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Mantle Cell Lymphoma (MCL) is still an incurable B-cell malignancy characterized by poor prognosis and frequent relapses. B Cell Receptor (BCR) signaling inhibitors, in particular of the kinases BTK and PI3Kγ/δ, have demonstrated clinically meaningful anti-proliferative effects in B cell tumors. However, refractoriness to these drugs may develop, portending a dismal prognosis. Protein kinase CK1α is an emerging pro-growth enzyme in B cell malignancies. In multiple myeloma, this kinase sustains β-catenin and AKT-dependent survival and is involved in the activation of NF-κB in B cells. In this study, we analyzed the role of CK1α on MCL cell survival and proliferation, on the regulation of BCR-related BTK, NF-κB, PI3K/AKT signaling cascades and the effects of CK1α chemical inhibition or gene silencing in association with the BTK inhibitor Ibrutinib or the PI3Kγ/δ inhibitor Duvelisib. CK1α was found highly expressed in MCL cells as compared to normal B cells. The inactivation/loss of CK1α caused MCL cell apoptosis and proliferation arrest. CK1α sustained BCR signaling, in particular the NF-κB, AKT and BTK pathways by modulating the phosphorylation of Ser 652 on CARD11, Ser 536 p65 on NF-κB, Ser 473 on AKT, Tyr 223 on BTK, as well as the protein levels. We also provided evidence that CK1α-mediated regulation of CARD11 and BTK likely implicates a physical interaction. The combination of CK1α inhibition with Ibrutinib or Duvelisib synergistically increased cytotoxicity, leading to a further decrease of the activation of BCR signaling pathways. Therefore, CK1α sustains MCL growth through the regulation of BCR-linked survival signaling cascades and protects from Ibrutinib/Duvelisib-induced apoptosis. Thus, CK1α could be considered as a rational molecular target for the treatment of MCL, in association with novel agents.

Limbic encephalitis is a rare paraneoplastic neurological syndrome usually associated with small cell lung cancers, testicular and breast cancers or B-cell lymphomas. We herein report the first patients with paraneoplastic limbic encephalitis associated with HU antibodies and anaplastic T-cell lymphoma.

Idiopathic pulmonary fibrosis (IPF) is mainly characterized by aberrant extracellular matrix deposition, consequent to epithelial lung injury and myofibroblast activation, and inflammatory response. Glycogen synthase kinase 3 (GSK-3) is a serine–threonine kinase involved in several pathways, and its inhibition has been already suggested as a therapeutic strategy for IPF patients. There is evidence that GSK-3 is able to induce matrix metalloproteinase (MMP) expression and that its inhibition modulates MMP expression in the tissues. The aim of our study was to investigate the role of GSK-3 and its inhibition in the modulation of MMP-9 and -2 in anin vivomouse model of lung fibrosis andin vitrousing different cell lines exposed to pro-inflammatory or pro-fibrotic stimuli. We found that GSK-3 inhibition down-modulates gene expression and protein levels of MMP-9, MMP-2, and their inhibitors TIMP-1 and TIMP-2 in inflammatory cells harvested from bronchoalveolar lavage fluid (BALF) of mice treated with bleomycin as well as in interstitial alveolar macrophages and cuboidalized epithelial alveolar cells. To the same extent, GSK-3 inhibition blunted the increased MMP-9 and MMP-2 activity induced by pro-fibrotic stimuli in a human lung fibroblast cell line. Moreover, the αSMA protein level, a marker of fibroblast-to-myofibroblast transition involved in fibrosis, was decreased in primary fibroblasts treated with TGFβ following GSK-3 inhibition. Our results confirm the implication of GSK-3 in lung inflammation and fibrosis, suggesting that it might play its role by modulating MMP expression and activity but also pushing fibroblasts toward a myofibroblast phenotype and therefore enhancing extracellular matrix deposition. Thus, its inhibition could represent a possible therapeutic strategy.

Introduction: The outcome of patients with acute myeloid leukemia (AML) secondary to myelodisplastic syndrome (MDS) or therapy-related (t-AML) receiving conventional treatment and allogeneic stem cell transplantation consolidation (HSCT) is poor. CPX-351 is a new drug composed by liposomal encapsulated cytarabine and daunorubicin, at a fixed molecular ratio of 5:1. It showed superior results, compared to standard 3+7 induction, in a phase III trial (Lancet et al, JCO 2018) in patients affected by t-AML or AML with myelodisplasia-related changes and it is now commercially available for secondary AML (sAML). We recently published results from CPX-351 Italian Named (Compassionate) Use Program (CUP) which enrolled 73 elderly sAML patients (Guolo et al, Blood Cancer J. 2020) showing that CPX-351 is an effective induction regimen for high risk AML patients treated with a curative aim. With a limited follow up, our data suggested the good activity and tolerability of CPX-351. Good quality remissions with acceptable toxicity in the majority of patients was achieved and CPX-351 increased the feasibility of HSCT in a poor risk AML cohort. Scarce data are available on long term outcome of high risk patients receiving CPX-351 in the real life setting. Here we report the results from the extended follow up analysis of the Italian CUP. Results: Seventy three patients were enrolled between December 2018 and June 2019 in a compassionate use program (CUP) in 33 Italian Hematology Centers. Data collection began on July 2019 and included 71/73 patients (97.2%), enrolled in 31 Centers. As previously reported, median age was 65.5 years (52-79). Sixty-two (88%) patients had at least one relevant comorbidity upon enrollment. Six patients (9%) presented with ECOG 3-4 upon enrollment. With a median follow up of 22 months, median overall survival (OS) was 13 months (21.2 - 22.8 95% IC). Two-years OS was 28.6% in the whole cohort. In order to confirm the positive impact of HSCT in first complete remission (CR) and the correlation with the other variables, a landmark model was applied, including only patients alive and in CR at day 90. In landmark analysis, HSCT performed in first CR after CPX-351 was the only significant predictor of longer survival: median OS was not reached for patients transplanted in first CR Vs 12 months for patients who did not undergo HSCT, p < 0.05, Figure1). Two-year OS for patients who received HSCT was 57.6% vs 15.8% for patients who did not undergo HSCT. Conclusions: Results from the extended follow up of Italian CPX-351 CUP confirm the good activity CPX-351 in such a difficult cohort as sAML. Two-year OS for transplanted patients is high despite the high median age, the high frequency of severe comorbidities in this real life cohort of patients and the high frequency of high risk AML. On the contrary, non-transplanted patients show a poor outcome, thus confirming that CPX-351 induction as an optimal bridge to transplant induction therapy. Figure 1 Figure 1. Disclosures Galimberti: Incyte: Speakers Bureau; AbbVie, Janssen: Honoraria, Other: Travel grants. Marco: Insight,: Consultancy; Jazz: Consultancy; Janssen: Consultancy. Fracchiolla: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Speakers Bureau. Tafuri: Roche: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Rossi: Novartis: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alexion: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria; Takeda: Membership on an entity's Board of Directors or advisory committees. Pagano: Gilead Science, MSD, Pfizer, Basilea, Janssen, Novartis, Jazz Pharmaceutical, Cidara: Membership on an entity's Board of Directors or advisory committees; Menarini: Consultancy; Gilead Sciences, MSD, Pfizer Pharmaceuticals, Astellas Pharma: Speakers Bureau.

