Genetic Variants in the Apoptosis Gene BCL2L1 Improve Response to Interferon-Based Treatment of Hepatitis C Virus Genotype 3 Infection
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Authors: Clausen, Louise Nygaard; Weis, Nina; Ladelund, Steen; Madsen, Lone; Lunding, Suzanne; Tarp, Britta; Christensen, Peer Brehm; Krarup, Henrik Bygum; Moller, Axel; Gerstoft, Jan; Clausen, Mette Rye; Benfield, Thomas
Abstract
Genetic variation upstream of the apoptosis pathway has been associated with outcome of hepatitis C virus (HCV) infection. We investigated genetic polymorphisms in the intrinsic apoptosis pathway to assess their influence on sustained virological response (SVR) to pegylated interferon-alpha and ribavirin (pegIFN/RBV) treatment of HCV genotypes 1 and 3 infections. We conducted a candidate gene association study in a prospective cohort of 201 chronic HCV-infected individuals undergoing treatment with pegIFN/RBV. Differences between groups were compared in logistic regression adjusted for age, HCV viral load and interleukin 28B genotypes. Four single nucleotide polymorphisms (SNPs) located in the B-cell lymphoma 2-like 1 (BCL2L1) gene were significantly associated with SVR. SVR rates were significantly higher for carriers of the beneficial rs1484994 CC genotypes. In multivariate logistic regression, the rs1484994 SNP combined CC + TC genotypes were associated with a 3.4 higher odds ratio (OR) in SVR for the HCV genotype 3 (p = 0.02). The effect estimate was similar for genotype 1, but the association did not reach statistical significance. In conclusion, anti-apoptotic SNPs in the BCL2L1 gene were predictive of SVR to pegIFN/RBV treatment in HCV genotypes 1 and 3 infected individuals. These SNPs may be used in prediction of SVR, but further studies are needed.
FOXO1 downregulation contributes to the oncogenic program of primary mediastinal B-cell lymphoma
ONCOTARGET
Authors: Xie, Linka; Ritz, Olga; Leithaeuser, Frank; Guan, Hanfeng; Faerbinger, Johanna; Weitzer, Clarissa D.; Gehringer, Franziska; Bruederlein, Silke; Holzmann, Karlheinz; Vogel, Marion J.; Moeller, Peter; Wirth, Thomas; Ushmorov, Alexey
Abstract
Recently we have shown that the transcription factor FOXO1, highly expressed in B cells, is downregulated in classical Hodgkin lymphoma (cHL). As primary mediastinal B cell lymphoma (PMBL) has similarities with the cHL transcription program we investigated FOXO1 expression in this entity. By using immunohistochemistry we found that FOXO1 was absent or expressed at low levels in 19 of 20 primary PMBL cases. PMBL cell lines reproduce the low FOXO1 expression observed in primary cases. By analyzing gene expression profiling data we found that FOXO1 expression inversely correlated with JAK2 in PMBL cases. Targeting JAK2 activity by the small molecular weight inhibitor TG101348 resulted in upregulation of FOXO1 mRNA and protein expression in MedB-1 and U2940 cell lines, and the MYC inhibitor 10058-F4 increased FOXO1 mRNA in MedB-1 cells. Moreover, in MedB-1 cells FOXO1 expression was strongly upregulated by the inhibitor of DNA methylation 5-aza-2-deoxycytidine and by the histone deacetylase inhibitor trichostatin A. Since FOXO1 promoter was unmethylated, this effect is most likely indirect. FOXO1 activation in the FOXO1-negative MedB-1 cell line led to growth arrest and apoptosis, which was accompanied by repression of MYC and BCL2L1/BCLx(L). Thus, FOXO1 repression might contribute to the oncogenic program and phenotype of PMBL.