Human Epidermal Growth Factor Receptor-2 Protein Overexpression Research Articles

In vivo studies of a peptidomimetic that targets EGFR dimerization in NSCLC.

Studies related to lung cancer have shown a link between human epidermal growth factor receptor-2 (HER2) expression and poor prognosis in patients with non-small cell lung cancer (NSCLC). HER2 overexpression has been observed in 3-38% of NSCLC, while strong HER2 protein overexpression is found in 2.5% of NSCLC. However, HER2 dimerization is important in lung cancer, including EGFR mutated NSCLC. Since HER2 dimerization leads to cell proliferation, targeting the dimerization of HER2 will have a significant impact on cancer therapies. A peptidomimetic has been designed that can be used as a therapeutic agent for a subset of NSCLC patients overexpressing HER2 or possessing HER2 as well as EGFR mutation. A cyclic peptidomimetic (18) has been designed to inhibit protein-protein interactions of HER2 with its dimerization partners EGFR and HER3. Compound 18 exhibited antiproliferative activity in HER2-positive NSCLC cell lines at nanomolar concentrations. Western blot analysis showed that 18 inhibited phosphorylation of HER2 and Akt in vitro and in vivo. Stability studies of 18 at various temperature and pH (pH 1 and pH 7.6), and in the presence of liver microsomes indicated that 18 was stable against thermal and chemical degradation. Pharmacokinetic parameters were evaluated in nude mice by administrating single doses of 4 mg/kg and 6 mg/kg of 18 via IV. The anticancer activity of 18 was evaluated using an experimental metastasis lung cancer model in mice. Compound 18 suppressed the tumor growth in mice when compared to control. A proximity ligation assay further proved that 18 inhibits HER2:HER3 and EGFR: HER2 dimerization. Overall, these results suggest that 18 can be a potential treatment for HER2-dimerization related NSCLC.

HER-2 Protein Overexpression in Patients with Gastric and Oesophageal Adenocarcinoma at a Tertiary Care Facility in Ghana.

The prognosis of gastric and oesophageal adenocarcinoma remains generally poor. However, mounting evidence suggests a positive role of human epidermal growth factor receptor-2 (HER-2) expression in the prognosis of patients with these cancers. In this work, the patterns of HER-2 protein expression were determined in patients with gastric or oesophageal adenocarcinoma. Retrospectively, we reviewed records of gastric and oesophageal biopsies received from 2008 to 2012 and their corresponding archived formalin-fixed paraffin-embedded tissue blocks selected for immunohistochemical analysis. The prevalence of gastric and oesophageal adenocarcinomas and their association with HER-2 protein overexpression were evaluated. Gastric adenocarcinoma made up 18.79% of the gastric biopsies reviewed, and majority of these cancers occurred in males. Regarding the tumour type, HER-2 overexpression was common in the intestinal subtype compared to the diffuse type. Although squamous cell carcinoma was observed to be the commonest (31%) tumour type in the oesophagus compared to adenocarcinoma (8.79%), HER-2 was overexpressed in 42.9% of oesophageal adenocarcinomas, like gastric adenocarcinoma (41.4%). There is a high prevalence of gastric and oesophageal adenocarcinoma, with significant overexpression of HER-2 in these tumours, a window of hope for the management of patients with these cancers.

Human Epidermal Growth Factor Receptor-2 (HER2) expression in Gastric adenocarcinoma and relevant clinicopathological features in a cohort of Sri Lankan patients