Blinatumomab (Blina) and inotuzumab (InO) have improved the outcome of relapsed/refractory B-lymphoblastic leukemia (R/R B-ALL). However, many patients (pts) relapse after these treatments and little is known on their outcomes after recurrence and re-treatment with subsequent immunotherapy. We hereby describe the clinical characteristics and outcome of 71 pts with R/R B-ALL treated with both Blina and InO in any sequence - Blina/InO or InO/Blina - at different disease recurrences. At diagnosis, the median age was 34 years (15-64) and the male/female ratio was 1.6. Sixteen pts (22%) were Ph+ ALL, 3 (4%) were t(4;11)+ and 9 (13%) carried a complex karyotypes. ECOG PS was 0-1 in 66 pts (93%). At the time of the first immunotherapy, pts had received a median of 2 previous lines of treatment (1-8). All Ph- pts received intensive chemotherapy front-line; Ph+ pts received TKIs and steroids in 13 cases and intensive chemotherapy plus TKIs in 3 cases. Blina was the first salvage treatment (Blino/InO sequence) in 57 pts (80%) and InO (InO/Blina sequence) in 14 (20%). Twenty-seven pts (38%) had underwent a previous allogeneic hematopoietic stem cell transplantation (HSCT). At the start of Blina as first immunotherapy, the median bone marrow (BM) blast count was 40% (0-100%); at the start of InO as first immunotherapy, the median BM blast count was 64% (2-90%). An extramedullary involvement was present in 5 patients (9%) in the Blina/InO group and in 1 patients (7%) in the InO/Blina group. During immunotherapy, the median number of lumbar punctures was 2 (0-9). A median of 2 cycles were administered for both Blina (range 1-9) and Ino (range 1-4). In the Blina/InO group, after Blina a G3/4 toxicity occurred in 15 cases (26%): non-hematologic in 12 cases (21%), neurologic in 6 (8%). Infections occurred in 17 pts (30%). In the InO/Blina group, after InO a G3/4 toxicity occurred in 3 pts (21%), with extra-hematologic toxicity in 2 cases (14%, liver toxicity 1 case). Infections occurred in 4 cases (28%). In the Blina/InO group, after Blina 36 pts (63%) achieved a complete remission (CR), with a negative minimal residual disease (MRD) in 24 (42%) pts; after InO, a CR was re-achieved in 47 pts (82.4%), with 34 (59.6%) being MRD-. In the InO/Blina group, after InO a CR was reached in 13 cases (93%), with 6 pts (42.8%) being MRD-; after Blina, a CR was re-achieved in 6 pts (42.8%), with 3 (21.4%) being MRD-. This salvage immunotherapy strategy represented a bridge to alloHSCT for 26 pts (37%). From the first immunotherapy, in the Blina/InO group, the median overall survival (OS) was 19 months and after InO 6.3 months (OS in MRD- vs MRD+, p ns). Disease free survival (DFS) after Blina was 7.4 months (11.6 vs 2.7 months in MRD- vs MRD+ pts, p .03) and after InO it was 5.4 months (MRD- vs MRD+ pts, p ns). In the InO/Blina group, the median OS was 9.4 months and after Blina 4.6 months (7.5 vs 2.8 months in MRD- vs MRD+ pts, p .02). DFS after InO was 5.1 months (MRD- vs MRD+ pts, p ns) and after Blina it was 1.5 months (8.7 vs 2.5 gg in MRD- vs MRD+ pts, p .02). OS and DFS in MRD- pts after Blina was significantly better, both in the Blina/InO and the InO/Blina groups. With a median follow-up of 16.5 months from the start of immunotherapy and 33.8 months from initial diagnosis, 24 pts (34%) are alive and 16 (22%) are alive in CR. Four patients (6%) died in CR due to veno-occlusive disease during HSCT after InO treatment. Interestingly, OS and DFS from the first immunotherapy was better in pts with a previous alloHSCT (median survival 24.2 vs 13 months, p=.0135). AlloHSCT after second immunotherapy was associated with a better OS and DFS (OS 9.8 and DFS 7.2 months vs 7.8 and 4.4 months, p ns). Our real-life study in R/R B-cell ALL pts with multiple previous lines of treatment demonstrates the feasibility and efficacy of a sequential immunotherapy strategy in terms of MRD response, DFS and OS, and as a bridge to HSCT. SM and PC: equal contributors Disclosures Papayannidis: Janssen: Honoraria; Astellas: Honoraria; AbbVie: Honoraria; Amgen: Honoraria; Pfizer: Honoraria; Novartis: Honoraria. Curti: Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Chiaretti: amgen: Consultancy; pfizer: Consultancy; novartis: Consultancy; Incyte: Consultancy. Forghieri: Jannsen: Membership on an entity's Board of Directors or advisory committees; Novartis: Speakers Bureau; Jazz: Honoraria. Bonifacio: Bristol Myers Squibb: Honoraria; Amgen: Honoraria; Novartis: Honoraria; Pfizer: Honoraria. Cerrano: Janssen: Honoraria; Insight: Honoraria; Jazz: Honoraria. Fracchiolla: Gilead: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Bacterial infections represent life-threatening complications in patients with febrile neutropenia (FN). Diagnostic biomarkers of infections may help to differentiate bacteraemia from non-bacteraemia FN. We aimed to evaluate the utility of procalcitonin (PCT), presepsin (PS), C-reactive protein (CRP) and interleukin-8 (IL-8) as biomarkers of bacteraemia in adult FN patients with haematological malignancies. Concentrations of PCT, PS, CRP and IL-8 were prospectively measured in 36 FN episodes experienced by 28 oncohaematological patients. 11 out of 36 episodes were classified as bacteraemia. PCT was the best biomarker to predict bacteraemia with the area under the curve (AUC) ROC of 0,9; specificity 100% and positive predictive value 100%, while the most sensitive was IL-8 (90,9%) with AUC ROC of 0,88 and negative predictive value 95,2%. All patients with PCT concentrations above 1,6 μg/l had bacteraemia. Patients with IL-8 concentrations superior to 170 pg/ml had a 40 times higher risk for bacteraemia than the ones with lower levels. Patients with PS concentrations superior to 410 pg/ml had 24 times higher risk for bacteraemia than the patients with lower levels. PCT has higher accuracy than CRP, IL-8 and PS in predicting bacteraemia in adult hematologic patients with FN.

