Citations

AbstractBackgroundTransforming growth factor (TGF)‐β1 produced in airway epithelia has been suggested as a contributor to the airway remodeling observed in asthma patients. The protein tyrosine phosphatase SHP2 is a demonstrable modulator of TGF‐β1 production and thus a potential regulator of airway remodeling.ObjectivesTo define the signal event by which SHP2 regulates asthmatic responses in airway epithelial cells by using a mouse model of experimental OVA‐induced airway remodeling.MethodsThe airways of Shp2flox/flox mice were infected with recombinant adenovirus vectors expressing a Cre recombinase–green fluorescence protein (GFP) fusion protein as part of allergen provocation studies using mice sensitized with ovalbumin (OVA) and repeatedly challenged with OVA. Several endpoint pathologies were assessed, including airway hyper‐responsiveness (AHR), lung inflammatory score, peribronchial collagen deposition, and α‐smooth muscle actin (SMA) hyperplasia. In vitro studies using airway epithelial cells (BEAS‐2B) were used to investigate the role of SHP2 in the regulation of pulmonary remodeling events, including the expression of collagen, α‐SMA, and TGF‐β1.ResultsChronic OVA challenges in wild‐type mice resulted in airway remodeling and lung dysfunction (e.g., increased inflammatory scores, collagen deposition (fibrosis), smooth muscle hyperplasia, and a significant increase in AHR). These endpoint pathology metrics were each significantly attenuated by conditional shp2 gene knockdown in airway epithelia. In vitro studies using BEAS‐2B cells also demonstrated that the level of TGF‐β1 production by these cells correlated with the extent of shp2 gene expression.ConclusionsSHP2 activities in airway epithelial cells appear to modulate TGF‐β1 production and, in turn, regulate allergic airway remodeling following allergen provocation.Clinical ImplicationsOur findings identify SHP2 as a previously underappreciated contributor to the airway remodeling and lung dysfunction associated with allergen challenge. As such, SHP2 represents a potentially novel therapeutic target for the treatment of asthmatics.Capsule summaryAirway epithelial protein tyrosine phosphatase SHP2 appears to modulate TGF‐β1 activities as part of one or more cellular pathways leading to regulating the airway remodeling and lung dysfunction occurring in mouse models of allergic respiratory inflammation.

Background Recently, rare germline variants in XRCC2 were detected in non-BRCA1/2 familial breast cancer cases, and a significant association with breast cancer was reported. However, the breast cancer risk associated with these variants needs further evaluation. Methods The coding regions and exon–intron boundaries of XRCC2 were scanned for mutations in an international cohort of 3548 non-BRCA1/2 familial breast cancer cases and 1435 healthy controls using various mutation scanning methods. Predictions on functional relevance of detected missense variants were obtained from three different prediction algorithms. Results The only protein-truncating variant detected was found in a control. Rare non-protein-truncating variants were detected in 20 familial cases (0.6%) and nine healthy controls (0.6%). Although the number of variants predicted to be damaging or neutral differed between prediction algorithms, in all instances these categories were evenly represented among cases and controls. Conclusions Our data do not confirm an association between XRCC2 variants and breast cancer risk, although a relative risk smaller than two could not be excluded. Variants in XRCC2 are unlikely to explain a substantial proportion of familial breast cancer.

AbstractMany common genetic variants have been associated with non-Hodgkin lymphoma (NHL), but individual study results are often conflicting. To confirm the role of putative risk alleles in B-cell NHL etiology, we performed a validation genotyping study of 67 candidate single nucleotide polymorphisms within InterLymph, a large international consortium of NHL case-control studies. A meta-analysis was performed on data from 5633 B-cell NHL cases and 7034 controls from 8 InterLymph studies. rs3789068 in the proapoptotic BCL2L11 gene was associated with an increased risk for B-cell NHL (odds ratio = 1.21, P random = 2.21 × 10−11), with similar risk estimates for common B-cell subtypes. PRRC2A rs3132453 in the HLA complex class III region conferred a reduced risk of B-cell NHL (odds ratio = 0.68, P random = 1.07 × 10−9) and was likewise evident for common B-cell subtypes. These results are consistent with the known biology of NHL and provide insights into shared pathogenic components, including apoptosis and immune regulation, for the major B-cell lymphoma subtypes.

