The novel member of the BCL2 gene family, BCL2L12, is substantially elevated in chronic lymphocytic leukemia patients, supporting its value as a significant biomarker.

BCL2L12 is a recently identified gene belonging to the BCL2 family, members of which are implicated in hematologic malignancies, including chronic lymphocytic leukemia (CLL). The aim of this study was to analyze the mRNA expression of the novel apoptosis-related gene BCL2L12 in patients with CLL and to examine its prognostic and predictive value and potential clinical application as a novel molecular biomarker for CLL. For this purpose, total RNA was isolated from peripheral blood of 65 CLL patients and 23 healthy donors. An ultrasensitive quantitative real-time polymerase chain reaction methodology for BCL2L12 and BCL2 mRNA quantification was developed using SYBR Green chemistry. After preparing cDNA by reverse transcription, relative quantification analysis was performed using the comparative C(T) (2(-ΔΔCT)) method. Furthermore, analysis of IGHV mutational status, CD38 expression, and detection of early apoptosis by double staining with Annexin V-FITC and propidium iodide were performed. According to our findings, BCL2L12 mRNA expression is significantly higher in CLL patients than in healthy donors. Receiver operating characteristic analysis demonstrated that BCL2L12 expression had significant discriminatory value, distinguishing very efficiently CLL patients from the non-leukemic population. Moreover, BCL2L12 expression predicts the presence of CLL, as demonstrated by both univariate and multivariate logistic regression analyses. Finally, high BCL2L12 mRNA levels are associated with advanced clinical stage and predict shorter overall survival in CLL patients.

Hypoxia-inducible factors in mantle cell lymphoma: implication for an activated mTORC1→HIF-1α pathway.

Aberrant activation of phosphoinositide-3 kinase/Akt (PI3K/Akt) and mammalian target of rapamycin (mTOR) signaling is implicated in the pathogenesis of mantle cell lymphoma (MCL). We previously showed oncogenic activation of PI3K/Akt pathway in a subset of MCL patients. In this study, we investigated downstream the immunohistochemical expression of (Ser2448)pmTOR [indicative of mTOR complex 1 (mTORC1) activation status] as well as of hypoxia-inducible factor 1 alpha (HIF-1α), hypoxia-inducible factor 2 alpha (HIF-2α), p53, and p21 in the same series of MCL patients. Additionally, correlation of these proteins with activated Akt ((Ser473)pAkt) and established histological prognostic factors was examined. Thirty-five tissue samples (28 classical type and seven blastoid variant) were included. The neoplastic cells expressed (Ser2448)pmTOR in 61.7%, HIF-1α in 73.5%, HIF-2α in 23.5%, and p53 in 18.2% of patients, while p21 was negative in all examined samples. In addition, 72% of patients who expressed HIF-1α had also (Ser2448)pmTOR expression (p = 0.041). HIF-1α expression was also correlated to an elevated (≥30%) Ki-67 (p = 0.031) and blastoid variant of disease (p = 0.017). In conclusion, we report for the first time common expression of HIF-alphas, especially HIF-1α, in MCL patients. Furthermore, an overall activation of mTORC1→HIF-1α axis and a potential role of (Ser2448)pmTOR in the regulation of HIF-1α in MCL patients are suggested. Finally, HIF-1α appears to be associated with more aggressive disease. A pathogenetic role for both mTORC1 and HIF-1α in MCL is implied, which will possibly lead to more efficient target therapies.

Cell cycle and apoptosis regulatory gene expression in the bone marrow of patients with de novo myelodysplastic syndromes (MDS).

