RESUMO
Background:Overexpression/amplification of the HER2 gene in advanced gastric cancer is a predictor of response to adjuvant therapy with monoclonal antibodies.Aim: To determine the frequency of HER2 gene overexpression and amplificationin advanced gastric cancer. Material and Methods: One hundred nine advancedgastric cancer biopsy specimens, from 76 men and 33 women aged 67 ± 14 and 62± 12 years respectively, were selected. Three histological patterns (diffuse, intestinaland mixed) were recognized. Automated immunohistochemistry was performedwith monoclonal c-erbB-2 (NCL-356) Novocastra. Fluorescent in situ hybridization (FISH) for HER2 was performed in positive cases. Results: In 39% of cases,immunohistochemical staining was negative. It was 1+, 2+ and 3+ positive in 15,36 and 11% of cases, respectively. It was positive in 16% and 3% of intestinal typeand mixed carcinomas, respectively. It was negative in all diffuse carcinomas. FISHwas performed in 39 (2 +) cases and in 11 (3 +) cases. The gene amplification waspositive in two (2 +) and 11 (3 +) cases (11.9%). The overall concordance betweenimmunohistochemical staining and in situ hybridization was 85%. Conclusions: Inadvanced gastric cancer, HER2 gene overexpression or amplification was observed in11% and 12% of cases, respectively.
Assuntos
Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adenocarcinoma/genética , Amplificação de Genes/genética , /genética , Neoplasias Gástricas/genética , Adenocarcinoma/patologia , Expressão Gênica , Hibridização in Situ Fluorescente , Neoplasias Gástricas/patologia , Análise Serial de TecidosRESUMO
Overexpression of HER2 correlates with more aggressive tumors and increased resistance to cancer chemotherapy. However, a functional comparison between the HER2high/HER3 and the HER2low/HER3 dimers on tumor metastasis has not been conducted. Herein we examined the regulation mechanism of heregulin-beta1 (HRG)-induced MMP-1 and -9 expression in breast cancer cell lines. Our results showed that the basal levels of MMP-1 and -9 mRNA and protein expression were increased by HRG treatment. In addition, HRG-induced MMP-1 and -9 expression was significantly decreased by MEK1/2 inhibitor, U0126 but not by phosphatidylinositol 3-kinase (PI-3K) inhibitor, LY294002. To confirm the role of MEK/ERK pathway on HRG-induced MMP-1 and -9 expression, MCF7 cells were transfected with constitutively active adenoviral-MEK (CA-MEK). The level of MMP-1 and -9 expressions was increased by CA-MEK. MMP-1 and -9 mRNA and protein expressions in response to HRG were higher in HER2 overexpressed cells than in vector alone. The phosphorylation of HER2, HER3, ERK, Akt, and JNK were also significantly increased in HER2 overexpressed MCF7 cells compared with vector alone. HRG-induced MMP-1 and -9 expressions were significantly decreased by lapatinib, which inhibits HER1 and HER2 activity, in both vector alone and HER2 overexpressed MCF7 cells. Finally, HRG-induced MMP-1 and MMP-9 expression was decreased by HER3 siRNA overexpression. Taken together, we suggested that HRG-induced MMP-1 and MMP-9 expression is mediated through HER3 dependent pathway and highly expressed HER2 may be associated with more aggressive metastasis than the low expressed HER2 in breast cancer cells.
Assuntos
Feminino , Humanos , Neoplasias da Mama/enzimologia , Butadienos/farmacologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases , Células MCF-7 , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Neuregulina-1/farmacologia , Nitrilas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Multimerização Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quinazolinas/farmacologia , Receptor ErbB-2/genética , Receptor ErbB-3/metabolismoRESUMO
BACKGROUND: The human epidermal growth factor receptor 2 (HER2) is amplified in 20-25% of breast cancers. HER2 overexpression or amplification is associated with a worse clinical outcome and it can predict the benefit from anthracycline and anti-HER2 therapies. The HER2 status has usually been assessed by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) in clinical samples. A new silver-enhanced in situ hybridization (SISH) technique was recently introduced. Therefore we evaluated the usefulness of SISH for detecting HER2 amplification. METHODS: Tissue microarrays (TMAs) were constructed with 144 invasive breast cancer tissue samples. We performed IHC, FISH and SISH for HER2 on the tissue sections from the TMAs and we interpreted the results according to the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines. The concordant rates between the two different tests were calculated. RESULTS: HER2 was overexpressed and amplified in 16.9%, 16.9%, and 18% of the cases by IHC, FISH and SISH, respectively. The concordant rates between IHC and FISH, IHC and SISH, and FISH and SISH were 95.1%, 95.7%, and 97.8%, respectively. CONCLUSIONS: SISH can be an alternative test for evaluating HER2 amplification because the 97.8% concordance with FISH satisfies the ASCO/CAP requirement of > 95% concordance with an alternative validated method.