Chromosomal rearrangements involving 3q26 are recurrent findings in myeloid malignancies leading to MECOM overexpression, which has been associated with a very poor prognosis. Other 3q abnormalities have been reported and cryptic MECOM rearrangements have been identified in some cases. By fluorescence in situ hybridization (FISH) analysis, we investigated 97 acute myeloid leukemia/myelodysplastic syndrome patients with various 3q abnormalities to determine the role and the frequency of the involvement of MECOM. We identified MECOM rearrangements in 51 patients, most of them showed 3q26 involvement by chromosome banding analysis (CBA): inv(3)/t(3;3) (n = 26) and other balanced 3q26 translocations (t(3q26)) (n = 15); the remaining cases (n = 10) showed various 3q abnormalities: five with balanced translocations involving 3q21 or 3q25; two with homogenously staining region (hsr) on 3q; and three with other various 3q abnormalities. Complex rearrangements with multiple breakpoints on 3q, masking 3q26 involvement, were identified in cases with 3q21/3q25 translocations. Furthermore, multiple breaks were observed in two cases with t(3q26), suggesting that complex rearrangement may also occur in apparently simple t(3q26). Intrachromosomal gene amplification was another mechanism leading to MECOM overexpression in two cases with hsr on 3q. In the last three cases, FISH analysis revealed 3q26 involvement that was missed by CBA because of metaphases' suboptimal quality. All cases with MECOM rearrangements showed overexpression by real-time quantitative PCR. Finally, MECOM rearrangements can occur in patients with 3q abnormalities even in the absence of specific 3q26 involvement, underlining that their frequency is underestimated. As MECOM rearrangement has been associated with very poor prognosis, its screening should be performed in patients with any 3q abnormalities.

Protein kinase CK2 sustains acute myeloid leukemia cell growth, but its role in leukemia stem cells is largely unknown. Here, we discovered that the CK2 catalytic α and regulatory β subunits are consistently expressed in leukemia stem cells isolated from acute myeloid leukemia patients and cell lines. CK2 inactivation with the selective inhibitor CX-4945 or RNA interference induced an accumulation of leukemia stem cells in the late S-G2-M phases of the cell cycle and triggered late-onset apoptosis. As a result, leukemia stem cells displayed an increased sensitivity to the chemotherapeutic agent doxorubicin. From a molecular standpoint, CK2 blockade was associated with a downmodulation of the stem cell-regulating protein BMI-1 and a marked impairment of AKT, nuclear factor-κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) activation, whereas FOXO3a nuclear activity was induced. Notably, combined CK2 and either NF-κB or STAT3 inhibition resulted in a superior cytotoxic effect on leukemia stem cells. This study suggests that CK2 blockade could be a rational approach to minimize the persistence of residual leukemia cells.

Most important markers in chronic lymphocytic leukemia (CLL) are TP53 abnormalities, including mutations and deletions, and the mutational status of immunoglobulin heavy chain (IGHV) genes. However, some recent publications suggest that the IGHV mutational load could have a prognostic effect on CLL patients.We performed a single-center retrospective study on 459 patients with productive rearrangement of the B-cell receptor to evaluate the prognostic and predictive role of IGHV mutational status and burden within the germline sequence. In particular we focused on FCR (fludarabine with cyclophosphamide, and rituximab)- (64 naive and 30 relapsed) and BR (bendamustine with rituximab)-treated patients (17 naive and 61 relapsed). A cutoff value of 2% of difference within the IGHV germline was used to define the IGHV mutational status.We reported that unmutated IGHV (U-IGHV) patients were characterized by a significant shorter progression-free survival (PFS) and overall survival (P .0001) compared with mutated IGHV (M-IGHV) patients. Moreover, treatment-naive M-IGHV patients experienced a long-term disease control after FCR or BR, with PFS reaching a plateau regardless of mutational load. In our series the extent of IGHV gene mutation did not provide further relevant prognostic data over the mutational status. Relapsed patients showed dismal outcome with chemoimmunotherapy regardless of IGHV status or load.Our data, together with from those from the literature, confirmed the cutoff value of 2% to define the mutational status of IGHV gene and suggest that FCR/BR are good first-line treatment strategies for M-IGHV patients, whereas U-IGHV patients should be managed with B-cell receptor and/or B-cell lymphoma 2 (BCL2) inhibitors.

Background Major infections (MIs), secondary cancers (SCs) and autoimmune diseases (ADs) are the most common and relevant complications in patients with chronic lymphocytic leukaemia. Methods We performed a single-centre retrospective study to investigate the prevalence of the above quoted complications, the association with most important prognostic markers and their impact on survival (n = 795). Results Almost one out of three patients experienced at least one complication and only 0.9% of the cohort developed all three complications. One hundred and twenty (20%) subjects developed SC, 98 MI (12%) and 80 AD (10%); these complications seem to occur in a mutually exclusive manner. By Kaplan–Meier analysis we estimated that after 20 years from the diagnosis SC, MI and AD occurred in 48%, 42% and 29% of patients, respectively. Furthermore, we showed that some clinical and biological markers are skewed among patients with different complications and that subjects with MI and SC had a worse prognosis than those with AD and all other patients (p Conclusions This study reveals the existence of different clinical subsets of chronic lymphocytic leukaemia patients characterised by an increased and different risk for developing specifically MI, SC and AD.

Glycogen synthase kinase (GSK)-3 modulates the production of inflammatory cytokines. Because bleomycin (BLM) causes lung injury, which is characterized by an inflammatory response followed by a fibrotic degeneration, we postulated that blocking GSK-3 activity with a specific inhibitor could affect the inflammatory and profibrotic cytokine network generated in the BLM-induced process of pulmonary inflammation and fibrosis. Thus, here we investigated the effects of the GSK-3 inhibitor 3-(2,4-dichlorophenyl)-4-(1-methyl-1H-indol-3-yl)-1H-pyrrole-2,5-dione (SB216763) on a BLM-induced lung fibrosis model in mice. SB216763 prevented lung inflammation and the subsequent fibrosis when coadministered with BLM. Bronchoalveolar lavage fluid analysis of mice treated with BLM plus SB216763 revealed a significant reduction in BLM-induced alveolitis. Furthermore, SB216763 treatment was associated with a significantly lower production of inflammatory cytokines by macrophages. BLM-treated mice that received SB216763 developed alveolar epithelial cell damage and pulmonary fibrosis to a significantly lower extent compared with BLM-treated controls. These findings suggest that GSK-3 inhibition has a protective effect on lung fibrosis induced by BLM and candidate GSK-3 as a potential therapeutic target for preventing pulmonary fibrosis.

We have shown previously that the che- mokine receptors CXCR3 and CXCR6 are coex- pressed by Th1 cells infiltrating the lung and the granuloma of patients with sarcoidosis. In this study, we evaluated the role of CCL20/CCR6 in- teraction in the pathogenesis of acute and chronic pulmonary sarcoidosis. By flow cytometry and mo- lecular analyses, we have demonstrated that Th1 cells isolated from the bronchoalveolar lavage (BAL) of patients with sarcoidosis and T cell alve- olitis are equipped with CCR6. Furthermore, CCR6 T cells coexpressed the chemokine recep- tors CXCR3 and CXCR6. Immunohistochemical analysis of lung specimens has shown that CCR6 T cells infiltrate lung interstitium and surround the central core of the granuloma. It is interesting that CCR6 was never detected on the alveolar macro- phage (AM) surface, and it is observed in the cyto- plasm of AMs from patients with sarcoidosis and alveolitis. The CCR6 ligand CCL20 was expressed by macrophages, multinucleated giant cells, and epithelioid cells infiltrating the granuloma. Fur- thermore, detectable levels of CCL20 protein are seen in the BAL fluid components of patients with active sarcoidosis, and sarcoid AMs release the CCR6 ligand in vitro. From a functional point of view, sarcoid Th1 cells were able to respond to CXCL10, CXCL16, and CCL20 in migratory as- says. In vitro kinetic studies demonstrated that CCR6 is induced rapidly by IL-2, IL-18, and IFN-. In conclusion, T cells expressing CCR6, CXCR3, and CXCR6 act coordinately with respec- tive ligands and Th1 inflammatory cytokines in the alveolitic/granuloma phases of the disease. J. Leu- koc. Biol. 82: 946-955; 2007.

