Citations

Background— Genetic studies of cardiomyopathy and heart failure have limited throughput in mammalian models. Adult zebrafish have been recently pursued as a vertebrate model with higher throughput, but genetic conservation must be tested. Methods and Results— We conducted transcriptome analysis of zebrafish heart and searched for fish homologues of 51 known human dilated cardiomyopathy–associated genes. We also identified genes with high cardiac expression and genes with differential expression between embryonic and adult stages. Among tested genes, 30 had a single zebrafish orthologue, 14 had 2 homologues, and 5 had ≥3 homologues. By analyzing the expression data on the basis of cardiac abundance and enrichment hypotheses, we identified a single zebrafish gene for 14 of 19 multiple-homologue genes and 2 zebrafish homologues of high priority for ACTC1 . Of note, our data suggested vmhc and vmhcl as functional zebrafish orthologues for human genes MYH6 and MYH7 , respectively, which are established molecular markers for cardiac remodeling. Conclusions— Most known genes for human dilated cardiomyopathy have a corresponding zebrafish orthologue, which supports the use of zebrafish as a conserved vertebrate model. Definition of the cardiac transcriptome and fetal gene program will facilitate systems biology studies of dilated cardiomyopathy in zebrafish.

Although transformation to Hodgkin lymphoma (HL) is a recognized complication in patients with chronic lymphocytic leukemia (CLL), its incidence, clinical characteristics and outcomes are not well defined. We used the Mayo Clinic CLL and Lymphoma Databases to identify CLL patients who developed biopsy‐proven HL (CLL/HL) on follow‐up, as well as cases of de novo HL (i.e., without prior CLL). Among 3887 CLL patients seen at Mayo Clinic from January 1995 through August 2011, 26 (0.7%) developed HL. In a nested cohort of 2,465 newly diagnosed CLL patients followed prospectively, the incidence of HL was 0.05%/year (10 year risk = 0.5%). The median overall survival (OS) from date of HL diagnosis in patients with CLL/HL was 3.9 years compared to not reached for de novo HL patients ( n = 709) seen during the same time interval ( P < 0.001). The shorter OS of CLL/HL patients persisted after adjusting for differences in age and Ann Arbor stage of disease. The International Prognostic score (IPS) developed for de novo HL stratified prognosis among CLL/HL patients with median survival of not reached, 6.2, 2.4, and 0.3 years ( P = 0.006) for those with IPS scores of ≤2, 3, 4, and ≥5, respectively. In summary, approximately 1 of every 200 CLL patients will develop HL within 10 years. Survival after HL diagnosis in patients with CLL is shorter than de novo HL patients. The IPS for de novo HL may be useful for stratifying survival in CLL/HL patients. Am. J. Hematol. 90:334–338, 2015. © 2015 Wiley Periodicals, Inc.

Key Points BCL2 mutations in FL correlate with activation-induced cytidine deaminase expression and frequently alter the amino acid sequence of the protein. Mutations in the BCL2 coding sequence at diagnosis are associated with shortened time to transformation and earlier death due to lymphoma.

Abstract Background:BRCA1 and BRCA2 mutation carriers are at substantially increased risk for developing breast and ovarian cancer. The incomplete penetrance coupled with the variable age at diagnosis in carriers of the same mutation suggests the existence of genetic and nongenetic modifying factors. In this study, we evaluated the putative role of variants in many candidate modifier genes. Methods: Genotyping data from 15,252 BRCA1 and 8,211 BRCA2 mutation carriers, for known variants (n = 3,248) located within or around 445 candidate genes, were available through the iCOGS custom-designed array. Breast and ovarian cancer association analysis was performed within a retrospective cohort approach. Results: The observed P values of association ranged between 0.005 and 1.000. None of the variants was significantly associated with breast or ovarian cancer risk in either BRCA1 or BRCA2 mutation carriers, after multiple testing adjustments. Conclusion: There is little evidence that any of the evaluated candidate variants act as modifiers of breast and/or ovarian cancer risk in BRCA1 or BRCA2 mutation carriers. Impact: Genome-wide association studies have been more successful at identifying genetic modifiers of BRCA1/2 penetrance than candidate gene studies. Cancer Epidemiol Biomarkers Prev; 24(1); 308–16. ©2014 AACR.

