HER2-positive Cancer Research Articles

MOUNTAINEER:open-label, phase II study of tucatinib combined with trastuzumab for HER2-positive metastatic colorectal cancer (SGNTUC-017, trial in progress).

TPS153 Background: The clinical benefit of approved therapies in patients (pts) with metastatic colorectal cancer (mCRC) who progress on first- and second-line chemotherapy (FOLFOX and FOLFIRI) is limited. In pts with chemotherapy-refractory RAS wild type mCRC, antibodies targeting EGFR offer a monotherapy response rate of approximately 20% and a progression-free survival (PFS) of 4 months (Price 2014). HER2 is a validated target in gastric and breast cancers, with HER2 amplification occurring in ~3–5% of pts with mCRC. Tucatinib (TUC), recently approved for HER2+ metastatic breast cancer, is a tyrosine kinase inhibitor (TKI) highly selective for HER2 with minimal inhibition of EGFR. In pt-derived xenograft models of HER2+ mCRC, the combination of TUC + trastuzumab (TRAS) showed significantly greater antitumor activity compared with either agent alone (Kulukian 2020). The MOUNTAINEER trial was initiated to evaluate the efficacy and safety of TUC in combination with TRAS in pts with HER2+ RAS wild-type mCRC. Interim analysis of the initial 26 pts enrolled in MOUNTAINEER demonstrated an objective response rate (ORR) of 52.2% (12 partial responses [PRs] in 23 evaluable pts), median duration of response of 10.4 months, with a median PFS of 8.1 months and a median overall survival (OS) of 18.7 months (Strickler 2019). Based on these results, the trial was expanded to enable better estimation of ORR and safety. Methods: MOUNTAINEER (NCT03043313) is an open-label, pivotal phase 2 trial that initially consisted of a single cohort of up to 45 pts (Cohort A) treated with TUC (300 mg BID) and TRAS (8 mg/kg IV followed by 6 mg/kg IV every 3 weeks). The trial was expanded to include an additional 70 pts randomized 4:3 into 2 cohorts: Cohort B (N = 40) who will receive TUC + TRAS, and Cohort C (N = 30) who will receive TUC monotherapy. Pts in Cohort C will be treated with TUC (300 mg orally twice daily) with the option to crossover to TUC + TRAS if an objective response is not achieved by 12 weeks, or if progressive disease develops at any time. Eligible pts have RAS wild-type and HER2+ mCRC, and must have previously received regimens that include fluoropyrimidines, oxaliplatin, irinotecan, anti-VEGF therapy, and an anti-PD-1 if the tumor has dMMR proteins or is MSI-H. Pts who have received prior HER2-directed therapies are not eligible. Additionally, pts must have measurable disease and ECOG PS of 0 to 2. The primary endpoint of this trial is confirmed ORR (per RECIST v1.1) in Cohorts A + B as assessed by blinded independent central review. Secondary endpoints include duration of response, PFS, OS, and safety and tolerability. Enrollment is ongoing in the US and planned for the EU. Clinical trial information: NCT03043313.

Zanidatamab (ZW25) in HER2-positive biliary tract cancers (BTCs): Results from a phase I study.

299 Background: Treatment options are limited for patients with unresectable, locally advanced or metastatic BTCs progressing after first line treatment. Standard second line chemotherapy yields objective response rates (ORR) of < 10% and median overall survival of these patients is < 6 months. Human epidermal growth factor receptor 2 (HER2) overexpression/ amplification is observed in 5–19% of BTCs. Zanidatamab is a bispecific HER2-targeted antibody that has demonstrated durable single agent activity with good tolerability in a range of HER2-overexpressing cancers. Methods: In the expansion cohort of this phase I study (NCT02892123), the primary objective is to characterize safety and tolerability of zanidatamab and secondary objectives include evaluation of anti-tumor activity. This cohort includes BTC patients with centrally confirmed HER2 overexpression (immunohistochemistry [IHC] 3+ or IHC 2+/ fluorescence in situ hybridization [FISH]+), disease progression after standard of care therapy, and measurable disease per RECIST 1.1. Zanidatamab is administered at the previously identified recommended dose of 20 mg/kg every 2 weeks (Q2W). Tumors are assessed every 8 weeks (response confirmed at ≥ 4 weeks). Results: As of the data cutoff date (Jul 28, 2020), 20 patients (median age: 63 years [range, 42–78]) with BTC (11 gallbladder cancers, 5 intra- and 4 extra-hepatic cholangiocarcinomas) have been treated with zanidatamab. The median number of prior systemic therapies was 2.5 (range, 1–8), including five patients who had received prior HER2-targeted therapy (trastuzumab). Fourteen (70%) patients experienced zanidatamab-related adverse events (AEs), all of which were grade 1 or 2 in severity. The most common (occurring in ≥ 20%) zanidatamab-related AEs were diarrhea (n = 9) and infusion-related reactions (n = 6). A single treatment-related serious AE of grade 2 fatigue was reported in one patient. Among patients evaluable for response (n = 17), the confirmed ORR was 47% (n = 8; 95% confidence interval [CI]: 23, 72), the disease control rate was 65% (n = 11; 95% CI: 38, 86) and the median duration of response was 6.6 months (95% CI: 3.2, not estimable). Conclusions: Zanidatamab is well tolerated with promising and durable anti-tumor activity in patients with HER2 overexpressing BTC. Based on these data, zanidatamab is now being evaluated in an ongoing global Phase 2b study in patients with advanced HER2+ BTC that have progressed after treatment with a gemcitabine-containing regimen (NCT04466891). Clinical trial information: NCT02892123.

