Disrupting EGFR-HER2 Transactivation by Pertuzumab in HER2-Positive Cancer: Quantitative Analysis Reveals EGFR Signal Input as Potential Predictor of Therapeutic Outcome.

Pertuzumab (Perjeta®), a humanized antibody binding to the dimerization arm of HER2 (Human epidermal growth factor receptor-2), has failed as a monotherapy agent in HER2 overexpressing malignancies. Since the molecular interaction of HER2 with ligand-bound EGFR (epidermal growth factor receptor) has been implied in mitogenic signaling and malignant proliferation, we hypothesized that this interaction, rather than HER2 expression and oligomerization alone, could be a potential molecular target and predictor of the efficacy of pertuzumab treatment. Therefore, we investigated static and dynamic interactions between HER2 and EGFR molecules upon EGF stimulus in the presence and absence of pertuzumab in HER2+ EGFR+ SK-BR-3 breast tumor cells using Förster resonance energy transfer (FRET) microscopy and fluorescence correlation and cross-correlation spectroscopy (FCS/FCCS). The consequential activation of signaling and changes in cell proliferation were measured by Western blotting and MTT assay. The autocorrelation functions of HER2 diffusion were best fitted by a three-component model corrected for triplet formation, and among these components the slowly diffusing membrane component revealed aggregation induced by EGFR ligand binding, as evidenced by photon-counting histograms and co-diffusing fractions. This aggregation has efficiently been prevented by pertuzumab treatment, which also inhibited the post-stimulus interaction of EGFR and HER2, as monitored by changes in FRET efficiency. Overall, the data demonstrated that pertuzumab, by hindering post-stimulus interaction between EGFR and HER2, inhibits EGFR-evoked HER2 aggregation and phosphorylation and leads to a dose-dependent decrease in cell proliferation, particularly when higher amounts of EGF are present. Consequently, we propose that EGFR expression on HER2-positive tumors could be taken into consideration as a potential biomarker when predicting the outcome of pertuzumab treatment.

Combination of STAT3 inhibitor with Herceptin reduced immune checkpoints expression and provoked anti-breast cancer immunity: An in vitro study.

Breast cancer (BC) is the most prevalent diagnosed cancer among women. Herceptin blocks the effects of Her-2 and tumour cell growth. Despite many achievements using Herceptin in Her-2+ invasive BC treatment, there are treatment failures and resistances. The signal transducer and activator of transcription 3 (STAT3) is persistently activated in BC and is associated with immune suppression and tumour cell proliferation. We evaluated whether STAT3 inhibition could increase Herceptin impact on in vitro reduction of immune checkpoint inhibitors and polarize T cells to a protective immune response. We treated SK-BR-3 cells with Herceptin and the STAT3-inhibitor (FLLL32) and assessed the apoptosis and expression of apoptosis-related proteins, VEGF, Her-2 and apoptosis targets of STAT3. PBMCs were isolated from healthy donors and co-cultured with SK-BR-3 cells in the presence or absence of Herceptin and FLLL32. PD-L1, CTLA-4, TIM-3 and T-cell intracellular cytokines were then evaluated. Our results demonstrated that STAT3 inhibition and Herceptin increased SK-BR-3 cell apoptosis, significantly. STAT3 inhibition through combination treatment had a more significant effect on regulating PD-1, TIM-3 and CTLA-4 expression on PBMCs. Alternatively, the combination of FLLL32 and Herceptin promoted T helper-1 protective immune response. The combination of FLLL32 and Herceptin suppress the expression of immune checkpoints and provoke the T-helper1 immune response in lymphocytes. Our analysis indicates STAT3 as a promising target that improves Herceptin's role in breast cancer cell apoptosis.

Stability of trastuzumab during nanomedicine formulation using SEC-HPLC coupled with polyacrylamide gel electrophoresis.