Deregulation of cell cycle and apoptosis pathways are known contributors to the pathogenesis of myelodysplastic syndromes (MDS). However, the underlying mechanisms are not fully clarified. The aim of our study was to examine mRNA expression levels of cell cycle and apoptosis regulatory genes, as well as the percentage of apoptotic and S phase cells and to correlate the findings with clinical characteristics and prognosis. Sixty patients with MDS, classified according to FAB (17 RA, five RARS, 19 RAEB, nine RAEBT, ten CMML) and WHO (ten RA, three RARS, seven RCMD, two RCMD-RS, 11 RAEBI, eight RAEBII, ten CMML, and nine AML) were included in the study. We found increased expression of anti-apoptotic bclxL and mcl1 genes and decreased expression of p21 gene in MDS patients. Moreover, we found increased expression of anti-apoptotic mcl1 gene in patients with higher than Intermediate-1 IPSS group. Multivariate analysis confirmed that combined expression of apoptotic caspases 8, 3, 6, 5, 2, 7, and Granzyme B was decreased in MDS patients. Regarding cell cycle regulatory genes expression, we demonstrated increased expression of cyclin D1 in patients with CMML Increased combined expression of cyclins B, C, D1, and D2 was found in patients with cytogenetic abnormalities. The two pathways seem to be interconnected as shown by the positive correlation between CDKs 1, 2, 4, p21 and the level of apoptosis and positive correlation between apoptotic caspase 3 expression and the percentage of S phase cells. In conclusion, our study showed altered expression of genes involved in apoptosis and cell cycle in MDS and increased expression of cyclin D1 in patients with CMML.

Expression analysis of proteins involved in the non homologous end joining DNA repair mechanism, in the bone marrow of adult de novo myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are characterized by genetic instability which is associated with abnormal DNA repair mechanisms. The most lethal type of DNA damage are double strand DNA breaks (DSBs), which are mainly repaired by Non Homologous End Joining Mechanism (NHEJ), whose core enzyme components include the Ku70/Ku80 heterodimer, DNA-PKcs, XRCC4 and DNA Ligase IV. The aim of the present study was the analysis of expression of proteins required for NHEJ in bone marrow cells of adult de novo MDS and their association with clinical characteristics and prognosis. Our analysis included 48 cases of MDS; 19 RA, 5 RARS, 19 RAEB, 3 RAEB-T, 1 CMML, 1 transformation to AML according to FAB classification. The expression of the enzymes Ku70, Ku80, XRCC4, DNA-PKcs and Ligase IV was determined by Western Blotting. The mean Ligase IV expression value was significantly lower in MDS patients compared to normal controls (0.53 vs. 0.78, p = 0.03). A negative correlation was found between karyotype risk group and Ligase IV values. (p = 0.05). Moreover, Ku70 expression levels were significantly lower in patients with a good prognosis karyotype (p = 0.04). Furthermore, a negative correlation between Ku70 expression values and Hb levels was observed (p = 0.04). Finally, a positive correlation was observed between enzyme Ku70 expression values and level of blasts (p = 0.04). Our findings suppor-t a potential role of NHEJ enzyme Ligase IV in the pathogenesis of MDS. Larger numbers of cases need to be screened in order to draw definite conclusion.

The role of microRNAs in normal and malignant hematopoiesis.

MicroRNAs are small non-coding RNAs that act at the post-transcriptional level, regulating protein expression by repressing translation or destabilizing mRNA target. Because of their discovery, microRNAs have been associated with almost every normal cell function, including proliferation, differentiation and apoptosis. Several lines of evidence suggest that they have an important role in normal hematopoiesis as exemplified by the role of mir-155 and mir-150 in the differentiation of B and T lymphocytes, the suppressive role of mir-221 and mir-222 in erythroid differentiation, the inhibitory effect of mir-181 on hematopoietic differentiation and the induction of myeloid differentiation by mir-223. Moreover, they play a role both as oncogenes, probably by a variety of mechanisms, namely through elimination of tumor suppressor proteins, or as tumor suppressor genes by targeting oncogenic mRNAs. Their aberrant expression has been associated with solid tumors and hematopoietic malignancies as suggested by the frequent deletion of mir-15a and mir-16-1 in chronic lymphocytic leukemia, the increased levels of mir-155 in diffuse large B-cell lymphomas and the increased levels of mir-181 in acute myeloid leukemia M1 and M2. The purpose of this review is to summarize current knowledge on the role of microRNAs in normal hematopoiesis and hematopoietic malignancies and, moreover, to highlight their role as potential therapeutic tools.