Controlling Conjugated Antibodies at the Molecular Level for Active Targeting Nanoparticles toward HER2-Positive Cancer Cells.

For active targeting nanodrug delivery systems conjugated with antibodies, both lack of control of the antibody at the molecular level and protein corona formation remarkably decreases targeting efficacy. Herein, we designed a series of silica nanoparticles toward HER2-positive breast cancer cells, with an anti-HER2 Fab-6His density ranging from 50 to 180 molecules per nanoparticle. Through the site-directed immobilization method we developed, the antigen-binding domain of anti-HER2 Fab was mostly accessible to the HER2 receptor. Both polyethylene glycol (PEG) chains and a high density of Fab were shown to suppress protein corona formation and macrophage uptake. The dependency of targeting efficacy and cytotoxicity on Fab density was shown using a series of breast cancer cell lines with different levels of the HER2 expression. The high density of Fab stimulates quick responses from HER2-positive cells. Combined with PEG chains, conjugated antibodies with a well-controlled orientation and density significantly improves delivery performance and sheds light on the design and preparation of an improved active targeting nanodrug delivery system.

Antibody-Based Targeting of Interferon-Beta-1a Mutein in HER2-Positive Cancer Enhances Antitumor Effects Through Immune Responses and Direct Cell Killing.

Type I interferon (IFN) has been approved as an anticancer agent to treat some malignancies. However, IFNs have a short in vivo half-life, systemic toxicity, and poor biophysical properties, which prevent it from being widely used for cancer therapy. This study aimed to construct recombinant IFN-β-1a mutein immunocytokines that comprise a human epidermal growth factor receptor 2 (HER2)-targeting antibody and IFN-β muteins with an additional glycosylation, which can overcome the limitation of the cytokine itself. Hence, the molecular design aims to 1) enhance productivity and biophysical properties by adding secondary glycosylation in IFN-β, 2) increase the therapeutic index of IFN-β therapy by preferential retention at the tumor by possessing high affinity for HER2-expressing cancer cells, and 3) improve the pharmacokinetics and, thus, the convenience of IFN-β administration. The yield of trastuzumab-IFN-β mutein was higher than that of trastuzumab-wild-type IFN-β in the mammalian cell culture system. Trastuzumab-IFN-β mutein showed similar IFN activity and HER2-targeting ability equivalent to that of IFN-β mutein and trastuzumab, respectively. Trastuzumab-IFN-β mutein directly inhibited the growth of HER2-positive gastric cancer cell lines and was more effective than trastuzumab or IFN-β mutein alone. Trastuzumab-IFN-β mutein and IFN-β mutein displayed enhanced immune cell-mediated cytotoxicity. Collectively, trastuzumab-IFN-β mutein may have indirect immune cell-mediated antitumor effects and direct cell growth inhibitory effects. Tumor-targeting effect of trastuzumab-IFN-β mutein was analyzed using in vivo fluorescence imaging. The accumulation of trastuzumab-IFN-β mutein was observed in HER2-positive tumors rather than other tissues except the liver. To evaluate the both direct tumor growth inhibition effect and indirect immune cell-mediated antitumor effect, we tested the effect of trastuzumab-IFN-β mutein in HER2-positive cancer xenograft models using nude mice or humanized mice. Trastuzumab-IFN-β mutein could significantly enhance tumor regression when compared with trastuzumab or IFN-β mutein. In addition, an increase in tumor-infiltrating lymphocytes was observed in the trastuzumab-IFN-β mutein-treated group, implying that the tumor-targeting IFN-β may have an enhanced antitumor effect through increased immune response. Therefore, targeting IFN-β with an anti-HER2 monoclonal antibody makes the immunocytokine more potent than either agent alone. These novel findings suggest that trastuzumab-IFN-β mutein merits clinical evaluation as a new candidate of anticancer therapeutics.

