scholarly journals Cytoplasmic Overexpression of HER2: A Key Factor in Colorectal Cancer

2013 ◽  
Vol 7 ◽  
pp. CMO.S10811 ◽  
Author(s):  
Erik J Blok ◽  
Peter JK Kuppen ◽  
Jeroen EM van Leeuwen ◽  
Cornelis FM Sier
Keyword(s):  
Colorectal Cancer ◽  
Significant Proportion ◽  
Growth Factor Receptor ◽  
Her2 Overexpression ◽  
Her2 Expression ◽  
Humanized Mouse ◽  
Intracellular Fraction ◽  
Key Factor ◽  
Epidermal Growth

Trastuzumab, a humanized mouse monoclonal antibody directed against HER2 (Human Epidermal Growth Factor Receptor 2), is currently a keystone in the treatment of breast cancer. Meanwhile, trastuzumab has been validated for use in other types of cancer too. But the data on HER2 expression in colorectal cancer are ambiguous, with reported overexpression of HER2 varying between zero and 84%. In this review these studies are evaluated and compared. It shows that many factors influence the determination of HER2-expression, especially of the intracellular fraction of HER2. It is concluded that although membranous overexpression of HER2 is low in colorectal cancer with only 5% of all patients being positive, a significant proportion of the patients (30%) shows cytoplasmic HER2 overexpression. The clinical impact of enhanced intracellular HER2 is not known, because the nature and origin have not completely been revealed yet. Enlightening this process could be a stepping stone towards targeting of intracellular HER2 as a treatment option.

scholarly journals Dicer increases the indication for trastuzumab treatment in gastric cancer patients via overexpression of human epidermal growth factor receptor 2

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianhua Wu ◽  
Qun Zhao ◽  
Yue Zhao ◽  
Xiaoyun Zhang ◽  
Yuan Tian ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Her2 Overexpression ◽  
Her2 Expression ◽  
Antibody Treatment ◽  
Inhibition Effect ◽  
Epidermal Growth

AbstractThe low proportion of gastric cancer (GC) patients with high HER2 expression limits the clinical application of trastuzumab, a humanized epidermal growth factor receptor 2 (HER2) antibody targeting for GC treatment. We found that Dicer was positively correlated with HER2 expression in GC tissue by immunostaining as well as induce HER2 overexpression without increasing invasiveness of GC cell. In addition, both the growth of GC referring to cell proliferation, invasion, migration and apoptosis was inhibited by Dicer overexpression. Moreover, the HER2 overexpression induced by Dicer provided more effective and additive target for trastuzumab to amplify the inhibition effect for GC cells in vitro and in vivo. Furthermore, as assessed in a subsequent experiment, calcitriol induced HER2 overexpression and amplified the inhibition effect of trastuzumab in GC cells referring to proliferation. Our finding demonstrated the calcitriol might increase indication of trastuzumab by inducing HER2 overexpression in GC patients. Dicer would be a potential target that extend the clinical indications of HER2 antibody in patients with low or negative HER2, who were not fit for HER2 antibody treatment before.

scholarly journals PI3K-driven HER2 expression is a potential therapeutic target in colorectal cancer stem cells

Gut ◽  
2021 ◽  
pp. gutjnl-2020-323553
Author(s):  
Laura Rosa Mangiapane ◽  
Annalisa Nicotra ◽  
Alice Turdo ◽  
Miriam Gaggianesi ◽  
Paola Bianca ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Stem Cells ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Cancer Stem Cells ◽  
Growth Factor Receptor ◽  
Her2 Expression ◽  
Phosphatidylinositol 3 Kinase ◽  
Epidermal Growth ◽  
Colorectal Cancer Stem Cells

ObjectiveCancer stem cells are responsible for tumour spreading and relapse. Human epidermal growth factor receptor 2 (HER2) expression is a negative prognostic factor in colorectal cancer (CRC) and a potential target in tumours carrying the gene amplification. Our aim was to define the expression of HER2 in colorectal cancer stem cells (CR-CSCs) and its possible role as therapeutic target in CRC resistant to anti- epidermal growth factor receptor (EGFR) therapy.DesignA collection of primary sphere cell cultures obtained from 60 CRC specimens was used to generate CR-CSC mouse avatars to preclinically validate therapeutic options. We also made use of the ChIP-seq analysis for transcriptional evaluation of HER2 activation and global RNA-seq to identify the mechanisms underlying therapy resistance.ResultsHere we show that in CD44v6-positive CR-CSCs, high HER2 expression levels are associated with an activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which promotes the acetylation at the regulatory elements of the Erbb2 gene. HER2 targeting in combination with phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase kinase (MEK) inhibitors induces CR-CSC death and regression of tumour xenografts, including those carrying Kras and Pik3ca mutation. Requirement for the triple targeting is due to the presence of cancer-associated fibroblasts, which release cytokines able to confer CR-CSC resistance to PI3K/AKT inhibitors. In contrast, targeting of PI3K/AKT as monotherapy is sufficient to kill liver-disseminating CR-CSCs in a model of adjuvant therapy.ConclusionsWhile PI3K targeting kills liver-colonising CR-CSCs, the concomitant inhibition of PI3K, HER2 and MEK is required to induce regression of tumours resistant to anti-EGFR therapies. These data may provide a rationale for designing clinical trials in the adjuvant and metastatic setting.

scholarly journals The Prognostic Impact of HER2 Genetic and Protein Expression in Pancreatic Carcinoma—HER2 Protein and Gene in Pancreatic Cancer

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 653
Author(s):  
Song-Hee Han ◽  
Ki Hyun Ryu ◽  
Ah-Young Kwon
Keyword(s):  
Protein Expression ◽  
Genetic Heterogeneity ◽  
Growth Factor Receptor ◽  
Ductal Adenocarcinoma ◽  
Prognostic Impact ◽  
Her2 Expression ◽  
Her2 Protein ◽  
Epidermal Growth ◽  
Her2 Heterogeneity

Pancreatic ductal adenocarcinoma (PDAC) is a lethal and clinically heterogeneous disease with a limited benefit from human epidermal growth factor receptor 2 (HER2)-targeted therapy. Recently, some studies have addressed the antitumoral effect of novel anti-HER2 drugs in HER2 low-expressing tumors. However, there have been few studies on the significance of low HER2 expression and genetic heterogeneity in PDAC. Using immunohistochemistry and dual-color silver-enhanced in situ hybridization based on the Trastuzumab for a gastric cancer scoring scheme, we evaluated HER2 protein expression, gene amplification, and genetic heterogeneity in three groups (HER2-neg, HER2-low, HER2-pos) of 55 patients. Among the 55 cases, 41.8% (23/55) showed HER2 expression of any intensity. HER2 amplification independent of HER2 expression was 25.5% (14/55). Patients in both these groups had a shorter overall survival than did patients in the HER2-neg group. HER2 genetic heterogeneity was identified in 37 (70.9%) of the 55 cases, mainly in HER2-neg and HER2-low groups. HER2 genetic heterogeneity significantly correlated with worse survival in the HER2-low and HER2-neg groups of PDAC. These findings support the hypothesis that low-level HER2 expression and heterogeneity have significant clinical implications in PDAC. HER2 heterogeneity might indicate the best strategies of combination therapies to prevent the development of subdominant clones with resistance potential.

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