Abstract 2939: Heregulin-induced resistance against HER2-targeted therapies in HER2 positive breast and gastric cancer in vitro and in vivo

ObjectiveTo monitor trastuzumab resistance and determine the underlying mechanisms for the limited response rate and rapid emergence of resistance of HER2+ metastatic gastric cancer (mGC).DesignTargeted sequencing of 416 clinically relevant genes was performed in 78 paired plasma and tissue biopsy samples to determine plasma-tissue concordance. Then, we performed longitudinal analyses of 97 serial plasma samples collected from 24 patients who were HER2+ to track the resistance during trastuzumab treatment and validated the identified candidate resistance genes.ResultsThe results from targeted sequencing-based detection of somatic copy number alterations (SCNA) of HER2 gene were highly consistent with fluorescence in situ hybridisation data, and the detected HER2 SCNA was better than plasma carcinoembryonic antigen levels at predicting tumour shrinkage and progression. Furthermore, most patients with innate trastuzumab resistance presented high HER2 SCNA during progression compared with baseline, while HER2 SCNA decreased in patients with acquired resistance. PIK3CA mutations were significantly enriched in patients with innate resistance, and ERBB2/4 genes were the most mutated genes, accounting for trastuzumab resistance in six (35.3%) and five (29.4%) patients in baseline and progression plasma, respectively. Patients with PIK3CA/R1/C3 or ERBB2/4 mutations in the baseline plasma had significantly worse progression-free survival. Additionally, mutations in NF1 contributed to trastuzumab resistance, which was further confirmed through in vitro and in vivo studies, while combined HER2 and MEK/ERK blockade overcame trastuzumab resistance.ConclusionLongitudinal circulating tumour DNA sequencing provides novel insights into gene alterations underlying trastuzumab resistance in HER2+mGC.

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Strengthening Gastric Cancer Therapy by Trastuzumab-Conjugated Nanoparticles with Simultaneous Encapsulation of Anti-MiR-21 and 5-Fluorouridine

Cellular Physiology and Biochemistry ◽

10.1159/000485955 ◽

2017 ◽

Vol 44 (6) ◽

pp. 2158-2173 ◽

Cited By ~ 12

Author(s):

Nan Hu ◽

Jun Feng Yin ◽

Ze Ji ◽

Yidong Hong ◽

Puyuan Wu ◽

...

Keyword(s):

Gastric Cancer ◽

Cellular Uptake ◽

Photoelectron Spectroscopy ◽

Growth Factor Receptor ◽

Double Emulsion ◽

Her2 Receptor ◽

Her2 Positive ◽

Antitumor Effects

Background/Aims: MicroRNA-21 is an oncogenic miR (oncomiR) frequently elevated in gastric cancer (GC). Overexpression of miR-21 decreases the sensitivity of GC cells to 5-fluorouridine (5-Fu) and trastuzumab, a humanized monoclonal antibody targeting human epidermal growth factor receptor 2 (HER2). Receptor-mediated endocytosis plays a crucial role in the delivery of biotherapeutics including anti-miRNA oligonucleotides (AMOs). This study is a continuation of earlier findings involving poly(ε-caprolactone) (PCL)-poly (ethylene glycol) (PEG) nanoparticles (PEG-PCL NPs), which were coated with trastuzumab to target GC with HER2 receptor over-expression using anti-miRNA-21 (AMO-21) and 5-Fu. Methods: HER-PEG-PCL NPs were prepared by one-step carbodiimide coupling using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAc) and Sulfo-NHS in aqueous phase. Covalent coupling of amino groups at the surface of PEG-PCL with the carboxyl groups of trastuzumab was analyzed by X-ray photoelectron spectroscopy (XPS). AMO-21/5-Fu NPs were formulated by a double-emulsion solvent evaporation technique. The cell line specificity, cellular uptake and AMO-21 delivery were investigated through the rhodamine-B-labeled 6-carboxyfluorescein (FAM)-AMO-21-PEG-PCL NPs coated with or without the antibody in both Her2-positive (NUGC4) and negative GC cells (SGC7901) visualized by fluorescence microscopy. The cytotoxicity of the HER-PEG-PCL NPs encapsulating AMO-21 was evaluated by MTT and apoptosis. Real-time reverse-transcription polymerase chain reaction (RT-PCR) was used to examine miR-21 and phosphatase and tensin homolog (PTEN) and Sprouty2 expression in GC cell lines. The antitumor effects of AMO-21/5-Fu NPs were compared with other groups in xenograft gastric cancer mice. Results: The antibody conjugates significantly enhanced the cellular uptake of NPs. The AMO-21/5-Fu NPs effectively suppressed the target miRNA expression in GC cells, which further up-regulated PTEN and Sprouty2. As a result, the sensitivity of HER2-expressing gastric cancer to trastuzumab and 5-Fu were enhanced both in vitro and in vivo. The approach enhanced the targeting by trastuzumab as well as antibody-dependent cellular cytotoxicity (ADCC) of immune effector cells Conclusions: Taken together, the results provide insight into the biological and clinical potential of targeted AMO-21 and 5-Fu co-delivery using modified trastuzumab for GC treatment.