Introduction Human epidermal growth factor receptor -2 (HER2) gene over-expression heralds adverse prognosis in gastric adenocarcinoma (GCa). HER2 protein over-expression by immunohistochemistry (IHC) ranges from 10%-22.8% and 11.7%-15.74% in Western and Asian studies respectively. We aimed to evaluate HER2 positivity in GCa by IHC and to study relevant clinicopathological relationships, as information is locally unavailable. Methodology Hundred consecutive GCa (excluding gastrooesophageal junction tumours) were recruited prospectively from the National Hospital of Sri Lanka over two years. The diagnosis was made on endoscopic biopsy/gastrectomy specimens. HER2 was assessed in paraffinized tumour using c-erB-2 oncoprotein (DAKO A0485) and Real-TM Envision system. Scores of 2+ and 3+ were considered positive, using standard HER2 expression criteria. Relationship between HER2 and clinicopathological parameters were analyzed using SPSS-21 and Chi-squared test. Results Study included 44 gastrectomies and 56 biopsies. Mean age was 61.1 years (range 32- 82). HER2 was positive in 9 (9%) GCas: 2+ in 3(5.4%) biopsies and 3(6.8%) resections, 3+ in 1(1.8%) biopsy and 2(4.5%) resections. Eight (88.9%) HER2 positive GCa occurred in =T3) (p=0.31). HER2 positive cases showed, poor differentiation (p=0.047), higher nuclear grade (p=0.029), mitotic counts >5/HPF (p=0.003), extracellular mucin (p=0.05), tumour necrosis (p=0.037), perineural invasion (p=0.002) and nodal metastasis (p=0.04) assessed only in gastric resections. Discussion and conclusion HER2 positivity with immunohistochemistry was 9% in the gastric carcinoma cohort and were associated with higher stage, adverse histological parameters and nodal metastasis in gastric resections. Adverse histological features can be used as screening features for HER2 testing in gastric carcinoma in limited resource settings.

Clinicopathological study on human epidermalgrowth factor receptor-2/neu gene amplification and protein expression in esophageal squamous cell carcinoma

Objective To investigate human epidermalgrowth factor receptor-2 (HER2)/neu gene amplification and protein expression in esophageal squamous cell carcinoma (ESCC) and to explore their clinicopathological correlations.Methods The HER2/neu gene status and protein expression in 120 cases of ESCC were evaluated by using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC).Results HER2/neu gene amplification and HER2 protein overexpression (+++) were found in 5 (4.17％) and 4 (3.33％) cases of ESCC respectively.HER2 overexpression was associated significantly with HER2/neu gene amplification.There was no correlation between the HER2/neu gene amplification or overexpression of HER2 protein and the ESCC patients' clinicopathological features.Conclusion The HER2/neu gene amplification rate and its protein overexpression rate in ESCC were low,and the role HER2/neu gene plays in ESCC still need further studies. Key words: Esophageal squamous cell carcinoma; Human epidermalgrowth factor receptor-2/neu gene; Immunohistochemistry

HER-2 gene amplification in human breast cancer without concurrent HER-2 over-expression

BackgroundTesting for human epidermal growth factor receptor-2 (HER-2) in breast cancer is performed by either immunohistochemistry (IHC) or in situ hybridization (ISH). The growth factor receptor-bound protein-7 (GRB7) gene is in close proximity to HER-2 on chromosome 17q11-12 and codes a signal transduction molecule shown to be an independent adverse marker in breast cancer.MethodsHER-2 and GRB7 protein expression from 613 frozen breast tumors was determined by Western analysis. HER-2 protein results were confirmed with IHC. Commercial HER-2 FISH was performed on a subset of tumors with multi-probe FISH used to assess the extent of HER-2 gene amplification. mRNA expression was determined by Multi-plex RT-PCR.ResultsSeven tumors with GRB7 protein over-expression scored HER-2 FISH amplified but had no HER-2 protein over-expression. Four of the 7 tumors showed elevated GRB7 but not HER-2 mRNA over-expression. The breast cancer cell line HCC3153 did not over-express HER-2 protein but showed HER-2 FISH amplification of a limited segment around the HER-2 gene. Ten breast cancer tumors from the TCGA database had gene copy number increases around HER-2 without HER-2 mRNA or protein over-expression.ConclusionsA subset of human breast cancers that test positive with FISH for HER-2 gene amplification do not over-express HER-2 protein. One mechanism for this discordance is the incomplete amplification of the smallest HER-2 region of chromosome 17q11-12, which includes GRB7. HER-2 gene amplification without protein over-expression is clinically significant because patients with such tumors are unlikely to benefit from HER-2 targeted therapy.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-386) contains supplementary material, which is available to authorized users.