The anti-HER2 antibody trastuzumab has been proven to be an effective targeting ligand for drug delivery. This study investigates the structural integrity of trastuzumab under different stress factors in formulation development and its long-term stability. A validated size exclusion high performance liquid chromatographic (SEC-HPLC) method was first developed. The stability of trastuzumab (0.21-21 mg/ml) under stress conditions (mechanical, freeze-and-thaw, pH and temperature) and long-term storage in the presence of formulation excipients were monitored for up to 12 months, using both the SEC-HPLC method and sodium-dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The anti-proliferation activity of the reconstituted antibody stored at 4 °C against HER2+ BT-474 breast cells was also monitored over 12 months. The developed SEC-HPLC method was sensitive and accurate. Solutions of trastuzumab were resistant to mechanical stress and repeated freeze-and-thaw; but were unstable under acidic (pH 2.0 and 4.0) and alkaline (pH 10.0 and 12.0) environments. The samples degraded over 5 days at 60 °C, and within 24 h at 75 °C. Low temperature (-80 °C or 4 °C) and low concentration (0.21 mg/ml) favoured the long-term stability. The anti-proliferation activity was conserved at 4 °C for at least 12 months. This study provided valuable stability information in developing trastuzumab involved nano-formulation as well as in clinical settings.

The multitargeted receptor tyrosine kinase inhibitor sunitinib induces resistance of HER2 positive breast cancer cells to trastuzumab-mediated ADCC.

Despite recent advances in the development of novel personalized therapies, breast cancer continues to challenge physicians with resistance to various advanced therapies. The anticancer action of the anti-HER2 antibody, trastuzumab, involves antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer (NK) cells. Here, we report a repurposing screen of 774 clinically used compounds on NK-cell + trastuzumab-induced killing of JIMT-1 breast cancer cells. Using a calcein-based high-content screening (HCS) assay for the image-based quantitation of ADCC that we have developed and optimized for this purpose, we have found that the multitargeted tyrosine kinase inhibitor sunitinib inhibits ADCC in this model. The cytoprotective effect of sunitinib was also confirmed with two other assays (lactate dehydrogenase release, and electric cell substrate impedance sensing, ECIS). The drug suppressed NK cell activation as indicated by reduced granzyme B deposition on to the target cells and inhibition of interferon-γ production by the NK cells. Moreover, sunitinib induced downregulation of HER2 on the target cells' surface, changed the morphology and increased adherence of the target cells. Moreover, sunitinib also triggered the autophagy pathway (speckled LC3b) as an additional potential underlying mechanism of the cytoprotective effect of the drug. Sunitinib-induced ADCC resistance has been confirmed in a 3D tumor model revealing the prevention of apoptotic cell death (Annexin V staining) in JIMT-1 spheroids co-incubated with NK cells and trastuzumab. In summary, our HCS assay may be suitable for the facile identification of ADCC boosting compounds. Our data urge caution concerning potential combinations of ADCC-based immunotherapies and sunitinib.

A pharmacokinetic study to comparatively evaluate the bioequivalence and safety of a humanized recombinant monoclonal antibody targeting human epidermal growth factor receptor-2 with the reference Herceptin in healthy Chinese subjects.

PURPOSE: This study aimed to compare the safety, tolerability, pharmacokinetics (PK), and bioequivalence of a test humanized recombinant monoclonal antibody targeting human epidermal growth factor receptor-2 (HER-2) with the reference Herceptin®. MATERIALS AND METHODS: The trial consisted of two parts (part I and part II). Part I was an open-label, sequential-cohort dose-escalation study, where 16 healthy subjects were either intravenously infused with QLHER2 (test) at single doses escalating from 0.2 to 6 mg/kg (0.2, 1, 2, 4, and 6 mg/kg) or given 4 mg/kg Herceptin (reference) for evaluating the safety, tolerability, and PK of QLHER2. Part II was a randomized, double-blind, parallel-group study to evaluate the bioequivalence of QLHER2 and Herceptin in 60 subjects. RESULTS: Following a 1.5-h intravenous infusion of single ascending doses of QLHER2 (1, 2, 4, or 6 mg/kg) in part I, Cmax and Tmax were 19.43-120.01 µg/mL and 68.91-157.87 h, respectively. AUC0-t and CL were 1.91-34.21 h·µg/mL and 0.54-0.12 mL/h/kg, indicating lower clearance at higher doses, with a greater than proportional increase in AUC0-t and t1/2 of 68.91-157.87 h. In part II, serum concentrations were comparable between QLHER2 and Herceptin over a 70-day sampling period, and the QLHER2/Herceptin ratios of Cmax and AUC0-t were 105.90% [90% confidence interval (CI): 95.69%-117.26%] and 95.79% (90% CI: 87.74%-106.40%), respectively. CONCLUSION: The 90% CI value of Cmax and AUC0-t for QLHER2/Herceptin ratio ranged between 80.0%-125.00%, indicating that QLHER2 was bioequivalent to Herceptin. These results support further evaluation of QLHER2. Trial registration number: ChiCTR2000041577 and ChiCTR2100041802. Date of registration: 30th December, 2020 and 5th January 2021.