A clinicopathological study of B-cell differentiation markers and transcription factors in classical Hodgkin's lymphoma: a potential prognostic role of MUM1/IRF4.

BACKGROUND AND OBJECTIVES: Although most patients with classical Hodgkin's lymphoma (CHL) are cured, a significant minority are refractory to treatment. The investigation of biological markers could improve the predictive capacity of clinical staging systems. The aim of our study was to detect B-cell differentiation markers and transcription factors in CHL in order to define subgroups with different histogeneses and prognoses. DESIGN AND METHODS: We evaluated 107 cases of CHL for BCL6, CD79a, MUM1/IRF4 and B-cell transcription factors BOB.1, OCT.2 expression by immunohistochemistry. Statistical analysis was performed using Fisher's exact test, the Mann-Whitney test, the Kaplan-Meier method and the log rank test. Univariate and multivariate regression analyses were performed to identify variables with a significant effect on survival. RESULTS: CD79a was expressed in 5.8%, BCL6 in 14.7%, MUM1/IRF4 in 92.3%, BOB.1 in 53.4% and OCT.2 in 12.6% of cases. There was no significant association between CD79a or BCL6 expression and clinical characteristics. Univariate analysis showed that age of 45 or more, stage III and IV disease and MUM/IRF4 negative status were associated with significantly shorter time to progression (TTP) and overall survival (OS). On multivariate analysis the lack of MUM/IRF4 expression was associated with significantly shorter TTP while age of 45 or more and the presence of extralymphatic sites of disease were associated with significantly shorter OS. INTERPRETATION AND CONCLUSIONS: Our study has confirmed that MUM1/IRF4 is expressed in most cases of CHL and shows that lack of this expression in a minority of cases may be a potential adverse prognostic factor.

Acute myelogenous leukemia with tetrasomy 8 is a disease with a poor prognosis.

Tetrasomy 8 is an extremely rare chromosome abnormality, one that has been reported in only a few cases with myeloid malignancies. The majority of reported cases consist of acute myelogenous leukemias (AML) of monocytic lineage. In slightly more than half of the patients, tetrasomy 8 was the single cytogenetic abnormality. Fluorescence in situ hybridization revealed tetrasomy 8 and trisomy 8 concurrently in all but one of the bone marrow samples. The clonal relationship between trisomy 8 and tetrasomy 8 in these cases remains to be clarified. Patients with tetrasomy 8 have a poor prognosis, and only 1 out of 33 patients was free of disease 3 years after autologous bone marrow transplantation. Here, we report the case of a 25-year-old female patient with monocytic leukemia and tetrasomy 8.

Rituximab in combination with CNOP chemotherapy in patients with previously untreated indolent non-Hodgkin's lymphoma.

Rituximab, a chimeric monoclonal antibody, produces response rates of up to 73% in patients with previously untreated indolent non-Hodgkin's lymphoma (NHL), and has high activity when combined with chemotherapy. The purpose of this phase II study was to determine the efficacy and safety of rituximab plus cyclophosphamide, mitoxantrone, vincristine and prednisone (CNOP) chemotherapy in patients with indolent NHL. In all, 42 patients (median age 67 years) with previously untreated follicular, marginal zone or small lymphocytic/lymphoplasmacytic NHL received six infusions of rituximab (375 mg/m(2)) in combination with six cycles of CNOP. The overall response rate was 90% comprising 30 complete (71%) and eight partial (19%) responses. Although patients with marginal zone lymphoma or International Prognostic Index (IPI) score 3 had lower complete response rates, no significant difference in overall response rate was observed between the histological groups (P=0.24) or between patients stratified according to IPI score (P>0.05). Median overall survival, time-to-progression and response duration had not been reached after a median 19.5-month follow-up. In all, 31 patients (74%) are currently free from progression and 38 (90%) remain alive. Treatment was well tolerated. One patient (2%) experienced grade 3/4 infusion-related toxicity; 13 (31%) grade 3/4 leukopenia and 18 (43%) grade 3/4 neutropenia. Infection was observed in nine patients: eight (19%) grade 1/2 and one (2.4%) grade 3. This study demonstrates that combining rituximab with CNOP achieves high remission rates without significant additional toxicity in patients with previously untreated indolent NHL. Further follow-up will determine response duration and survival.

