The NO-modified HIV protease inhibitor as a valuable drug for hematological malignancies: Role of p70S6K.

Covalent attachment of NO to the first approved HIV protease inhibitor Saquinavir (Saq-NO) expands the therapeutic potential of the original drug. Apart from retained antiviral activity, the modified drug exerts strong antitumor effects and lower toxicity. In the present study, we have evaluated the sensitivity of different hematological malignancies to Saq-NO. Saq-NO efficiently diminished the viability of Jurkat, Raji, HL-60 and K562 cells. While Jurkat and Raji cells (established from pediatric patients) displayed abrogated proliferative potential, HL-60 and K652 cells (originated from adults) exposed to Saq-NO treatment underwent caspase dependent apoptosis. In addition, similar sensitivity to Saq-NO was observed in mononuclear blood cells obtained from pediatric patients with acute lymphoblastic leukemia (ALL) and adult patients with acute myeloid leukemia (AML). Western blot analysis indicated p70S6 kinase as a possible intracellular target of Saq-NO action. Moreover, the addition of a NO moiety to Lopinavir resulted in improved antitumor potential as compared to the parental compound, suggesting that NO-derived HIV protease inhibitors are a potential new source of anticancer drugs with unique mode of action.

JAK2V617F Mutation in a Patient with B-cell Chronic Lymphocytic Leukemia and Prefibrotic Primary Myelofibrosis.

INTRODUCTION: Secondary malignancies, particularly solid tumors, are common in patients with chronic lymphocytic leukemia (CLL), but association of myeloproliferative neoplasms and chronic lymphocytic leukemia in the same patient is very rare. CASE OUTLINE: We report of a 67-year-old man with B-cell chronic lymphoid leukemia (B-CLL) who developed primary myelofibrosis (PMF) nine years after initial diagnosis. Patient received alkylation agents and purine analogue, which can be a predisposing factor for the development of myeloproliferative neoplasms. JAK2V617F mutation was not present initially at the time of CLL diagnosis, but was found after nine years when PMF occurred, which indicates that B-CLL and PMF represent two separate clonal origin neoplasms. CONCLUSION: Pathogenic mechanisms for the development of myeloproliferative and lymphoproliferative neoplasms in the same patient are unknown. Further research is needed to determine whether these malignancies originate from two different cell clones or arise from the same pluripotent hematopoietic stem cell.

Dipeptidyl peptidase IV: serum activity and expression on lymphocytes in different hematological malignancies.

The aim of this research was to determine the serum dipeptidyl peptidase IV (DPPIV) activity as well as the percentages of CD26 + lymphocytes and CD26 + overall white blood cells in patients with hematological malignancies: non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), leukemia, plasmacytoma and multiple myeloma, and in healthy individuals. Data from our study showed significantly decreased serum DPPIV activity and a significant decrease in the percentage of: CD26 + lymphocytes, CD26 + overall white blood cells and lymphocytes in patients with NHL in comparison to healthy controls. Patients with leukemia had a statistically significant lower activity of DPPIV in serum and significant decrease in the percentage of CD26 + lymphocytes in relation to healthy controls. Furthermore, significantly decreased DPPIV serum activity associated with a significantly reduced percentage of CD26 + overall white blood cells and percentage of lymphocytes was found in patients with multiple myeloma when compared to the healthy control group. The obtained results indicate that immune disturbances that can occur in hematological malignancies might be related to the decreased expression and activity of CD26/DPPIV that we observed.

Reversal of FLT3 mutational status and sustained expression of NPM1 mutation in paired presentation, and relapse samples in a patient with acute myeloid leukemia.

We report a case of de novo acute myeloid leukemia (AML) with unstable FLT3 gene mutations and stable NPM1 mutation. FLT3/D835 and NPM1 (Type A) mutations were detected upon diagnosis. During the relapse, the FLT3/D835 mutation changed to an FLT3/ITD mutation while the NPM1 (Type A) mutation was retained. Cytogenetic analyses showed the normal karyotype at diagnosis and relapse. Our findings raise interesting questions about the significance of these mutations in the leukemogenic process, about their stability during the evolution of the disease, and regarding the selection of appropriate molecular markers for the monitoring of minimal residual disease.

Response to cladribine in patient with systemic mastocytosis.