Introduction In this retrospective real-life study in relapsed/refractory multiple myeloma patients, we analyzed clinical and biologic features distinguishing patients with rapidly progressing disease while receiving lenalidomide therapy from those without progression. Patients and Methods According to time of stopping lenalidomide, patients were subdivided into 3 groups: early stop (ES) (n = 23), when therapy was discontinued within 6 months; intermediate (INT) (n = 23), when therapy was stopped between 7 to 24 months; and long survival (LS) (n = 45), when therapy was maintained for more than 2 years. The median age of the whole cohort was 70 years (range, 42-85 years); 40% had an International Staging System score of 2 or 3. Results High-risk cytogenetic findings, including 1q gain, was reported in 65% ES, 43% INT, and 21% LS. Overall response rate was 63%, with median progression-free survival and overall survival of 33 and 56 months, respectively. Conclusion Although high-risk cytogenetic findings negatively affect progression-free survival and overall survival, 28% of cytogenetic high-risk patients experienced long survival, provided that lenalidomide therapy was not discontinued, thus pointing to the role of maintenance therapy in this subset of patients.

CASE REPORT An 86 year-old woman experienced chest pain, dyspnea, and dysphagia two days following orthopaedic surgery for a bimalleolus fracture of the right ankle. The patient was on prophylactic low weight molecular heparin and was affected by chronic renal failure. The chest computed tomography (CT) ruled out a pulmonary embolism but showed an intramural esophageal mass involving the entire esophagus. The lesion exhibited a blood like CT attenuation content that did not enhance after contrast administration. The esophagogram with gastrografin did not reveal filling defects nor communications between lumen and mucosa. Magnetic resonance confirmed CT results and excluded an aortic dissection. All radiological findings were suggestive of intramural hematoma of the esophagus. DISCUSSION AND CONCLUSIONS Intramural hematoma of the esophagus (IHE) is part of the spectrum of esophageal injuries that includes Mallory-Weiss tear and Boerhaave’s syndrome. IHE is the result of a hemorrhage within the submucosal layer. Predisposing conditions are abnormal hemostasis, traumatic events, aortic diseases. It can also occur spontaneously (idiopathic). Treatment should be conservative and includes risk factors withdrawal. The hematoma usually resolves in 1 to 3 weeks.

Chronic lymphocytic leukemia (CLL) arises from the clonal expansion of a CD5+ B lymphocyte that is thought not to undergo intraclonal diversification. Using VHDJH cDNA single strand conformation polymorphism analyses, we detected intraclonal mobility variants in 11 of 18 CLL cases. cDNA sequence analyses indicated that these variants represented unique point-mutations (1–35/patient). In nine cases, these mutations were unique to individual submembers of the CLL clone, although in two cases they occurred in a large percentage of the clonal submembers and genealogical trees could be identified. The diversification process responsible for these changes led to single nucleotide changes that favored transitions over transversions, but did not target A nucleotides and did not have the replacement/silent nucleotide change characteristics of antigen-selected B cells. Intraclonal diversification did not correlate with the original mutational load of an individual CLL case in that diversification was as frequent in CLL cells with little or no somatic mutations as in those with considerable mutations. Finally, CLL B cells that did not exhibit intraclonal diversification in vivo could be induced to mutate their VHDJH genes in vitro after stimulation. These data indicate that a somatic mutation mechanism remains functional in CLL cells and could play a role in the evolution of the clone.

Bone marrow stromal cell-fueled multiple myeloma growth and osteoclastogenesis are sustained by protein kinase CK2

Background Invasive fungal infections (IFI) are serious and life-threatening complications of hematological malignancies particularly in patients affected by acute myeloid leukemia and following hematopoietic stem cell transplantation. However, only few epidemiological data concerning fungal infections in chroniclymphoproliferativedisorders are available. In this work we aimed to identify the clinical and biological features of patients with chronic lymphocytic leukemia (CLL) affected by IFI. Methods We performed a single-center retrospective study based on the CLL patients referred to the Hematology Unit of University of Padua from 1983 to 2015. IFI were defined as infective events caused by yeasts ormouldsthat required inpatient management and/or intravenous antifungal therapies. We included only proven and probable IFI. Time to IFI (TIFI) and overall survival (OS) were calculated from the date of CLL diagnosis to IFI development or death (event), respectively, or last available follow-up (censored). Diagnostic work-up of fungal infection included blood cultures, serumgalactomannanantigen test for 3 consecutive days (cut-off 0.5), β-1,3-(D)-glucanand high resolution chest computed tomography andbronchoalveolarlavages when clinically indicated. We also collected the closest immunoglobulin (IG) levels data before the onset of each IFI or serious bacterial infective events. IGs measured during infections were not included in the analysis, because they could have been influenced by the infectious event. The last available serum IG levels were considered for patients who did not suffer from any IFI. Results 795 patients with CLL were recruited in this study. 60% were male and the median age at diagnosis and at IFI onset were 65 and 68 years, respectively. The median follow-up was 8.5 years and 316 patients required treatment during the follow-up. 11 out of 795 (1.4%) patients developed IFI during the follow-up. Among them, 7 patients (64%) had probable Aspergillosisand 4 had proven IFI (3 Aspergillusspp and 1 Candida kruseii) based on histological confirmation and/or microbiological isolation of the specific fungal agent. 9 patients wereBinet stage A, 2Binet B and noneBinet C at CLL diagnosis. The median lines of treatment were 5 ranging from 2 to 9. Six out of 11 (55%) patients showed high-risk cytogenetic by FISH analysis (11q or 17p deletion), 2 harbored complex karyotypes, 62% (5/8) hadunmutated IGVH gene. By Kaplan-Meyer analysis we showed that IFI occurred in 2.1% and 7.0% of the cohort after 10 and 20 years of follow-up, respectively (Figure 1A). However, considering the number of chemotherapy regimens, the estimated cumulative incidence of IFI was higher in patients who were treated with at least 4 lines of chemo-immunotherapy (10-year TIFI were 9.0% and 0.3%, p IFI occurrence was associated with a very poor prognosis. In fact, the median overall survival of patients who developed IFI was 125 months as compared to 250 months of the remaining cohort (Log-rank test, p=0.0001, Figure 1C). Since IFI was itself the main cause of death of these subjects. In multivariable analysis, patients with IFI had almost 10 times higher-risk of death (HR 10, p=0.0012) that other patients. We demonstrated that, at the time of IFI events, patients had lower levels of IG as compared to a group of 72 patients who had serious bacterial infections or to 712 subjects who did not have any infections. The medianIgGlevels were 4.11, 6.38 and 8.38 g/L for patients with IFI, bacterial infections and without history of infections, respectively (ANOVA test, p Conclusions Herein, we described the epidemiology of invasive fungal infections among a large cohort of CLL patients from a single institution over 32 years. We demonstrated that IFI significantly impacts on the survival of CLL patients and we provided evidence of the importance of previous chemo-immunotherapy and IG levels on the risk of developing IFI. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

