Suggestive genetic linkage to chromosome 11p11.2-q12.2 in hereditary prostate cancer families with primary kidney cancer

BACKGROUND: The Seattle-based PROGRESS study was started in 1995 to ascertain hereditary prostate cancer (HPC) families for studies of genetic susceptibility. Subsequent studies by several research groups, including our own, suggest that HPC is a genetically heterogeneous disease. To be successful in mapping loci for such a complex disease, one must consider ways of grouping families into subsets that likely share the same genetic origin. Towards that end, we analyzed a genome-wide scan of HPC families with primary kidney cancer. METHODS: An 8.1 cM genome-wide scan including 441 microsatellite markers was analyzed by both parametric and non-parametric linkage approaches in fifteen HPC families with the co-occurrence of kidney cancer. RESULTS: There was no evidence for significant linkage in the initial findings. However, two regions of suggestive linkage were observed at 11q12 and 4q21, with HLOD scores of 2.59 and 2.10, respectively. The primary result on chromosome 11 was strengthened after excluding two families with members who had rare transitional cell carcinoma (TCC). Specifically, we observed a non-parametric Kong and Cox P-value of 0.004 for marker D11S1290 at 11p11.2. The 8 cM region between 11p11.2 and 11q12.2 was refined by the addition of 16 new markers. The subset of HPC families with a median age of diagnosis >65 years demonstrated the strongest evidence for linkage, with an HLOD = 2.50. The P-values associated with non-parametric analysis ranged from 0.004 to 0.05 across five contiguous markers. CONCLUSIONS: Analysis of HPC families with members diagnosed with primary renal cell carcinoma demonstrates suggestive linkage to chromosome 11p11.2-q12.2.     

Pharmacogenetics and stomach cancer: an update

Although new drugs and association regimens have been used in recent years, the chemotherapeutic outcome for gastric cancer is still poor and improvement in patient survival is not satisfactory. Pharmacogenetics could represent a useful approach to optimize chemotherapeutic treatments in order to identify individuals that are true candidates for clinical benefits from therapy, avoiding the development of severe side effects. The most recent update regarding gastric cancer pharmacogenetics highlights a prominent role of genetic polymorphisms of thymidylate synthase and glutathione S-transferase in the pharmacological treatment with commonly used drugs, such as 5-fluorouracil and platinum derivatives. In order to validate the genetic markers, further larger scale and controlled studies are required. A future challenge is represented by the introduction of targeted therapy in gastric cancer treatment, with the potential emerging tool of pharmacogenetic impact on this field.     

Chromosomal translocations induced at specified loci in human stem cells

The precise genetic manipulation of stem and precursor cells offers extraordinary potential for the analysis, prevention, and treatment of human malignancies. Chromosomal translocations are hallmarks of several tumor types where they are thought to have arisen in stem or precursor cells. Although approaches exist to study factors involved in translocation formation in mouse cells, approaches in human cells have been lacking, especially in relevant cell types. The technology of zinc finger nucleases (ZFNs) allows DNA double-strand breaks (DSBs) to be introduced into specified chromosomal loci. We harnessed this technology to induce chromosomal translocations in human cells by generating concurrent DSBs at 2 endogenous loci, the PPP1R12C/p84 gene on chromosome 19 and the IL2Rγ gene on the X chromosome. Translocation breakpoint junctions for t(19;X) were detected with nested quantitative PCR in a high throughput 96-well format using denaturation curves and DNA sequencing in a variety of human cell types, including embryonic stem (hES) cells and hES cell-derived mesenchymal precursor cells. Although readily detected, translocations were less frequent than repair of a single DSB by gene targeting or nonhomologous end-joining, neither of which leads to gross chromosomal rearrangements. While previous studies have relied on laborious genetic modification of cells and extensive growth in culture, the approach described in this report is readily applicable to primary human cells, including mutipotent and pluripotent cells, to uncover both the underlying mechanisms and phenotypic consequences of targeted translocations and other genomic rearrangements.     

Increased Perioculomotor Urocortin 1 Immunoreactivity in Genetically Selected Alcohol Preferring Rats

