HER2 targeted therapy

BackgroundAnti-HER2 targeted therapy has significantly reduced the recurrence and death of HER2-overexpressing breast cancer patients, but might lead to cardiotoxicity. Some patients with normal myocardial function may suffer from subclinical myocardial dysfunction after anti-HER2 targeted therapy. We sought to evaluate earlier the subclinical myocardial dysfunction in breast cancer patients after single or dual anti-HER2 targeted therapy, and identify the risk factors related to subclinical myocardiotoxicity.MethodsIn our study, 40 breast cancer patients after single anti-HER2 targeted therapy, and 40 breast cancer patients after dual anti-HER2 targeted therapy were enrolled. Global longitudinal strain (GLS) was measured through echocardiography.ResultsSeven patients in single anti-HER2 therapy group and eight patients in dual anti-HER2 therapy group had GLS lower than − 18%, suggesting subclinical myocardial dysfunction, but no difference between these two groups. Furthermore, we found that increased BMI was associated with reduction of GLS in breast cancer patients after anti-HER2 targeted therapy. Increased BMI (OR 2.683; 95% CI 1.225–5.879) was a risk factor of subclinical cardiotoxicity in dual anti-HER2 targeted therapy group. In addition, the patients with BMI ≥ 25 were more prone to have subclinical myocardial dysfunction in dual anti-HER2 therapy group compared with those with BMI ≥ 25 in single anti-HER2 therapy group.ConclusionOur results indicate dual anti-HER2 therapy does not increase the risk of subclinical myocardial dysfunction for breast cancer patients, compared with single anti-HER2 therapy. Patients with BMI ≥ 25 are more prone to have subclinical cardiotoxicity after dual anti-HER2 therapy than after single anti-HER2 therapy. Weight reduction should be the major measure to prevent subclinical myocardial dysfunction for these patients.

Fluorescence Lifetime Imaging for Quantification of Targeted Drug Delivery in Varying Tumor Microenvironments.

Trastuzumab (TZM) is a monoclonal antibody that targets the human epidermal growth factor receptor 2 (HER2) and is clinically used for the treatment of HER2-positive breast tumors. However, the tumor microenvironment can limit the access of TZM to the HER2 targets across the whole tumor and thereby compromisingTZM's therapeutic efficacy. An imaging methodology that can non-invasively quantify the binding of TZM-HER2, which is required for therapeutic action, and distribution within tumors with varying tumor microenvironments is much needed. Near-infrared (NIR) fluorescence lifetime (FLI) Forster Resonance Energy Transfer (FRET) is performed to measure TZM-HER2 binding, using in vitro microscopy and in vivo widefield macroscopy, in HER2 overexpressing breast and ovarian cancer cells and tumor xenografts, respectively. Immunohistochemistry is used to validate in vivo imaging results. NIR FLI FRET in vitro microscopy data show variations in intracellular distribution of bound TZM in HER2-positive breast AU565 and AU565 tumor-passaged XTM cell lines in comparison to SKOV-3 ovarian cancer cells. Macroscopy FLI (MFLI) FRET in vivo imaging data show that SKOV-3 tumors display reduced TZM binding compared to AU565 and XTM tumors, as validated by ex vivo immunohistochemistry. Moreover, AU565/XTM and SKOV-3 tumor xenografts display different amounts and distributions of TME components, such as collagen and vascularity. Therefore, these results suggest that SKOV-3 tumors are refractory to TZM delivery due to their disrupted vasculature and increased collagen content. The study demonstrates that FLI is a powerful analytical tool to monitor the delivery of antibodydrugs both in cell cultures and in vivo live systems. Especially, MFLI FRET is a unique imaging modality that can directly quantify target engagement with the potential to elucidate the role of the TME in drug delivery efficacy in intact live tumor xenografts.