Combining Neratinib with CDK4/6, mTOR, and MEK Inhibitors in Models of HER2-positive Cancer.

Neratinib is an irreversible, pan-HER tyrosine kinase inhibitor that is FDA approved for HER2-overexpressing/amplified (HER2+) breast cancer. In this preclinical study, we explored the efficacy of neratinib in combination with inhibitors of downstream signaling in HER2+ cancers in vitro and in vivo. Cell viability, colony formation assays, and Western blotting were used to determine the effect of neratinib in vitro. In vivo efficacy was assessed with patient-derived xenografts (PDX): two breast, two colorectal, and one esophageal cancer (with HER2 mutations). Four PDXs were derived from patients who received previous HER2-targeted therapy. Proteomics were assessed through reverse phase protein arrays and network-level adaptive responses were assessed through Target Score algorithm. In HER2+ breast cancer cells, neratinib was synergistic with multiple agents, including mTOR inhibitors everolimus and sapanisertib, MEK inhibitor trametinib, CDK4/6 inhibitor palbociclib, and PI3Kα inhibitor alpelisib. We tested efficacy of neratinib with everolimus, trametinib, or palbociclib in five HER2+ PDXs. Neratinib combined with everolimus or trametinib led to a 100% increase in median event-free survival (EFS; tumor doubling time) in 25% (1/4) and 60% (3/5) of models, respectively, while neratinib with palbociclib increased EFS in all five models. Network analysis of adaptive responses demonstrated upregulation of EGFR and HER2 signaling in response to CDK4/6, mTOR, and MEK inhibition, possibly providing an explanation for the observed synergies with neratinib. Taken together, our results provide strong preclinical evidence for combining neratinib with CDK4/6, mTOR, and MEK inhibitors for the treatment of HER2+ cancer.

Invited commentary on “Neoadjuvant pertuzumab plus trastuzumab in combination with anthracycline-free chemotherapy regimen in patients with HER2 positive breast cancer: Real-world data from a single center in India”.

The article “Neoadjuvant pertuzumab plus trastuzumab in combination with anthracycline-free chemotherapy regimen in patients with HER2 positive breast cancer: Real-world data from a single center in India” have presented the experience of neoadjuvant DCPH in Indian population. Though being a small retrospective study, results from this study have provided the medical community a real-world data on Asian (in particular Indian) population.In Hong Kong, we have reviewed our prospective database. 264 primary breast cancer patients underwent neoadjuvant chemotherapy followed by definitive breast surgery in my institution from 2005 to 2015. Mean age was 48.9 years old. Mean tumor size was 44.9 mm. 58 (22%) patients had HER2 positive invasive cancer. 16 (6.1%) were stage 1, 213 (80.7%%) were stage 2, the rest were stage 3 cancers.PCR rate was observed in 29 (11%) patients after neoadjuvant chemotherapy. Amongst which, PCR rate is higher in HER2 positive breast cancers (25.9%) followed by triple negative cancers (13.3%) and then luminal cancers (5.7%). Patients with HER2 positive cancers had 70.7% reduction of breast tumor volume on sonographic measurement after anti-HER2 neoadjuvant treatment. Breast cancers with HER2 positive cancers were associated with higher PCR rate (p= 0.029). Overall rate of breast conserving surgery (BCS) increased to from 14.7% to 30.5% after neoadjuvant treatment.Neoadjuvant systemic treatment results in significant tumor shrinkage in many patients. It has expanded the indication of BCS, although BCS rate in Asia remains relatively low due to personal choice and small breast volume in the population.

The Efficacy and Safety of Additional Anti-HER2-Targeting Drugs in the Treatment of HER2-Positive Advanced Breast Cancer: A Meta-Analysis.

