Concetta Conticello

CD200 expression may help in differential diagnosis between mantle cell lymphoma and B-cell chronic lymphocytic leukemia

Chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma (MCL) share many features and their differential diagnosis may be challenging, especially when a leukemic picture alone is present. Monoclonal antibody panels are often useful, with CD23 being the most reliable. However, MCL diagnosis should be confirmed by immunohistochemical cyclin D1 detection, sometimes with equivocal or even negative results. Other cytofluorimetric, cytogenetics or molecular techniques are reliable but not widely available. B-CLL leukemic cells express CD200, a membrane glycoprotein belonging to the immunoglobulin superfamily. We investigated its expression on fresh neoplastic cells of 93 patients with a CD5+ lymphoproliferative disease (79 selected B-CLL and 14 MCL in leukemic phase). Although these data cannot be generalized, all B-CLL samples we examined were positive, with CD200 present on the vast majority of the cells while, in MCL patients, CD200 was expressed by a small minority of CD5+ cells in three subjects and totally absent in the remaining 11. We then examined CD200 expression on paraffin-embedded lymphoid tissues and bone marrow (BM) trephine biopsies from 23 B-CLL and 44 MCL patients. Again, all B-CLL cells were CD200+ both in lymph nodes and in BM while all MCL cells were negative. Adding CD200 in routine panels could be of diagnostic utility in excluding MCL diagnosis.

Carfilzomib, cyclophosphamide, and dexamethasone in patients with newly diagnosed multiple myeloma: a multicenter, phase 2 study

This multicenter, open-label phase 2 trial determined the safety and efficacy of carfilzomib, a novel and irreversible proteasome inhibitor, in combination with cyclophosphamide and dexamethasone (CCyd) in patients with newly diagnosed multiple myeloma (NDMM) ≥65 years of age or who were ineligible for autologous stem cell transplantation. Patients (N = 58) received CCyd for up to 9 28-day cycles, followed by maintenance with carfilzomib until progression or intolerance. After a median of 9 CCyd induction cycles (range 1-9), 95% of patients achieved at least a partial response, 71% achieved at least a very good partial response, 49% achieved at least a near complete response, and 20% achieved stringent complete response. After a median follow-up of 18 months, the 2-year progression-free survival and overall survival rates were 76% and 87%, respectively. The most frequent grade 3 to 5 toxicities were neutropenia (20%), anemia (11%), and cardiopulmonary adverse events (7%). Peripheral neuropathy was limited to grades 1 and 2 (9%). Fourteen percent of patients discontinued treatment because of adverse events, and 21% of patients required carfilzomib dose reductions. In summary, results showed high complete response rates and a good safety profile. This trial was registered at clinicaltrials.gov as #NCT01346787.

Multiple members of the TNF superfamily contribute to IFN-γ-mediated inhibition of erythropoiesis

IFN-γ inhibits the growth and differentiation of erythroid precursor cells and mediates hemopoietic suppression through mechanisms that are not completely understood. We found that treatment of human erythroid precursor cells with IFN-γ up-regulates the expression of multiple members of the TNF family, including TRAIL and the recently characterized protein TWEAK. TWEAK and its receptor fibroblast growth factor-inducible 14 (Fn14) were expressed by purified erythroblasts at all the stages of maturation. Exposure to recombinant TWEAK or agonist anti-Fn14 Abs was able to inhibit erythroid cell growth and differentiation through caspase activation. Because other members of the TNF family such as TRAIL and CD95 ligand (CD95L) are known to interfere with erythroblast growth and differentiation, we investigated the role of different TNF/TNFR family proteins as potential effectors of IFN-γ in the immature hemopoietic compartment. Treatment of erythroid precursor cells with agents that blocked either TRAIL, CD95L, or TWEAK activity was partially able to revert the effect of IFN-γ on erythroid proliferation and differentiation. However, the simultaneous inhibition of TRAIL, TWEAK, and CD95L resulted in a complete abrogation of IFN-γ inhibitory effects, indicating the requirement of different receptor-mediated signals in IFN-γ-mediated hemopoietic suppression. These results establish a new role for TWEAK and its receptor in normal and IFN-γ-mediated regulation of hematopoiesis and show that the effects of IFN-γ on immature erythroid cells depend on multiple interactions between TNF family members and their receptors.