BIOM-34. INTRACRANIAL MANAGEMENT OF HER-2 OVEREXPRESSION BREAST CANCER WITH EXTENSIVE VOLUME OR SYMPTOMATIC BRAIN METASTASES

Abstract BACKGROUND HER-2 overexpression in breast cancer often leads to brain metastases, necessitating effective intracranial control strategies. This study aimed to evaluate the correlation between intracranial disease volume, symptomatic presentation, and treatment outcomes in HER-2 overexpressing breast cancer patients with brain metastases. METHODS A retrospective analysis was conducted on cases of HER-2 overexpressing breast cancer patients with brain metastases. Clinical records were reviewed to extract patient demographics, treatment modalities, and intracranial disease characteristics. Intracranial tumor burden was quantified at diagnosis and post-initial treatment. High intracranial tumor burden was defined as either total metastatic volume >15 cc, or the largest lesion >3 cm. Responses were assessed using established criteria. The correlation between intracranial disease parameters and intracranial progression-free survival (PFS) and overall survival (OS) was determined. RESULTS The study comprised 65 patients with HER-2 overexpression breast cancer and brain metastases. Symptomatic presentation was observed in 69.2% of patients at the diagnosis of brain metastases. Treatment with HER-2 target therapy alone or in combination with other modalities resulted in substantial intracranial responses, with 81.5% achieving at least a partial response at 3 months from therapy initiation. Median intracranial PFS and OS for patients with high intracranial burden were 9 and 22 months, respectively. Patients with high intracranial burden and symptomatic presentation at diagnosis demonstrated worse PFS and OS to those with lower burden and absence of symptoms (p < 0.05 for each). CONCLUSION Intracranial control in HER-2 overexpressing breast cancer patients with large volume or symptomatic brain metastases appears promising with combination with HER-2 targeted therapy and radiotherapy. Despite the varying intracranial disease burdens and symptomatic presentations, the use of HER-2 targeted therapy combined with radiotherapy demonstrates favorable intracranial responses, highlighting their potential in managing such cases.

Poly(Epsilon-Lysine) Dendrons Inhibit Proliferation in HER2-Overexpressing SKBR3 Breast Cancer Cells at Levels Higher than the Low-Expressing MDA-MB-231 Phenotype and Independently from the Presentation of HER2 Bioligands in Their Structure.

Among the known breast cancers, the subtype with HER2 receptors-overexpressing cells is associated with a poor prognosis. The adopted monoclonal antibody Trastuzumab has improved clinical outcomes, but it is associated with drug resistance and relatively high costs. The present work adopted the peptide solid-phase synthesis method to synthesise branched poly(ε-lysine) peptide dendrons with 8 branching arms integrating, at their carboxy terminal molecular root, either an arginine or the HER2 receptor-binding sequence LSYCCK or the scramble sequence CSCLYK. These dendrons were synthesised in quantities higher than 100 mg/batch and with a purity exceeding 95%. When tested with two types of breast cancer cells, the dendrons led to levels of inhibition in the HER2 receptor-overexpressing breast cancer cells (SKBR3) comparable to Trastuzumab and higher than breast cancer cells with low receptor expression (MDA-MB-231) where inhibition was more moderate. Noticeably, the presence of the amino acid sequence LSYCCK at the dendron molecular root did not appear to produce any additional inhibitory effect. This was demonstrated also when the scramble sequence CSCLYK was integrated into the dendron and by the lack of any antiproliferative effect by the control linear target sequence. The specific inhibitory effect on proliferation was finally proven by the absence of cytotoxicity and normal expression of the cell migration marker N-Cadherin. Therefore, the present study shows the potential of poly(ε-lysine) dendrons as a cost-effective alternative to Trastuzumab in the treatment of HER2-positive breast cancer.

Is Autophagy Targeting a Valid Adjuvant Strategy in Conjunction with Tyrosine Kinase Inhibitors?

Tyrosine kinase inhibitors (TKIs) represent a relatively large class of small-molecule inhibitors that compete with ATP for the catalytic binding site of tyrosine kinase proteins. While TKIs have demonstrated effectiveness in the treatment of multiple malignancies, including chronic myelogenous leukemia, gastrointestinal tumors, non-small cell lung cancers, and HER2-overexpressing breast cancers, as is almost always the case with anti-neoplastic agents, the development of resistance often imposes a limit on drug efficacy. One common survival response utilized by tumor cells to ensure their survival in response to different stressors, including anti-neoplastic drugs, is that of autophagy. The autophagic machinery in response to TKIs in multiple tumor models has largely been shown to be cytoprotective in nature, although there are a number of cases where autophagy has demonstrated a cytotoxic function. In this review, we provide an overview of the literature examining the role that autophagy plays in response to TKIs in different preclinical tumor model systems in an effort to determine whether autophagy suppression or modulation could be an effective adjuvant strategy to increase efficiency and/or overcome resistance to TKIs.