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Establishment of esophagogastric xenografts: A model for characterizing disease heterogeneity.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.30_suppl.95 ◽

2012 ◽

Vol 30 (30_suppl) ◽

pp. 95-95

Author(s):

Yelena Yuriy Janjigian ◽

Christopher M. Gromisch ◽

Gregory Carbonetti ◽

Laura H. Tang ◽

David Paul Kelsen ◽

...

Keyword(s):

Gastric Cancer ◽

Rational Design ◽

Single Agent ◽

Cytotoxic Agents ◽

Her2 Positive ◽

Disease Heterogeneity ◽

Esophagogastric Cancer ◽

Xenograft Models

95 Background: Gastric cancer is a heterogeneous disease that may be subdivided into distinct subtypes—proximal/gastroesophageal (GE) junction, diffuse/signet ring type, and distal gastric cancer/intestinal type—based on histopathologic and anatomic criteria. Each subtype is associated with unique epidemiology and gene expression. Human epidermal growth factor receptor (HER2) is a validated treatment target in gastric cancer. For patients with metastatic disease, the available cytotoxic agents are applied indiscriminately to all disease subtypes, and with only modest success. The purpose of this study is to establish xenograft models from gastric cancer subtypes to improve our understanding of disease heterogeneity and develop therapies geared for each subtype of gastric cancer. Methods: Fresh specimens obtained from resected primary or metastatic tumors under aseptic conditions. 1 g tumor samples injected SQ into flanks of NSG mice. Xenografts established after 5 passages and maintained by serial transplantation into new mice. Cell cultures established after 5 in vitro passages; cell lines after 15 passages Results: To date, 66 tumor samples have been implanted from which 16 xenografts have been established. The table below summarizes the results. Single-agent afatinib (pan-ErbB inhibitor) demonstrated antitumor activity in an HER2-positive xenograft established from MSKCC patient’s tumor harvested from a skin metastasis. Conclusions: We have established xenograft models of gastric cancer. In vivo testing of afatinib showed a reduction of tumor growth of HER2-positive gastric cancer. These models provide a platform to study potential therapeutics for esophagogastric cancer to further validate difference in their biology and guide rational design of clinical trials. [Table: see text]

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Positron emission tomography (PET) with 89Zr-labeled trastuzumab (89Zr-trastuzumab): Monitoring HER2 expression in HER2-positive gastric cancer in vivo.

Journal of Clinical Oncology ◽

10.1200/jco.2011.29.4_suppl.35 ◽

2011 ◽

Vol 29 (4_suppl) ◽

pp. 35-35

Author(s):

Y. Y. Janjigian ◽

N. T. Villegas ◽

J. P. Holland ◽

M. A. Shah ◽

V. Divilov ◽

...