Background and purpose Mechanisms of both healing and complications, including spontaneous aneurysm rupture, remain unclear following flow diverter treatment. The aim of this study was to compare gene expression of various key molecules involved in the healing of aneurysms, between aneurysms treated with microcoils and flow diverters. Methods Saccular aneurysms were created in rabbits. Aneurysms were treated with coils (n=6) or flow diverters (n=6). Aneurysms were harvested at 4 weeks following treatment and used for gene expression and zymography experiments. Genes with a fold change of 1.2 or more were considered upregulated whereas those with a fold change of 0.8 or less were considered downregulated. Results All coil embolized aneurysms were completely occluded at follow-up. Two aneurysms were occluded and the remaining four samples were incompletely occluded in the flow diverter treated group. The following genes were expressed at lower levels in the flow diverter group compared with the coiled aneurysm group: proteinases (matrix metalloproteinases 2 and 9), cellular markers (endothelial nitric oxide synthase and smooth muscle actin), and structural proteins (collagens and fibronectin). Genes related to inflammation (tumor necrosis factor α and monocyte chemoattractant protein 1) were upregulated in flow diverter treated aneurysms compared with coil embolized aneurysms. Notably, the enzymatic activity of active matrix metalloproteinase 9 was high in aneurysms treated with flow diverters. Conclusions Our findings may provide improved understanding of rupture risk and healing following aneurysm treatment and inform development of therapies aimed at lowering rupture risk and accelerating healing.

Abstract Background: Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) is the most common adult leukemia in the United States. Prior studies in Olmsted County, Minnesota, showed a CLL age and sex adjusted incidence rate of 6.6 per 100,000 during 1985-89. Subsequently, the definition of CLL is now based on the 2008 International Workshop on CLL (IWCLL) Guidelines. Individuals having a CLL immunophenotype by flow cytometry are classified as CLL if the absolute B-cell count (ABC) is &gt;5 x 109/L or classified as monoclonal B-cell lymphocytosis (MBL) if ABC is &lt;5 x 109/L. To assess the impact of these changes on the incidence of CLL and clinically discovered MBL, we conducted an incidence study in Olmsted County for the years 2000-2010. Methods Using diagnostic indexes available through the Rochester Epidemiology Project and the Mayo CLL database, we identified all CLL and clinically identified MBL cases from 2000-2010. Incidence rates and demographics were compared between the older National Cancer Institute-Working Groups 1996 guidelines (NCI-WG 96) defined as absolute lymphocyte count (ALC)&gt; 5 x 109/L and the IWCLL 2008 guidelines defined as ABC &gt; 5 x 109/L. Incidence rates were age and sex adjusted using the 2010 US white population. Time to treatment (TTT) survival analyses was from time of diagnosis to date of first treatment or last follow-up and Cox regression analysis was used. Results Using the NCI-WG 96 classification, there were 8 MBL cases and 115 CLLs in whom 61% were Rai stage 0, 34% were Rai stage 1-2, and 5% were Rai stage 3-4. Using the IWCLL 2008 classification, there were 44 MBL cases and 79 CLLs in whom 43% Rai stage 0, 49% were Rai stage 1-2 and 8% Rai stage 3-4. Median ALC at diagnosis was 8.1 x 109/L for CLL and 5.9 x 109/L for MBL. Median ABC count at diagnosis was 7.1 x 109/L for CLL and 2.8 x 109/L for MBL. The age and sex adjusted incidence rate (per 100,000) for CLL for 2000-2010 was 10.0 using NCI-WG 96 and 6.8 using IWCLL 2008. Rates for MBL were 0.66 using NCI-WG 96 and 3.5 using IWCLL 2008. The median TTT for CLL was 9.2 years using NCI-WG 96 and 6.5 years by IWCLL 2008. Discussion This study demonstrates that reclassification of CLL using the IWCLL 2008 guidelines decreases CLL incidence relative to the NCI-WG 96 criteria. For the first time, this population based study also establishes an incidence rate for clinically identified MBL. Approximately 50% of previously labeled Rai 0 CLL are now reclassified as MBL. Re-classification increases the percent of Rai stage 1-2 and decreases the percent of Rai 0 cases at diagnosis. Reclassification also substantially shortens the median TTT for newly diagnosed CLL cases classified by the 2008 criteria relative to the NCI-WG 96 criteria. In summary, the IWCLL 2008 reclassification has significant implications for incidence studies, staging, and prognosis of CLL and MBL. Citation Format: Aaron D. Norman, Timothy G. Call, Curtis A. Hanson, Neil E. Kay, Clive S. Zent, Wei Ding, James R. Cerhan, Sara J. Achenbach, Kari G. Rabe, Celine M. Vachon, Emily J. Hallberg, Tait D. Shanafelt, Susan L. Slager. Incidence of chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis in Olmsted county, 2000-2010: impact of the 2008 International Workshop on CLL Guidelines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2287. doi:10.1158/1538-7445.AM2013-2287