Trastuzumab biosimilars vs trastuzumab originator in the treatment of HER2-positive breast cancer: a systematic review and network meta-analysis.

AIM: Breast cancer is the most frequently diagnosed cancer in women and ranks second among causes for cancer related death in women. Trastuzumab originator (Herceptin) is a monoclonal antibody used as a standard treatment for breast and metastatic gastric cancer when the cancer cells over-express human epidermal growth factor receptor type 2 (HER2). As the patent of Trastuzumab has now expired, biosimilars are moving into the market. It is still controversial to chose which trastuzumab biosimilar has the best treatment of HER2-positive breast cancer patients. We conducted this network meta-analysis to explore the best trastuzumab biosimilar in the treatment of HER2-positive breast cancer patients. METHODS: PubMed, Cochrane library databases, China National Knowledge infrastructure (CNKI) and WanFang database up to November 2021 were systematically searched. The following search terms were used: 'trastuzumab originator', and 'trastuzumab biosimilar'. No language restriction was imposed. The reference lists of all retrieved articles were also reviewed to identify additional articles missed by using these search terms. RESULTS: We got 10 studies to conduct network meta-analysis to evaluate efficacy and serious adverse reactions among various trastuzumab biosimilars and trastuzumab originator. The overall response rate (ORR) and pathological complete response (pCR) of SB3 were worse than trastuzumab originator significantly, while the ORR and pCR of other trastuzumab biosimilars had not yet reached statistical differences compared with each other. The cumulative ranking curve (SUCRA) probability indicated that the ORR from best to worst was CT-P6, Herceptin, HLX02, PF-05280014, R-TPR-016, BCD-022, MYL-1401O, SB3, and the pCR from best to worst was PF-05280014, CT-P6, Herceptin, ABP-980, SB3. The serious adverse events (SAEs) of CT-P6 were more than Herceptin and MYL-1401O significantly, while the SAEs of other trastuzumab biosimilars had not statistical differences. The SUCRA probability indicated that the SAEs from best to worst was MYL-1401O, Herceptin, PF-05280014, SB3, HLX02, BCD-22, CT-P6. CONCLUSION: There was no statistical difference in both ORR and pCR of various trastuzumab biosimilars and Herceptin except SB3. The ORR and pCR of SB3 were worse than Herceptin. Both CT-P6 and PF-05280014 are better in the overall curative effect, but CT-P6 had the highest serious adverse reactions when compared with others. The PF-05280014 might be a better trastuzumab biosimilar in the treatment of HER2-positive breast cancer patients.

Mass Spectrometry-Based De Novo Sequencing of Monoclonal Antibodies Using Multiple Proteases and a Dual Fragmentation Scheme.

Antibody sequence information is crucial to understanding the structural basis for antigen binding and enables the use of antibodies as therapeutics and research tools. Here, we demonstrate a method for direct de novo sequencing of monoclonal IgG from the purified antibody products. The method uses a panel of multiple complementary proteases to generate suitable peptides for de novo sequencing by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in a bottom-up fashion. Furthermore, we apply a dual fragmentation scheme, using both stepped high-energy collision dissociation (stepped HCD) and electron-transfer high-energy collision dissociation (EThcD), on all peptide precursors. The method achieves full sequence coverage of the monoclonal antibody herceptin, with an accuracy of 99% in the variable regions. We applied the method to sequence the widely used anti-FLAG-M2 mouse monoclonal antibody, which we successfully validated by remodeling a high-resolution crystal structure of the Fab and demonstrating binding to a FLAG-tagged target protein in Western blot analysis. The method thus offers robust and reliable sequences of monoclonal antibodies.