Immunological Dysregulation in Multiple Myeloma Microenvironment

Multiple Myeloma (MM) is a systemic hematologic disease due to uncontrolled proliferation of monoclonal plasma cells (PC) in bone marrow (BM). Emerging in other solid and liquid cancers, the host immune system and the microenvironment have a pivotal role for PC growth, proliferation, survival, migration, and resistance to drugs and are responsible for some clinical manifestations of MM. In MM, microenvironment is represented by the cellular component of a normal bone marrow together with extracellular matrix proteins, adhesion molecules, cytokines, and growth factors produced by both stromal cells and PC themselves. All these components are able to protect PC from cytotoxic effect of chemo- and radiotherapy. This review is focused on the role of immunome to sustain MM progression, the emerging role of myeloid derived suppressor cells, and their potential clinical implications as novel therapeutic target.

Effects of imatinib mesylate in osteoblastogenesis.

Imatinib mesylate (IM), a tyrosine kinase inhibitor currently used in chronic myeloid leukemia (CML), may also affect the growth of other cellular systems besides CML cells. Because it has been reported that IM may affect bone tissue remodeling, we evaluated the effects of IM on osteoblastic differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs). After 21 days of culture, hBM-MSCs treated with IM (1 microM) alone or osteogenic medium (OM) + IM showed changes in morphology with evidence of extracellular mineralization and increased mRNA expression of osteogenic markers, such as RUNX2, osteocalcin (OCN), and bone morphogenetic protein (BMP-2). We also observed that levels of OCN and the osteoprotegerin (OPG)/receptor activator of nuclear factor-kappa B ligand (RANKL) ratio (OPG/RANKL ratio) were increased in the surnatant of the 21-day culture with IM or OM + IM compared to controls (p<0.005). In addition, we found that in 46 serum samples collected from CML patients treated with IM for 3 to 24 months, the OPG/RANKL ratio increased after 3 and 6 months (p<0.004) returning back to the basal level after 24 months of IM treatment. In these patients, OCN levels were low at diagnosis but they increased throughout the IM treatment, approaching normal levels at 24 months of IM therapy. In summary, our data show that IM increases mRNA expression of osteogenic markers in hBM-MSCs and increases the OPG/RANKL ratio and the OCN levels both in surnatant of hBM-MSCs cultured with IM and in serum of patients treated with IM, thus indicating that IM potentially favors osteoblastogenesis.

Paclitaxel loading in PLGA nanospheres affected the in vitro drug cell accumulation and antiproliferative activity

BackgroundPTX is one of the most widely used drug in oncology due to its high efficacy against solid tumors and several hematological cancers. PTX is administered in a formulation containing 1:1 Cremophor® EL (polyethoxylated castor oil) and ethanol, often responsible for toxic effects. Its encapsulation in colloidal delivery systems would gain an improved targeting to cancer cells, reducing the dose and frequency of administration.MethodsIn this paper PTX was loaded in PLGA NS. The activity of PTX-NS was assessed in vitro against thyroid, breast and bladder cancer cell lines in cultures. Cell growth was evaluated by MTS assay, intracellular NS uptake was performed using coumarin-6 labelled NS and the amount of intracellular PTX was measured by HPLC.ResultsNS loaded with 3% PTX (w/w) had a mean size < 250 nm and a polydispersity index of 0.4 after freeze-drying with 0.5% HP-Cyd as cryoprotector. PTX encapsulation efficiency was 30% and NS showed a prolonged drug release in vitro. An increase of the cytotoxic effect of PTX-NS was observed with respect to free PTX in all cell lines tested.ConclusionThese findings suggest that the greater biological effect of PTX-NS could be due to higher uptake of the drug inside the cells as shown by intracellular NS uptake and cell accumulation studies.

Disulfiram, an old drug with new potential therapeutic uses for human hematological malignancies

Disulfiram (DSF) is an aldehyde dehydrogenase inhibitor currently used for the treatment of alcoholism. Here, we show that multiple myeloma (MM) cell lines and primary cells from newly diagnosed and relapsed/resistant patients affected by MM, acute myeloid and lymphoblastic leukemia are significantly sensitive to DSF alone and in combination with copper. These effects are present at doses lower than those achievable in vivo after DSF standard administration. The cytotoxic effect achieved by this treatment is comparable to that obtained by conventional chemotherapy and is absent in normal hematopoietic cells. In addition, we found that DSF plus copper induces loss of mitochondrial membrane potential, triggers reactive oxygen species (ROS) production and activates executioner caspases. DSF‐copper‐induced apoptosis and caspases activation are strongly reversed by antioxidant N‐acetylcysteine, thus indicating a critical role of ROS. These results might suggest the use of the old drug DSF, alone or in combination with copper, in the treatment of hematological malignancies.