CK2 is a pivotal pro-survival protein kinase in multiple myeloma that may likely impinge on bortezomib-regulated cellular pathways. In the present study, we investigated CK2 expression in multiple myeloma and mantle cell lymphoma, two bortezomib-responsive B cell tumors, as well as its involvement in bortezomib-induced cytotoxicity and signaling cascades potentially mediating bortezomib resistance. In both tumors, CK2 expression correlated with that of its activated targets NF-κB and STAT3 transcription factors. Bortezomib-induced proliferation arrest and apoptosis were significantly amplified by the simultaneous inhibition of CK2 with two inhibitors (CX-4945 and K27) in multiple myeloma and mantle cell lymphoma cell lines, in a model of multiple myeloma bone marrow microenvironment and in cells isolated from patients. CK2 inhibition empowered bortezomib-triggered mitochondrial-dependent cell death. Phosphorylation of NF-κB p65 on Ser529 (a CK2 target site) and rise of the levels of the endoplasmic reticulum stress kinase/endoribonuclease Ire1α were markedly reduced upon CK2 inhibition, as were STAT3 phospho Ser727 levels. On the contrary, CK2 inhibition increased phospho Ser51 eIF2α levels and enhanced the bortezomib-dependent accumulation of poly-ubiquitylated proteins and of the proteotoxic stress-associated chaperone Hsp70. Our data suggest that CK2 over expression in multiple myeloma and mantle cell lymphoma cells might sustain survival signaling cascades and can antagonize bortezomib-induced apoptosis at different levels. CK2 inhibitors could be useful in bortezomib-based combination therapies.

CK2 is a multitask kinase whose role is essential for a countless number of cellular processes, many of which are critical for blood cell development. A prevailing task for this kinase rests on counteracting programmed cell death triggered by multiple stimuli. CK2 is overexpressed in many solid tumors and in vivo mouse models have proven its tumorigenic potential. Recent data have suggested that CK2 may also have a significant role in the pathogenesis of hematopoietic tumors, such as multiple myeloma, chronic lymphocytic leukemia, acute myelogenous leukemia, acute lymphoblastic leukemia and chronic myeloproliferative neoplasms. CK2 regulates hematopoiesis-associated signaling pathways and seems to reinforce biochemical cascades indispensable for tumor growth, proliferation and resistance to conventional and novel cytotoxic agents. Although its activity is multifold, recent evidence supports the rationale of CK2 inhibition as a therapeutic strategy in solid and hematological tumors and phase-I clinical trials are in progress to test the efficacy of this innovative therapeutic approach. In this review, we will summarize the data supporting CK2 as an oncogenic kinase in blood tumors and we will describe some critical signaling pathways, whose regulation by this protein kinase may be implicated in tumorigenesis.

Background and objectives. Bendamustine in combination with rituximab has demonstrated a relevant clinical activity and a good toxicity profile in patients with mantle cell lymphoma (MCL). Cytosine arabinoside (Ara-C) is a key drug in induction chemotherapy regimens of young patients with MCL. In vitro studies have shown that bendamustine increases the cytotoxic effect of Ara‐C in leukemic blasts and lymphoma cells, and the two drugs display high synergistic activity when used in consecutive combinations. Clinically, it has recently been demonstrated that rituximab + bendamustine + Ara‐C (R-BAC) combination has a remarkable activity and is well tolerated both in untreated and in relapsed/refractory patients with MCL (Visco C et al. J Clin Oncol 2013 31:1442-1449). In the present study, we report data from an Italian single-center experience evaluating the efficacy and tolerability of R-BAC association in previously untreated MCL patients both eligible and ineligible for transplantation. Design and methods. From January 2009 to November 2014, 25 newly diagnosed patients with MCL (median 67 years; range 57-83 years) were treated with immunochemotherapy according to R-BAC schedule (Rituximab 375 mg/mq day 1; Bendamustine 70 mg/mq days 2, 3; Ara-C 500 mg/mq days 2-4) x 4 or 6 28-day cycles. All patients received G-CSF prophylaxis. Ninety-six percent of patients had stage III/IV disease; MIPI score was high in 24%, intermediate in 60% and low in 12%; in one patient it was not evaluable. Results. Twenty-two patients (88%) completed the scheduled treatment (4 or 6 cycles). The ORR was 88%: CR 84% (21 patients); PR 4% (1 patient); 1 patient was in SD, but he received only 1 cycle due to toxicity and died still in SD about three years later. Seven patients (28%) underwent autologous stem cell transplantation (ASCT); seven patients (28%) received rituximab maintenance for two years. Two patients (8%) experienced disease progression during first line therapy, both had intermediate MIPI score. After a median follow up of 33 months (range 4-65 months), the OS was 80% (one patient died for unrelated causes) and the PFS was 80%. At this time point, 19 (76%) and 1 (4%) patient were in CR and in PD, respectively. The latter patient is currently undergoing salvage chemotherapy. Patients who received either maintenance immunotherapy with rituximab or consolidation with ASCT after R-BAC (overall 56%) seemed to experience longer PFS and OS. In the ASCT group the OS was 100% at a median follow up of 23 months; in the rituximab maintenance group the OS was 71% at a median follow up of 41 months. In the group of patients that received R-BAC induction therapy only, the OS was 61% at a median follow up of 26 months (p=0.14, likely due to the low number). The most common adverse events (AEs) during R-BAC were hematological: grade 3-4 neutropenia (88%), grade 3-4 thrombocytopenia (64%) and grade 3-4 anemia (36%). The numbers of common grade 3/4 non hematological AEs in the study included: febrile neutropenia (28%), acute coronary syndrome (4%), lung infection (4%) and hyperglycemia (4%). No treatment-related mortality was observed, one patient died of secondary acute myeloid leukemia four years later from induction therapy. Conclusions. The present retrospective study confirms that R-BAC as frontline regimen in MCL is well tolerated and highly effective in ASCT ineligible patients and that it can be administered also in ASCT eligible patients as induction therapy. Moreover, our data suggest that a consolidation therapy (ASCT or maintenance immunotherapy) after R-BAC induction could improve the outcome. Disclosures No relevant conflicts of interest to declare.