Trastuzumab-induced cardiotoxicity: a review of clinical risk factors, pharmacologic prevention, and cardiotoxicity of other HER2-directed therapies.

PURPOSE: Despite great success as a targeted breast cancer therapy, trastuzumab use may be complicated by heart failure and loss of left ventricular contractile function. This review summarizes the risk factors, imaging, and prevention of cardiotoxicity associated with trastuzumab and other HER2-targeted therapies. FINDINGS: Cardiovascular disease risk factors, advanced age, and previous anthracycline treatment predispose to trastuzumab-induced cardiotoxicity (TIC), with anthracycline exposure being the most significant risk factor. Cardiac biomarkers such as troponins and pro-BNP and imaging assessments such as echocardiogram before and during trastuzumab therapy may help in early identification of TIC. Initiation of beta-adrenergic antagonists and angiotensin converting enzyme inhibitors may prevent TIC. Cardiotoxicity rates of other HER2-targeted treatments, such as pertuzumab, T-DM1, lapatinib, neratinib, tucatinib, trastuzumab deruxtecan, and margetuximab, appear to be significantly lower as reported in the pivotal trials which led to their approval. CONCLUSIONS: Risk assessment for TIC should include cardiac imaging assessment and should incorporate prior anthracycline use, the strongest risk factor for TIC. Screening and prediction of cardiotoxicity, referral to a cardio-oncology specialist, and initiation of effective prophylactic therapy may all improve prognosis in patients receiving HER2-directed therapy. Beta blockers and ACE inhibitors appear to mitigate risk of TIC. Anthracycline-free regimens have been proven to be efficacious in early HER2-positive breast cancer and should now be considered the standard of care for early HER2-positive breast cancer. Newer HER2-directed therapies appear to have significantly lower cardiotoxicity compared to trastuzumab, but trials are needed in patients who have experienced TIC and patients with pre-existing cardiac dysfunction.

Attaching palladium catalysts to antibodies.

Antibody-directed enzyme prodrug therapy (ADEPT) is a powerful concept in which antibody targeting is linked to enzymatic prodrug activation. The work herein describes the first steps in the development of a technology analogous to ADEPT but in which a palladium catalyst is attached of an antibody rather than an enzyme. Antibody-metal conjugates have been used in a variety of contexts including for radiotherapy; however, none of the metals attached to the antibodies have been used for catalytic purposes. This work represents the first example a metal being attached to an antibody for the purposes of carrying a functional catalyst.

In Vitro Cytotoxicity of Trastuzumab (Tz) and Se-Trastuzumab (Se-Tz) against the Her/2 Breast Cancer Cell Lines JIMT-1 and BT-474.

Her/2+ breast cancer accounts for ~25% mortality in women and overexpression of Her/2 leads to cell growth and tumor progression. Trastuzumab (Tz) with Taxane is the preferred treatment for Her/2+ patients. However, Tz responsive patients often develop resistance to Tz treatment. Herein, redox selenides (RSe-) were covalently linked to Tz using a selenium (Se)-modified Bolton-Hunter Reagent forming Seleno-Trastuzumab (Se-Tz; ~25 µgSe/mg). Se-Tz was compared to Tz and sodium selenite to assess the viability of JIMT-1 and BT-474 cells. Comparative cell viability was examined by microscopy and assessed by fluorometric/enzymatic assays. Se-Tz and selenite redox cycle producing superoxide (O2•-) are more cytotoxic to Tz resistant JIMT-1 and Tz sensitive BT-474 cells than Tz. The results of conjugating redox selenides to Tz suggest a wider application of this technology to other antibodies and targeting molecules.

