Deregulation of apoptosis is a frequent alteration in early benign lesions of the colon mucosa and is thought to be a major contributor to tumor progression and cancer. Single nucleotide polymorphisms (SNPs) within apoptosis-related genes could affect apoptotic responses and their identification might provide a basis to assess individual risk for development of early lesions. To investigate a possible association between genetic polymorphisms and the occurrence of hyperplastic polyps (HP), we developed a custom DNA chip assay for 1,536 SNPs in the coding and flanking regions of 826 genes with known functional roles in apoptosis or apoptosis-associated (e.g., stress-related) pathways. During a first round of screening, genotypes were determined for 272 endoscopy patients harboring hyperplastic colorectal polyps and for 512 sex and aged-matched controls. A set of 14 candidate SNPs associated with HP (P?0.01) was then evaluated in an independent cohort of patients (n?=?38) and controls (n?=?38). Following meta-analysis of Stages I and II, a false discovery rate approach was applied. Among the 14 candidate SNPs, eight showed significant association (combined P?0.01) with the occurrence of HP. The SNPs rs4709583 (PARK2) and rs10476823 (HDAC3) were analyzed for potential functional effects on RNA splicing and RNA half-life. Despite its location near a splice site, alternative splicing was not detected for rs4709583 (PARK3). By contrast, cDNA analysis revealed use of a cryptic polyadenylation signal in the 3'UTR of HDAC3 mRNA and a longer mRNA half-life in a cell line heterozygous for rs10476823.
Colorectal cancer is one of the most common forms of cancer, and the development of novel tools for detection and efficient treatment of metastases is needed. One promising approach is the use of radiolabeled antibodies for positron emission tomography (PET) imaging and radioimmunotherapy. Since carcinoembryonic antigen (CEA) is an important target in colorectal cancer, the CEA-specific M5A antibody has been extensively studied in subcutaneous xenograft models; however, the M5A antibody has not yet been tested in advanced models of liver metastases. The aim of this study was to investigate the (64)Cu-DOTA-labeled M5A antibody using PET in mice bearing CEA-positive liver metastases.
Micro-CT imaging of liver disease in mice relies on high soft tissue contrast to detect small lesions like liver metastases. Purpose of this study was to characterize the localization and time course of contrast enhancement of a nanoparticular alkaline earth metal-based contrast agent (VISCOVER ExiTron nano) developed for small animal liver CT imaging.
Respiratory gating with and without controlled ventilation has been applied for in vivo micro-computed tomography (micro-CT) of thoracic and abdominal structures in mice. We describe a simplified method for intubation and demonstrate its applicability for single-breath-hold micro-CT in mice.
According to their carcinogenesis, colorectal cancer (CRC) subtypes show distinct molecular parameters. Hereditary non-polypous colorectal cancer (HNPCC) is the most common inherited CRC characterized by clinical criteria and confirmed microsatellite instability (MSI). Interestingly, a recently identified subtype, familial colorectal cancer type X (FCC-X), shows the same clinical criteria but microsatellite stability (MSS). CEACAM1 is a known tumor suppressor that regulates apoptosis in colon cells, and its loss is one of the most frequent events in early tumorigenesis of CRC. Therefore its loss may characterize precursor colon cells prior to neoplastic transformation. We analyzed tumor specimens of HNPCC and FCC-X patients in order to investigate whether there is a loss of CEACAM1 expression analogous to sporadic CRC and whether the expression of CEACAM1 would distinguish between these tumor entities. No differences in CEACAM1 expression were noted between HNPPC (n = 38) and FCC-X (n = 30) tumors. CEACAM1 was reduced in near-identical frequencies in 36/38 (95%) HNPCC and 29/30 (97%) FCC-X. This is the first report to demonstrate the loss of CEACAM1 expression in hereditary CRC. There was no difference between HNPCC and FCC-X. The frequency of expression loss was comparable to sporadic CRC, indicating that loss of CEACAM1 is an early event in colorectal tumorigenesis linking the genesis of sporadic and hereditary CRC.
Separase, an endopeptidase required for the separation of sister-chromatides in mitotic anaphase, triggers centriole disengagement during centrosome duplication. In cancer, separase is frequently overexpressed, pointing to a functional role as an aneuploidy promoter associated with centrosomal amplification and genomic instability. Recently, we have shown that centrosomal amplification and subsequent chromosomal aberrations are a hallmark of chronic myeloid leukemia (CML), increasing from chronic phase (CP) toward blast crisis (BC). Moreover, a functional linkage of p210BCR-ABL tyrosine kinase activity with centrosomal amplification and clonal evolution has been established in long-term cell culture experiments. Unexpectedly, therapeutic doses of imatinib (IM) did not counteract; instead induced similar centrosomal alterations in vitro. We investigated the influence of IM and p210BCR-ABL on Separase as a potential driver of centrosomal amplification in CML. Short-term cell cultures of p210BCR-ABL-negative (NHDF, UROtsa, HL-60, U937), positive (K562, LAMA-84) and inducible (U937p210BCR-ABL/c6 (Tet-ON)) human cell lines were treated with therapeutic doses of IM and analyzed by qRT-PCR, Western blot analysis and quantitative Separase activity assays. Decreased Separase protein levels were observed in all cells treated with IM in a dose dependent manner. Accordingly, in all p210BCR-ABL-negative cell lines, decreased proteolytic activity of Separase was found. In contrast, p210BCR-ABL-positive cells showed increased Separase proteolytic activity. This activation of Separase was consistent with changes in the expression levels of Separase regulators (Separase phosphorylation at serine residue 1126, Securin, CyclinB1 and PP2A). Our data suggest that regulation of Separase in IM-treated BCR-ABL-positive cells occurs on both the protein expression and the proteolytic activity levels. Activation of Separase proteolytic activity exclusively in p210BCR-ABL-positive cells during IM treatment may act as a driving force for centrosomal amplification, contributing to genomic instability, clonal evolution and resistance in CML.
Various murine models are currently used to study acute and chronic pathological processes of the liver, and the efficacy of novel therapeutic regimens. The increasing availability of high-resolution small animal imaging modalities presents researchers with the opportunity to precisely identify and describe pathological processes of the liver. To meet the demands, the objective of this study was to provide a three-dimensional illustration of the macroscopic anatomical location of the murine liver lobes and hepatic vessels using small animal imaging modalities. We analysed micro-CT images of the murine liver by integrating additional information from the published literature to develop comprehensive illustrations of the macroscopic anatomical features of the murine liver and hepatic vasculature. As a result, we provide updated three-dimensional illustrations of the macroscopic anatomy of the murine liver and hepatic vessels using micro-CT. The information presented here provides researchers working in the field of experimental liver disease with a comprehensive, easily accessable overview of the macroscopic anatomy of the murine liver.
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