The DNA repair pathway as a therapeutic target to synergize with trastuzumab deruxtecan in HER2-targeted antibody–drug conjugate–resistant HER2-overexpressing breast cancer

BackgroundAnti-HER2 therapies, including the HER2 antibody–drug conjugates (ADCs) trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd), have led to improved survival outcomes in patients with HER2-overexpressing (HER2+) metastatic breast cancer. However, intrinsic or acquired resistance to anti-HER2–based therapies remains a clinical challenge in these patients, as there is no standard of care following disease progression. The purpose of this study was to elucidate the mechanisms of resistance to T-DM1 and T-DXd in HER2+ BC patients and preclinical models and identify targets whose inhibition enhances the antitumor activity of T-DXd in HER2-directed ADC-resistant HER2+ breast cancer in vitro and in vivo.MethodsTargeted DNA and whole transcriptome sequencing were performed in breast cancer patient tissue samples to investigate genetic aberrations that arose after anti-HER2 therapy. We generated T-DM1 and T-DXd–resistant HER2+ breast cancer cell lines. To elucidate their resistance mechanisms and to identify potential synergistic kinase targets for enhancing the efficacy of T-DXd, we used fluorescence in situ hybridization, droplet digital PCR, Western blotting, whole-genome sequencing, cDNA microarray, and synthetic lethal kinome RNA interference screening. In addition, cell viability, colony formation, and xenograft assays were used to determine the synergistic antitumor effect of T-DXd combinations.ResultsWe found reduced HER2 expression in patients and amplified DNA repair–related genes in patients after anti-HER2 therapy. Reduced ERBB2 gene amplification in HER2-directed ADC–resistant HER2+ breast cancer cell lines was through DNA damage and epigenetic mechanisms. In HER2-directed ADC–resistant HER2+ breast cancer cell lines, our non-biased RNA interference screening identified the DNA repair pathway as a potential target within the canonical pathways to enhance the efficacy of T-DXd. We validated that the combination of T-DXd with ataxia telangiectasia and Rad3-related inhibitor, elimusertib, led to significant breast cancer cell death in vitro (P < 0.01) and in vivo (P < 0.01) compared to single agents.ConclusionsThe DNA repair pathways contribute to HER2-directed ADC resistance. Our data justify exploring the combination treatment of T-DXd with DNA repair–targeting drugs to treat HER2-directed ADC–resistant HER2+ breast cancer in clinical trials.

β2-microglobulin induced apoptosis of tumor cells via the ERK signaling pathway by directly interacting with HFE in HER2-overexpressing breast cancer

BackgroundOur previous study demonstrated that β2-microglobulin (β2M) promoted ER+/HER2– breast cancer survival via the SGK1/Bcl-2 signaling pathway. However, the role of β2M has not been investigated in ER–/HER2+ breast cancer. Here, we aimed to determine the role of β2M in ER–/HER2+ breast cancer.MethodsThe interaction between β2M and HFE was confirmed by co-immunoprecipitation, mass spectrometry, yeast two-hybrid screening, and His pull-down. The knockdown and overexpression of β2M or HFE were performed in MDA-MB-453 cells, and ERK signaling pathway was subsequently analyzed via western blotting. Apoptotic cells were detected using flow cytometer. β2M, HFE, and p-ERK1/2 were examined in tumor and paired adjacent tissues via immunohistochemistry.ResultsHFE was found to be an interacting protein of β2M in ER–/HER2+ breast cancer cells MDA-MB-453 by co-immunoprecipitation and mass spectrometry. A yeast two-hybrid system and His-pull down experiments verified that β2M directly interacted with HFE. β2M and HFE as a complex were mainly located in the cytoplasm, with some on the cytomembrane of MDA-MB-453 cells. In addition to breast cancer cells BT474, endogenous β2M directly interacted with HFE in breast cancer cells MDA-MB-453, MDA-MB-231, and MCF-7. β2M activated the ERK signaling pathway by interacting with HFE and induced apoptosis of MDA-MB-453 cells. The expression of HFE and p-ERK1/2 showed significantly high levels in HER2-overexpressing breast cancer tumor tissue compared with adjacent normal tissue, consistent with the results obtained from the cell experiments.Conclusionsβ2M induced apoptosis of tumor cells via activation of the ERK signal pathway by directly interacting with HFE in HER2-overexpressing breast cancer.

