RESUMO
Laboratories are increasingly required to perform molecular tests for the detection of mutations in the KRAS gene in metastatic colorectal cancers to allow better clinical management and more effective treatment for these patients. KRAS mutation status predicts a patient's likely response to the monoclonal antibody cetuximab. To provide a high standard of service, these laboratories require external quality assessment (EQA) to monitor the level of laboratory output and measure the performance of the laboratory against other service providers. National External Quality Assurance Services for Molecular Genetics provided a pilot EQA scheme for KRAS molecular analysis in metastatic colorectal cancers during 2009. Very few genotyping errors were reported by participating laboratories; however, the reporting nomenclature of the genotyping results varied considerably between laboratories. The pilot EQA scheme highlighted the need for continuing EQA in this field which will assess the laboratories' ability not only to obtain accurate, reliable results but also to interpret them safely and correctly ensuring that the referring clinician has the correct information to make the best clinical therapeutic decision for their patient.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas Proto-Oncogênicas/genética , Proteínas ras/genética , Anticorpos Monoclonais Humanizados , Cetuximab , Neoplasias Colorretais/patologia , Análise Mutacional de DNA , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Biologia Molecular , Mutação , Metástase Neoplásica , Projetos Piloto , Proteínas Proto-Oncogênicas p21(ras) , Garantia da Qualidade dos Cuidados de Saúde , Reino UnidoRESUMO
The International Stem Cell Initiative characterized 59 human embryonic stem cell lines from 17 laboratories worldwide. Despite diverse genotypes and different techniques used for derivation and maintenance, all lines exhibited similar expression patterns for several markers of human embryonic stem cells. They expressed the glycolipid antigens SSEA3 and SSEA4, the keratan sulfate antigens TRA-1-60, TRA-1-81, GCTM2 and GCT343, and the protein antigens CD9, Thy1 (also known as CD90), tissue-nonspecific alkaline phosphatase and class 1 HLA, as well as the strongly developmentally regulated genes NANOG, POU5F1 (formerly known as OCT4), TDGF1, DNMT3B, GABRB3 and GDF3. Nevertheless, the lines were not identical: differences in expression of several lineage markers were evident, and several imprinted genes showed generally similar allele-specific expression patterns, but some gene-dependent variation was observed. Also, some female lines expressed readily detectable levels of XIST whereas others did not. No significant contamination of the lines with mycoplasma, bacteria or cytopathic viruses was detected.