Pentoxifylline-Induced Apoptosis in Chronic Lymphocytic Leukemia: New Insights into Molecular Mechanism.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is an indolent B-lineage neoplasm, characterized by clonal expansion of CD5 positive B cells with constitutive activation of survival pathways including NF-kB. Pentoxifylline, a xanthine-derivative compound indicated for the treatment of microvascular disturbancies, has been suggested to have anti-proliferative and anti-metastatic activities in various types of cancer. In the present study we extend these data showing one of the potential molecular mechanisms through which Pentoxifylline may promote apoptosis in CLL clonal lymphocytes. METHODS: Peripheral blood mononuclear cells were isolated from 15 CLL patients 0 RAI stage and 15 healthy volunteers and treated for 24 and 48 hours with Pentoxifylline. Apoptosis induction was evaluated through Annexin V and TUNEL assays. Mitochondrial membrane potential depolarization analysis, active Caspase-3 assay, reactive oxygen species generation and Western Blot were assessed to further investigate the alterations induced by Pentoxifylline. RESULTS: We observed a statistically significant occurrence of apoptosis, DNA fragmentation and active Caspase-3 in lymphocytes from CLL patients compared to healthy volunteers after 48 hours of Pentoxifylline treatment. To clarify the molecular mechanism of the drug, we also evaluated the expression levels of NF-kB/p65 and its related proteins. In treated CLL cells, NF-kB/p65 was significantly decreased in comparison to normal cells, whereas we observed a less marked reduction of Bcl-2 expression. The treatment also induced a decrease of Mcl-1 in CLL cells with a greater down-regulation of the anti-apoptotic alternatively spliced isoform. CONCLUSION: These findings showed that Pentoxifylline induced apoptosis in leukemic cells through a molecular mechanism that involves the NF-kB signaling.

Monocyte count at diagnosis is a prognostic parameter in diffuse large B-cell lymphoma: results from a large multicenter study involving 1191 patients in the pre- and post-rituximab era.

In this study we assessed the prognostic significance of absolute monocyte count and selected the best cut-off value at diagnosis in a large cohort of patients with diffuse large B-cell lymphoma. Data were retrieved for therapy-naïve patients with diffuse large B-cell lymphoma followed in Israel and Italy during 1993-2010. A final cohort of 1017 patients was analyzed with a median follow up of 48 months and a 5-year overall survival rate of 68%. The best absolute monocyte count cut-off level was 630/mm(3) and the 5-year overall survival for patients with counts below this cut-off was 71%, whereas it was 59% for those with a count >630 mm(3) (P=0.0002). Of the 1017 patients, 521 (51%) were treated with chemo-immunotherapy, and in this cohort, using multivariate analysis, elevated monocyte count retained a negative prognostic value even when adjusted for International Prognostic Index (HR1.54, P=0.009). This large study shows that a simple parameter such as absolute monocyte count (>630/mm(3)) can easily be used routinely in the evaluation of newly diagnosed diffuse large B-cell lymphoma to identify high-risk patients with a worse survival in the rituximab era.

Monocytosis has adverse prognostic significance and impacts survival in patients with T-cell lymphomas.

In this retrospective study we evaluated the prognostic impact of peripheral blood monocytosis in patients with T-cell non Hodgkin lymphomas with "aggressive-typically nodal presentation". In this dataset monocytes >0.8 × 10(9)/L had a strong and statistically significant negative impact on overall survival (OS). In univariate analysis several parameters, including age >60 years, advanced stage, bone marrow involvement, ECOG PS >1, high LDH level, monocytes >0.8 × 10(9)/L, hemoglobin<120 g/L, albumin<35 g/L) had a negative influence on outcome, but in multivariate analysis, monocytosis alone had a stronger association with poor OS.

Radiation therapy improves treatment outcome in patients with diffuse large B-cell lymphoma.

The effects of radiotherapy (RT) after chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL) remain unclear; several trials have yielded conflicting results. This study examined the effect of RT after cyclophosphamide, doxorubicin, vincristine, and prednisone + rituximab (R-CHOP) treatment on event-free (EFS) and overall (OS) survival. Data from 216 patients with DLBCL who were enrolled in two clinical trials at Italian Lymphoma Study Group sites and were subjected to six R-CHOP cycles and involved-field radiotherapy (IFRT) were retrospectively analyzed. IFRT treatment yielded significant EFS benefit, with a 66% reduction in the risk of death and/or disease progression. Cox analysis, when adjusted for age, gender, stage, performance status (PS), lactate dehydrogenase (LDH), and disease bulk, confirmed the significant EFS benefit of IFRT. The role of RT in DLBCL in the rituximab era is unclear. Future studies must take into account new radiation techniques and the response to chemotherapy based on functional imaging. Prospective randomized trials incorporating response-adapted therapy and modern radiation techniques are needed.

Therapy-related myeloid neoplasm in non-hodgkin lymphoma survivors.

Relatively little data on secondary cancers is available regarding patients treated for non-Hodgkin lymphoma (NHL), compared with those treated for Hodgkin lymphoma. Evolving treatment regimens have improved survival outcomes for NHL patients. As a result of this improvement, secondary malignancies are becoming an important issue in NHL survivors. This review aims to report data on this topic previously published by our group, adding unpublished results from the Modena Cancer Registry (MCR). We recently performed four studies about secondary neoplasms in NHL survivors: two studies analysing the risk of secondary neoplasms in patients treated for indolent and aggressive NHL; a meta-analysis of 23 studies investigating the risk of secondary malignant neoplasm (SMN) after NHL treatment; and a still-unpublished study evaluating the incidence of therapy-related myeloid neoplasm (t-MN) in patients treated for NHL (from the MCR database). The first two studies analysed 563 patients with indolent NHL and 1280 patients with diffuse large B-cell lymphoma (DLBCL) enrolled in the Gruppo Italiano Studio Linfomi (GISL) trials. Results showed that the cumulative incidence of secondary tumours was 10.5% at 12 years for indolent NHL and 8.2% at 15 years for DLBCL. Results of the meta-analysis indicated that NHL patients experienced a 1.88-fold increased risk for SMN compared with the general population; the standardized incidence risk (SIR) for secondary acute myeloid leukaemia (AML) was 11.07. Based on data from the MCR from 2000 through 2008, we found that the SIR was 1.63 for developing a secondary malignancy after NHL, and 1.99 for developing secondary haematological malignancies. Regarding myelodysplastic syndrome and/or AML incidence, nine NHL patients developed t-MN with a higher risk than expected (SIR 8.8, 95% CI: 4.0-16.6). In conclusion, patients treated for NHL are at increased risk of developing SMN. Regarding t-MN, data from the meta-analysis and the MCR demonstrate an excessive risk of developing AML (SIR 11.07 and 5.7, respectively) compared with solid SMN after treatment for NHL. Thus long-term monitoring should be considered for NHL survivors.