HER2-positive breast cancer patients account for one-fifth of the total breast cancer population. Besides, more anti-HER2-targeting drugs have appeared clinically. This study aimed to analyze the efficacy and safety of additional anti-HER2 (Human Epidermal growth Factor Receptor 2)-targeting drugs in the treatment of HER2-positive advanced breast cancers. The following databases were searched for published articles containing data on the efficacy and safety of additional anti-HER2-targeting drugs in HER2-positive advanced breast cancer from the time of their inception until December 2019: PubMed, Web of Science, EBSCO, and Cochrane library. The primary outcomes were Progression-Free Survival (PFS) and Overall Survival (OS). The additional anti-HER2-targeting drugs significantly improved the PFS (HR: 0.66, p<0.001) and OS (HR: 0.77, p<0.001) of HER2-positive advanced breast cancer patients. Regarding drug types, lapatinib was the most effective (HR: 0.53, 95% Cl: 0.39-0.67, p<0.001), followed by pertuzumab (HR: 0.72, 95% Cl: 0.55-0.89, p=0.001). Trastuzumab was the least beneficial (HR: 0.87, 95% Cl: 0.31-1.44, p=0.594). Concerning treatment regimen, first-line treatment (HR: 0.67, 95% Cl: 0.52-0.82, p<0.001) was more effective than non-first-line treatment (HR: 0.82, 95% Cl: 0.71-0.94, p=0.004). The main Adverse Events (AEs) observed were diarrhea and decreased ejection fraction. Additional anti-HER2-targeting drugs can improve long-term prognosis in HER2-positive advanced breast cancers. Besides, they are associated with fewer AEs and are tolerable. Lapatinib is the most effective drug, followed by pertuzumab, whereas trastuzumab is the least effective. Concerning treatment, we recommend the use of anti-HER2-targeting drugs in first-line therapy of HER2-positive advanced breast cancers.

Trastuzumab emtansine of the treatment of HER2-positive breast cancer with brain metatases

Patients with brain metastases of HER2-positive breast cancer (BC) is a special group of patients who are difficult to treat and have a short life expectancy. The possibilities of whole brain radiotherapy, stereotactic radiosurgery and surgery in such patients are rather limited. Trastuzumab emtansine (T-DM1) showed potential activity in this subset of patients. T-DM1 is an antibody-chemical conjugate (ADC) that delivers directly to HER2-positive cancer cells, thereby limiting damage to healthy tissue. At this point, the efficacy of trastuzumab emtansine has been demonstrated in several randomized trials as a second and subsequent lines of therapy for advanced breast cancer with a favorable toxicity profile of the drug. This article describes a clinical case of a patient with luminal B HER-2 positive breast cancer who, underwent stereotactic radiosurgery and was treated with trastuzumab emtansine as a the second line of treatment for disease progression with metastatic brain lesions after trastuzumab/pertuzumab-containing therapy. Partial regression of metastases with long-term duration of the effect was achieved treatment with trastuzumab emtazine has been being continued for 24 months. Tolerability of therapy was good: thrombocytopenia 2 degree was the main among side effects. The effect has been persisted for 2 years and the patient continues the treatment. Discussion of the results of real clinical practice with well-known studies was carried out.

PCN104 Cost-Utility MODEL of Trastuzumab Emtansine (T-DM1) in HER2-Positive, Unresectable, Locally Advanced or Metastatic Breast Cancer Previously Treated with Trastuzumab and a Taxane, Compared with Capecitabine PLUS Lapatinib, Trastuzumab PLUS Capecitabine and Capecitabine ALONE in Turkey