ObjectiveOur aim was to identify patient and procedure characteristics that correlate with increased likelihood of bleeding during and after endoscopic mucosal resection (EMR), and thus anticipate the need for preventative therapy.MethodsThis was a retrospective, observational, descriptive study using a prospective EMR database, performed in a tertiary‐care center. A total of 935 EMR of various locations within the gastrointestinal tract were collected. The main outcome measurement was early bleeding (occurring during the procedure) and delayed bleeding (occurring after the completion of the procedure and up to 30 days after).ResultsEarly bleeding occurred in 5.3% (50/935) of the procedures. In multivariate logistic regression analysis, esophageal EMR (OR 2.5, 95% CI 1.2–5, P = 0.0009) and increase in lesion size (OR 1.24, 95% CI 1.1–1.5, P = 0.003) were both associated with higher odds of early bleeding in EMR when controlling for age, gender and non‐steroidal anti‐inflammatory drugs (NSAIDs)/clopidogrel use. Delayed bleeding occurred after 3.1% (n = 29) of the procedures. Of these, 86.2% (25/29) required hospital admission and endoscopic intervention to confirm and/or treat bleeding site. In multivariate logistic regression analysis, increased lesion size (OR 1.3, 95% CI 1.1–1.5, P = 0.004) was associated with higher incidence of delayed bleeding post‐EMR.ConclusionsIn experienced hands bleeding during and after EMR appears to be uncommon. Larger lesions are at increased risk of early and delayed bleeding.

Abstract Background: Non-Hodgkin lymphoma (NHL) is a malignancy of lymphocytes, and there is growing evidence for a role of germline genetic variation in immune genes in NHL etiology. Methods: To identify susceptibility immune genes, we conducted a 2-stage analysis of single-nucleotide polymorphisms (SNP) from 1,253 genes using the Immune and Inflammation Panel. In Stage 1, we genotyped 7,670 SNPs in 425 NHL cases and 465 controls, and in Stage 2 we genotyped the top 768 SNPs on an additional 584 cases and 768 controls. The association of individual SNPs with NHL risk from a log-additive model was assessed using the OR and 95% confidence intervals (CI). Results: In the pooled analysis, only the TAP2 coding SNP rs241447 (minor allele frequency = 0.26; Thr655Ala) at 6p21.3 (OR = 1.34, 95% CI 1.17–1.53) achieved statistical significance after accounting for multiple testing (P = 3.1 × 10−5). The TAP2 SNP was strongly associated with follicular lymphoma (FL, OR = 1.82, 95%CI 1.46–2.26; p = 6.9 × 10−8), and was independent of other known loci (rs10484561 and rs2647012) from this region. The TAP2 SNP was also associated with diffuse large B-cell lymphoma (DLBCL, OR = 1.38, 95% CI 1.08–1.77; P = 0.011), but not chronic lymphocytic leukemia (OR = 1.08; 95% CI 0.88–1.32). Higher TAP2 expression was associated with the risk allele in both FL and DLBCL tumors. Conclusion: Genetic variation in TAP2 was associated with NHL risk overall, and FL risk in particular, and this was independent of other established loci from 6p21.3. Impact: Genetic variation in antigen presentation of HLA class I molecules may play a role in lymphomagenesis. Cancer Epidemiol Biomarkers Prev; 21(10); 1799–806. ©2012 AACR.

Summary A recent meta‐analysis of three genome‐wide association studies of chronic lymphocytic leukaemia ( CLL ) identified two common variants at the 6p21.31 locus that are associated with CLL risk. To verify and further explore the association of these variants with other non‐ H odgkin lymphoma ( NHL ) subtypes, we genotyped 1196 CLL cases, 1699 NHL cases, and 2410 controls. We found significant associations between the 6p21.31 variants and CLL risk (rs210134: P = 0·01; rs210142: P = 6·8 × 10 −3 ). These variants also showed a trend towards association with some of the other NHL subtypes. Our results validate the prior work and support specific genetic pathways for risk among NHL subtypes.