Keyword(s):

Gastric Cancer ◽

Specific Activity ◽

Gastric Cancer Cell Line ◽

In Vivo Studies ◽

In Vitro Assays ◽

Organ Distribution ◽

Her2 Positive ◽

Bibw 2992

35 Background: The ToGA study established HER2 is a target in the treatment of gastric cancer. Trastuzumab pharmacokinetics and organ distribution is varied in each patient and is heavily affected by the extent of tumor load (Oude Munnink, JCO 2010). 89Zr-trastuzumab HER2 PET can be used to image that variability and may aid in detection and staging of HER2-positive tumors. We are implementing 89Zr-radiolabeled trastuzumab PET in vivo for imaging of HER2-positive gastric cancer and for future non-invasive assessment of HER2 inhibition with a dual irreversible HER1/HER2 inhibitor, BIBW-2992. Methods: 89Zr (t1/2 = 3.17 days) was prepared via the 89Y(p,n)89Zr transmutation with high radiochemical yields (1.52±0.11 mCi/μAh) and purity (>99.99%). Trastuzumab was functionalized with the tris-hydroxamate chelate, desferrioxamine B (DFO) and radiolabeled with [89Zr]Zr-oxalate at room temperature. 89Zr-trastuzumab PET experiments in athymic nu/nu mice bearing sub-cutaneous NCI-N87 (HER2+) and/or SNU1 (HER2-) tumors were conducted. NCI-N87 gastric cancer cells were treated with BIBW-2992. Results: 89Zr-trastuzumab radiolabeling proceeded in high radiochemical yield and specific-activity of 2.82±0.05 mCi/mg. In vitro assays demonstrated >99% radiochemical purity with an immunoreactive fraction of 0.87±7. In vivo biodistribution experiments revealed high and specific uptake in HER2-positive tumors after 72 h (85.2±11.1% ID/g) with retention of activity for over 120 h. No uptake was seen in HER2-negative gastric cancer xenografts. In vitro, BIBW-2992 demonstrates dose dependent growth inhibition in the HER2+ gastric cancer cell line. Conclusions: 89Zr-trastuzumab provides quantitative and highly-specific delineation of HER2-positive gastric cancer. In vivo studies of BIBW2-2992 in gastric cancer with 89Zr-trastuzumab HER2 PET response assessment are underway. A Phase I study of 89Zr-trastuzumab PETin HER2-positive patients is to open at MSKCC imminently. No significant financial relationships to disclose.

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Apatinib exhibits synergistic effect with pyrotinib and reverses acquired pyrotinib resistance in HER2-positive gastric cancer via stem cell factor/c-kit signaling and its downstream pathways

Gastric Cancer ◽

10.1007/s10120-020-01126-9 ◽

2020 ◽

Author(s):

Beibei Su ◽

Tingting Huang ◽

Yu Jin ◽

Han Yin ◽

Hong Qiu ◽

...

Keyword(s):

Gastric Cancer ◽

Stem Cell ◽

Synergistic Effect ◽

Stem Cell Factor ◽

Her2 Positive ◽

Mapk Pathways ◽

Factor C ◽

Resistant Cells

Abstract Background Recently, progress has been made in the development of targeted therapies for human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC). However, drug resistance has severely limited the efficacy of anti-HER2 therapies. Pyrotinib is a novel pan-HER inhibitor. Although it is effective in HER2-positive GC treatment, its efficacy in combination with apatinib and associated resistance mechanisms in HER2-positive GC remains unclear. Methods In this study, the combination effects of pyrotinib and apatinib were examined in two pyrotinib-sensitive GC cells and xenografts. The RNA sequencing was used to determine the underlying mechanisms of acquired pyrotinib resistance. The role of imatinib and apatinib in reversing pyrotinib resistance was tested in pyrotinib-resistant cells and xenografts. Results Here, we reported that a combination of pyrotinib and apatinib exhibits synergistic effect in HER2-positive NCI-N87 xenografts, and showed enhanced antitumor efficacy in HER2-positive GC, both in vitro and in vivo. Moreover, up-regulation of the stem cell factor (SCF) levels, and the PI3K/AKT and MAPK pathways was associated with acquired pyrotinib resistance in HER2-positive GC. Mechanistically, we demonstrated that the activation of the SCF/c-kit signaling and its downstream PI3K/AKT and MAPK pathways mediated pyrotinib resistance by promoting cell survival and proliferation. Imatinib and apatinib augmented the sensitivity of pyrotinib-resistant cells and xenografts to pyrotinib, by blocking SCF/c-kit signaling. Conclusion These results highlight the effectiveness of pyrotinib combined with apatinib in HER2-positive GC and acquired pyrotinib resistance, thus providing a theoretical basis for new treatment methods.