In Turkey, 5,930 people are affected by HER2-positive breast cancer in 2019. Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate being studied in HER2-positive cancers and it is designed to target and inhibit HER2 signaling. The aim of the cost effectiveness (CE) model is to assess the CE of T-DM1 versus: Capecitabine plus lapatinib (LapCap), trastuzumab plus capecitabine (TrastCap), capecitabine alone (Cap) and vinorelbine alone (Vin) for patients previously treated with taxane and trastuzumab in HER2-positive mBC from the perspective of Social Security Institution (national payer) in Turkey. T-DM1 is compared with all relevant mBC treatments using a partitioned survival cost effectiveness model. The model considers three health states: progression-free survival (PFS), progression (PD), and death. Transition probabilities determine the movement of patients between these health states. The model cycle length is one week. Time horizon is 7 years in the base scenario due to the progressive state of metastatic breast cancer. Discount rate of 3.5% applied for utilities & costs. The model findings validated with Probabilistic Sensitivity Analysis (PSA). The main model outcome is determined according to the incremental cost-effectiveness ratio (ICER) based on the life years gained. Base case model analysis shows an ICER of T-DM1 vs. LapCap as 165,301TRY. The results of economic comparison based on the systematic review and indirect treatment comparison show a life years gained ICER of T-DM1 vs. TrastCap as 91,412TRY, T-DM1 vs. Cap as 119,146TRY and T-DM1 vs Vin as 116,239TRY. In conclusion, trastuzumab emtansine is a cost effective option compare to a lapatinib plus capecitabine regimen. Regardless of treatment line, trastuzumab emtansine regime is cost effective compared to LapCap regimen in Turkey. Probabilistic sensitivity analysis concludes that ICER compared to LapCap is 166,057TRY which is similar to base-case.

Functionalized silk spheres selectively and effectively deliver a cytotoxic drug to targeted cancer cells in vivo

BackgroundChemotherapy is often a first-line therapeutic approach for the treatment of a wide variety of cancers. Targeted drug delivery systems (DDSs) can potentially resolve the problem of chemotherapeutic drug off-targeting effects. Herein, we examined in vivo models to determine the efficacy of Her2-targeting silk spheres (H2.1MS1) as DDSs for delivering doxorubicin (Dox) to Her2-positive and Her2-negative primary and metastatic mouse breast cancers.ResultsThe specific accumulation of H2.1MS1 spheres was demonstrated at the site of Her2-positive cancer. Dox delivered only by functionalized H2.1MS1 particles selectively inhibited Her2-positive cancer growth in primary and metastatic models. Moreover, the significant effect of the Dox dose and the frequency of treatment administration on the therapeutic efficacy was indicated. Although the control MS1 spheres accumulated in the lungs in Her2-positive metastatic breast cancer, the Dox-loaded MS1 particles did not treat cancer. Histopathological examination revealed no systemic toxicity after multiple administrations and at increased doses of Dox-loaded silk spheres. Although the studies were performed in immunocompetent mice, the H2.1MS1 silk spheres efficiently delivered the drug, which exerted a therapeutic effect.ConclusionOur results indicated that functionalized silk spheres that enable cell-specific recognition, cellular internalization, and drug release represent an efficient strategy for cancer treatment in vivo.

Targeting and imaging of HER2 overexpression tumor with a new peptide-based 68Ga-PET radiotracer

Human epidermal growth factor receptor 2 (HER2) overexpression, as a predictive biomarker, is associated with more tumor aggressiveness and worse clinical outcomes in cancer, whereas it’s accurate identification has led to the choice of effective treatments in many patients. In this study, a peptide-based PET probe (68Ga-DOTA-(Ser)3-LTVSPWY) was developed for imaging HER2 expression in tumors. The DOTA-(Ser)3-LTVSPWY was labeled with 68Ga and then was evaluated in vitro with HER2-positive SKOV-3 cell line; moreover, the in vivo biodistribution and PET/CT imaging were performed in xenografted tumor-bearing nude mice. The 68Ga-DOTA-(Ser)3-LTVSPWY displayed the high radiochemical purity greater than 95% and good stability in normal saline and human serum. The cellular binding experiments showed that the cell uptake in HER2-positive ovarian cancer cells could be effectively blocked by non-labeled peptide. The Kd and Bmax values for radiolabeled peptide were obtained at 2.5 ± 0.6 nM and (3.4 ± 0.2) × 105 sites per cell, respectively. Biodistribution study demonstrated that tumor-to-blood and tumor-to-muscle ratios were about 1.73 ± 0.36 and 3.78 ± 0.17 at 120 min after the injection of the radiolabeled peptide, respectively. Tumor imaging by PET/CT exhibited high contrast tumor image at 60 min after injection in animal models. Consequently, the results were indicative of the specific accumulation of 68Ga-DOTA-(Ser)3-LTVSPWY peptide in HER2-positive tumors and the suitability of its application as a PET probe for the diagnosis of HER2-overexpression tumor.