Background Glycogen Synthase Kinase-3 (GSK-3) α and β are two serine-threonine kinases controlling insulin, Wnt/β-catenin, NF-κB signaling and other cancer-associated transduction pathways. Recent evidence suggests that GSK-3 could function as growth-promoting kinases, especially in malignant cells. In this study, we have investigated GSK-3α and GSK-3β function in multiple myeloma (MM). Methods GSK-3 α and β expression and cellular localization were investigated by Western blot (WB) and immunofluorescence analysis in a panel of MM cell lines and in freshly isolated plasma cells from patients. MM cell growth, viability and sensitivity to bortezomib was assessed upon treatment with GSK-3 specific inhibitors or transfection with siRNAs against GSK-3 α and β isoforms. Survival signaling pathways were studied with WB analysis. Results GSK-3α and GSK-3β were differently expressed and phosphorylated in MM cells. Inhibition of GSK-3 with the ATP-competitive, small chemical compounds SB216763 and SB415286 caused MM cell growth arrest and apoptosis through the activation of the intrinsic pathway. Importantly, the two inhibitors augmented the bortezomib-induced MM cell cytotoxicity. RNA interference experiments showed that the two GSK-3 isoforms have distinct roles: GSK-3β knock down decreased MM cell viability, while GSK-3α knock down was associated with a higher rate of bortezomib-induced cytotoxicity. GSK-3 inhibition caused accumulation of β-catenin and nuclear phospho-ERK1, 2. Moreover, GSK-3 inhibition and GSK-3α knockdown enhanced bortezomib-induced AKT and MCL-1 protein degradation. Interestingly, bortezomib caused a reduction of GSK-3 serine phosphorylation and its nuclear accumulation with a mechanism that resulted partly dependent on GSK-3 itself. Conclusions These data suggest that in MM cells GSK-3α and β i) play distinct roles in cell survival and ii) modulate the sensitivity to proteasome inhibitors.

A 71-year-old woman with refractory T-cell (CD4+) chronic lymphocytic leukemia who had been treated with chemotherapy and leukapheresis with poor control of leucocytosis was admitted because of fever, cough, and chest pain. A chest x-ray showed a right basal pneumonia, and the cytological examination of sputum showed Aspergillus fumigatus (Figure 1). The ECG at admission showed a first-degree atrioventricular block (Figure 2A). The patient was started on broad-spectrum antibiotics and liposomal amphotericin B. Shortly before admission, because of sinus tachycardia, an ECG with Holter monitoring was performed; it showed a run of supraventricular tachycardia (Figure 2B). Therefore, while in the hospital, the patient underwent cardiac evaluation. Two-dimensional echocardiography showed a round (20×16 mm) floating mass …

Multiple myeloma (MM) is an incurable disease characterized by the proliferation of end-stage B lymphocytes (plasma cells, PCs). As a consequence of myeloma growth in the bone marrow, a number of signaling pathways are activated that trigger malignant PC proliferation, escape from apoptosis, migration, and invasion. Thanks to new insights into the molecular pathogenesis of MM, novel approaches aimed at targeting these abnormally activated cascades have recently been developed and others are under study. These strategies include the inhibition of membrane receptor tyrosine kinases, inhibition of the proteasome/aggresome machinery, inhibition of histone deacetylases, inhibition of farnesyltransferases, targeting of molecular chaperones, and others. We will herein review and discuss these novel biological approaches with particular emphasis on those based on biochemical pathways which drive cell signaling. By providing the rationale for innovative therapeutic strategies, the above mechanisms represent targets for new compounds being tested in the management of this disease.

The serine-threonine GSK3 displays a crucial role in different cancer-pathogenetic pathways, including the PI3K/AKT, Wnt β-catenin and NF-κB signaling cascades, either promoting or counteracting cell survival. The aim of this study was to investigate the role of GSK3 in multiple myeloma (MM) cell growth. GSK3α and β total and phosphorylated protein levels were found differentially expressed in malignant plasma cells as compared to normal resting B-lymphocytes and to normal in vitro generated plasmablasts. Intriguingly, in freshly isolated malignant plasmacells from patients, most of GSK3 was found colocalized with Wnt receptor LRP6 and casein kinase I next to the cell membrane as compared to normal plasmacells or B-cells from other malignancies, wher it was distributed in the cytosol and in the nucleus, thus suggesting a peculiar role of this kinase in these cells. Upon stimulation of MM cells with IL-6 and IGF-I, GSK3 enzymatic activity was hampered, while stimulation with TNFα did not affect GSK3 function nor the early events in NF-κB activation. Basal and IL-6 and IGF-I driven proliferation of MM cells was slightly impaired by GSK3 blockade. Interestingly, GSK3β−/− mouse embryo fibroblasts (MEFs) proliferated slightly slower as compared to GSK3β+/+ cells; however, GSK3α inhibition and IL-6 and IGF-I stimulation, resulted in much higher proliferation of GSK3β −/− cells. Intriguingly, GSK3 inhibition with specific compounds (SB216763 and SB415286) caused a significant rescue from cell death of growth factor-deprived MM cells while resulted in reduced cell proliferation and apoptosis of MM cells grown with serum or growth factors. When GSK3 inhibitors were added to MM cell cultured with bone marrow stromal cells (BMSC), MM cells survival increased and NF-κB and β-catenin-mediated gene transcription (of IAPs and cyclinD1, respectively) was deregulated. GSK3 activity inhibition did not modify the rate of proteasome inhibitor-induced cell death in co-colture experiments with BMSC, suggesting that the sensitivity to bortezomib-induced MM cell apoptosis is independent on GSK3. Altogether, our data indicate thatGSK3 localizes on the cell membrane in primary MM cells;GSK3 is differently regulated downstream from growth factors or TNFα-induced signaling pathways in MM cells;a peculiar role of GSK3 in malignant MM cells as compared to normal MEFs with regard to cell proliferation; anda critical role of this kinase in regulating the MM microenvironment.

Acute Promyelocytic Leukemia, (APL, M3 FAB-subtype) is characterized by the chromosomal translocation t(15;17) and the expression of the oncogenic fusion protein PML-RARα (promyelocytic leukemia gene-retinoic acid receptor -α); this AML subtype is strikingly responsive to pharmacological doses of retinoic acid (RA), which can overcome the proliferative and anti-differentiation effects of PML-RARα, thus representing a mainstay of the induction and maintenance therapy of this leukemia. Despite the progress achieved in the last decade in the understanding of the RA-dependent molecular pathways, the discrete regulation of RA receptors function in APL still remains unclear. CK2 is a tetrameric (2 α catalytic and 2 β regulatory subunits) protein kinase overexpressed in a large array of tumors, which has been found to phosphorylate and regulate the activity of key myeloid transcription factors and proteins involved in chromatin remodelling. However, CK2 ability to modulate the myeloid developmental program and the RA-dependent cascade has never been investigated. In this work, we found that CK2 is highly expressed and active in APL cells. Its localization was usually detected in the cytoplasm, with a scant speckled nuclear pattern; upon RA stimulation most of the protein relocalized in perinuclear areas in the cytosol. Moreover, while the protein levels of the β regulatory subunit progressively fell, the levels and activity of the α catalytic subunit, after RA treatment of APL cells, was found consistently elevated. To understand whether CK2 plays a role in RA-induced myeloid differentiation, we employed specific CK2 inhibitors (tetrabromobenzotriazole (TBB)-derivatives K27 and K17) and RNA interference to hamper its function. NB4 and primary APL cells displayed an inhibited terminal differentiation upon RA if CK2 activity was blocked with either one of these means, as evaluated by i) the persistence of an immature morphology, ii) the absence of expression of CD11b and CD11c and iii) the greatly reduced production of superoxide anion at the NBT-reduction assay. All these effects were not caused by an increased apoptosis of APL cells, nor by an inhibition of the reshaping of PML nuclear bodies. Instead, CK2 inhibition affected the RA-dependent G1 arrest of APL cells, a prerequisite for the terminal differentiation program to take place. We have also found that RARα-dependent transcription was greatly impaired by CK2 inhibition, and we have evidence of a physical interaction between these two molecules. Last, to clarify the molecular basis of this unpredicted role of CK2 in myeloid differentiation, we have undertaken a proteomic/phosphoproteomic analysis in response to RA. Surprisingly, CK2 inhibition prevented or attenuated a significant amount of the major phosphorylation changes occurring in response to RA. This study emphasizes the role of CK2 in the differentiation induced by RA in AML. Further studies are needed to identify the CK2 targets involved the RA action.