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Targeting the autophagy promoted antitumor effect of T-DM1 on HER2-positive gastric cancer

Cell Death and Disease ◽

10.1038/s41419-020-03349-1 ◽

2021 ◽

Vol 12 (4) ◽

Author(s):

Jinghui Zhang ◽

Jiajun Fan ◽

Xian Zeng ◽

Mingming Nie ◽

Wei Chen ◽

...

Keyword(s):

Gastric Cancer ◽

Antitumor Effect ◽

Underlying Mechanism ◽

Immunoblot Analysis ◽

Autophagic Flux ◽

Antibody Drug Conjugate ◽

Her2 Positive ◽

Induced Apoptosis

AbstractTrastuzumab emtansine (T-DM1), an antibody-drug conjugate consisted of the HER2-targeted monoclonal antibody trastuzumab and the tubulin inhibitor emtansine, has shown potent therapeutic value in HER2-positive breast cancer (BC). However, a clinical trial indicated that T-DM1 exerts a limited effect on HER2-positive gastric cancer (GC), but the underlying mechanism is inconclusive. Our research attempted to reveal the probable mechanism and role of autophagy in T-DM1-treated HER2-positive GC. In this study, our results showed that T-DM1 induced apoptosis and exhibited potent therapeutic efficacy in HER2-positive GC cells. In addition, autophagosomes were observed by transmission electron microscopy. Autophagy was markedly activated and exhibited the three characterized gradations of autophagic flux, consisting of the formation of autophagosomes, the fusion of autophagosomes with lysosomes, and the deterioration of autophagosomes in autolysosomes. More importantly, autophagic inhibition by the suppressors 3-methyladenine (3-MA) and LY294002 significantly potentiated cytotoxicity and apoptosis in HER2-positive GC cells in vitro, while the combined use of LY294002 and T-DM1 elicited potent anti-GC efficacy in vivo. In mechanistic experiments, immunoblot analysis indicated the downregulated levels of Akt, mTOR, and P70S6K and confocal microscopy analysis clearly showed that autophagic inhibition promoted the fusion of T-DM1 molecules with lysosomes in GC cells. In conclusion, our research demonstrated that T-DM1 induced apoptosis as well as cytoprotective autophagy, and autophagic inhibition could potentiate the antitumor effect of T-DM1 on HER2-positive GC. Furthermore, autophagic inhibition might increase the fusion of T-DM1 with lysosomes, which might accelerate the release of the cytotoxic molecule emtansine from the T-DM1 conjugate. These findings highlight a promising therapeutic strategy that combines T-DM1 with an autophagy inhibitor to treat HER-positive GC more efficiently.

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From AVATAR Mice to Patients: RC48-ADC Exerted Promising Efficacy in Advanced Gastric Cancer With HER2 Expression

Frontiers in Pharmacology ◽

10.3389/fphar.2021.757994 ◽

2022 ◽

Vol 12 ◽

Author(s):

Zuhua Chen ◽

Jiajia Yuan ◽

Yingying Xu ◽

Cheng Zhang ◽

Zhongwu Li ◽

...