Targeted therapies in HER2-positive breast cancer with receptor-redirected Arazyme-linker-Herceptin as a novel fusion protein.

Targeted treatment of different types of cancers through highly expressed cancer cell surface receptors by fusion proteins is an efficient method for cancer therapy. The HER2 receptor is a member of the tyrosine kinase receptors family, which plays a notable role in breast cancer tumor development. About 25-30% of breast cancers overexpress human epidermal growth factor receptor 2 (HER2). In this study, we evaluated the particulars of a designed recombinant protein formed by HER2-specific Mab Herceptin linked with Arazyme on a HER2-overexpressing breast cancer cell line (SKBR3). Arazyme, a metalloprotease produced by Serratia proteamaculans was fused to the variable area of light and heavy chains of the Herceptin. The cytotoxic assay of the Arazyme-linker-Herceptin in the SKBR3 and MDA-MB-468 cells was evaluated by the MTT and flow cytometry techniques. The Caspase‑3 activity determination and adhesion assay were performed to evaluate the antitumor activity of the Arazyme-linker-Herceptin against SKBR3 cells. Furthermore, RT-PCR was used to measure the expression levels of the Bcl-2, Bax, MMP2, MMP9, and RIP3 genes. The Arazyme-linker-Herceptin showed higher cytotoxicity in SKBR3 cells compared to MDA-MB-468 cells. In addition, flow cytometry results revealed that the Arazyme-linker-Herceptin can significantly induce apoptosis in the HER2-overexpressing breast cancer cell line (SKBR3), which was confirmed by Bax upregulation and the decrease in adhesion of tumor cells and MMP2/MMP9. The findings of this study demonstrated that the Arazyme-linker-Herceptin induced apoptosis and decreased metastatic genes in SKBR3 cells; however, further research is required to confirm the effectiveness of the fusion protein.

Enhanced anti-tumor effects by combination of tucatinib and radiation in HER2-overexpressing human cancer cell lines

BackgroundTucatinib (TUC), a HER2-directed tyrosine kinase inhibitor, is the first targeted drug demonstrating intracranial efficacy and significantly prolonged survival in metastatic HER2-positive breast cancer (BC) patients with brain metastases. Current treatments for brain metastases often include radiotherapy, but little is known about the effects of combination treatment with TUC. Therefore, we examined the combined effects of irradiation and TUC in human HER2-overexpressing BC, non-small cell lung cancer (NSCLC), and colorectal cancer (CRC) cell lines. For the latter two, a standard therapy successfully targeting HER2 is yet to be established.MethodsNine HER2-overexpressing (BC: BT474, ZR7530, HCC1954; CRC: LS411N, DLD1, COLO201; NSCLC: DV90, NCI-H1781) and three control cell lines (BC: MCF7, HCC38; NSCLC: NCI-H2030) were examined. WST-1 assay (metabolic activity), BrdU ELISA (proliferation), γH2AX assay (DNA double-strand breaks (DSB), Annexin V assay (apoptosis), and clonogenic assay (clonogenicity) were performed after treatment with TUC and/or irradiation (IR). The relevance of the treatment sequence was analyzed exemplarily.ResultsIn BC, combinatorial treatment with TUC and IR significantly decreased metabolic activity, cell proliferation, clonogenicity and enhanced apoptotis compared to IR alone, whereby cell line-specific differences occurred. In the PI3KCA-mutated HCC1954 cell line, addition of alpelisib (ALP) further decreased clonogenicity. TUC delayed the repair of IR-induced DNA damage but did not induce DSB itself. Investigation of treatment sequence indicated a benefit of IR before TUC versus IR after TUC. Also in CRC and NSCLC, the combination led to a stronger inhibition of metabolic activity, proliferation, and clonogenic survival (only in NSCLC) than IR alone, whereby about 10-fold higher concentrations of TUC had to be applied than in BC to induce significant changes.ConclusionOur data indicate that combination of TUC and IR could be more effective than single treatment strategies for BC. Thereby, treatment sequence seems to be an important factor. The lower sensitivity to TUC in NSCLC and particularly in CRC (compared to BC) implicates, that tumor promotion there might be less HER2-related. Combination with inhibitors of other driver mutations may aid in overcoming partial TUC resistance. These findings are of high relevance to improve long-time prognosis especially in brain-metastasized situations given the intracranial activity of TUC.

