Citations

Abstract Ovarian cancer is a clinically and molecularly heterogeneous disease. The driving forces behind this variability are unknown. Here, we report wide variation in the expression of the DNA cytosine deaminase APOBEC3B, with elevated expression in the majority of ovarian cancer cell lines (three SDs above the mean of normal ovarian surface epithelial cells) and high-grade primary ovarian cancers. APOBEC3B is active in the nucleus of several ovarian cancer cell lines and elicits a biochemical preference for deamination of cytosines in 5′-TC dinucleotides. Importantly, examination of whole-genome sequence from 16 ovarian cancers reveals that APOBEC3B expression correlates with total mutation load as well as elevated levels of transversion mutations. In particular, high APOBEC3B expression correlates with C-to-A and C-to-G transversion mutations within 5′-TC dinucleotide motifs in early-stage high-grade serous ovarian cancer genomes, suggesting that APOBEC3B-catalyzed genomic uracil lesions are further processed by downstream DNA "repair" enzymes including error-prone translesion polymerases. These data identify a potential role for APOBEC3B in serous ovarian cancer genomic instability. Cancer Res; 73(24); 7222–31. ©2013 AACR.

Laparoendoscopic single-site surgery (LESS) is a new minimally invasive surgical technique that presents physical and mental challenges to surgeons. Currently, LESS procedures are commonly performed using surgical instruments designed for traditional multi-incision laparoscopic surgery. A pilot study was conducted to determine which laparoscopic instruments were the most efficient for LESS procedures. In a LESS surgical trainer, 24 novice users completed a simple surgical task using standard (non-articulating) straight laparoscopic graspers and two different articulating instruments. Task performance was scored based on completion time and the number of errors. Analyses showed that the use of the simpler straight instruments produced significantly faster times (p = 0.004 and p = 0.014) and higher task scores (p = 0.005 and p = 0.021) than the articulating instruments. These results suggest that standard laparoscopic hand instruments enable better novice performance for a basic LESS task.

Objective Genome-wide association studies have identified a large number of single nucleotide polymorphisms (SNPs) associated with a wide array of cancer sites. Several of these variants demonstrate associations with multiple cancers, suggesting pleiotropic effects and shared biological mechanisms across some cancers. We hypothesised that SNPs previously associated with other cancers may additionally be associated with colorectal cancer. In a large-scale study, we examined 171 SNPs previously associated with 18 different cancers for their associations with colorectal cancer. Design We examined 13 338 colorectal cancer cases and 40 967 controls from three consortia: Population Architecture using Genomics and Epidemiology (PAGE), Genetic Epidemiology of Colorectal Cancer (GECCO), and the Colon Cancer Family Registry (CCFR). Study-specific logistic regression results, adjusted for age, sex, principal components of genetic ancestry, and/or study specific factors (as relevant) were combined using fixed-effect meta-analyses to evaluate the association between each SNP and colorectal cancer risk. A Bonferroni-corrected p value of 2.92×10 −4 was used to determine statistical significance of the associations. Results Two correlated SNPs—rs10090154 and rs4242382—in Region 1 of chromosome 8q24, a prostate cancer susceptibility region, demonstrated statistically significant associations with colorectal cancer risk. The most significant association was observed with rs4242382 (meta-analysis OR=1.12; 95% CI 1.07 to 1.18; p=1.74×10 −5 ), which also demonstrated similar associations across racial/ethnic populations and anatomical sub-sites. Conclusions This is the first study to clearly demonstrate Region 1 of chromosome 8q24 as a susceptibility locus for colorectal cancer; thus, adding colorectal cancer to the list of cancer sites linked to this particular multicancer risk region at 8q24.

Meniscal attachments serve to anchor and transfer loads from menisci to the tibia. These ligamentous tissues are composed of collagen fibers, elastin, ground substance and water. Ligaments have a time- and history-dependent viscoelastic behavior due in part to the interaction of the water and the ground substance [1]. The movement of water within ligamentous tissue is limited because of charged proteoglycan molecules. It has been shown that some exudation of water is present during cyclic loading of ligamentous tissue [2]. The movement and its inhibition could lead to changes of pressure within the meniscal attachments. Therefore, the purpose of this study was to quantify the internal pressure in human meniscal attachments subjected to physiological loading. Since it is thought that the posterior attachment is subjected to both tension and compression, while the anterior attachment is primarily subjected to tension [3–5], we hypothesized that the attachments mechanical environment is dictated by the external loads, and hence, the posterior attachment would elicit higher pressures.

The surgical goal in total knee arthroplasty (TKA) is to obtain neutral mechanical alignment within three degrees [4]. This has been considered necessary to achieve optimal function, produce balanced medial and lateral loading distributions, and prolong implant longevity [7]. Under static loading, tibial-femoral alignment angle deviations of 3° have been shown to greatly alter the distribution of pressure and load between the medial and lateral tibial plateaus [13]. However, other studies have challenged the practice that coronal tibiofemoral alignment improves implant longevity [9,10]. These studies did not show a statistical difference in the number of revision surgeries between well aligned knees and mechanical alignment outliers (varus/valgus knees). While it has been suggested that accurate alignment allows for improved joint kinematics and improved outcomes in TKA patients [6], no studies have evaluated the effect of tibial-femoral alignment on tibial plateau loading distribution during gait in the TKA population. Therefore, the purpose of this study was to assess tibial plateau loading following TKA.

