mRNA expression profiles in circulating tumor cells of metastatic colorectal cancer patients
MOLECULAR ONCOLOGY
Authors: Mostert, Bianca; Sieuwerts, Anieta M.; Bolt-de Vries, Joan; Kraan, Jaco; Lalmahomed, Zarina; van Galen, Anne; van der Spoel, Petra; de Weerd, Vanja; Ramirez-Moreno, Raquel; Smid, Marcel; Verhoef, Cornelis; IJzermans, Jan N. M.; Gratama, Jan W.; Sleijfer, Stefan; Foekens, John A.; Martens, John W. M.
Abstract
Introduction: The molecular characterization of circulating tumor cells (CTCs) is a promising tool for the repeated and non-invasive evaluation of predictive and prognostic factors. Challenges associated with CTC characterization using the only FDA approved method for CTC enumeration, the CellSearch technique, include the presence of an excess of leukocytes in CTC-enriched blood fractions. Here we aimed to identify colorectal tumor-specific gene expression levels in the blood of patients with and without detectable CTCs according to CellSearch criteria. Materials and methods: Blood of 30 healthy donors (HDs) and 142 metastatic colorectal cancer (mCRC) patients was subjected to CellSearch CTC enumeration and isolation. In all samples, 95 mRNAs were measured by reverse transcriptase quantitative PCR (RT-qPCR). HD blood samples and patient samples with three or more CTCs were compared to identify CTC-specific mRNAs. Patient samples without detectable CTCs were separately analyzed. Results: Thirty-four CTC-specific mRNAs were higher expressed in patients with >= 3 CTCs compared with HDs (Mann Whitney U-test P < 0.05). Among patients without detectable CTCs, a HD-unlike subgroup was identified which could be distinguished from HDs by the expression of epithelial genes such as KRT19, KRT20 and AGR2. Also, in an independent patient set, a similar HD-unlike group could be identified among the patients without detectable CTCs according to the CellSearch system. Conclusion: Extensive molecular characterization of colorectal CTCs is feasible and a subgroup of patients without detectable CTCs according to CellSearch criteria bears circulating tumor load, which may have clinical consequences. This CTC-specific gene panel for mCRC patients may enable the exploration of CTC characterization as a novel means to further individualize cancer treatment. (C) 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Cross-fostering of the tammar wallaby (Macropus eugenii) pouch young accelerates fore-stomach maturation
MECHANISMS OF DEVELOPMENT
Authors: Kwek, Joly H. L.; De Iongh, Robbert; Digby, Matthew R.; Renfree, Marilyn B.; Nicholas, Kevin R.; Familari, Mary
Abstract
There are two phases of fore-stomach development during the first 200 days of pouch life in tammar wallaby For the first 170 days, the mucosa displays an immature gastric glandular phenotype that changes to a cardia glandular phenotype, which remains for the rest of the animal's life. During this 200-day period after birth, the pouch young (PY) is dependent on maternal milk, which progressively changes in composition. We showed previously that PY cross-fostered to host mothers at a later stage of lactation accelerated development. In this study, we investigated whether cross-fostering and exposure to late lactation stage milk affected the transition to cardia glandular phenotype. in fostered PY fore-stomach, there was increased apoptosis, but no change in cell proliferation. The parietal cell population was significantly reduced, and expression of gastric glandular phenotype marker genes (ATP4A, GKN2, GHRL and NDRG2) was down-regulated, suggesting down-regulation of gastric phenotype in fostered PY fore-stomach. The expression of cardia. glandular phenotype genes (MUC4, KRT20, CSTB, ITLN2 and LPLUNC1) was not changed in fostered PY. These data suggest that fore-stomach maturation proceeds via two temporally distinct processes: down-regulation of gastric glandular phenotype and initiation of cardia glandular phenotype. In fostered PY, these two processes appear uncoupled, as gastric glandular phenotype was down-regulated but cardia glandular phenotype was not initiated. We propose that milk from later stages of lactation and/or herbage consumed by the PY may play independent roles in regulating these two processes. (C) 2009 Elsevier Ireland Ltd. All rights reserved.