Trends in Presentation, Management, and Survival of Women With Breast Cancer in a Multiethnic, Middle-Income Asian Setting.

Granular data on breast cancer (BC) are pertinent for surveillance, planning, and monitoring of cancer care delivery. We determined the trends in clinical presentation, management, and survival of women with BC in a multiethnic middle-income Asian setting over 15 years. Data of 7,478 Malaysian women newly diagnosed with invasive BC between 2005 and 2019 from three hospital-based cancer registries were included. Trends in demographic, tumor, and treatment characteristics were compared across period 1 (P1): 2005-2009, period 2 (P2): 2010-2014, and period 3 (P3): 2015-2019. Overall survival and net survival were determined. More women in P3 than P1 were older than 60 years at diagnosis. Only a marginal increase in proportion of women with stage I disease was observed (23.7% v 27.2% in P1 and P3, respectively, P = .004). Nonetheless, patients were increasingly presenting with smaller tumors, fewer axillary node involvement, well-differentiated tumors, and hormone receptor expression in recent times. Proportion of women with human epidermal growth factor receptor 2 (HER2)-overexpressed tumors significantly decreased. Among indicated patients, receipt of anticancer therapies was somewhat similar over the calendar periods, except for neoadjuvant chemotherapy and anti-HER2 therapy, where increases in administration were noted. Significant improvements in survival were observed over the 15 years, particularly for HER2-overexpressed BCs. Although the improvements in BC survival that we have observed validate ongoing cancer control efforts and treatment advances, study findings suggest that more could be done for earlier detection and improved access to effective therapies in our settings.

Molecular Targets of Plant-based Alkaloids and Polyphenolics in Liver and Breast Cancer- An Insight into Anticancer Drug Development.

Liver and Breast cancer are ranked as the most prevailing cancers that cause high cancer-related mortality. As cancer is a life-threatening disease that affects the human population globally, there is a need to develop novel therapies. Among the available treatment options include radiotherapy, chemotherapy, surgery, and immunotherapy. The most superlative modern method is the use of plant-derived anticancer drugs that target the cancerous cells and inhibit their proliferation. Plant-derived compounds are generally considered safer than synthetic drugs/traditional therapies and could serve as potential novel targets to treat liver and breast cancer to revolutionize cancer treatment. Alkaloids and Polyphenols have been shown to act as anticancer agents through molecular approaches. They disrupt various cellular mechanisms, inhibit the production of cyclins and CDKs to arrest the cell cycle, and activate the DNA repairing mechanism by upregulating p53, p21, and p38 expression. In severe cases, when no repair is possible, they induce apoptosis in liver and breast cancer cells by activating caspase-3, 8, and 9 and increasing the Bax/Bcl-2 ratio. They also deactivate several signaling pathways, such as PI3K/AKT/mTOR, STAT3, NF-kB, Shh, MAPK/ERK, and Wnt/β-catenin pathways, to control cancer cell progression and metastasis. The highlights of this review are the regulation of specific protein expressions that are crucial in cancer, such as in HER2 over-expressing breast cancer cells; alkaloids and polyphenols have been reported to reduce HER2 as well as MMP expression. This study reviewed more than 40 of the plant-based alkaloids and polyphenols with specific molecular targets against liver and breast cancer. Among them, Oxymatrine, Hirsutine, Piperine, Solamargine, and Brucine are currently under clinical trials by qualifying as potent anticancer agents due to lesser side effects. As a lot of research is there on anticancer compounds, there is a desideratum to compile data to move towards clinical trials phase 4 and control the prevalence of liver and breast cancer.