CD4 T-cell immune stimulation of HER2 + breast cancer cells alters response to trastuzumab in vitro.

INTRODUCTION: The HER2 + tumor immune microenvironment is composed of macrophages, natural killer cells, and tumor infiltrating lymphocytes, which produce pro-inflammatory cytokines. Determining the effect of T-cells on HER2 + cancer cells during therapy could guide immunogenic therapies that trigger antibody-dependent cellular cytotoxicity. This study utilized longitudinal in vitro time-resolved microscopy to measure T-cell influence on trastuzumab in HER2 + breast cancer. METHODS: Fluorescently-labeled breast cancer cells (BT474, SKBR3, MDA-MB-453, and MDA-MB-231) were co-cultured with CD4 + T-cells (Jurkat cell line) and longitudinally imaged to quantify cancer cell viability when treated with or without trastuzumab (10, 25, 50 and 100 µg/mL). The presence and timing of T-cell co-culturing was manipulated to determine immune stimulation of trastuzumab-treated HER2 + breast cancer. HER2 and TNF-α expression were evaluated with western blot and ELISA, respectively. Significance was calculated using a two-tailed parametric t-test. RESULTS: The viability of HER2 + cancer cells significantly decreased when exposed to 25 µg/mL trastuzumab and T-cells, compared to cancer cells exposed to trastuzumab without T-cells (p = 0.01). The presence of T-cells significantly increased TNF-α expression in trastuzumab-treated cancer cells (p = 0.02). Conversely, cancer cells treated with TNF-α and trastuzumab had a similar decrease in viability as trastuzumab-treated cancer cells co-cultured with T-cells (p = 0.32). CONCLUSIONS: The presence of T-cells significantly increases the efficacy of targeted therapies and suggests trastuzumab may trigger immune mediated cytotoxicity. Increased TNF-α receptor expression suggest cytokines may interact with trastuzumab to create a state of enhanced response to therapy in HER2 + breast cancer, which has potential to reducing tumor burden.

Anti-HER2 induced myeloid cell alterations correspond with increasing vascular maturation in a murine model of HER2+ breast cancer.

BACKGROUND: Therapy targeted to the human epidermal growth factor receptor type 2 (HER2) is used in combination with cytotoxic therapy in treatment of HER2+ breast cancer. Trastuzumab, a monoclonal antibody that targets HER2, has been shown pre-clinically to induce vascular changes that can increase delivery of chemotherapy. To quantify the role of immune modulation in treatment-induced vascular changes, this study identifies temporal changes in myeloid cell infiltration with corresponding vascular alterations in a preclinical model of HER2+ breast cancer following trastuzumab treatment. METHODS: HER2+ tumor-bearing mice (N = 46) were treated with trastuzumab or saline. After extraction, half of each tumor was analyzed by immunophenotyping using flow cytometry. The other half was quantified by immunohistochemistry to characterize macrophage infiltration (F4/80), vascularity (CD31 and α-SMA), proliferation (Ki67) and cellularity (H&E). Additional mice (N = 10) were used to quantify differences in tumor cytokines between control and treated groups. RESULTS: Immunophenotyping showed an increase in macrophage infiltration 24 h after trastuzumab treatment (P ≤ 0.05). With continued trastuzumab treatment, the M1 macrophage population increased (P = 0.02). Increases in vessel maturation index (i.e., the ratio of α-SMA to CD31) positively correlated with increases in tumor infiltrating M1 macrophages (R = 0.33, P = 0.04). Decreases in VEGF-A and increases in inflammatory cytokines (TNF-α, IL-1ß, CCL21, CCL7, and CXCL10) were observed with continued trastuzumab treatment (P ≤ 0.05). CONCLUSIONS: Preliminary results from this study in a murine model of HER2+ breast cancer show correlations between immune modulation and vascular changes, and reveals the potential for anti-HER2 therapy to reprogram immunosuppressive components of the tumor microenvironment. The quantification of immune modulation in HER2+ breast cancer, as well as the mechanistic insight of vascular alterations after anti-HER2 treatment, represent novel contributions and warrant further assessment for potential clinical translation.