INTRODUCTION: Systemic mastocytosis is a heterogeneous group of hematological disorders characterized by accumulation of mast cells in different organs. CASE REPORT: A 41-year-old woman presented with a three-year history of fatigue, occasional diarrhea, mild fever, skin rash and splenomegaly. Laboratory results showed severe anemia and thrombocytopenia. Cytological and histological investigation of bone marrow showed a marked increase of mast cells infiltration with following immunophenotype: CD117+, CD68+, CD34-, MPO-, CD15-. She was treated with cladribine 0.15 mg/kg body weight from day 1 to day 5, a total of six cycles, and achieved a good partial response, transfusion independency and normalization of spleen size. Although the patient responded to the treatment, the relapse with splenomegaly and bicytopenia was observed after 10 months. CONCLUSION: Cladribine therapy was efficient in the patient' with systemic mastocytosis but the response was transient, so there is the need to search for new therapeutic options and more effective strategies in the treatment of patients with aggressive mast cell disorders.

[Diffuse large cell lymphoma and colon adenocarcinoma in patient with Waldenström's macroglobulinaemia].

INTRODUCTION: Waldenström's macroglobulinaemia is a rare B cell lymphoproliferative disorder characterized by lymphoplasmocyte bone marrow infiltration and monoclonal IgM gammopathy. In the majority of cases, Waldenström's macroglobulinaemia is a chronic disease with variable course. Therapy consists of alkylating agents, purine analogs and antiCD20 monoclonal antibody. In the literature, there have been descriptions of rare cases of progression of Waldenström's macroglobulinaemia to aggressive lymphoma, as well as secondary carcinoma in the patients after treatment of macroglobulinaemia. CASE OUTLINE: A 63-year-old patient was diagnosed with serum monoclonal IgM kappa gammopathy (Waldenström's macroglobulinaemia). Chemotherapy was applied and a good clinical and haematological response had been achieved. Ten years later, the patient was diagnosed with colon adenocarcinoma as a secondary malignancy, and operated on. Within one month, the patient rapidly developed a large neck tumour mass. Tumour biopsy revealed the diagnosis of diffuse large B-cell lymphoma with the expression of monoclonal lambda chain, which more likely pointed out to coexistence of two different B cell lymphoproliferative disorders, rather than the transformation of Waldenström's macroglobulinaemia to aggressive lymphoma. The patient was treated with chemotherapy following R-CHOP protocol, and clinical remission was achieved. Seven months later, despite the successful treatment of lymphoproliferative disorder, dissemination of adenocarcinoma led to the lethal outcome. CONCLUSION: The patient was diagnosed with a rare occurrence of three neoplastic diseases: Waldenstrom's macroglobulinaemia, colon adenocarcinoma and diffuse large B cell lymphoma. The possible mechanisms of the combined appearance of lymphoproliferative and other malignant diseases include the previous treatment with alkylating agents, genetic, immunomodulatory and environmental factors.

Novel ORC4L gene mutation in B-cell lymphoproliferative disorders.

B-cell lymphoproliferative disorders are characterized by marked genetic, morphological, and clinical heterogeneity. The identification of prognostic markers could help to develop risk-adapted treatment strategies. Because proliferation of cells is essential for tumor growth, analysis of the cell cycle might give additional information on tumor progression and clinical behavior. Because initiation of DNA replication represents a significant step in cell division, it is worthwhile to focus the attention to the origin recognition complex (ORC), protein complex essential for initiation of DNA replication. Studies have already shown that ORC-associated factors give a more accurate assessment of cell proliferation than previous markers for many types of malignancies, but so far there have been no studies of eventual role of ORC4L in B-cell lymphoproliferative disorders. Here, we describe 3 patients with B-cell lymphoproliferative disorders (2 with non-Hodgkin lymphoma and 1 with nonsecretory multiple myeloma) carrying a novel A286V mutation within ORC4L gene. All 3 patients were in the advanced stage of disease, but their response to the chemotherapy treatment was good and they achieved complete clinical remission in a relatively short period. Although the functional relevance of this mutation has not yet been elucidated, our observation raises a possibility that A286V mutation, which is constitutively present in these patients, might represent a favorable prognostic marker in B-cell lymphoproliferative disorders.