RESUMO
INTRODUCTION: Fluorescence in situ hybridization (FISH) is the standard procedure for the detection of anaplastic lymphoma receptor tyrosine kinase (ALK) rearrangement in non-small-cell lung carcinoma (NSCLC) but is expensive and time consuming. We tested three antibodies to ALK, using various detection systems, and hypothesized that ALK immunohistochemistry (IHC) may represent a cost-effective and efficient means of screening for ALK rearrangement in NSCLC. METHODS: We screened 377 stage I or II NSCLC cases in a tissue microarray by FISH and IHC (5A4 [Leica Biosystems Newcastle Ltd, Newcastle upon Tyne, UYnited Kingdom] by Nichirei's N-Histofine ALK detection kit [Nichirei Biosciences inc., Tokyo, Japan], 5A4 by Novocastra with ADVANCE [Dako Canada inc., Burlington, Ontario, Canada], D5F3 by Cell Signaling Technology with ADVANCE [Cell Signalling Technologies inc., Danvers, MA], and DAKO clone ALK1 with FLEX [Dako Canada inc., Burlington, Ontario, Canada] and ADVANCE). IHC was scored as 0, 1+, 2+, or 3+. Possibly positive or positive cases were further analyzed by IHC and FISH on whole section. RESULTS: Tissue microarray results were available on 377 cases by IHC and 273 cases by FISH. Eleven cases were positive or possibly positive by either IHC or FISH, and three cases were positive or possibly positive by both methods. Three cases were ALK-positive by FISH on whole section validation. There was no correlation between semiquantitative IHC score (1+, 2+, 3+) and ALK rearrangement by FISH. D5F3 (Cell Signaling by ADVANCE) and 5A4 (Novocastra by ADVANCE) showed the greatest combination of sensitivity (100%) and specificity (87.5% for 5A4 by Novocastra and 75% for D5F3 by Cell Signaling), and produced no false-negative results. CONCLUSIONS: IHC is a reliable screening tool for identification of ALK rearrangement in NSCLC and is antibody dependent. D5F3 (Cell Signaling) and 5A4 (Novocastra) can be used with FISH for identification of IHC-positive cases to reduce screening costs.
Assuntos
Anticorpos , Carcinoma Pulmonar de Células não Pequenas/genética , Imuno-Histoquímica , Neoplasias Pulmonares/genética , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/imunologia , Adenocarcinoma/genética , Idoso , Quinase do Linfoma Anaplásico , Carcinoma de Células Grandes/genética , Carcinoma de Células Escamosas/genética , Análise Custo-Benefício , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Rearranjo Gênico , Humanos , Imuno-Histoquímica/economia , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Análise Serial de TecidosRESUMO
Connexin proteins form gap junctions, which permit direct exchange of cytoplasmic contents between neighboring cells. Evidence indicates that gap junctional intercellular communication (GJIC) is important for maintaining homeostasis and preventing cell transformation. Furthermore, connexins may have independent functions including tumor growth suppression. Most tumors express less connexins, have reduced GJIC and have increased growth rates compared with non-tumorigenic cells. The purpose of this study was to determine whether common flavonoids, genistein and quercetin, increase connexin43 (Cx43) levels, improve GJIC and suppress growth of a metastatic human breast tumor cell line (MDA-MB-231). Quercetin (2.5, 5 microg/ml) and genistein (0.5, 2.5, 15 microg/ml) upregulated Cx43 but failed to increase GJIC. Cx43 localized to the plasma membrane following genistein treatment (2.5, 15 mug/ml). In contrast, Cx43 aggregated in the perinuclear region following quercetin treatment (0.5, 2.5, 5, 15 microg/ml). Both genistein (15 microg/ml) and quercetin (2.5, 5, 15 microg/ml) significantly reduced MDA-MB-231 cell proliferation. In summary, genistein and quercetin increase Cx43 and suppress MDA-MB-231 cell proliferation at physiologically relevant concentrations. These results demonstrate that genistein and quercetin are potential anti-breast cancer agents.