Nanoparticles Containing a Combination of a Drug and an Antibody for the Treatment of Breast Cancer Brain Metastases.

In women with human epidermal growth factor 2 (HER2)-positive breast cancer, the improved control of systemic disease with new therapies has unmasked brain metastases that historically would have remained clinically silent. The efficacy of therapeutic agents against brain metastases is limited by their inability to permeate the blood-brain and blood-tumor barriers (BBB and BTB) in therapeutic amounts. Here, we investigate the potential of mucic acid-based, targeted nanoparticles designed to transcytose the BBB/BTB to deliver a small molecule drug, camptothecin (CPT), and therapeutic antibody, Herceptin, to brain metastases in mice. Treatment with BBB-targeted combination CPT/Herceptin nanoparticles significantly inhibits tumor growth compared to free CPT/Herceptin and BBB-targeted nanoparticles carrying CPT alone. Though not as efficacious, BBB-targeted nanoparticles carrying only Herceptin also elicit considerable antitumor activity. These results demonstrate the potential of the targeted nanoparticle system for the delivery of an antibody alone or in combination with other drugs across the BBB/BTB to improve the therapeutic outcome.

Trastuzumab/Hyaluronidase-oysk: A New Option for Patients With HER2-Positive Breast Cancer.

OBJECTIVE: To assess the use of subcutaneous trastuzumab/hyaluronidase-oysk (SQ trastuzumab) in comparison to intravenous (IV) trastuzumab. DATA SOURCES: A comprehensive PubMed literature search was performed from August 2012 to August 2019 using search terms Herceptin Hylecta, trastuzumab, hyaluronidase, subcutaneous, preference, safety, efficacy, and cost. STUDY SELECTION & DATA EXTRACTION: English-language clinical trials focusing on SQ trastuzumab were evaluated. DATA SYNTHESIS: In phase III trials, adverse event (AE) rates ranged from 64% to 97.6% of patients receiving SQ trastuzumab in 3 studies compared to 94.6% of patients receiving IV trastuzumab. In the phase III trial comparing SQ trastuzumab to IV trastuzumab, six-year overall survival (OS) was 84% in both groups. In pharmacokinetic analyses, trough concentrations and AUC0-21 were slightly higher in patients receiving SQ trastuzumab and differences were larger at the extremes of body weight. Two pharmacoeconomic analyses reported cost-savings associated with a 52-week treatment cycle of trastuzumab of $2,090 USD and $4,600 USD. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: Food and Drug Administration (FDA)-approved in February 2019, SQ trastuzumab, a monoclonal antibody that binds to human epidermal growth factor receptor 2 (HER2) protein in combination with hyaluronidase, offers an alternative dosage form for patients with breast tumors overexpressing HER2. CONCLUSIONS: SQ trastuzumab has a similar safety profile to IV trastuzumab. Although it may be slightly more cost-effective, its role in the treatment of HER2-overexpressing tumors requires further study in those at the extremes of body weight due to differences in drug exposure compared to IV trastuzumab.

mRNA Delivery for Therapeutic Anti-HER2 Antibody Expression In Vivo.

Antibody-based drugs are a leading class of biologics used to treat a variety of diseases, including cancer. However, wide antibody implementation is hindered by manufacturing challenges and high production cost. Use of in-vitro-transcribed mRNA (IVT-mRNA) for endogenous protein expression has the potential to circumvent many of the shortcomings of antibody production and therapeutic application. Here, we describe the development of an IVT-mRNA system for in vivo delivery of a humanized anti-HER2 (also known as ERBB2) antibody, trastuzumab, and demonstrate its anticancer activity. We engineered the IVT-mRNA sequence to maximize expression, then formulated the IVT-mRNA into lipid-based nanoparticles (LNPs) to protect the mRNA from degradation and enable efficient in vivo delivery. Systemic delivery of the optimized IVT-mRNA loaded into LNPs resulted in antibody serum concentrations of 45 ± 8.6 µg/mL for 14 days after LNP injection. Further studies demonstrated an improved pharmacokinetic profile of the produced protein compared to injection of trastuzumab protein. Finally, treatment of tumor-bearing mice with trastuzumab IVT-mRNA LNPs selectively reduced the volume of HER2-positive tumors and improved animal survival. Taken together, the results of our study demonstrate that using IVT-mRNA LNPs to express full-size therapeutic antibodies in the liver can provide an effective strategy for cancer treatment and offers an alternative to protein administration.