Intracranial management of HER-2 overexpression breast cancer with extensive volume or symptomatic brain metastases.

This study aimed to evaluate the impact of high intracranial burden and symptomatic presentation of brain metastases on treatment outcomes in patients with HER-2 positive breast cancer. Through a retrospective analysis, we explored the intracranial responses following the application of HER-2 targeted therapy alone or in combination with other modalities and further elucidated the relationship between treatment efficacy, intracranial progression-free survival (PFS), overall survival (OS), and the burden of intracranial lesions and symptomatic presentations. A retrospective analysis was conducted on cases of HER-2 overexpressing breast cancer patients with brain metastases. Clinical records were reviewed to extract patient demographics, treatment modalities, and intracranial disease characteristics. Intracranial tumor burden was quantified at diagnosis and post-initial treatment. High intracranial tumor burden was defined as either total metastatic volume >15 cc, or the largest lesion >3 cm. Responses were assessed using established criteria. The correlation between intracranial disease parameters and intracranial progression-free survival (PFS) and overall survival (OS) was determined. The study comprised 65 patients with HER-2 overexpression breast cancer and brain metastases. Symptomatic presentation was observed in 69.2% of patients at the diagnosis of brain metastases. Treatment with HER-2 target therapy alone or in combination with other modalities resulted in substantial intracranial responses, with 81.5% achieving at least a partial response at 3 months from therapy initiation. Median intracranial PFS and OS for patients with high intracranial burden were 9 and 22 months, respectively. Patients with high intracranial burden and symptomatic presentation at diagnosis demonstrated worse PFS and OS to those with lower burden and absence of symptoms (p < 0.05 for each). Her-2 overexpressing breast cancer and brain metastases face significant challenges, particularly those with high intracranial tumor burden, which correlates with poorer outcomes and higher incidence of leptomeningeal metastasis. Most patients responded positively to initial therapies, especially anti-HER-2 treatments combined with radiotherapy. Larger tumors necessitated more comprehensive treatment approaches, such as WBRT and SRS. Key factors influencing intracranial tumor control included the Ki-67 index, intracranial tumor burden, and continuous use of HER-2 targeted therapy post-diagnosis.

Disitamab vedotin, a HER2-directed antibody-drug conjugate, in patients with HER2-overexpression and HER2-low advanced breast cancer: a phase I/Ib study.

Disitamab vedotin (DV; RC48-ADC) is an antibody-drug conjugate comprising a human epidermal growth factor receptor 2 (HER2)-directed antibody, linker and monomethyl auristatin E. Preclinical studies have shown that DV demonstrated potent antitumor activity in preclinical models of breast, gastric, and ovarian cancers with different levels of HER2 expression. In this pooled analysis, we report the safety and efficacy of DV in patients with HER2-overexpression and HER2-low advanced breast cancer (ABC). In the phase I dose-escalation study (C001 CANCER), HER2-overexpression ABC patients received DV at doses of 0.5-2.5 mg/kg once every two weeks (Q2W) until unacceptable toxicity or progressive disease. The dose range, safety, and pharmacokinetics (PK) were determined. The phase Ib dose-range and expansion study (C003 CANCER) enrolled two cohorts: HER2-overexpression ABC patients receiving DV at doses of 1.5-2.5 mg/kg Q2W, with the recommended phase 2 dose (RP2D) determined, and HER2-low ABC patients receiving DV at doses of 2.0 mg/kg Q2W to explore the efficacy and safety of DV in HER2-low ABC. Twenty-four patients with HER2-overexpression ABC in C001 CANCER, 46 patients with HER2-overexpression ABC and 66 patients with HER2-low ABC in C003 CANCER were enrolled. At 2.0 mg/kg RP2D Q2W, the confirmed objective response rates were 42.9% (9/21; 95% confidence interval [CI]: 21.8%-66.0%) and 33.3% (22/66; 95% CI: 22.2%-46.0%), with median progression-free survival (PFS) of 5.7 months (95% CI: 5.3-8.4 months) and 5.1 months (95% CI: 4.1-6.6 months) for HER2-overexpression and HER2-low ABC, respectively. Common (≥5%) grade 3 or higher treatment-emergent adverse events included neutrophil count decreased (17.6%), gamma-glutamyl transferase increased (13.2%), asthenia (11.0%), white blood cell count decreased (9.6%), peripheral neuropathy such as hypoesthesia (5.9%) and neurotoxicity (0.7%), and pain (5.9%). DV demonstrated promising efficacy in HER2-overexpression and HER2-low ABC, with a favorable safety profile at 2.0 mg/kg Q2W.