Effects of polysomy 17 on HER-2 gene and protein expression and its clinicopathologic significance in breast cancer

To explore the effects of polysomy 17 on human epidermal growth factor receptor-2 (HER-2) testing and study its clinicopathologic significance. We retrospectively analyzed the HER-2 status by fluorescence in situ hybridization (FISH) and HER-2 protein expression by immunohistochemistry (IHC) in a cohort of 619 patients with invasive breast cancer. The relationship between polysomy 17 and various clinicopathologic parameters was assessed. Polysomy 17 was observed in 31.8% of cases, but more frequently in the IHC(3+) (41.9%) than in the IHC(2+)(27.7%) and IHC(1+/0) (11.1%) subgroup (P = 0.001). There was no significant correlation between the frequency of polysomy 17 and HER-2 status in each IHC subgroup (P > 0.05). Among the cases without gene amplification by FISH, 9 of 15 IHC(3+) cases showed polysomy 17. As compared with the amplified group, un-amplified polysomy 17 patients were associated with such good prognostic indicators as greater hormone receptor positivity (P < 0.001) and lower Ki-67 index (P = 0.003) with a trend towards those with neither amplification or polysomy. The frequency of polysomy 17 is partially correlated with HER-2 protein expression but not HER-2 amplification. And polysomy 17 is a major factor in strong HER-2 protein overexpression in 3+ non amplified cases. Tumors displaying un-amplified polysomy 17 resemble more HER-2-negative than HER-2-positive counterparts.

PTU-174 Systematic review and meta-analysis of the influence of human epidermal growth factor receptor 2 (HER2) expression and amplification on survival in patients with oesophageal cancer

IntroductionSurvival and recurrence rates following oesophagectomy remain poor despite the use of neoadjuvant therapy. Human epidermal growth factor receptor-2 (HER2) overexpression is associated with poorer survival in patients with gastric...

Human epidermal growth factor receptor-2 gene amplification in gastric cancer using tissue microarray technology

To assess human epidermal growth factor receptor-2 (HER2)-status in gastric cancer and matched lymph node metastases by immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH). 120 cases of primary gastric carcinomas and 45 matched lymph node metastases from patients with full clinicopathological features were mounted onto multiple-punch and single-punch tissue microarrays, respectively, and examined for HER2 overexpression and gene amplification by IHC and CISH. Twenty-four tumors (20%) expressed HER2 immunohistochemically. An IHC score of ≥ 2+ was observed in 20 tumors (16.6%). HER2 amplification was detected by CISH in 19 tumors (15.8%) and in their matched lymph node metastases. A high concordance rate was found between HER2 positivity (as detected by IHC) and HER2 gene amplification (as detected by CISH), since 19 of the 20 IHC positive cases were amplified (95%). All amplified cases had 2+ or 3+ IHC results. Amplification was associated with intestinal phenotype (P < 0.05). No association with grading, staging or survival was found. In gastric cancer, HER2 amplification is the main mechanism for HER2 protein overexpression and is preserved in lymph node metastases.

Abstract P4-08-03: False Positive HER-2 Testing by Fluorescence In Situ Hybridization in Human Breast Cancer

Abstract Background: Testing for human epidermal growth factor receptor-2 (HER-2) is routinely performed after breast cancer diagnosis by either immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). FISH is more accurate and reproducible, often considered the gold standard, and a more reliable predictor of a patient's response to HER-2 directed therapies in clinical practice. The growth factor receptor-bound protein-7 gene (GRB7) encodes a multi-domain signal transduction molecule located in close proximity to HER-2 on chromo some 17q11-12 and has been shown to be an independent adverse prognostic marker in breast cancer. Methods: We performed western blotting analysis of protein extracts from 563 annotated frozen breast tumors, collected from 1988 - 1998. GRB7 and HER-2 bands were assigned low or high values compared to specific protein controls, and tubulin bands. HER-2 FISH was performed on a subset of these tumors using an FDA approved Path Vysion kit on 4 μm frozen sections. HER-2 and chromosome 17 centromere (CEP17) signals were enumerated according to ASCO/CAP guidelines. Results: Sixty-six tumors (11.5%) over-expressed HER-2 and GRB7 proteins by Western analysis, 66 (11.5%) over-expressed HER-2 but not GRB7, and 30 (5.5%) over-expressed GRB7 but not HER-2. All 32 tumors (32/32) submitted to FISH analysis that over-expressed both HER-2 and GRB7 proteins demonstrated HER-2 gene amplification, while only one out of thirty-five (1/35) tumors that over-expressed HER-2 without GRB7 protein over-expression were HER-2 amplified. Interestingly, 7 of 28 tumors over-expressing GRB7 but not HER-2 protein were amplified for the HER-2 gene. Clinical laboratory HER-2 IHC testing confirmed the absence of HER-2 protein over-expression in all 7 of these tumors. Conclusions: Our study demonstrates that about ten percent of human breast cancers that test positive with FISH for HER-2 gene amplification do not over-express HER-2 protein, which may influence sensitivity to HER-2 directed therapy. All tumors that show false positive HER-2 gene amplification over-express GRB7 protein, suggesting the presence of GRB7 driven gene amplification in these tumors. Given that the HER-2 FISH probe contains GRB7 sequences, it is possible that HER-2 FISH false positivity may reflect GRB7 gene amplification. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-03.

