RESUMO
BACKGROUND: Blood is the most extensively studied body fluid and, because it contains circulating tumour cells (CTCs) and circulating tumour-derived cell-free DNA (ctDNA), it may represent a liquid biopsy for cancer. Methods for enrichment and detection of CTCs and ctDNA, their clinical applications and future opportunities in gastrointestinal cancers were the focus of this review. METHODS: The PubMed database was searched for literature up to 24 June 2017, with a focus on the past 10 years. Identified articles were further scrutinized for relevant references. Articles were those in English relating to colorectal, gastric and pancreatic cancer. RESULTS: Both CTCs and ctDNA are in low abundance compared with other cellular components of blood, but effective enrichment and highly sensitive techniques are available for their detection. Potential clinical applications of these liquid biopsies include screening, prognostic stratification, therapy administration, monitoring of treatment effect or resistance, and surveillance. Liquid biopsies provide opportunities to reduce the need for invasive tissue sampling, especially in the context of intratumoral heterogeneity and the need for tumour genotyping. CONCLUSION: Liquid biopsies have applications in gastrointestinal cancers to improve clinical decision-making.
Assuntos
Biomarcadores Tumorais/sangue , DNA Tumoral Circulante , Neoplasias Gastrointestinais/sangue , Células Neoplásicas Circulantes , Biomarcadores Tumorais/genética , Detecção Precoce de Câncer/métodos , Neoplasias Gastrointestinais/genética , Neoplasias Gastrointestinais/patologia , Humanos , Biópsia Líquida/métodos , PrognósticoRESUMO
The Jun activation domain binding protein 1 (JAB1) was first identified as an interaction partner and coactivator of c-Jun. Subsequently, it was found to be a subunit of the COP9 signalosome (CSN) and termed CSN subunit 5 (CSN5). This complex regulates light-mediated development in plants and plays an essential role in a variety of organisms. A striking feature of JAB1/CSN5 is its reported interaction with a wide range of proteins and its modulation of their activity or stability. We applied the yeast two-hybrid system to screen for proteins interacting with the DNA-binding domain of the transcription factor c-Myb and found JAB1/CSN5 among the double-positive clones. To our surprise JAB1/CSN5 was shown to interact with the DNA-binding domain of GAL4 alone and had to be rejected as a false positive in the GAL4-based two-hybrid system. This finding emphasizes the necessity of particular caution when JAB1/CSN5 is found in two-hybrid screenings.
