Cancer worry frequency vs. intensity and self-reported colorectal cancer screening uptake: A population-based study

Objectives: Many studies of cancer worry use items measuring frequency or intensity. Little is known about how each of these relate to cancer screening uptake. This study compared the association between worry frequency vs. intensity and colorectal cancer screening intention/uptake. Methods: Across four surveys (2014–2016), we collected data from 2878 screening-eligible men and women (aged 60–70) in England. Measures included single-items assessing cancer worry frequency and intensity, and a derived combination of both. We also assessed self-reported past faecal occult blood testing uptake (ever vs. never), intention to participate when next invited (yes vs. no), and demographics. Using logistic regression, we compared a model containing sociodemographic characteristics (Model 1), with four models adding cancer worry frequency (Model 2), intensity (Model 3), both (Model 4), or the combined measure (Model 5). Results: A model with cancer worry intensity and demographics (Model 3) explained significantly more variance in uptake and intention (R2 ¼ 0.068 and 0.062, respectively) than demographics alone (Model 1: R2 ¼ 0.058 and 0.042; p < 0.001), or a model with demographics and cancer worry frequency (Model 2: R2 ¼ 0.059 and 0.052; p < 0.001). The model was also equally as effective as models including both the frequency and intensity items (Model 4: R2¼ 0.070 n.s. and 0.062 n.s.), or using the derived combination of both (Model 5: R2 ¼ 0.063 n.s. and 0.053 n.s.). Conclusion: A single item measure of cancer worry intensity appeared to be most parsimonious for explaining variance in colorectal cancer screening intention and uptak

Nonsense Mediated Decay Resistant Mutations Are a Source of Expressed Mutant Proteins in Colon Cancer Cell Lines with Microsatellite Instability

BACKGROUND: Frameshift mutations in microsatellite instability high (MSI-High) colorectal cancers are a potential source of targetable neo-antigens. Many nonsense transcripts are subject to rapid degradation due to nonsense-mediated decay (NMD), but nonsense transcripts with a cMS in the last exon or near the last exon-exon junction have intrinsic resistance to nonsense-mediated decay (NMD). NMD-resistant transcripts are therefore a likely source of expressed mutant proteins in MSI-High tumours. METHODS: Using antibodies to the conserved N-termini of predicted mutant proteins, we analysed MSI-High colorectal cancer cell lines for examples of naturally expressed mutant proteins arising from frameshift mutations in coding microsatellites (cMS) by immunoprecipitation and Western Blot experiments. Detected mutant protein bands from NMD-resistant transcripts were further validated by gene-specific short-interfering RNA (siRNA) knockdown. A genome-wide search was performed to identify cMS-containing genes likely to generate NMD-resistant transcripts that could encode for antigenic expressed mutant proteins in MSI-High colon cancers. These genes were screened for cMS mutations in the MSI-High colon cancer cell lines. RESULTS: Mutant protein bands of expected molecular weight were detected in mutated MSI-High cell lines for NMD-resistant transcripts (CREBBP, EP300, TTK), but not NMD-sensitive transcripts (BAX, CASP5, MSH3). Expression of the mutant CREBBP and EP300 proteins was confirmed by siRNA knockdown. Five cMS-bearing genes identified from the genome-wide search and without existing mutation data (SFRS12IP1, MED8, ASXL1, FBXL3 and RGS12) were found to be mutated in at least 5 of 11 (45%) of the MSI-High cell lines tested. CONCLUSION: NMD-resistant transcripts can give rise to expressed mutant proteins in MSI-High colon cancer cells. If commonly expressed in primary MSI-High colon cancers, MSI-derived mutant proteins could be useful as cancer specific immunological targets in a vaccine targeting MSI-High colonic tumours

The transcriptional activity of hepatocyte nuclear factor 4 alpha is inhibited via phosphorylation by ERK1/2

Hepatocyte nuclear factor 4 alpha (HNF4alpha) nuclear receptor is a master regulator of hepatocyte development, nutrient transport and metabolism. HNF4alpha is regulated both at the transcriptional and post-transcriptional levels by different mechanisms. Several kinases (PKA, PKC, AMPK) were shown to phosphorylate and decrease the activity of HNF4alpha. Activation of the ERK1/2 signalling pathway, inducing proliferation and survival, inhibits the expression of HNF4alpha. However, based on our previous results we hypothesized that HNF4alpha is also regulated at the post-transcriptional level by ERK1/2. Here we show that ERK1/2 is capable of directly phosphorylating HNF4alpha in vitro at several phosphorylation sites including residues previously shown to be targeted by other kinases, as well. Furthermore, we also demonstrate that phosphorylation of HNF4alpha leads to a reduced trans-activational capacity of the nuclear receptor in luciferase reporter gene assay. We confirm the functional relevance of these findings by demonstrating with ChIP-qPCR experiments that 30-minute activation of ERK1/2 leads to reduced chromatin binding of HNF4alpha. Accordingly, we have observed decreasing but not disappearing binding of HNF4alpha to the target genes. In addition, 24-hour activation of the pathway further decreased HNF4alpha chromatin binding to specific loci in ChIP-qPCR experiments, which confirms the previous reports on the decreased expression of the HNF4a gene due to ERK1/2 activation. Our data suggest that the ERK1/2 pathway plays an important role in the regulation of HNF4alpha-dependent hepatic gene expression

