Francesco D'Alo'

Glutathione S-transferase P1 Genotype and Prognosis in Hodgkin's Lymphoma

Purpose: Glutathione S-transferase P1 (GSTP1) is a member of the GST enzyme superfamily that is important for the detoxification of several cytotoxic drugs and their by-products. A single nucleotide polymorphism results in the substitution of isoleucine (Ile) to valine (Val) at codon 105, causing a metabolically less active variant of the enzyme. We assessed the impact of the GSTP1 codon 105 genotype on treatment outcome in patients with Hodgkins lymphoma. Experimental Design: The Ile105Val polymorphism in the GSTP1 gene was analyzed using a PCR-RFLP technique. Ninety-seven patients with Hodgkins lymphoma were included and associations with patient characteristics and treatment outcome were analyzed. Results: The GSTP1 Ile105Val polymorphism was associated in a dose-dependent fashion with an improved failure-free survival in patients with Hodgkins lymphoma (P = 0.02). The probability of 5-year survival for patients homozygous for the 105Val/105Val GSTP1 genotype was 100%, for heterozygous patients 74% (95% confidence interval, 56-85), and for patients homozygous for the 105Ile/105Ile genotype 43% (95% confidence interval, 23-61). The Cox multivariate analysis showed that GSTP1 codon 105 genotype was an independent prognostic factor. Conclusions: The GSTP1 genotype predicts clinical outcome in patients with Hodgkins lymphoma.

Anemia in Hodgkin's Lymphoma: The Role of Interleukin-6 and Hepcidin

PURPOSE Cytokines play a pivotal role in Hodgkins lymphoma (HL). Because interleukin-6 (IL-6) induces expression of hepcidin, one of the principal regulators of iron metabolism, we studied the contribution of hepcidin in anemia in HL at diagnosis. PATIENTS AND METHODS Plasma samples from 65 patients with HL were analyzed for hepcidin levels using a combination of weak cation exchange chromatography and time-of-flight mass spectrometry; cytokine levels were analyzed using enzyme-linked immunosorbent assays and parameters of iron metabolism and acute-phase reaction. RESULTS Hepcidin plasma levels were significantly higher in HL patients when compared with controls, independent of the presence of anemia (P = .001). In the subset of patients with anemia, hepcidin levels inversely correlated with hemoglobin levels (P = .01). Analyzing parameters of iron metabolism, hepcidin levels showed a positive correlation with ferritin (P < .001) and an inverse correlation to iron and iron-binding capacity. Hepcidin strongly correlated to IL-6 levels (P < .001) but not to IL-10 or thymus and activation-regulated cytokine (TARC)/chemokine (C-C motif) ligand 17 (CCL17) levels. In a multivariate regression analysis, IL-6 and fibrinogen levels were independently associated with hepcidin. Higher hepcidin levels were observed in patients with more aggressive disease characteristics: stage IV disease (P = .01), presence of B symptoms (P = .03), and International Prognostic Score > 2 (P = .005). CONCLUSION Our findings suggest that in HL, hepcidin is upregulated by IL-6. Elevated hepcidin levels result in iron restriction and signs of anemia of chronic inflammation, although hepcidin-independent mechanisms contribute to development of anemia in HL.

A Transcriptional Profiling Study of CCAAT/Enhancer Binding Protein Targets Identifies Hepatocyte Nuclear Factor 3β as a Novel Tumor Suppressor in Lung Cancer

We showed previously that CCAAT/enhancer binding protein α (C/EBPα), a tissue-specific transcription factor, is a candidate tumor suppressor in lung cancer. In the present study, we have performed a transcriptional profiling study of C/EBPα target genes using an inducible cell line system. This study led to the identification of hepatocyte nuclear factor 3β (HNF3β), a transcription factor known to play a role in airway differentiation, as a downstream target of C/EBPα. We found down-regulation of HNF3β expression in a large proportion of lung cancer cell lines examined and identified two novel mutants of HNF3β, as well as hypermethylation of the HNF3β promoter. We also developed a tetracycline-inducible cell line model to study the cellular consequences of HNF3β expression. Conditional expression of HNF3β led to significant growth reduction, proliferation arrest, apoptosis, and loss of clonogenic ability, suggesting additionally that HNF3β is a novel tumor suppressor in lung cancer. This is the first study to show genetic abnormalities of lung-specific differentiation pathways in the development of lung cancer.