Living with the dilemma of the treatment for human epidermal growth factor receptor 2-positive breast cancer and the risk of incident heart disease: A qualitative investigation of patients' experiences.

OBJECTIVE: Herceptin treatment improves survival and reduces the risk of recurrence in human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Yet, it increases women's risk of developing burdensome cardiovascular complications. This study examines how women experience living with HER2-positive breast cancer and the risk of incident heart disease. METHODS: Danish women with breast cancer (n = 12; aged 32-75) participated in semi-structured interviews. Themes were deducted using interpretative phenomenological analysis (IPA). RESULTS: Women described breast cancer as having strong associations with death, whereas heart disease to them meant decreased physical functioning or "something fixable." MUGA scans of the heart during the treatment course made them feel safe, and generally, they did not worry about risk of heart disease. Coping strategies included the following: focus on the good aspects of herceptin and acceptance of risk of heart disease as the price to pay to survive. The two most predominant coping strategies used were information and avoidance. CONCLUSION: The women's focus on cancer as the primary disease seems partly to be the result of a complex coping process, by which they dealt with the dilemma of weighing risks, where the risk of dying from breast cancer was perceived as the biggest risk.

hsa_circ_0000520 influences herceptin resistance in gastric cancer cells through PI3K-Akt signaling pathway.

BACKGROUND: To investigate whether hsa_circ_0000520 affects Herceptin resistance in gastric cancer by regulating the PI3K-AKT signaling. METHODS: The expression of hsa_circ_0000520 was detected by qRT-PCR in gastric cancer tissues and cell lines. A Herceptin-resistant gastric cancer cell was established. PcDNA and pcDNA-hsa_circ_0000520 were transfected into NCI-N87R cells and treated with Herceptin at a concentration of 10 µg/mL for 24 hours. MTT tested cell proliferation, and apoptosis was measured by flow cytometry. IGF-1 treatment was used to activate PI3K-Akt signaling. The expression levels of related proteins were detected. RESULTS: The expression of hsa_circ_0000520 was reduced in gastric cancer tissues and cell lines, and hsa_circ_0000520 in NCI-N87R cells was significantly lower than that of NCI-N87 cells. Compared with the CON group, the cell viability of the Herceptin group was significantly reduced, the apoptosis rate was significantly increased, the level of Bax protein was significantly increased, and the levels of Bcl-2, p-PI3K, and p-Akt protein were significantly reduced. Compared with the Herceptin + pcDNA group, the cell viability of the Herceptin + hsa_circ_0000520 group was significantly reduced, the apoptosis rate was significantly increased, the level of Bax protein was significantly increased, and the levels of p-PI3K and p-Akt proteins were significantly reduced. After IGF-1 treatment, the cell viability was significantly increased, the apoptosis rate was significantly reduced, the level of Bax protein was significantly reduced, and the level of Bcl-2 protein was significantly increased. CONCLUSION: Hsa_circ_0000520 overexpression may reverse the Herceptin resistance of gastric cancer cells by inhibiting the PI3K-Akt signaling pathway.

Expression and In Vitro Function of Anti-Breast Cancer Llama-Based Single Domain Antibody VHH Expressed in Tobacco Plants.