Abstract Prostate carcinogenesis is a complicated process involving both genetic and epigenetic changes. Aberrant expression of LSD1 (Lysine-specific demethylase 1) has been reported in human prostate cancers. Although high expression of LSD1 is implicated in prostate tumorigenesis, the underlying molecular mechanisms are not fully understood. Here we reported that LSD1 promotes proliferation and migration of prostate cancer cells via up-regulation of SKP2 expression. Knockdown of LSD1 using small interfering RNA (siRNA) decreases SKP2 expression and inhibits prostate cancer cell proliferation and migration. Promoter luciferase reporter and chromatin immunoprecipitation (ChIP) experiments show that LSD1 regulates SKP2 expression by controlling the levels of H3K4 methylation in SKP2 promoter and this function of LSD1 is mediated through its demethylase activity. As demonstrated by immunohistochemistry, LSD1 and SKP2 proteins positively correlate with each other and their expression is associated with cell proliferation in human prostate cancer tissues. Our data not only identify SKP2 as a direct regulated target gene of LSD1 but also reveal that SKP2 plays an important role in contributing LSD1 mediated prostate cancer cell proliferation and migration, suggesting that the LSD1-SKP2 axis can serve as therapeutic targets for treatment of prostate cancers. Citation Format: Liya Ding, Haojie Huang. LSD1 regulation of SKP2 expression in prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1805. doi:10.1158/1538-7445.AM2013-1805

Abstract Human chromosome 13q14 is one of the hotspots of chromosomal deletion in prostate cancer, multiple myeloma, and chronic lymphocytic leukemia. Chromosome Condensation 1-like (CHC1L) is an uncharacterized gene in this region. CHC1L is found within the smallest common region of loss of heterozygosity in prostate cancer, and its decreased expression is linked to pathogenesis and progression of both prostate cancer and multiple myeloma. In the present study, we describe the generation and characterization of Chc1L gene knockout mice. Knockout mice develop normally and display an exaggerated proliferative response to LPS stimulation of cultured bone marrow and spleen cells at ten weeks of age. At approximately two years of age, both homozygous and heterozygous mice have markedly increased incidence of tumorigenesis, 80% and 56% respectively, compared to wild-type mice, 26%. The tumors are distributed most commonly to the spleen, mesenteric lymph nodes, liver and small intestine. The morphologic and immunophenotypic features of the tumor cells are consistent with those of tissue histiocytes, and most Chc1L knockout and heterozygote mice succumb to either Histiocytic Sarcoma or Histiocyte-Associated Lymphoma. These data provide the first direct evidence that Chc1L is a tumor suppressor gene involved in suppression of histiocyte-rich neoplasms. Citation Format: David Spillane, Ding Yan Wang, Changxin Shi, Youdong Wang, Anthony Gramolini, Keith Stewart, Susan Newbigging, Mingyao Liu, Xiao-Yan Wen. Chc1L is a tumor suppressor involved in development of histiocyte-rich neoplasms. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C41.

ObjectiveDisease relapses are frequent in antineutrophil cytoplasmic antibody–associated vasculitis (AAV). This study was undertaken to evaluate outcomes in patients with AAV who are re‐treated with rituximab (RTX) and prednisone for severe disease relapses.MethodsThe Rituximab in AAV trial was a randomized, double‐blind, placebo‐controlled trial comparing the rates of remission induction among patients treated with RTX (n = 99) and patients treated with cyclophosphamide (CYC) followed by azathioprine (AZA) (n = 98). Prednisone was tapered to discontinuation after 5.5 months. After remission was achieved, patients who experienced a severe disease relapse between months 6 and 18 were eligible to receive RTX and prednisone on an open‐label basis according to a prespecified protocol. Investigators remained blinded with regard to the original treatment assignment.ResultsTwenty‐six patients received RTX for disease relapse after remission had initially been achieved with their originally assigned treatment. Fifteen of these patients were initially randomized to receive RTX and 11 to receive CYC/AZA. Thirteen (87%) of the patients originally assigned to receive RTX and 10 (91%) originally assigned to receive CYC/AZA achieved remission again with open‐label RTX (an overall percentage of 88%). In half of the patients treated with open‐label RTX, prednisone could be discontinued entirely. Patients in this cohort experienced fewer adverse events compared to the overall study population (4.7 adverse events per patient‐year versus 11.8 adverse events per patient‐year).ConclusionRe‐treatment of AAV relapses with RTX and glucocorticoids appears to be a safe and effective strategy, regardless of previous treatment.