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible fibrosing lung disease of unknown etiology and with an unfavorable outcome, leading ultimately to death due to respiratory failure. To date, no treatment strategies have been effective in modifying the natural course of IPF and its fatal outcome. The aberrant parenchymal remodeling is characterized by the expansion of fibroblasts/myofibroblasts, which form characteristic subepithelial foci, and by the abnormal deposition of extracellular matrix in the lung parenchyma. Although the pathophysiology underlying this disease has not yet been fully elucidated, animal models of pulmonary fibrosis have provided contributions in dissecting the molecular basis of this disease, focusing on the role of cytokines and chemokines as important pathogenetic mediators of lung fibrosis. Starting with the data obtained from animal models, this article provides a comment on a number of findings that suggest the possible role of the chemokine/cytokine system in the pathogenesis of IPF.

BACKGROUND The PML gene is fused to the RARalpha gene in the vast majority of acute promyelocytic leukemias (APL) and has been implicated in the control of key tumor-suppressive pathways. However, its role in the pathogenesis of human cancers other than APL is still unclear. We therefore assessed the status and expression of the PML gene in solid tumors of multiple histologic origins. METHODS We created tumor tissue microarrays (TTMs) with samples from patients with colon adenocarcinoma (n = 109), lung carcinoma (n = 19), prostate adenocarcinoma (n = 36), breast carcinoma (n = 38), central nervous system (CNS) tumors (n = 51), germ cell tumors (n = 60), thyroid carcinoma (n = 32), adrenal cortical carcinoma (n = 12), and non-Hodgkin's lymphoma (n = 251) and from normal tissue corresponding to each histotype and analyzed PML protein and mRNA expression by immunohistochemistry and in situ hybridization, respectively. Tumor cell lines (n = 64) of various histologic origins were analyzed for PML protein and mRNA expression by immunofluorescence and northern blotting, respectively. DNA from microdissected tumor samples and cell lines was analyzed for PML mutations and loss of heterozygosity (LOH). For some tumor types, the association between PML expression and tumor stage and grade was analyzed. Statistical tests were two-sided. RESULTS All normal tissues expressed PML protein. PML protein expression was reduced or abolished in prostate adenocarcinomas (63% [95% confidence interval [CI] = 48% to 78%] and 28% [95% CI = 13% to 43%], respectively), colon adenocarcinomas (31% [95% CI = 22% to 40%] and 17% [95% CI = 10% to 24%]), breast carcinomas (21% [95% CI = 8% to 34%] and 31% [95% CI = 16% to 46%]), lung carcinomas (36% [95% CI = 15% to 57%] and 21% [95% = 3% to 39%]), lymphomas (14% [95% CI = 10% to 18%] and 69% [95% CI = 63% to 75%]), CNS tumors (24% [95% CI = 13% to 35%] and 49% [95% CI = 36% to 62%]), and germ cell tumors (36% [95% CI = 24% to 48%] and 48% [95% CI = 36% to 60%]) but not in thyroid or adrenal carcinomas. Loss of PML protein expression was associated with tumor progression in prostate cancer (the progression from prostatic intraepithelial neoplasia to invasive carcinoma was associated with complete PML loss; P

Acute promyelocytic leukemia (APL) is associated with reciprocal and balanced chromosomal translocations always involving the Retinoic Acid Receptor alpha (RARalpha) gene on chromosome 17 and variable partner genes (X genes) on distinct chromosomes. RARalpha fuses to the PML gene in the vast majority of APL cases, and in a few cases to the PLZF, NPM, NuMA and STAT5b genes. As a consequence, X-RARalpha and RARalpha-X fusion genes are generated encoding aberrant fusion proteins that can interfere with X and/or RARalpha function. Here we will review the relevant conclusions and the open questions that stem from a decade of in vivo analysis of APL pathogenesis in the mouse in transgenic and knock-out models.

Acute promyelocytic leukemia (APL) is characterized by the expansion of malignant myeloid cells blocked at the promyelocytic stage of differentiation and is associated with reciprocal chromosomal translocations always involving the retinoic acid receptor alpha (RARalpha) gene on chromosome 17. As a consequence of the translocation, RARalpha variably fuses to the PML, PLZF, NPM, NuMA, and Stat5b genes (X genes), respectively, leading to the generation of RARalpha-X and X-RARalpha fusion genes. The aberrant chimeric proteins encoded by these genes, as well as the inactivation of the X and RARalpha functions, may exert a crucial role in leukemogenesis. To define the molecular genetics of APL and the contribution of each molecular event in APL pathogenesis, we have generated transgenic mice harboring X-RARalpha and/or RARalpha-X genes as well as mice where the various X genes have been inactivated by homologous recombination. Here we show that while the X-RARalpha fusion gene is crucial for leukemogenesis, the presence of RARalpha-X and the inactivation of X function are critical in modulating the onset as well as the phenotype of the leukemia.

Zinc finger proteins play a crucial role in regulating normal hemopoiesis (Shivdasani and Orkin 1996). Furthermore, several genes encoding zinc finger transcription factors are involved in chromosomal translocations associated with hemopoietic malignancies (Look 1997), and their functional deregulation or inactivation is an essential step in leukemogenesis (He et al. 2000 and references therein). Myeloid zinc finger 1 (MZF-1) is a transcription factor of the Kruppel family of zinc finger proteins originally cloned from a cDNA library from a patient with chronic myeloid leukemia (Hromas et al. 1991). Within the hemopoietic compartment MZF-1 expression is restricted to totipotent bone marrow (BM) progenitor cells and early myeloid progenitors and precursors, and is not detectable in fully differentiated blood cells (Bavisotto et al. 1991). MZF-1 contains 13 zinc finger domains divided into two groups, which can bind DNA independently of each other (Morris et al. 1994; Hromas et al. 1996). In vitro, in transient transfection experiments, MZF-1 can activate transcription in cells of hemopoietic origin, and it has also been found to repress transcription in nonhemopoietic cells (Morris et al. 1995; Hromas et al. 1996). MZF1 antisense oligonucleotides inhibit granulocyte colony-stimulating factor (G-CSF)-driven granulocyte colony formation (Bavisotto et al. 1991). However, MZF1 overexpression in embryonic stem (ES) cells also appears to interfere with the ability of these cells to undergo hemopoietic commitment as well as erythromyeloid colony formation (Perrotti et al. 1995). These data may suggest a role for MZF1 in the control of myeloid differentiation. However, the biological function of MZF1 is presently unknown, also in view of the seemingly contradictory nature of these observations. Here we show, in vivo, in knockout (KO) mice, that Mzf1 controls the proliferative potential of hemopoietic cells acting as a growth and tumor suppressor.