Delivery of Barnase to Cells in Liposomes Functionalized by Her2-Specific DARPin Module

In this work for the first time we demonstrate the possibility of ribonuclease barnase delivery to HER2-positive human cancer cells in a liposomal form. The principle of loading liposomes with ribonuclease is based on the electrostatic interaction of the protein with the inner surface of the liposomes. The specificity of liposomes to the HER2-receptor is determined by the presence of the anti-HER2-address module DARPin on the outer membrane of the liposome. It was shown that cytotoxicity specific for HER2-positive cells is determined precisely by the presence of an address HER2-specific module on the surface of liposomes, and the severity of the cytotoxic effect correlates with the level of expression of the HER2 receptor on the cell membrane.

Relationship of early tumor shrinkage and depth of response with the prognosis and treatment effect of trastuzumab combined with chemotherapy as first-line treatment in advanced gastric cancer patients with epidermal growth factor receptor 2 positive

Objective: To explore the relationship of early tumor shrinkage (ETS) and depth of response (DpR) with the prognosis and treatment effect of trastuzumab combined with chemotherapy as first-line treatment in advanced gastric cancer with epidermal growth factor receptor 2 (HER-2) positive. Methods: We retrospectively analyzed the clinical and pathological data of 23 patients with metastatic gastric adenocarcinoma diagnosed by imaging in The Second Affiliated Hospital of Zhejiang University School of Medicine from January 1st, 2008 to December 31th, 2017. Kaplan-Meier method and the log-rank test were used for the survival analysis. Cox regression was used to analyze the factors associated with prognosis. Results: The objective response rate (ORR) of the 23 patients was 43.5% and the disease control rate (DCR) was 82.6%. Univariate analysis showed the median progress-free survival (mPFS) of ETS≥20% and ETS<20% were 13.0 months and 4.5 months, respectively, with statistical significance (P<0.001). The median overall survival (mOS) of ETS≥20% and ETS<20% were 26.8 months and 10.1 months, respectively, with statistical significance (P<0.001). The median progress-free survival (mPFS) of DpR≥15% and DpR<15% were 13.0 months and 4.5 months, respectively, with statistical significance (P=0.001). The median overall survival (mOS) of DpR≥15% and DpR<15% were 26.8 months and 9.5 months, respectively, with statistical significance (P<0.001). Multivariable Cox regression analysis revealed ETS was an independent factor of PFS (P=0.030), tumor site and Eastern Cooperative Oncology Group (ECOG) score were independent factors of OS (P<0.05). Conclusion: ETS and DpR might be used to predict the treatment efficacy and prognosis of trastuzumab combined with chemotherapy as the first-line treatment of HER-2 positive gastric cancer.

USP8 Inhibitor Suppresses HER-2 Positive Gastric Cancer Cell Proliferation and Metastasis via the PI3K/AKT Signaling Pathway.

PurposeReferring to global cancer statistics, the incidence of gastric cancer (GC) was ranked sixth; however, detailed mechanisms underlying its development were not thoroughly investigated. Previous studies have reported that inhibition of ubiquitin-specific peptidase 8 (USP8) induced degradation of several receptor tyrosine kinases, such as epidermal growth factor receptor (EGFR), embryonic stem cells (ESCs), etc. Nevertheless, the regulation of HER-2 by USP8 and the molecular mechanisms controlling their role in the pathogenesis of GC remain unknown.Patients and MethodsA total of 69 patients with histologically confirmed GC were recruited to satisfy the purpose of this study. Initially, tumor samples and GC cell lines were used to detect USP8 and HER-2 levels. Next, MTT and colony formation assays were applied to analyze cell proliferation capability. Cell migration and invasion ability were examined by transwell assays. To examine related mRNA and protein expressions, Western blot assays and quantitative real-time PCR (qRT-PCR) were performed. Immunofluorescence was used to detect the effect of USP8 inhibitor on GC cells. Finally, in vivo experiments were used to examine the effect of USP8 inhibitor.ResultsPatients with USP8 high-expression tumors have shown worse overall survival while opposite results found in patients with low USP8 expressions. Regarding disease prognosis, patients with low expression of USP8 and HER-2 were performed better prognosis, whereas those with overexpression of USP8 and HER-2 shown poor prognosis. USP8 inhibitor significantly inhibited HER-2 positive cell NCI-N87 proliferation and metastasis. In addition, USP8 stabilizes HER-2, preventing it from ubiquitin proteasome-mediated degradation. In vivo studies confirmed that the USP8 inhibitor inhibited HER-2 positive cell NCI-N87 tumor growth. However, it did not affect the HER2-negative cell MGC-803. Careful investigation unraveled that the USP8 inhibitor significantly inhibited NCI-N87 cell proliferation and metastasis via phosphatidylinositol-3-kinases/protein-serine-threonine kinase (PI3K/AKT) pathway.ConclusionThe USP8 inhibited HER-2 positive GC cell proliferation and migration in vivo and in vitro and probably served as a novel potential therapeutic biomarker for HER-2 positive GC.

