RESUMEN
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.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Resistencia a Antineoplásicos/genética , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Anticuerpos Monoclonales Humanizados , Cetuximab , Neoplasias Colorrectales/patología , Análisis Mutacional de ADN , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Biología Molecular , Mutación , Metástasis de la Neoplasia , Proyectos Piloto , Proteínas Proto-Oncogénicas p21(ras) , Garantía de la Calidad de Atención de Salud , Reino UnidoRESUMEN
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.