Triplet vs doublet lenalidomide-containing regimens for the treatment of elderly patients with newly diagnosed multiple myeloma

Lenalidomide-dexamethasone improved outcome in newly diagnosed elderly multiple myeloma patients. We randomly assigned 662 patients who were age ≥65 years or transplantation-ineligible to receive induction with melphalan-prednisone-lenalidomide (MPR) or cyclophosphamide-prednisone-lenalidomide (CPR) or lenalidomide plus low-dose dexamethasone (Rd). The primary end point was progression-free survival (PFS) in triplet (MPR and CPR) vs doublet (Rd) lenalidomide-containing regimens. After a median follow-up of 39 months, the median PFS was 22 months for the triplet combinations and 21 months for the doublet (P = .284). The median overall survival (OS) was not reached in either arms, and the 4-year OS was 67% for the triplet and 58% for the doublet arms (P = .709). By considering the 3 treatment arms separately, no difference in outcome was detected among MPR, CPR, and Rd. The most common grade ≥3 toxicity was neutropenia: 64% in MPR, 29% in CPR, and 25% in Rd patients (P < .0001). Grade ≥3 nonhematologic toxicities were similar among arms and were mainly infections (6.5% to 11%), constitutional (3.5% to 9.5%), and cardiac (4.5% to 6%), with no difference among the arms. In conclusion, in the overall population, the alkylator-containing triplets MPR and CPR were not superior to the alkylator-free doublet Rd, which was associated with lower toxicity. This study was registered at www.clinicaltrials.gov as #NCT01093196.

Antitumor activity of bortezomib alone and in combination with TRAIL in human acute myeloid leukemia.

Acute myeloid leukemia (AML) is a malignant disease characterized by abnormal proliferation of clonal precursor cells. Although different strategies have been adopted to obtain complete remission, the disease actually progresses in about 60–70% of patients. Bortezomib has been used in multiple myeloma and other lymphoid malignancies because of its antitumor activity. Here we examined the sensitivity of bone marrow cells from AML patients (34 patients: 25 newly diagnosed, 4 relapsed, 5 refractory) to bortezomib alone or in combination with TRAIL, a member of the TNF family that induces apoptosis in tumor cells while sparing normal cells. Bortezomib induced cell death in blasts from each patient sample. The cytotoxic effect was dose- and time-dependent (concentration from 0.001 to 10 µM for 24 and 48 h) and was associated with a downregulation of Bcl-xL and Mcl-1, an upregulation of TRAIL-R1, TRAIL-R2, p21, activation of executioner caspases and a loss of the mitochondrial membrane potential. Moreover, low doses of bortezomib primed TRAIL-resistant AML cells for enhanced TRAIL-mediated killing. These results suggest that a combination of proteasome inhibitors and TRAIL could be effective for treating AML patients, even patients who are refractory to conventional chemotherapy.

Effects of second-generation tyrosine kinase inhibitors towards osteogenic differentiation of human mesenchymal cells of healthy donors

The BCR‐ABL inhibitor imatinib is a standard first‐line therapy for patients with chronic myeloid leukemia. However, it has been demonstrated that this long‐term treatment is associated with altered bone metabolism. The mechanisms of this effect are not fully understood, but an inhibition of the platelet‐derived growth factor receptor (PDGF‐R) β axis has been suspected on the basis of some in vitro findings. We evaluated the osteoblastic differentiation of mesenchymal stem cells derived from bone marrow (hBM‐MSCs) after in vitro treatment with dasatinib, nilotinib or bosutinib. Human bone marrow mesenchymal stem cells were induced to differentiate in osteoblastic cells by treatment with osteogenic medium with or without dasatinib, nilotinib or bosutinib. We found that the addition of dasatinib, and to a greater extend nilotinib, induced expression of osteogenic mRNA markers as compared with cultures with standard medium or osteogenic medium only. However, treatment with bosutinib did not induce an increase of osteogenic markers. In conclusion, we show that besides imatinib, other tyrosine kinase inhibitors (TKIs) such as dasatinib and nilotinib, but not bosutinib, increase osteogenic markers in hBM‐MSCs. Because bosutinib differs from the other TKIs because of its low affinity to other kinases such as PDGF‐R, these experiments suggest that inhibition of PDGF‐R may be involved in the induction of osteoblastogenesis by TKIs. Copyright