RESUMO
Research is in a crisis of credibility, and this is to the peril of all paediatricians. Billions of dollars are being wasted each year because research is not planned, badly conducted or poorly reported, and this is on a background of rapidly reducing research budgets. How can paediatricians, families and patients make informed treatment choices if the evidence base is absent or not trustworthy? This article discusses why meta-research now matters more than ever, how it can help solve this crisis of credibility and how this should lead to more efficient and effective clinical care. The field of meta-research or research-on-research is the ultimate big picture approach to identifying and solving issues of bias, error, misconduct and waste in research. Meta-researchers value authenticity over aesthetics and quality over quantity. The utility of meta-research does not rely on accusations or critical assessments of individual research, but through highlighting where and how the scientific method and research standards across all fields can be improved. Meta-researchers study, analyse and critique the research pathway, focusing on elements such as methods (how to conduct), evaluation (how to test), reporting (how to communicate), reproducibility (how to verify) and incentives (how to reward). In the current climate it is now more critical than ever that we make use of meta-research and prioritise high-quality high-impact research, ultimately leading to improved patient outcomes.
Assuntos
Enganação , Humanos , Reprodutibilidade dos TestesRESUMO
PURPOSE: Despite significant progress in understanding the molecular pathology of pancreatic cancer and its precursor lesion: pancreatic intraepithelial neoplasia (PanIN), there remain no molecules with proven clinical utility as prognostic or therapeutic markers. Here, we used oligonucleotide microarrays to interrogate mRNA expression of pancreatic cancer tissue and normal pancreas to identify novel molecular pathways dysregulated in the development and progression of pancreatic cancer. EXPERIMENTAL DESIGN: RNA was hybridized to Affymetrix Genechip HG-U133 oligonucleotide microarrays. A relational database integrating data from publicly available resources was created to identify candidate genes potentially relevant to pancreatic cancer. The protein expression of one candidate, homeobox B2 (HOXB2), in PanIN and pancreatic cancer was assessed using immunohistochemistry. RESULTS: We identified aberrant expression of several components of the retinoic acid (RA) signaling pathway (RARalpha, MUC4, Id-1, MMP9, uPAR, HB-EGF, HOXB6, and HOXB2), many of which are known to be aberrantly expressed in pancreatic cancer and PanIN. HOXB2, a downstream target of RA, was up-regulated 6.7-fold in pancreatic cancer compared with normal pancreas. Immunohistochemistry revealed ectopic expression of HOXB2 in 15% of early PanIN lesions and 48 of 128 (38%) pancreatic cancer specimens. Expression of HOXB2 was associated with nonresectable tumors and was an independent predictor of poor survival in resected tumors. CONCLUSIONS: We identified aberrant expression of RA signaling components in pancreatic cancer, including HOXB2, which was expressed in a proportion of PanIN lesions. Ectopic expression of HOXB2 was associated with a poor prognosis for all patients with pancreatic cancer and was an independent predictor of survival in patients who underwent resection.
Assuntos
Perfilação da Expressão Gênica , Proteínas de Homeodomínio/genética , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , Fatores de Transcrição/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Sequência com Séries de Oligonucleotídeos , Pâncreas/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Análise de Sobrevida , Fatores de Transcrição/metabolismo , Tretinoína/farmacologiaRESUMO
Pancreatic ductal adenocarcinoma (PDA) is an extremely aggressive malignancy, which carries a dismal prognosis. Activating mutations of the Kras gene are common to the vast majority of human PDA. In addition, recent studies have demonstrated that embryonic signaling pathway such as Hedgehog and Notch are inappropriately upregulated in this disease. The role of another embryonic signaling pathway, namely the canonical Wnt cascade, is still controversial. Here, we use gene array analysis as a platform to demonstrate general activation of the canonical arm of the Wnt pathway in human PDA. Furthermore, we provide evidence for Wnt activation in mouse models of pancreatic cancer. Our results also indicate that Wnt signaling might be activated downstream of Hedgehog signaling, which is an early event in PDA evolution. Wnt inhibition blocked proliferation and induced apoptosis of cultured adenocarcinoma cells, thereby providing evidence to support the development of novel therapeutical strategies for Wnt inhibition in pancreatic adenocarcinoma.