BACKGROUND B7 family molecules are involved in T–B-cell communications after interaction with their ligands CD28 and CD152. They play a key role in costimulatory mechanisms and during antigen presentation by efficient antigen presenting cells. B7 molecules are usually absent or expressed at low intensity on B lymphocytes from healthy subjects. In this study, the authors addressed the questions of whether B7 molecules are expressed and modulated in vitro on malignant B lymphocytes from patients with chronic lymphoproliferative diseases of B-cell type and whether they are able to trigger allogenic T-cell reactions. METHODS Malignant B cells from the peripheral blood of 32 patients with B-cell chronic lymphocytic leukemia, mantle cell lymphoma, hairy cell leukemia, and its variant form were investigated for the expression of B7 molecules on the cell surface and for the ability to trigger allogenic T lymphocytes in different experimental conditions. RESULTS Flow cytometry analysis demonstrated that freshly isolated malignant B cells express B7 molecules and that their expression may be up-regulated by the in vitro triggering of the CD40 molecule. Furthermore, freshly isolated malignant B cells induce allogenic T-cell proliferation. The in vitro triggering of malignant B lymphocytes by CD40, alone and in combination with interleukin-4, elicits a strong allogenic T-cell proliferation. This T-cell proliferation is related mainly to the presence of B7 molecules on malignant and normal B lymphocytes. CONCLUSIONS These findings indicate that malignant B cells are efficient antigen presenting cells. It might be suggested that vaccination with pulsed malignant B cells themselves or dendritic cells with in vitro preactivated tumor B cells may represent an alternative therapeutic approach in these patients to generate an antilymphoma T-cell response in vivo. Cancer 2000;89:1259–68. © 2000 American Cancer Society.

B- and T-cell recirculation is crucial for the function of the immune system, with the control of cell migration being mainly mediated by several chemokines and their receptors. In this study, we investigated the expression and function of CXCR3 on normal and malignant B cells from 65 patients with chronic lymphoproliferative disorders (CLDs). Although CXCR3 is lacking on CD5(+) and CD5(-) B cells from healthy subjects, it is expressed on leukemic B lymphocytes from all (31/31) patients with chronic lymphocytic leukemia (CLL). The presence of CXCR3 was heterogeneous in other B-cell disorders, being expressed in 2 of 7 patients with mantle cell lymphoma (MCL), 4 of 12 patients with hairy cell leukemia (HCL), and 11 of 15 patients with other subtypes of non-Hodgkin's lymphomas (NHLs). Chemotaxis assay shows that normal B cells from healthy subjects do not migrate in response to IFN-inducible protein 10 (IP-10) and IFN-gamma-induced monokine (Mig). In contrast, a definite migration in response to IP-10 and Mig has been observed in all malignant B cells from patients with CLL, but not in patients with HCL or MCL (1/7 cases tested). Neoplastic B cells from other NHLs showed a heterogenous pattern. The migration elicited by IP-10 and Mig was inhibited by blocking CXCR3. No effect of IP-10 and Mig chemokines was observed on the cytosolic calcium concentration in malignant B cells. The data reported here demonstrate that CXCR3 is expressed on malignant B cells from CLDs, particularly in patients with CLL, and represents a fully functional receptor involved in chemotaxis of malignant B lymphocytes.

Abstract 2501 Background. Leukemia stem cells (LSC) constitute the reservoir of acute and chronic leukemias, from which the relapse of the disease takes origin. The Wnt/βcatenin and the Hedgehog (Hh) signaling pathways regulate the balance between self-renewal and commitment of both normal hematopoietic stem cells (HSC) and LSC. Serine-Threonine protein kinases CK1 and CK2 phosphorylate members of Wnt and Hh and are therefore potential regulators of HSC and LSC biology; however, their function in HSC and LSC is unknown. Purpose. In the present work we have investigated the mRNA and protein levels of CK1 and CK2 in acute myeloid leukemia (AML) blasts and LSC isolated from patients. We have also integrated the expression data of CK1 and CK2 with the expression data of Wnt and Hh signaling pathways gene targets and with biological and clinical parameters of a group of AML patients and cell lines. We also tested the effects on the growth of AML blasts of CK1 and CK2 small chemical inhibitors. The aim of this study was to gain insights into the function of these pivotal protein kinases and on their expression levels relative to biological, clinical and prognostic variables that dictate the outcome of AML patients. Methods. mRNA was extracted from HSC and FACS-sorted LSC (as defined as Lineage- CD34+ CD38- CD123+ CD90+); proteins were obtained from the bulk of blasts from fifteen AML patients. Quantitative RT-PCR was employed to assess mRNA levels of: CK1α, CK1γ, CK2α (catalytic) and CK2β (regulatory subunit); Lef1, FoxO1, FoxO3, CyclinD1 (Wnt targets); Ptch, Gli1, Gli2, Gli3, Bmi1 (Hh targets); western blot analysis was performed to determine CK1α, CK2α, CK2β, p53, phospho-Ser529 NF-κB and phospho-Ser13 Cdc37 (two direct CK2 target sites) protein levels. Normal CD34+ bone marrow cells were used as controls. CK2 chemical inhibitors (CX4945 and tTBB) were assayed on LSC and AML cells. Results. CK1α, CK2α and CK2β mRNA and proteins were found overexpressed in LSC and in AML blasts. CK1γ mRNA levels were barely detectable. Notably, some AML cases displayed low levels of CK2β but high levels of CK2α, indicating a possible CK2β-independent function of CK2α. FoxO1, FoxO3 mRNAs were found upregulated while Lef1 and CyclinD1 ones were found slightly and Axin2 one strongly diminished, respectively. Ptch, Smo, Gli1, Gli2 and Gli3 mRNAs were unchanged or reduced, while we observed a strong upregulation of that of Bmi1. A correlation between the overexpression of CK1α and CK2 and high-risk cytogenetic groups was observed. Also, in most of CK2α high-expressing cases, TP53 was found downregulated, while phospho-Ser529 p65 upregulated. Importantly, inhibition of CK2 with selective compounds caused AML cell and LSC growth arrest, a restoration of TP53 and a downregulation of phospho-Ser529-NF-kB p65 and phospho-Ser13 Cdc37 protein levels. Conclusions. The present study is the first to report on the expression of CK1 and CK2 kinases in normal HSC and LSC. CK1 (α) and CK2 (α and β) mRNA and protein levels were higher in LSC (especially from high risk groups) than in HSC. CK1γ mRNA levels were low. Wnt and Hh pathways genes were differentially upregulated pointing to a gene specific LSC-associated function. Moreover, our data with CK2 inhibitors suggest that CK2 could be a suitable therapeutic target to eradicate residual AML LSCs. Future research will assess more in depth the in vivo functional role of CK1 and CK2 in HSC and LSC. Disclosures: No relevant conflicts of interest to declare.