Primary treatment of low-grade non-Hodgkin's lymphoma with the combination of fludarabine and mitoxantrone: a phase II study of the Hellenic Cooperative Oncology Group.

The treatment of patients with recurrent low-grade lymphoma with the combination of fludarabine, mitoxantrone and dexamethasone has been associated with significant activity but has also caused frequent infectious complications. We designed a phase II study for previously untreated patients with the combination of fludarabine and mitoxantrone but without steroids. Our aim was to assess the activity of this combination as primary treatment for low-grade lymphoma and to avoid the additional immunosuppression induced by dexamethasone. Twenty seven patients with low-grade lymphoma received fludarabine 25 mg/m2/day i.v. on days 1-3 and mitoxantrone 10 mg/m2 i.v. on day 1. The treatment was repeated every 28 days for a maximum of six cycles. Twenty patients (74%) achieved an objective response including 12 (44%) complete and 8 (30%) partial responses. The main toxicity was grade III or IV neutropenia, which occurred in 40% of patients but there were no severe opportunistic infections. The median time to progression for all patients was 32 months. With a median follow-up of 33.4 months, six patients have died and the probability of survival at 3 years is 75%. We conclude that the fludarabine and mitoxantrone regimen is safe and effective for newly diagnosed patients with low-grade lymphoma who require treatment. Prospective randomized trials are needed in order to assess the impact of this treatment on patients' survival.

Hypermethylation of the p15INK4B gene promoter in B-chronic lymphocytic leukemia.

The p15 gene is a putative tumor suppressor gene that encodes a member of the cyclin dependent kinase inhibitors. Inactivation of p15 by promoter hypermethylation has been postulated as a possible way by which tumor suppressor genes are inactivated in cancer. In this study, we examined the methylation status of the p15 gene promoter in 34 patients with B-Chronic Lymphocytic Leukemia (B-CLL), by the Methylation-Specific Polymerase Chain Reaction. Selective methylation of the p15 gene promoter was found in 4/34 cases (11.8%). According to Rai staging, the four patients with methylated p15 were staged on diagnosis as: 1 on Stage 0, 1 in Stage I, 1 in Stage III, and 1 in Stage IV. Our results suggest that methylation of the p15 gene promoter can be detected in a small subset of B-CLL patients, at all stages of the disease.

Mutational and methylation analysis of the cyclin-dependent kinase 4 inhibitor (p16INK4A) gene in chronic lymphocytic leukemia.

OBJECTIVES: Chronic lymphocytic leukemia (CLL) comprises a heterogeneous group of at least two types of disease entities characterized by distinctive clinical, immunophenotypical and genetic features. The molecular mechanisms underlying the pathogenesis and the histological transformation of CLL are not well known. The INK4A/p16, a cyclin dependent kinase inhibitor has been considered as a tumor suppressor gene. Inactivation of this gene by homozygous deletions, mutations and hypermethylation occurs in a variety of human neoplasms. The aim of the present study was to determine the frequency of p16 gene deletions and mutations as well as the methylation status of the same gene in CLL patients. METHODS: We examined 34 samples from CLL patients by Southern Blotting, Single-Strand Conformation Polymorphism (SSCP), DNA sequencing and Methylation-Specific PCR. RESULTS: Southern Blot analysis revealed non-rearranged bands in 33/34 cases. Homozygous deletions were not observed in any case. In 1/34 case a rearranged band was detected with EcoRI enzyme. The PCR-SSCP analysis of exons 1 and 3 revealed normal pattern of migration in all cases examined. The analysis of exon 2 revealed abnormal migration pattern in 2/34 cases (5.8%). Sequencing of these cases revealed the presence of the ALA148THR polymorphism. Methylation analysis of p16 gene promoter revealed hypermethylation of CpG islands in 6/34 cases (17.6%). CONCLUSION: These results indicate that genetic alterations of p16 gene are rare events in patients with CLL. The clarification of the role of p16 gene promoter methylation in the pathogenesis and evolution of CLL needs further investigation.