Development of chimeric antigen receptor-modified T cells for the treatment of esophageal cancer.

Human epidermal growth factor receptor 2 (HER2) is an overexpressed antigen in esophageal squamous cell carcinomas (ESCCs) but with limited expression levels in normal esophageal tissues. Therefore, employing the adoptive transfer of T cells genetically modified to express chimeric antigen receptor (CAR) targeting HER2 could be a promising therapeutic strategy against ESCC. Two different second-generation CAR-T cells expressing antibodies for HER2 and CD19 antigens were developed using retroviral vector transduction. The expression of HER2 antigen in ESCC tissue and cell lines was examined by immunohistochemistry and flow cytometry, respectively. The tumor killing efficacy of the CAR-T cells in mice model and ESCC cell lines and its potential for the treatment of ESCC was evaluated by determining tumor size in mice xenograft, and by crystal violet staining, MTS assay, and cytokine release. In vitro, HER2.CAR-T cells efficiently recognized and killed HER2-positive tumor cells as evidenced by the secretion of proinflammatory cytokines, interferon-γ, and interleukin 2 and by cytotoxicity assays. In vivo, intratumor injection of HER2.CAR-T cells resulted in a significant suppression of established ESCCs in a subcutaneous xenograft BALB/c nude mouse model. In contrast, the injection of CD19.CAR-T cells did not affect the tumor growth pattern. An effective HER2 CAR targeting ESCC was developed successfully. The HER2.CAR-T cell showed promising immunotherapeutic potential for the treatment of HER2-positive esophageal cancer.

Preparation and characterization of antibody-drug conjugates acting on HER2-positive cancer cells.

Two systems of antibody-drug conjugates (ADCs), noncleavable H32-DM1 and cleavable H32-VCMMAE, were developed by using different linkers and drugs attached to the anti-HER2 antibody H32, which is capable of cell internalization. Activated functional groups, including an N-hydroxysuccinimidyl (NHS) ester and a maleimide, were utilized to make the ADCs. Mass spectrometry, hydrophobic interaction chromatography, polyacrylamide gel electrophoresis, and in vitro cell assays were performed to analyze and optimize the ADCs. Several H32-VCMMAE ADCs were established with higher DARs and greater synthetic yields without compromising potency. The anticancer efficacy of H32-DM1 was 2- to 8-fold greater than that of Kadcyla®. The efficacy of H32-VCMMAE was in turn better than that of H32-DM1. The anticancer efficacy of these ADCs against N87, SK-BR-3 and BT474 cells was in the following order: H32-VCMMAE series > H32-DM1 series > Kadcyla®. The optimal DAR for H32-VCMMAE was found to be 6.6, with desirable attributes including good cell penetration, a releasable payload in cancer cells, and high potency. Our results demonstrated the potential of H32-VCMMAE as a good ADC candidate.

Monoclonal-Antibody-Templated Gold Nanoclusters for HER2 Receptors Targeted Fluorescence Imaging

HER2 receptor-specific monoclonal-antibody-templated gold nanoclusters, Herceptin-templated Au NCs (Her-Au NCs), have been successfully obtained via "green" synthesis. This strategy allows the fluorescent gold nanoclusters (Au NCs) formed in the three-dimensional structure of Herceptin without destroying the high specificity and affinity to HER2 receptors. The Her-Au NCs have been found to be superior compared to Cy3-Herceptin in the fluorescence emission (λem = 645 nm) and the photostability under high-intensity UV irradiation or long-time storage. Moreover, Her-Au NCs can achieve receptor-specific imaging without targeted modification owing to the HER2-binding ability of the Herceptin scaffold. For imaging applications, Her-Au NCs can be utilized as effective optical probes for not only fluorescence imaging of HER2-positive cancer cells but also imaging of HER2-positive tumors in vivo.

HER2-positive breast cancer that resists therapeutic drugs and ionizing radiation releases sphingomyelin-based molecules to circulating blood serum.