The viral load of Epstein-Barr virus (EBV)-DNA in Peripheral Blood Predicts for Biological and Clinical Characteristics in Hodgkin Lymphoma

Purpose: The Epstein–Barr virus (EBV) is present in the malignant Hodgkin/Reed–Sternberg (HRS) cells of 20% to 40% cases of Hodgkin lymphoma (HL) in Western countries. We were interested in the detection and quantification of cell-free plasma EBV-DNA as an indicator of biological and clinical characteristics in EBV-associated HL. Experimental Design: EBV was detected in peripheral blood compartments (whole blood, plasma, and mononuclear cells) at diagnosis by real-time PCR for the EBNA (EB nuclear antigen) region (n = 93) and in HRS cells by in situ hybridization for EBV-encoded small RNAs (EBER; n = 63). These data were correlated to histological and clinical characteristics, EBV serology, circulating cell-free DNA, and interleukin (IL)-6 levels. Results: Detection of EBV-DNA in plasma had a high specificity (90%), but a relatively low sensitivity (65%) to predict for EBV association. The viral load was higher in patients with advanced stage disease, older age in the presence of B-symptoms, and international prognostic score more than 2. The presence of EBV in HRS cells and higher plasma EBV-DNA copy numbers correlated to an increased frequency of tumor-infiltrating CD68+ macrophages in lymph node biopsies. Plasma EBV-DNA load correlated to circulating cell-free DNA and IL-6 levels, and inversely correlated to lymphocyte counts and EBNA1 antibody titers. Conclusion: Although the presence of EBV-DNA in peripheral blood cannot be regarded as a surrogate marker for EBER, the plasma EBV-DNA load at HL diagnosis is an indicator of disease activity and biological characteristics associated with negative prognosis. Moreover, the inverse correlation to EBNA1 antibody titers and lymphocyte counts may indicate a reduction in immunosurveillance, favoring the expansion of EBV-HRS cells in HL. Clin Cancer Res; 17(9); 2885–92. ©2011 AACR.

Reduced BRCA1 expression due to promoter hypermethylation in therapy-related acute myeloid leukaemia

BRCA1 plays a pivotal role in the repair of DNA damage, especially following chemotherapy and ionising radiation. We were interested in the regulation of BRCA1 expression in acute myeloid leukaemia (AML), in particular in therapy-related forms (t-AML). Using real-time PCR and Western blot, we found that BRCA1 mRNA was expressed at barely detectable levels by normal peripheral blood granulocytes, monocytes and lymphocytes, whereas control BM-mononuclear cells and selected CD34+ progenitor cells displayed significantly higher BRCA1 expression (P=0.0003). Acute myeloid leukaemia samples showed heterogeneous BRCA1 mRNA levels, which were lower than those of normal bone marrows (P=0.0001). We found a high frequency of hypermethylation of the BRCA1 promoter region in AML (51/133 samples, 38%), in particular in patients with karyotypic aberrations (P=0.026), and in t-AML, as compared to de novo AML (76 vs 31%, P=0.0002). Examining eight primary tumour samples from hypermethylated t-AML patients, BRCA1 was hypermethylated in three of four breast cancer samples, whereas it was unmethylated in the other four tumours. BRCA1 hypermethylation correlated to reduced BRCA1 mRNA (P=0.0004), and to increased DNA methyltransferase DNMT3A (P=0.003) expression. Our data show that reduced BRCA1 expression owing to promoter hypermethylation is frequent in t-AML and that this could contribute to secondary leukaemogenesis.

Cell-free circulating DNA in Hodgkin's and non-Hodgkin's lymphomas

BACKGROUND Levels of cell-free circulating DNA have been correlated to clinical characteristics and prognosis in patients with cancers of epithelial origin, while there are no data on patients with B-lymphoproliferative diseases. PATIENTS AND METHODS Cell-free DNA levels in the plasma samples of 142 patients with lymphomas [45 with Hodgkins lymphoma (HL), 63 with diffuse large B-cell non-Hodgkins lymphoma (DLBCL), 24 with follicular, and 10 with mantle cell non-Hodgkins lymphoma (NHL)] at diagnosis and of 41 healthy individuals were determined using a quantitative PCR for the beta-globin gene. RESULTS Levels of circulating DNA in patients with HL, DLBCL, and mantle cell NHL were significantly higher than in controls (P < 0.01 for all). Increased levels of plasma DNA were associated with advanced stage disease, presence of B-symptoms, elevated lactate dehydrogenase levels, and age >60 years (P = 0.009; <0.0001; <0.0001; 0.04, respectively). In HL, histological signs of necrosis and grade 2 type of nodular sclerosis were associated with increased plasma DNA. Elevated plasma DNA levels were associated with an inferior failure-free survival in patients with HL (P = 0.01) and DLBCL (P = 0.03). CONCLUSION Quantification of circulating DNA by real-time PCR at diagnosis can identify patients with elevated levels that are associated with disease characteristics indicating aggressive disease and poor prognosis.