Combination chemotherapy with gemcitabine and vinorelbine in the treatment of relapsed or refractory diffuse large B-cell lymphoma: a phase-II trial by the Hellenic Cooperative Oncology Group.

To investigate the efficacy and toxicity of the combination of gemcitabine and vinorelbine in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBL), 22 patients with relapsed or refractory DLBL were treated with gemcitabine 1000 mg/m2 and vinorelbine 30 mg/m2 on days 1 and 8 every 3 wk for a maximum of six cycles. Fourteen patients were considered chemosensitive while eight patients were considered chemoresistant to the last treatment regimen. All 22 patients were assessed for response to treatment. Three patients (14%) achieved complete remission and eight patients (36%) had partial remission of their disease, with an overall response rate of 50%. With a median follow up of 44 months, the median time to progression (TTP) for all patients was 8.1 months while the median overall survival (OS) was 12.9 months. Toxicity was minimal and all patients were treated on an outpatient basis. The combination of gemcitabine and vinorelbine is an effective and well-tolerated regimen for patients with relapsed of refractory DLBL.

Absence of p16 and p27 gene rearrangements and mutations in de novo myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) represent a group of clonal hematopoietic disorders characterized by dyshemopoiesis and frequent evolution to acute leukemia. Tumor suppressor gene inactivation may be involved in MDS pathogenesis. The two families of cyclin-dependent kinase inhibitors (CDKIs) (INK4 family of p15, p16, p18 and p19 and CIP/KIP family of p21, p27 and p57) that negatively regulate cell cycle progression are known tumor suppressor genes. To determine whether genetic alterations of p16 and p27 genes play an important role in MDS pathogenesis, we examined DNA from 51 patients classified as 17 refractory anemias (RA), four refractory anemias with ringed sideroblasts (RARS), 19 refractory anemias with an excess of blasts (RAEB), 5 refractory anemias with excess of blasts in transformation (RAEB-t) and 6 chronic myelomonocytic leukemias (CMML). Southern blot analysis detected no homozygous deletions of p16 and p27. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and sequencing did not reveal point mutations for both genes with the exception of two allelic polymorphisms, namely a C --> G transition at 447 bp of p16exon3 and a T --> A transition at 791 bp of p27exon1 genes. Our results suggest that mutations of p16 and p27 genes resulting in abnormal p16 and p27 proteins do not represent a mechanism of gene inactivation involved in the pathogenesis of MDS.

Multifocal extranodal non-hodgkin lymphoma: a clinicopathologic study of 37 cases in Greece, a Hellenic Cooperative Oncology Group study.

The purpose of this retrospective study was to illustrate the clinicopathological features of patients presenting with multifocal extranodal non-Hodgkin lymphoma (NHL). Among 810 patients with NHL, 37 cases (4.2%) were found to have multiple extranodal involvement (two or more sites). There were 24 men and 13 women, with a median age of 63 years. The majority of these cases (n = 26) had gastric or intestinal (GI) involvement with or without other extranodal sites. Lung along with another extranodal site was relatively common in the present series. Stratification of the 37 cases according to the International Prognostic Index (IPI) showed that 89% of the patients belonged to the high-risk groups. Diffuse large-B-cell lymphoma (DLBCL) accounted for 62%, and mucosa-associated lymphoma tissue (MALT) lymphoma accounted for 27% of all cases. After induction treatment with anthracycline-based regimens, complete remission was achieved in 21 patients (57%), partial remission was achieved in six patients (16%), and seven patients (19%) had no response, while three patients (8%) were nonevaluable. In conclusion, multifocal extranodal NHL is a heterogeneous group of diseases. The majority of them arise at various sites in the GI tract. DLBCL was the most frequent histological subtype followed by MALT lymphoma. Risk group, as defined by the IPI, was predictive of survival.