Breast cancer is the second most common cancer in the world based on incidence, reaching more than 2 million new cases in 2018, while continuing to increase. Invasive ductal carcinoma is the most common type of this cancer, making up approximately 70-80% of all breast cancer diagnoses. In particular, the type of breast cancer overexpressing human epidermal growth factor receptor 2 (HER2) has potential of strong proliferation, migration and invasion and early treatment is necessary. The authors identified and studied a single patient displaying complete therapeutic resistance to monoclonal anti-HER2 antibody therapy, chemotherapy and radiotherapy. A patient who exhibited resistance to postoperative adjuvant therapy after mastectomy was selected from HER2-positive breast cancer, and this patient had the grade of T4bN2aM0, Stage IIIB. The patient samples, blood serum and cancer tissue, were analyzed by metabolome and immunostaining technique, respectively. The characteristics of peripheral blood serum and solid tumor were investigated, aiming to find new serum biomarker(s) using the metabolomics technique. A correlation between the appearance of HER2-positive cancer tissue and serum concentration of the sphingomyelin family was found. In addition, HER2-positive tumor tissue in both the primary and recurrent cancer express the sphingomyelinase. These results suggest that sphingomyelins from this cancer tissue leads to therapy resistance, induction of invasion and strong proliferation.

Functionalized nanoparticles with targeted antibody to enhance imaging of breast cancer in vivo

BackgroundTargeted contrast nanoparticles for breast tumor imaging facilitates early detection and improves treatment efficacy of breast cancer. This manuscript reports the development of an epidermal growth factor receptor-2 (HER-2) specific, bi-modal, dendrimer conjugate to enhance computed tomography (CT) and magnetic resonance imaging (MRI) of HER-2-positive breast cancer. This material employs generation 5 poly(amidoamine) dendrimers, encapsulated gold nanoparticles, chelated gadolinium, and anti-human HER-2 antibody to produce the nanoparticle contrast agent.ResultsTesting in two mouse tumor models confirms this contrast agent’s ability to image HER-2 positive tumors. Intravenous injection of this nanoparticle in mice bearing HER-2 positive mammary tumors significantly enhances MRI signal intensity by ~ 20% and improves CT resolution and contrast by two-fold. Results by flow cytometry and confocal microscopy validate the specific targeting of the conjugate and its internalization in human HER-2 positive cells.ConclusionThese results demonstrate that this nanoparticle conjugate can efficiently target and image HER-2 positive tumors in vivo and provide a basis for the development of this diagnostic tool for early detection, metastatic assessment and therapeutic monitoring of HER-2 positive cancers.

Details of human epidermal growth factor receptor 2 status in 454 cases of biliary tract cancer

Human epidermal growth factor receptor 2 (HER2)-targeted therapy has improved clinical outcomes in patients with HER2-positive breast and gastric cancers, although ineffective or recurrent cases are present. One reason for this is the heterogeneity of HER2 expression in cancer cells. The aim of this study was to investigate the clinicopathological characteristics and HER2 status of patients with biliary tract cancers (BTCs). We examined HER2 protein expression by immunohistochemistry, HER2 gene amplification by fluorescence in situ hybridization, and both HER2 protein and gene levels simultaneously by gene-protein assay. Samples were collected from 454 patients who underwent surgical resection for BTCs (110 intrahepatic cholangiocarcinomas [ICC], 67 perihilar extrahepatic cholangiocarcinomas [ECC-Bp], 119 distal extrahepatic cholangiocarcinomas [ECC-Bd], 80 gallbladder carcinomas [GBC], and 79 ampullary carcinomas [AVC]). HER2 status was assessed according to the guidelines for HER2 testing in gastroesophageal adenocarcinoma. HER2-positive status was detected in 14.5% of BTCs (3.7% of ICC, 3.0% of ECC-Bp, 18.5% of ECC-Bd, 31.3% of GBC, and 16.4% of AVC). Furthermore, HER2-positivity tended to correlate with low histological grade, tumor histology, and macroscopic features in certain tumors. HER2 heterogeneity was common and highly frequent (83%) in BTC cases. Reduced HER2 protein expression in the deeper invasive areas with simultaneous dedifferentiation was frequently observed in HER2-positive cancer cells. The findings of this study suggest that a large subgroup of HER2-positive BTC cases can be considered for HER2-targeted therapy. Moreover, the HER2 status in BTCs should be determined carefully using a sensitive approach toward larger cancer tissues.