RESUMO
BACKGROUND: Aberrant activation of the canonical WNT signaling is a feature of colorectal cancer (CRC). Van-Gogh-like 2 (VANGL2) belongs to the non-canonical WNT pathway whose activation inhibits canonical WNT signaling. In this study, we investigated the role of VANGL2 and its epigenetic regulation in CRC. METHODS: Van-Gogh-like 2 expression and promoter methylation after 5-aza-2'-deoxycytidine (5-aza) treatment were evaluated in CRC cells. DNA samples from 418 sporadic CRCs were tested for VANGL2 promoter methylation and microsatellite instability (MSI). Proliferation, colony formation and activation of the WNT pathway were tested in cells after VANGL2 overexpression. RESULTS: Van-Gogh-like 2 mRNA was significantly higher in 5-aza-treated RKO, LOVO and SW48, whereas no differences were found in SW480. Van-Gogh-like 2 was fully methylated in RKO, SW48, HCT116, DLD1 and Caco2; partially methylated in LOVO, LS174T and SW837; and unmethylated in SW480, SW620 and HT29. Higher expression of VANGL2 mRNA was found in the unmethylated cell lines. In CRC specimens (8.93% MSI), methylated VANGL2 was associated with MSI, higher grade, proximal colon location and BRAF mutation. Van-Gogh-like 2 overexpression in SW480 significantly decreased proliferation, colony formation and ß-catenin levels. CONCLUSION: Van-Gogh-like 2 is frequently methylated in MSI-CRCs with BRAF mutation and may act as a tumour suppressor gene, counteracting WNT/ß-catenin signaling.
Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Metilação de DNA , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Via de Sinalização Wnt , Idoso , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Células CACO-2 , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Decitabina , Feminino , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Células HCT116 , Células HT29 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Masculino , Proteínas de Membrana/biossíntese , Instabilidade de Microssatélites , Mutação , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas B-raf/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Wnt/antagonistas & inibidores , Proteínas Wnt/metabolismo , beta Catenina/antagonistas & inibidores , beta Catenina/metabolismoRESUMO
AIM: The aim of the study was to detect and compare the epidermal growth factor receptor (EGFr) content using different methods, to establish whether the quantitative detection and functional study of EGFr in colorectal cancer, using methods other than immunohistochemistry (IHC), are appropriate. METHOD: Analysis of EGFr by IHC was performed in 230 colorectal cancer patients using monoclonal anti-EGFr. Total and activated EGFr (pY1068) contents were determined in 92 patients and real-time PCR, to determine the level of EGFr messenger RNA, was carried out in 60 patients. RESULTS: There was no association between EGFr IHC groups and the mean total EGFr levels measured using ELISA. CONCLUSION: The study shows that the results of different EGFr detection methods do not correlate with each other. Hence, the real role of EGFr in colorectal cancer remains unsettled. Clinically, the receptor itself does not seem to be important and it would be better to focus on EGFr signalling in downstream pathways.
Assuntos
Biomarcadores Tumorais/análise , Neoplasias Colorretais/química , Neoplasias Colorretais/patologia , Receptores ErbB/análise , RNA Mensageiro/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
At present no reports on gene expression profiling of liver metastases from colorectal cancer are available. We identified two different signatures using Affymetrix platform: epidermal growth factor receptor pathway was upregulated in metachronous lesions, whereas the pathway mainly related to angiogenesis was in synchronous lesions. Synchronous or metachronous liver metastases could be treated differently on the basis of different molecular pathways.
Assuntos
Neoplasias Colorretais/genética , Perfilação da Expressão Gênica , Neoplasias Hepáticas/genética , Adulto , Idoso , Biomarcadores Tumorais/genética , Neoplasias Colorretais/patologia , Receptores ErbB/genética , Feminino , Humanos , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Neoplasias Primárias Múltiplas/genética , Segunda Neoplasia Primária/genéticaRESUMO
BACKGROUND: Many reports were produced on single epidermal growth factor receptor (EGFr) and cyclo-oxygenase-2 (Cox-2) evaluation using immunohistochemical techniques (IHC), but very few works considered concurrent expression of these two proteins in the light of their impact on proliferation and tumour spreading. At least three molecular pathways (EGFr, Cox-2, and APC/beta-catenin molecular cascade) may interact in this malignancy giving rise to cross talking effects on proliferation and cancer spreading. PATIENTS AND METHODS: To better detail these two latter aggressive features, we studied 205 sporadic colorectal cancer patients, comparing concurrent expression of EGFr, Cox-2, Ki-67, Cyclins D1-A, and E, with tumour spreading (budding) (BUD) and pN status. RESULTS: Our results point to a different aggressive molecular profile due to Cox-2 expression. Cox-2 High expressing cases showed a clear EGFr proliferation-promoting role. On the contrary, EGFr seems directly involved in cancer cells spreading rather than in promoting cancer proliferation in Cox-2 Low/Negative cases. CONCLUSIONS: Immunohistochemical profiling of colorectal cancer seems to be a promising approach, not only to define prognostic impact, but also to detail proliferation-related molecular interplays between EGFr and Cox-2 pathways, with these two latter proteins, at present, being the hottest pharmacological targets for colorectal cancer (CRC) chemoprevention and therapy.
Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Ciclo-Oxigenase 2/metabolismo , Receptores ErbB/metabolismo , Regulação Neoplásica da Expressão Gênica , Adulto , Idoso , Idoso de 80 Anos ou mais , Proliferação de Células , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Translocação Genética , beta Catenina/metabolismoRESUMO
Basal-like breast carcinoma is an aggressive form of breast cancer, characterized by the absence of oestrogen receptor and HER2 expression, the presence of cytokeratin 5 and epidermal growth factor receptor expression, and by the up-regulation of stem cell regulatory genes. We show here that tumour tissues expressing high levels of SLUG mRNA show a basal-like breast carcinoma phenotype and that such tumours also express high levels of stem cell-regulatory genes, ie CD133, Bmi1. Further, we show that stem/progenitor cells, isolated from ductal breast carcinoma and from normal mammary gland as mammospheres, express SLUG, CD133, and Bmi1 mRNA and show a phenotype similar to that of basal-like breast carcinoma. We also report that SLUG expression in tumour tissues correlates with that of the hypoxia survival gene carbonic anhydrase IX. In this regard, we report that the exposure of SLUG-negative/luminal-like MCF-7 cells to a hypoxic environment promotes the onset of the basal-like breast carcinoma phenotype, together with up-regulation of the SLUG gene, which in turn blunts oestrogen receptor-alpha and boosts carbonic anhydrase IX gene expression. Finally, we show that SLUG expression promotes the invasiveness of MCF-7 cells exposed to hypoxia and sustains the in vivo aggressiveness of hypoxia-selected, MCF-7-derived cells in xenografts. These data indicate that SLUG gene expression is part of a hypoxia-induced genetic programme which sets up a basal/stem cell-like, aggressive phenotype in breast cancer cells.
Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias da Mama/metabolismo , Fatores de Transcrição/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antígenos de Neoplasias/biossíntese , Antígenos de Neoplasias/genética , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Anidrase Carbônica IX , Anidrases Carbônicas/biossíntese , Anidrases Carbônicas/genética , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Hipóxia Celular/genética , Receptor alfa de Estrogênio/biossíntese , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Transplante de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Fenótipo , RNA Mensageiro/genética , RNA Neoplásico/genética , Fatores de Transcrição da Família Snail , Fatores de Transcrição/genética , Regulação para CimaRESUMO
The epidermal growth factor receptor (EGFr) is considered a major target for treatment of colorectal cancer (CRC). We found a mean EGFr content significantly lower but more activated in colonic neoplastic tissue than in paired normal mucosa. Phosphorylated (pY1068) EGFr detection in CRC may be a better tool than EGFr detection to select patients for targeted therapies.
Assuntos
Neoplasias Colorretais/metabolismo , Receptores ErbB/metabolismo , Mucosa Intestinal/metabolismo , Idoso , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , RNA Mensageiro/análise , Reto/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The presence and type of oncogenic papillomavirus (HPV) in classic warty/basaloid vulvar intraepithelial neoplasia and in differentiated vulvar intraepithelial neoplasia and keratinizing vulvar squamous cell carcinoma was investigated using three techniques, that is, histology, in situ hybridization, and PCR-ELISA. HPV typing was performed using in situ hybridization and PCR-ELISA. Differentiated vulvar intraepithelial neoplasia and invasive keratinizing vulvar squamous cell carcinoma proved completely negative for HPV by PCR-ELISA, in situ hybridization, and histologic examination, while in classic vulvar intraepithelial neoplasia, a HPV positivity of 66.1% was found. HPV 16 was the predominant type, with HPV 35, 33, and 52 types found rarely and sometimes together with HPV 16. PCR-ELISA proved to be the most suitable method to detect and type mucosal oncogenic HPVs. The absolute absence of HPV DNA in differentiated vulvar intraepithelial neoplasias and in keratinizing vulvar squamous cell carcinoma suggests a strong HPV-independent pathway of malignant progression to invasive carcinoma.