Keyword(s):

Gastric Cancer ◽

Antitumor Activity ◽

Antitumor Effect ◽

Dependent Manner ◽

Her2 Expression ◽

Preclinical Research ◽

Her2 Positive ◽

Pdx Models

RC48-ADC is a novel humanized antibody specific for human epidermal growth factor receptor 2 (HER2)in conjugation with a microtubule inhibitor via a cleavable linker. This study was to evaluate the antitumor activity and mechanism of RC48-ADC in gastric cancer (GC) and explore the population that may benefit from RC48-ADC treatment. Four human GC cell lines and nine patient-derived xenograft (PDX) models were exploited to evaluate the antitumor effect of RC48-ADC or trastuzumab treatment in vitro and in vivo. The expression and phosphorylation of HER2 were assessed by immunohistochemistry (IHC) staining. Critical molecules of downstream PI3K/AKT and cell cycle and apoptosis signaling pathways were detected and quantified by immunoblotting. Combined with preliminary results of preclinical research, three patients with IHC3+, IHC2+/FISH+, and IHC2+/FISH- of HER2 were enrolled to verify the efficacy of RC48-ADC treatment in advanced GC. In vitro, RC48-ADC had superior antiproliferative effects in a dose-dependent manner on GC cells, especially on HER2-positive cells. In vivo, RC48-ADC exceeded trastuzumab in GC PDX models with HER2 expression, even in models with moderate to low expression of HER2. Further exploration of mechanism showed that RC48-ADC exerted the antitumor effect by inhibiting phosphorylation of HER2, inducing G2/M phase arrest and cell apoptosis in HER2-expressed PDX models. In clinical practice, RC48-ADC had satisfactory efficacy in HER2-positive and HER2 moderately expressed GC patients and demonstrated promising efficacy in HER2-positive patients who have progressed after anti-HER2 therapy. In conclusion, RC48-ADC exerted promising antitumor activity in HER2-positive as well as score of 2+ in IHC and ISH-negative AGC patients after progression of systematic treatment.

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Interrogation of gender disparity uncovers androgen receptor as the transcriptional activator for oncogenic miR-125b in gastric cancer

Cell Death and Disease ◽

10.1038/s41419-021-03727-3 ◽

2021 ◽

Vol 12 (5) ◽

Author(s):

Ben Liu ◽

Meng Zhou ◽

Xiangchun Li ◽

Xining Zhang ◽

Qinghua Wang ◽

...

Keyword(s):

Gastric Cancer ◽

Androgen Receptor ◽

Signaling Pathway ◽

Gender Bias ◽

Gender Disparity ◽

Gene Set Enrichment Analysis ◽

Cancer Type ◽

Female Patients

AbstractThere is a male preponderance in gastric cancer (GC), which suggests a role of androgen and androgen receptor (AR). However, the mechanism of AR signaling in GC especially in female patients remains obscure. We sought to identify the AR signaling pathway that might be related to prognosis and examine the potential clinical utility of the AR antagonist for treatment. Deep learning and gene set enrichment analysis was used to identify potential critical factors associated with gender bias in GC (n = 1390). Gene expression profile analysis was performed to screen differentially expressed genes associated with AR expression in the Tianjin discovery set (n = 90) and TCGA validation set (n = 341). Predictors of survival were identified via lasso regression analyses and validated in the expanded Tianjin cohort (n = 373). In vitro and in vivo experiments were established to determine the drug effect. The GC gender bias was attributable to sex chromosome abnormalities and AR signaling dysregulation. The candidates for AR-related gene sets were screened, and AR combined with miR-125b was associated with poor prognosis, particularly among female patients. AR was confirmed to directly regulate miR-125b expression. AR-miR-125b signaling pathway inhibited apoptosis and promoted proliferation. AR antagonist, bicalutamide, exerted anti-tumor activities and induced apoptosis both in vitro and in vivo, using GC cell lines and female patient-derived xenograft (PDX) model. We have shed light on gender differences by revealing a hormone-regulated oncogenic signaling pathway in GC. Our preclinical studies suggest that AR is a potential therapeutic target for this deadly cancer type, especially in female patients.