Combined SERS-Raman screening of HER2-overexpressing or silenced breast cancer cell lines

BackgroundBreast cancer (BC) is a heterogeneous neoplasm characterized by several subtypes. One of the most aggressive with high metastasis rates presents overexpression of the human epidermal growth factor receptor 2 (HER2). A quantitative evaluation of HER2 levels is essential for a correct diagnosis, selection of the most appropriate therapeutic strategy and monitoring the response to therapy.ResultsIn this paper, we propose the synergistic use of SERS and Raman technologies for the identification of HER2 expressing cells and its accurate assessment. To this end, we selected SKBR3 and MDA-MB-468 breast cancer cell lines, which have the highest and lowest HER2 expression, respectively, and MCF10A, a non-tumorigenic cell line from normal breast epithelium for comparison. The combined approach provides a quantitative estimate of HER2 expression and visualization of its distribution on the membrane at single cell level, clearly identifying cancer cells. Moreover, it provides a more comprehensive picture of the investigated cells disclosing a metabolic signature represented by an elevated content of proteins and aromatic amino acids. We further support these data by silencing the HER2 gene in SKBR3 cells, using the RNA interference technology, generating stable clones further analysed with the same combined methodology. Significant changes in HER2 expression are detected at single cell level before and after HER2 silencing and the HER2 status correlates with variations of fatty acids and downstream signalling molecule contents in the context of the general metabolic rewiring occurring in cancer cells. Specifically, HER2 silencing does reduce the growth ability but not the lipid metabolism that, instead, increases, suggesting that higher fatty acids biosynthesis and metabolism can occur independently of the proliferating potential tied to HER2 overexpression.ConclusionsOur results clearly demonstrate the efficacy of the combined SERS and Raman approach to definitely pose a correct diagnosis, further supported by the data obtained by the HER2 gene silencing. Furthermore, they pave the way to a new approach to monitor the efficacy of pharmacologic treatments with the aim to tailor personalized therapies and optimize patients’ outcome.

Prognostic significance and value of further classification of lymphovascular invasion in invasive breast cancer: a retrospective observational study

PurposeTo investigate the prognostic significance of lymphovascular invasion in invasive breast cancer and the value of using specific vascular endothelial markers to further classify lymphovascular invasion.MethodsWe collected 2124 patients with invasive breast cancer who were hospitalized at the First Hospital of Dalian Medical University from 2012 to 2020. Statistical methods were used to investigate the relationship between lymphovascular invasion and clinicopathological characteristics of breast cancer, and the correlation between lymphovascular invasion on overall survival (OS) and disease-free survival (DFS) of various categories of breast cancers. Immunohistochemical staining of breast cancer samples containing lymphovascular invasion using specific vascular endothelial markers D2-40 and CD34 was used to classify lymphovascular invasion and to investigate the relationship between lymphovascular invasion and breast cancer progression.ResultsThere was a high correlation between lymphovascular invasion and T stage, N stage and nerve invasion. Survival analyses showed that patients with lymphovascular invasion, especially luminal B, triple-negative, and Her-2 overexpression breast cancer patients, had poorer OS and DFS prognosis, and that lymphovascular invasion was an independent prognostic factor affecting OS and DFS in breast cancer. The immunohistochemical staining results showed that positive D2-40 staining of lymphovascular invasion was linked to the N stage and localized recurrence of breast cancer.ConclusionLymphovascular invasion is associated with aggressive clinicopathological features and is an independent poor prognostic factor in invasive breast cancer. Breast cancer localized recurrence rate and lymph node metastases are influenced by lymphatic vessel invasion. Immunohistochemical techniques should be added to the routine diagnosis of lymphovascular invasion.

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.