Long-term culture of hepatocyte spheroids with high ammonia clearance is valuable for therapeutic applications, especially the bioartificial liver. However, the optimal conditions are not well studied. We hypothesized that liver urea cycle enzymes can be induced by high protein diet and maintain on a higher expression level in rat hepatocyte spheroids by serum-free medium (SFM) culture and coculture with mesenchymal stromal cells (MSCs). Rats were feed normal protein diet (NPD) or high protein diet (HPD) for 7 days before liver digestion and isolation of hepatocytes. Hepatocyte spheroids were formed and maintained in a rocked suspension culture with or without MSCs in SFM or 10% serum-containing medium (SCM). Spheroid viability, kinetics of spheroid formation, hepatic functions, gene expression, and biochemical activities of rat hepatocyte spheroids were tested over 14 days of culture. We observed that urea cycle enzymes of hepatocyte spheroids can be induced by high protein diet. SFM and MSCs enhanced ammonia clearance and ureagenesis and stabilized integrity of hepatocyte spheroids compared to control conditions over 14 days. Hepatocytes from high protein diet-fed rats formed spheroids and maintained a high level of ammonia detoxification for over 14 days in a novel SFM. Hepatic functionality and spheroid integrity were further stabilized by coculture of hepatocytes with MSCs in the spheroid microenvironment. These findings have direct application to development of the spheroid reservoir bioartificial liver.

PurposeAutoantibodies are implicated in the pathogenesis of cardiovascular diseases and cardiac arrhythmias. In this pilot study, we tested the hypothesis that autoantibodies are present in patients with postural orthostatic tachycardia syndrome (POTS).Experimental designSeven control subjects (6 F:1 M, average age 36.1 years) and ten patients with the diagnosis of POTS (7 F: 3 M, average age 35.1 years) provided informed consent and 30 mL of venous blood. Human heart membrane proteins were resolved by 2DE and immunoblotted against purified IgGs from controls and patients.ResultsEighteen protein spots immunoreactive specifically against patient IgGs were detected and they were excised from gels, trypsin‐digested, and analyzed by nanoLC‐electrospray MS/MS. Forty unique proteins were identified and these include proteins that are associated with cardiac hypertrophy (mimecan, myozenin), cardiac remodeling (periostin), cardiomyopathy (desmin, desmoplakin), cell survival (laminin), structural integrity (filamin), chaperone proteins (crystalline, HSP70), mitochondrial enzymes, and channel proteins. Ingenuity Pathway Analysis showed multiple pathways were involved including those that regulate energy metabolism, redox, fibrosis, cardiac hypertrophy, and degeneration.Conclusions and clinical relevanceAutoantibodies are present in patients with POTS. These autoantibodies cross‐react with a wide range of cardiac proteins and may induce alterations in cardiac function. Autoimmune pathogenetic mechanisms should be further explored in these patients.

Abstract Purpose: Lung cancer in never-smokers (LCINS) is increasingly recognized as a distinct disease from that in ever-smokers owing to substantial differences in etiology, clinical characteristics, and prognosis. Therefore, we aimed to identify prognostic markers specific for LCINS. Experimental Design: First, 11,930 single-nucleotide polymorphisms (SNP) in 904 inflammation-related genes were genotyped, and their associations with overall survival in 411 patients with LCINS at MD Anderson Cancer Center were analyzed. Next, validation of the top 27 SNPs in 311 patients with LCINS at Mayo Clinic was conducted. Results: Three SNPs (IL17RA:rs879576, BMP8A:rs698141, and STY:rs290229) were validated (P < 0.05), and two SNPs (CD74:rs1056400 and CD38:rs10805347) reached borderline significance (P = 0.08) in the Mayo Clinic population. We validated a survival-tree created in the MD Anderson population exploring gene–gene interactions in the Mayo Clinic population. This survival-tree stratified patients into subsets with significantly different risks of death: patients with the rs1056400_GG/rs698141_GA + AA genotype had significantly higher risk of death in both MD Anderson (HR:2.32, 95%CI: 1.58–3.41) and Mayo (HR:1.97, 95%CI: 1.11–3.50) populations compared with those with the rs1056400_GG/rs698141_GG or rs1056400_GA + AA genotype. We evaluated these five SNPs in 996 ever-smokers from MD Anderson and found no significant associations. Conclusions: Our study provides strong evidence that inflammation-related genetic variations can affect clinical outcomes in LCINS, which may lead to significant biologic insight into these outcomes. Clin Cancer Res; 18(21); 5983–91. ©2012 AACR.