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LncRNA UCA1 promotes development of gastric cancer via the miR-145/MYO6 axis

Cellular & Molecular Biology Letters ◽

10.1186/s11658-021-00275-8 ◽

2021 ◽

Vol 26 (1) ◽

Author(s):

An Yang ◽

Xin Liu ◽

Ping Liu ◽

Yunzhang Feng ◽

Hongbo Liu ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Proliferation ◽

Cancer Cells ◽

Cell Apoptosis ◽

Gastric Cancer Cell ◽

Gastric Cancer Cells ◽

Gastric Cancer Cell Lines ◽

Development Of Gastric Cancer

Abstract Background Long noncoding RNA (lncRNA), urothelial carcinoma-associated 1 (UCA1) is aberrantly expressed in multiple cancers and has been verified as an oncogene. However, the underlying mechanism of UCA1 in the development of gastric cancer is not fully understood. In the present study, we aimed to identify how UCA1 promotes gastric cancer development. Methods The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data were used to analyze UCA1 and myosin VI (MYO6) expression in gastric cancer. Western blot and quantitative real-time PCR (QPCR) were performed to test the expression level of the UCA1/miR-145/MYO6 axis in gastric cancer cell lines and tissues. The roles of the UCA1/miR-145/MYO6 axis in gastric cancer in vitro and in vivo were investigated by CCK-8 assay, flow cytometry, siRNAs, immunohistochemistry, and a mouse xenograft model. The targeted relationship among UCA1, miR-145, and MYO6 was predicted using LncBase Predicted v.2 and TargetScan online software, and then verified by luciferase activity assay and RNA immunoprecipitation. Results UCA1 expression was higher but miR-145 expression was lower in gastric cancer cell lines or tissues, compared to the adjacent normal cell line or normal tissues. Function analysis verified that UCA1 promoted cell proliferation and inhibited cell apoptosis in the gastric cancer cells in vitro and in vivo. Mechanistically, UCA1 could bind directly to miR-145, and MYO6 was found to be a downstream target gene of miR-145. miR-145 mimics or MYO6 siRNAs could partly reverse the effect of UCA1 on gastric cancer cells. Conclusions UCA1 accelerated cell proliferation and inhibited cell apoptosis through sponging miR-145 to upregulate MYO6 expression in gastric cancer, indicating that the UCA1/miR-145/MYO6 axis may serve as a potential therapeutic target for gastric cancer.

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Activation of MAT2A-RIP1 signaling axis reprograms monocytes in gastric cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-001364 ◽

2021 ◽

Vol 9 (2) ◽

pp. e001364

Author(s):

Yan Zhang ◽

Hui Yang ◽

Jun Zhao ◽

Ping Wan ◽

Ye Hu ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Metabolism ◽

Vital Role ◽

Methionine Metabolism ◽

Promoter Regions ◽

Normal Tissues ◽

Methionine Cycle

BackgroundThe activation of tumor-associated macrophages (TAMs) facilitates the progression of gastric cancer (GC). Cell metabolism reprogramming has been shown to play a vital role in the polarization of TAMs. However, the role of methionine metabolism in function of TAMs remains to be explored.MethodsMonocytes/macrophages were isolated from peripheral blood, tumor tissues or normal tissues from healthy donors or patients with GC. The role of methionine metabolism in the activation of TAMs was evaluated with both in vivo analyses and in vitro experiments. Pharmacological inhibition of the methionine cycle and modulation of key metabolic genes was employed, where molecular and biological analyses were performed.ResultsTAMs have increased methionine cycle activity that are mainly attributed to elevated methionine adenosyltransferase II alpha (MAT2A) levels. MAT2A modulates the activation and maintenance of the phenotype of TAMs and mediates the upregulation of RIP1 by increasing the histone H3K4 methylation (H3K4me3) at its promoter regions.ConclusionsOur data cast light on a novel mechanism by which methionine metabolism regulates the anti-inflammatory functions of monocytes in GC. MAT2A might be a potential therapeutic target for cancer cells as well as TAMs in GC.

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