Overexpression of human epidermal growth factor receptor type 2 (HER2) is considered as a prognostic factor of breast cancer, which is positively associated with recurrence when cancer metastasizes to the lymph nodes. Here, we expressed the single variable domain on a heavy chain (VHH) form of anti-HER2 camelid single domain antibody in tobacco plants and compared its in vitro anticancer activities with the anti-HER2 full size antibody. The gene expression cassette containing anti-HER2 camelid single domain antibody VHH fused to human IgG Fc region with KDEL endoplasmic reticulum (ER) (VHH-FcK) was transferred into the tobacco plant via the Agrobacterium-mediated transformation. The transformants were screened with polymerase chain reaction and Western blot analyses. Enzyme-linked immunosorbent assay (ELISA) confirmed the binding of the purified anti-HER2 VHH-FcK to the HER2-positive breast cancer cell line, SK-BR-3. Migration assay results confirmed anticancer activity of the plant-derived anticancer camelid single chain antibody. Taken together, we confirmed the possibility of using anti-HER2 VHH-FcK as a therapeutic anticancer agent, which can be expressed and assembled and purified from a plant expression system as an alternative antibody production system.

Herceptin-decorated paclitaxel-loaded poly(lactide-co-glycolide) nanobubbles: ultrasound-facilitated release and targeted accumulation in breast cancers.

Ultrasound can promote the drug release from drug-loaded substances and alter the tumor local microenvironment to facilitate the transport of drug carriers into the tumor tissues. Based on the altered tumor microenvironment, nanobubbles (NBs) as drug carriers with surfaces functionalized with targeting ligands can reach the tumor sites, thereby increasing the efficacy of chemotherapy. Herein, paclitaxel (PTX)-loaded poly(lactide-co-glycolide) (PLGA) NBs are prepared as drug carriers with covalently conjugated herceptin (anti-HER2 monoclonal antibody) on the surface to guide the target. The effect of ultrasound on the drug release and targeting of the herceptin-conjugated drug-loaded nanobubbles (PTX-NBs-HER) on the cancerous cells is determined. The use of ultrasound significantly improves the cell targeting capability in vitro, and efficiency of enhanced permeability and retention in vivo. The combination of PTX-NBs-HER and ultrasound facilitates the release of PTX, as well as the uptake and cell apoptosis in vitro. The in vivo application of both PTX-NBs-HER and ultrasound enhances the PTX targeting and accumulation in breast cancers while reducing the transmission and distribution of PTX in healthy organs. The combination of ultrasound with PTX-NBs-HER as contrast agents and drug carriers affords an image-guided drug delivery system for the precise targeted therapy of tumors.

Optimal duration of adjuvant trastuzumab in treatment of early breast cancer: a meta-analysis of randomized controlled trials.

BACKGROUND: One year of adjuvant trastuzumab, chosen empirically, improves survival of women with early-stage, Human Epidermal Growth Factor Receptor 2 (HER2) positive breast cancer. Two years of trastuzumab does not improve efficacy but increases cost, inconvenience, and adverse effects. We aimed to evaluate if less than 1 year of adjuvant trastuzumab retained efficacy while reducing toxicities and cost. METHODS: We performed a pooled analyses of efficacy and toxicity from Randomized Controlled Trials (RCTs) comparing 1 year of trastuzumab to shorter durations in adjuvant treatment of HER2-positive breast cancer. Hazard Ratios (HR) for Overall Survival (OS) and Disease-Free Survival (DFS), and Odds Ratios (OR) for cardiac events with respective 95% Confidence Intervals (CI) were weighted using generic inverse variance approach and pooled in meta-analyses using random effects models with RevMan 5.3 software. Sub-group analyses of outcomes based on Estrogen Receptor (ER) and nodal status were performed. RESULTS: Five RCTs involving approximately 12,000 patients qualified-three assessing 6 months and two assessing 9 weeks of trastuzumab compared to 1 year. All RCTs were designed to test non-inferiority of the shorter treatment. One year of trastuzumab resulted into better OS (pooled HR 1.23, 95% CI 1.07-1.42) and DFS (pooled HR 1.21, 95% CI 1.09-1.36) in overall population, but the benefit of longer treatment was statistically insignificant in node negative (HR 1. 20, p = 0.11), and ER positive disease (HR 1.15, p = 0.09). Odds ratio for cardiac events was significantly higher with the longer duration (OR 2.48, p < 0.001). CONCLUSION: One year of trastuzumab for adjuvant treatment of breast cancer improves outcomes compared to shorter treatments in overall population. Cardiotoxicity is increased with the longer treatment.