Deletion of transketolase triggers a stringent metabolic response in promastigotes and loss of virulence in amastigotes of Leishmania mexicana

Transketolase (TKT) is part of the non-oxidative branch of the pentose phosphate pathway (PPP). Here we describe the impact of removing this enzyme from the pathogenic protozoan Leishmania mexicana. Whereas the deletion had no obvious effect on cultured promastigote forms of the parasite, the Δtkt cells were not infective to mice. Δtkt promastigotes were more susceptible to oxidative stress and various leishmanicidal drugs than wild-type, and metabolomics analysis revealed profound changes to metabolism in these cells. In addition to changes consistent with those directly related to the role of TKT in the PPP, central carbon metabolism was substantially decreased, the cells consumed significantly less glucose, flux through glycolysis diminished, and production of the main end products of metabolism was decreased. Only minor changes in RNA abundance from genes encoding enzymes in central carbon metabolism, however, were detected although fructose-1,6-bisphosphate aldolase activity was decreased two-fold in the knock-out cell line. We also showed that the dual localisation of TKT between cytosol and glycosomes is determined by the C-terminus of the enzyme and by engineering different variants of the enzyme we could alter its sub-cellular localisation. However, no effect on the overall flux of glucose was noted irrespective of whether the enzyme was found uniquely in either compartment, or in both

Coordinate Regulation of Lipid Metabolism by Novel Nuclear Receptor Partnerships

Mammalian nuclear receptors broadly influence metabolic fitness and serve as popular targets for developing drugs to treat cardiovascular disease, obesity, and diabetes. However, the molecular mechanisms and regulatory pathways that govern lipid metabolism remain poorly understood. We previously found that the Caenorhabditis elegans nuclear hormone receptor NHR-49 regulates multiple genes in the fatty acid beta-oxidation and desaturation pathways. Here, we identify additional NHR-49 targets that include sphingolipid processing and lipid remodeling genes. We show that NHR-49 regulates distinct subsets of its target genes by partnering with at least two other distinct nuclear receptors. Gene expression profiles suggest that NHR-49 partners with NHR-66 to regulate sphingolipid and lipid remodeling genes and with NHR-80 to regulate genes involved in fatty acid desaturation. In addition, although we did not detect a direct physical interaction between NHR-49 and NHR-13, we demonstrate that NHR-13 also regulates genes involved in the desaturase pathway. Consistent with this, gene knockouts of these receptors display a host of phenotypes that reflect their gene expression profile. Our data suggest that NHR-80 and NHR-13's modulation of NHR-49 regulated fatty acid desaturase genes contribute to the shortened lifespan phenotype of nhr-49 deletion mutant animals. In addition, we observed that nhr-49 animals had significantly altered mitochondrial morphology and function, and that distinct aspects of this phenotype can be ascribed to defects in NHR-66– and NHR-80–mediated activities. Identification of NHR-49's binding partners facilitates a fine-scale dissection of its myriad regulatory roles in C. elegans. Our findings also provide further insights into the functions of the mammalian lipid-sensing nuclear receptors HNF4α and PPARα

The immunobiology of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease histologically characterized by the presence of intrahepatic and/or extrahepatic biliary duct concentric, obliterative fibrosis, eventually leading to cirrhosis. Approximately 75% of patients with PSC have inflammatory bowel disease. The male predominance of PSC, the lack of a defined, pathogenic autoantigen, and the potential role of the innate immune system suggest that it may be due to dysregulation of immunity rather than a classic autoimmune disease. However, PSC is associated with several classic autoimmune diseases, and the strongest genetic link to PSC identified to date is with the human leukocyte antigen DRB01*03 haplotype. The precise immunopathogenesis of PSC is largely unknown but likely involves activation of the innate immune system by bacterial components delivered to the liver via the portal vein. Induction of adhesion molecules and chemokines leads to the recruitment of intestinal lymphocytes. Bile duct injury results from the sustained inflammation and production of inflammatory cytokines. Biliary strictures may cause further damage as a result of bile stasis and recurrent secondary bacterial cholangitis. Currently, there is no effective therapy for PSC and developing a rational therapeutic strategy demands a better understanding of the disease