Introduction: Urocortin 1 (Ucn 1) is an endogenous peptide related to the corticotropin‐releasing factor (CRF). Ucn 1 is mainly expressed in the perioculomotor area (pIII), and its involvement in alcohol self‐administration is well confirmed in mice. In other species, the relationship between the perioculomotor Ucn 1‐containing population of neurons (pIIIu) and alcohol consumption needs further investigation. The pIII also has a significant subpopulation of dopaminergic neurons. Because of dopamine’s (DA) role in addiction, it is important to evaluate whether this subpopulation of neurons contributes to addiction‐related phenotypes. Furthermore, the effects of gender on the relationship between Ucn 1 and tyrosine hydroxylase (TH) in pIII and alcohol preference in rats have not been previously assessed. Methods: To address these issues, we compared 2 Sardinian alcohol‐preferring sublines of rats, a population maintained at the Scripps Research Institute (Scr:sP) and a population maintained at University of Camerino—Marchigian Sardinian preferring rats (msP), to corresponding nonselectively bred Wistar rats of both sexes. Ucn 1‐ and TH‐positive cells were detected on coronal midbrain sections from 6‐ to 8‐week‐old alcohol‐naïve animals using brightfield and fluorescent immunohistochemistry. Ucn 1‐ and TH‐positive cells in pIII were counted in the perioculomotor area, averaged across 2 to 3 sets, and binned into 3 bregma levels. Results: Results demonstrated increased average counts of Ucn 1‐positive cells in the middle bregma level in preferring male rats compared to Wistar controls and no difference in TH‐positive cell counts in pIII. In addition, fluorescent double labeling revealed no colocalization of Ucn 1‐positive and TH‐positive neurons. Ucn 1 but not TH distribution was influenced by gender with female animals expressing more Ucn 1‐positive cells than male animals in the peak bregma level. Conclusions: These findings extend previous reports of increased Ucn 1‐positive cell distribution in preferring lines of animals. They indicate that Ucn1 contributes to increased alcohol consumption across different species and that this contribution could be gender specific. The results also suggest that Ucn1 regulates positive reinforcing rather than aversive properties of alcohol and that these effects could be mediated by CRF₂ receptors, independent of direct actions of DA.     

Daycare attendance and risk for respiratory morbidity among young very low birth weight children

Daycare attendance and very low birth weight (VLBW, ≤1,500 g) are associated with respiratory morbidity during childhood. The objective of this study was to evaluate whether daycare attendance is associated with even higher risk for respiratory problems among VLBW children. We hypothesized that VLBW children attending daycare, in a private home or daycare center, are at higher risk for respiratory problems than VLBW children not attending daycare. We also investigated whether the effect of daycare is independent or synergistic with respiratory risk resulting from being VLBW, as indicated by having bronchopulmonary dysplasia (BPD) as a neonate. We conducted a prospective study of VLBW children followed from birth to age 2–3 (N = 715). Logistic regression was used to evaluate the relationship between daycare attendance and respiratory problems, adjusting for known neonatal risk factors for poor respiratory outcomes. Attending daycare in either a private home or in a daycare center was significantly associated with higher risk of lower respiratory infections than never attending. Attending a daycare center was also associated with higher risk for wheezy chest, cough without a cold, and respiratory medication use. While having BPD was associated with increased risk for respiratory problems, daycare attendance and BPD were not found to be synergistic risk factors for respiratory problems among VLBW children, but acted independently to increase risk. This implies that the increase in risk for respiratory problems associated with daycare attendance may be similar among VLBW children and those of normal birth weight. Pediatr Pulmonol. 2009; 44:1093–1099. ©2009 Wiley‐Liss, Inc.     

Flow cytometric analysis of skin blister fluid induced by mosquito bites in a patient with chronic active Epstein–Barr virus infection

In chronic active Epstein–Barr virus (EBV) infection (CAEBV), ectopic EBV infection has been described in T or natural killer (NK) cells. NK cell-type infection (NK-CAEBV) is characterized by large granular lymphocytosis, high IgE levels and unusual reactions to mosquito bites, including severe local skin reactions, fever and liver dysfunction. However, the mechanisms underlying these reactions remain undetermined. Herein, we describe a patient with NK-CAEBV whose blister fluid after mosquito bites was analyzed. The patient exhibited significant increases in the percentage of CD56⁺ NK cells in the fluid compared with a simple mosquito allergy, in which the majority of infiltrated cells were CD203c⁺ cells, indicating basophils and/or mast cells. His fluid also contained CD203c⁺ cells, and his circulating basophils were activated by mosquito extracts in vitro. These results suggest that CD203c⁺ cells as well as NK cells may play pathogenic roles in the severe skin reactions to mosquito bites in NK-CAEBV.     

MERTK on mononuclear phagocytes regulates T cell antigen recognition at autoimmune and tumor sites

Understanding mechanisms of immune regulation is key to developing immunotherapies for autoimmunity and cancer. We examined the role of mononuclear phagocytes during peripheral T cell regulation in type 1 diabetes and melanoma. MERTK expression and activity in mononuclear phagocytes in the pancreatic islets promoted islet T cell regulation, resulting in reduced sensitivity of T cell scanning for cognate antigen in prediabetic islets. MERTK-dependent regulation led to reduced T cell activation and effector function at the disease site in islets and prevented rapid progression of type 1 diabetes. In human islets, MERTK-expressing cells were increased in remaining insulin-containing islets of type 1 diabetic patients, suggesting that MERTK protects islets from autoimmune destruction. MERTK also regulated T cell arrest in melanoma tumors. These data indicate that MERTK signaling in mononuclear phagocytes drives T cell regulation at inflammatory disease sites in peripheral tissues through a mechanism that reduces the sensitivity of scanning for antigen leading to reduced responsiveness to antigen.