Trastuzumab in gastric cancer

Trastuzumab is a fully humanised monoclonal antibody directed at the human epidermal growth factor receptor-2 (HER-2) which has been a component of standard therapy for advanced and resected HER-2-positive breast cancers for almost a decade. HER-2 over-expression, defined as HER-2 protein over-expression using immunohistochemistry scored as 3+ and/or erbB-2 amplification detected by fluorescent in situ hybridisation, was detected in 22.1% of 3807 patients with advanced gastric and oesophagogastric junction (OGJ) adenocarcinoma screened for eligibility for the phase III ToGA study. The validated scoring system for HER-2 positivity in gastric cancers differs from that recommended for breast cancer due to an increased frequency of incomplete membranous immunoreactivity and heterogeneity of HER-2 expression in gastric cancers. The highest rates of HER-2 over-expression are observed in patients with OGJ rather than gastric tumours and intestinal-type rather than diffuse or mixed histology. The international multicentre randomised phase III ToGA study assessed the addition of trastuzumab to a cisplatin plus fluoropyrimidine (FP) chemotherapy doublet for patients with HER-2-positive advanced gastric or OGJ adenocarcinoma. The investigators reported a clinically and statistically significant benefit in terms of response rate (47.3% versus 34.5%, p = 0.0017), median progression-free survival (6.7 versus 5.5 months, p = 0.0002) and median overall survival (13.8 versus 11.1 months, p = 0.0046). Trastuzumab plus FP chemotherapy is now the standard of care for patients with advanced gastric and OGJ cancers which over-express HER-2. Further research to evaluate trastuzumab delivered beyond progression, in combination with alternative first-line chemotherapy regimens, and in the perioperative and adjuvant setting is urgently needed. Additionally, research into mechanisms of resistance and strategies to overcome primary or acquired resistance to trastuzumab must now be expedited, using lessons learnt over the past decade in HER-2-positive breast cancer to maximise the benefit from this agent.

HER-2 Protein Overexpressing Breast Cancer Without Gene Amplification Shows Higher Hormone Receptor Expression Than HER-2 Protein Overexpressing Breast Cancer With Gene Amplification

Cases of breast cancer showing human epidermal growth factor receptor-2 (HER-2) protein overexpression without corresponding gene amplification have been found in immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) results. We investigated the clinicopathological characteristics of cases showing HER-2 protein overexpression breast cancer without gene amplification (IHC3+/FISH-) and compared them to cases showing HER-2 protein overexpression breast cancer with gene amplification (IHC3+/FISH+). This study was conducted on 90 patients with HER-2 IHC3+ breast cancer. The clinicopathological factors analyzed included tumor size, histological grade, nuclear grade, nodal involvement, and hormone receptor status. HER-2 IHC3+/FISH- breast cancer was found in 14 of 84 tumors (16.7%) and showed a statistically significant lower histological and nuclear grade (P = .000) and higher expression of estrogen receptors (ERs) and progesterone receptors (PRs) (P = .006) than IHC3+/FISH+ breast cancer. In conclusion, HER-2 IHC3+/FISH- breast cancer could be a subgroup showing lower histological/nuclear grade and higher expression of ERs/PRs.