Slobodan Ristic

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.

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.

Predictive value of prognostic indices in patients with follicular lymphomas.

PurposeThe aim of this study was to compare which of three indices—International Prognostic Index (IPI), Italian Lymphoma Intergroup (ILI) index, Follicular Lymphoma adapted International Prognostic Index (FLIPI)—is the most useful in predicting outcome in follicular lymphoma (FL) patients and to identify other clinical and laboratory prognostic factors that influence survival.Patients and MethodsClinical and prognostic studies were carried out in 99 patients with FL.ResultsThe distribution of patients in IPI risk groups was 44.4%, 19.2%, and 36.4% of cases classified as low, intermediate, and high risk. According to ILI, low-, intermediate-, and high-risk scores were present in 34.3%; 27.3%, and 38.4% of FL patients. After applying the FLIPI index, the patients were divided into three risk groups; and (21.2% of cases), intermediate (39.4%), and high (39.4%) of FL patients. Survival curves demonstrated a high significant difference for the low- and high-risk group according to IPI and FLIPI (log rank=91.13 and 82.17 respectively; p<0.0001). Difference in overall survival (OS) and failure-free survival (FFS) among low-, intermediate-, and high-risk groups according to ILI was statistically significant (log rank test p<0.0001).ConclusionAll three indices are important tools for prognostic evaluation of FL patients, as well as useful in identifying FL patients with poor outcome. IPI and FLIPI classify patients into two risk groups (low/intermediate- and high-risk groups) with significance difference in OS and FFS, but ILI is more reliable in stratifying patients in low-, intermediate-, and high-risk groups.

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

Abstract 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.

Busulfan-induced loss of Ph chromosome in chronic myeloid leukemia

We report a 44-yr-old female with Philadelphia chromosome positive chronic myeloid leukemia who was initially treated with busulfan, and clinical remission has been achieved. After 4 yr, low-dose busulfan therapy was started again and induced bone marrow aplasia. The patient spontaneously has recovered from aplasia, and complete cytogenetic remission with loss of Ph+ chromosome in bone marrow has been achieved. However, reverse-transcription — polymerase chain reaction analysis showed presence of the bcr-abl transcript in bone marrow.

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

INTRODUCTION Waldenströms macroglobulinaemia is a rare B cell lymphoproliferative disorder characterized by lymphoplasmocyte bone marrow infiltration and monoclonal IgM gammopathy. In the majority of cases, Waldenströms 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 Waldenströms 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 (Waldenströms 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 Waldenströms 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: Waldenstroms 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.

Molecular response to imatinib in patient with Ph negative p190 BCR-ABL transcript positive chronic myeloid leukemia with cyclic leukocytosis.

An atypical case of Philadelphia (Ph) negative, e1a2 BCR-ABL transcript positive chronic myeloid leukemia (CML) characterized with cyclic periodic leukocytosis and spontaneous remissions is reported. The patient was treated with imatinib and good hematology response with molecular remission was achieved. So far, only few Ph positive CML patients expressing p190 BCR-ABL protein and different clinical characteristics and treatment have been described in the literature. This is the first report of Philadelphia negative, p190 BCR-ABL positive CML with cyclic spontaneous oscillation of white blood cell count (WBC), and excellent response to imatinib treatment.