BACKGROUNDPatients diagnosed with primary sclerosing cholangitis (PSC) and dominant strictures often undergo endoscopic retrograde cholangiopancreatography with brush cytology to exclude or confirm the development of malignancy. Equivocal (atypical or suspicious) routine cytologic results may confound patient management decisions, especially in the absence of a mass on imaging. The objective of the current study was to identify independent predictors of malignancy in patients with PSC with an equivocal cytology diagnosis.METHODSPatients with PSC underwent brush cytology for routine cytology and fluorescence in situ hybridization (FISH) during endoscopy as per standard care. FISH slides were classified as polysomy if at least 5 cells displayed a gain of ≥ 2 probes. A retrospective search identified 102 patients without a mass lesion noted on initial imaging studies, an equivocal routine cytology, and ≥ 2 years of follow‐up.RESULTSOf 102 patients, 30 (29%) with an equivocal cytology result developed cancer within 2 years. Serum carbohydrate antigen 19‐9 (CA 19‐9) levels ≥ 129 U/mL (hazard ratio [HR] 3.19; P = .001) and polysomy (HR 8.70; P < .001) were each found to be predictive of cancer. Of 10 patients who had elevated CA 19‐9 levels and polysomy, all went on to develop cancer (9 within 2 years). Although only 10 patients were included in this subset, the combination of elevated CA 19‐9 and polysomy was found to be predictive of cancer (HR 10.92; P < .001).CONCLUSIONSPolysomy by FISH identified those patients most likely to have or develop malignancy in the challenging clinical scenario of PSC with no mass at baseline and equivocal cytology. The combination of an elevated serum CA 19‐9 level with polysomy is highly suspicious for the presence of malignancy. Cancer (Cancer Cytopathol) 2013;121:708–717. © 2013 American Cancer Society.

ObjectiveTo identify genetic determinants of granulomatosis with polyangiitis (Wegener's) (GPA).MethodsWe carried out a genome‐wide association study (GWAS) of 492 GPA cases and 1,506 healthy controls (white subjects of European descent), followed by replication analysis of the most strongly associated signals in an independent cohort of 528 GPA cases and 1,228 controls.ResultsGenome‐wide significant associations were identified in 32 single‐nucleotide polymorphic (SNP) markers across the HLA region, the majority of which were located in the HLA–DPB1 and HLA–DPA1 genes encoding the class II major histocompatibility complex (MHC) DPβ chain 1 and DPα chain 1 proteins, respectively. Peak association signals in these 2 genes, emanating from SNPs rs9277554 (for DPβ chain 1) and rs9277341 (DPα chain 1) were strongly replicated in an independent cohort (in the combined analysis of the initial cohort and the replication cohort, P = 1.92 × 10−50 and 2.18 × 10−39, respectively). Imputation of classic HLA alleles and conditional analyses revealed that the SNP association signal was fully accounted for by the classic HLA–DPB1*04 allele. An independent single SNP, rs26595, near SEMA6A (the gene for semaphorin 6A) on chromosome 5, was also associated with GPA, reaching genome‐wide significance in a combined analysis of the GWAS and replication cohorts (P = 2.09 × 10−8).ConclusionWe identified the SEMA6A and HLA–DP loci as significant contributors to risk for GPA, with the HLA–DPB1*04 allele almost completely accounting for the MHC association. These two associations confirm the critical role of immunogenetic factors in the development of GPA.

Severe aplastic anemia (AA) is a bone marrow (BM) failure (BMF) disease frequently caused by aberrant immune destruction of blood progenitors. Although a Th1-mediated pathology is well described for AA, molecular mechanisms driving disease progression remain ill defined. The NOTCH signaling pathway mediates Th1 cell differentiation in the presence of polarizing cytokines, an action requiring enzymatic processing of NOTCH receptors by γ-secretase. Using a mouse model of AA, we demonstrate that expression of both intracellular NOTCH1IC and T-BET, a key transcription factor regulating Th1 cell differentiation, was increased in spleen and BM-infiltrating T cells during active disease. Conditionally deleting Notch1 or administering γ-secretase inhibitors (GSIs) in vivo attenuated disease and rescued mice from lethal BMF. In peripheral T cells from patients with untreated AA, NOTCH1IC was significantly elevated and bound to the TBX21 promoter, showing NOTCH1 directly regulates the gene encoding T-BET. Treating patient cells with GSIs in vitro lowered NOTCH1IC levels, decreased NOTCH1 detectable at the TBX21 promoter, and decreased T-BET expression, indicating that NOTCH1 signaling is responsive to GSIs during active disease. Collectively, these results identify NOTCH signaling as a primary driver of Th1-mediated pathogenesis in AA and may represent a novel target for therapeutic intervention.

The detection of aneuploidy by fluorescence in situ hybridization (FISH) has revolutionized how laboratories diagnose cholangiocarcinoma and pancreatic adenocarcinoma using cytology specimens. Numerous clinical studies have demonstrated that FISH increases the diagnostic sensitivity of routine cytology for detecting pancreatobiliary tract malignancy with minimal decreases in clinical specificity. FISH also provides useful information in difficult clinical scenarios, including the assessment of patients with biliary strictures who have equivocal cytology results and the assessment of patients with primary sclerosing cholangitis who have clinical features suggestive of malignancy. The improved ability to detect pancreatobiliary tract cancers offers the possibility of earlier detection when patients are amenable to surgical intervention and can decrease health care costs by reducing the amount of clinical evaluation required to arrive at a cancer diagnosis. Cytopathology personnel should maintain familiarity with molecular cytology testing methodologies, because morphologic and aneuploidy assessment of tumors will continue to be an integral part of large‐scale genome analyses of individual tumors. Cancer (Cancer Cytopathol) 2013;121:610‐9. © 2013 American Cancer Society.