Prognostic role of glutathione S-transferase polymorphisms in acute myeloid leukemia.

Glutathione S-transferases (GSTs) are phase II detoxification enzymes involved in the metabolism of carcinogens and anticancer drugs, known also to interact with kinase complexes during oxidative or chemical stress-induced apoptosis. We were interested whether their polymorphic variants may account for differences in outcome of patients with acute myeloid leukemia (AML) following chemotherapy. We studied the prognostic role of polymorphisms in three GST genes (GSTP1/M1/T1) in a large patient cohort of the German Austrian Acute Myeloid Leukemia Study Group, treated according to prospective multicenter clinical trials (AML HD98A: 254 patients; AML HD98-B: 100 patients), with a median follow-up of 46 months. Looking at short-term adverse drug reactions, homozygous carriers of the GSTP1*105 Val allele had a faster neutrophil and platelet recovery (P=0.002 and 0.02, respectively) and a reduced need of red cell and platelet transfusions (P=0.01 and 0.03, respectively). Response to induction chemotherapy did not vary according to GST polymorphisms. Multivariable Cox regression models revealed a significant better relapse-free (RFS) and overall survival for the GSTP1*105 Val (P=0.003 and 0.03, respectively), whereas GSTT1 and GSTM1 genotypes had no significant impact. The favorable impact of GSTP1*105 Val on RFS seems to be restricted to the subgroup of patients exhibiting a normal karyotype.

Analysis of genome-wide methylation and gene expression induced by 5-aza-2'-deoxycytidine identifies BCL2L10 as a frequent methylation target in acute myeloid leukemia

Epigenetic changes play a role in the pathogenesis of myeloid malignancies, and hypomethylating agents have shown efficacy in these diseases. We studied the apoptotic effect, genome-wide methylation, and gene expression profiles in HL60 cells following 5-aza-2′-deoxycytidine (decitabine; DAC) treatment, using microarray technologies. Decitabine treatment resulted in a decrease in global DNA methylation, corresponding to 4876 probeset IDs with significantly reduced methylation levels, while the expression of 2583 IDs was modified. The integrated analysis identified 160 genes demethylated and up-regulated by decitabine, mainly including development and differentiation pathway genes. Gene targets of Polycomb group protein regulation were overrepresented in this group. Apoptosis was induced by decitabine, and apoptosis-specific PCR arrays more precisely indicated decitabine-induced up-regulation of 13 apoptosis-related genes, in particular DAP-kinase 1 and BCL2L10. Correspondingly, in primary patient samples, BCL2L10 was hypermethylated in 45% of AML, 43% of therapy-related myeloid neoplasms, 12% of MDS, and in none of the controls. In conclusion, decitabine induces global demethylation and gene expression, in particular of Polycomb target genes involved in development and differentiation pathways. The apoptotic gene BCL2L10 is a frequent target for aberrant promoter methylation in patients with acute leukemia, de novo and therapy-related.

Clinical significance of interleukin-10 gene polymorphisms and plasma levels in Hodgkin lymphoma

We studied plasma levels of IL-10 and five single nucleotide polymorphisms in the interleukin-10 (IL-10) gene promoter in patients with Hodgkin lymphoma (HL) to address potential genotype-phenotype correlations. Patients with elevated IL-10 levels were more likely to have advanced stage disease and inferior event-free survival. Homozygous carriers of the variant alleles at position -592 (AA) and -1082 (GG) of the IL-10 promoter had higher IL-10 plasma levels, independent of male gender and advanced stage of disease which also determined increased IL-10 production. This analysis indicates that the genetic background can modulate plasma levels of IL-10, and ultimately prognosis in HL.

Epigenetic Treatment of Myelodysplastic Syndromes and Acute Myeloid Leukemias

Epigenetic mechanisms affecting chromatin structure contribute to regulate gene expression and assure the inheritance of information, which are essential for the proper expression of key regulatory genes in healthy cells, tissues and organs. In the medical field, an increasing body of evidence indicates that altered gene expression or de-regulated gene function lead to disease. Cancer cells also suffer a profound change in the genomic methylation patterns and chromatin status. Aberrant DNA methylation patterns, changes in chromatin structure and in gene expression are common in all kind of tumor types. However, studies on leukemias have provided paradigmatic examples for the functional implications of the epigenetic alterations in cancer development and progression as well as their relevance for therapeutical targeting.