Sequencing-based analysis of clonal evolution of 25 mantle cell lymphoma patients at diagnosis and after failure of standard immunochemotherapy

Our knowledge of genetic aberrations, that is, variants and copy number variations (CNVs), associated with mantle cell lymphoma (MCL) relapse remains limited. A cohort of 25 patients with MCL at diagnosis and the first relapse after the failure of standard immunochemotherapy was analyzed using whole-exome sequencing. The most frequent variants at diagnosis and at relapse comprised six genes: TP53, ATM, KMT2D, CCND1, SP140, and LRP1B. The most frequent CNVs at diagnosis and at relapse included TP53 and CDKN2A/B deletions, and PIK3CA amplifications. The mean count of mutations per patient significantly increased at relapse (n = 34) compared to diagnosis (n = 27). The most frequent newly detected variants at relapse, LRP1B gene mutations, correlated with a higher mutational burden. Variant allele frequencies of TP53 variants increased from 0.35 to 0.76 at relapse. The frequency and length of predicted CNVs significantly increased at relapse with CDKN2A/B deletions being the most frequent. Our data suggest, that the resistant MCL clones detected at relapse were already present at diagnosis and were selected by therapy. We observed enrichment of genetic aberrations of DNA damage response pathway (TP53 and CDKN2A/B), and a significant increase in MCL heterogeneity. We identified LRP1B inactivation as a new potential driver of MCL relapse.

The Reduction of the Cell Nuclear Size in the Cell Body Space During the Differentiation Might Be Cell Lineage Specific (A Retrospective Morphological Note)

The cell body space occupied by the nucleus decreased during the cell differentiation of the granulocytic cell lineage in CML (Chronic Myeloid Leukemia) patients. In contrary, in patients suffering from CLL (Chronic Lymphocytic Leukemia), the cell body space occupied by the nucleus during the cell differentiation of the lymphocytic lineage did not decrease despite the reduction of the cell size. Thus, the cell body space occupied by the cell nucleus during the differentiation was characteristic for each of these cell lineages.

RNA Concentration and Content in the Nucleoli and Cytoplasmic Rim in Differentiating Lymphocytes of Patients Suffering from B Chronic Lymphocytic Leukaemia - a Cytochemical Note

Nucleolar RNA optical density (concentration) measurements at the single cell level indicated that differentiation of lymphocytes is accompanied by a slightly decreased nucleolar RNA concentration in contrast to the cytoplasmic rim around the nucleus. On the other hand, the nucleolar size was markedly reduced and the cytoplasmic rim surrounding the nucleus was reduced only weakly. Concerning the calculated rough estimate of the RNA content, the differentiation induced its larger decrease in the nucleoli than in the cytoplasmic rim. These observations indicated that the nucleolar RNA concentration and RNA content together with the nucleolar morphology are more sensitive markers of the differentiation process than the RNA concentration and content in the cytoplasm. Thus, the nucleolar RNA transfer to the cytoplasm in advanced differentiation steps might still be going on regardless of the decreasing or inhibited nucleolar biosynthetic activity. In addition, the presence of ring-shaped nucleoli and micronucleoli characteristic of mature and terminal lymphocytes in some lymphocytic less differentiated steps, i.e., lymphoblasts and prolymphocytes, might indicate the premature differentiation state of such cells.

The cell body space occupied by the nucleus during the cell differentiation in human lymphocytic, granulocytic and erythroid cell lineages

The present nuclear and cell body diameter measurements demonstrated size differences of the approximate cell space estimate occupied by the cell nucleus during the cell differentiation in lymphocytic, granulocytic and erythroid cell lineages. These lineages were used as convenient models because all differentiation steps were easily identified and accessible in diagnostic peripheral blood or bone marrow smears of blood donors (BDs), patients suffering from chronic lymphocytic leukemia (CLL), patients with chronic myeloid leukemia (CML) and refractory anemia (RA) of the myelodysplastic syndrome (MDS). The cell space occupied by the nucleus was constant and did not change during the cell differentiation in the lymphocytic cell lineages of BDs and CLL patients despite the decreased cell size. In contrary, the cell space occupied by the nucleus markedly decreased in differentiating cells of granulocytic and erythroid lineages of patients suffering from CML. In the erythroid cell lineage in patients with RA of MDS the small reduction of the cell space occupied by the nucleus during the differentiation was not significant. The measurements also indicated that in progenitor cells of all studied cell lineages nuclei occupied more than 70 % of the cell space. Thus, the nucleus-cytoplasmic morphological and functional equilibrium appeared to be characteristic for each differentiation step and each specific cell lineage.

ESMO Consensus Conference on malignant lymphoma: general perspectives and recommendations for the clinical management of the elderly patient with malignant lymphoma

The European Society for Medical Oncology (ESMO) consensus conference on mature B cell lymphomas and chronic lymphocytic leukaemia (CLL) was held on 20 June 2015 in Lugano, Switzerland, and included a multidisciplinary panel of 25 leading experts. The aim of the conference was to develop recommendations on critical subjects difficult to consider in detail in the ESMO Clinical Practice Guidelines. The following areas were identified: (1) the elderly patient, (2) prognostic factors suitable for clinical use, and (3) the 'ultra-high-risk' group. Before the conference, the expert panel was divided into three working groups; each group focused on one of these areas in order to address clinically-relevant questions relating to that topic. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, each working group developed recommendations to address each of the four questions assigned to their group. These recommendations were presented to the entire panel and a consensus was reached. This consensus, which was further developed in continuous post-meeting discussions, formed the basis of three manuscripts, each covering one of the three key areas identified. This manuscript presents the consensus recommendations regarding the clinical management of elderly patients diagnosed with malignant lymphoma. Four clinically-relevant topics identified by the panel were: 1) how to define patient fitness, 2) assessing quality of life, 3) diagnostic work-up and 4) clinical management of elderly patients with lymphoma. Each of these key topics is addressed in the context of five different lymphoma entities, namely: CLL, follicular lymphoma, mantle cell lymphoma, peripheral T-cell lymphoma and diffuse large B-cell lymphoma. Results, including a summary of evidence supporting each recommendation, are detailed in this manuscript.

[Staging and Treatment Response Evaluation in Malignant Lymphomas - Czech Lymphoma Study Group Recommendations According to Criteria Revised in 2014 (Lugano Classification)]

BACKGROUND

Recent advances in the use of the imaging modalities, especially PET/CT, and their utilization for determining clinical stage (CS) and assessment treatment response (TR) in malignant lymphomas, along with development of prognostic tools and new treatment modalities, formed the basis for the revised criteria for evaluating CS and TR (published as the Lugano classification, 2014).

MATERIALS AND METHODS

The authors summarize the new Lugano recommendations (published in 2014) and the changes from the criteria published in 2007. Moreover, discussion of the changes places emphasis on practical use. The practicality of the Lugano classification, 2014 was the subject of consensus meeting at the annual meeting of the Cooperative Lymphoma Study Group (CLSG) in March 2015. This study reports the final consensus. The CLSG recommends use of the Lugano classification, 2014, but recommends some modifications.

CONCLUSIONS

Standardization of the criteria used to determine CS and TR in malignant lymphomas has led to improvements in initial staging and assessment of TR. The criteria are helpful for unifying response assessment in clinical trials and simplify the work of regulatory agencies (e.g., the EMA and the Czech State Institute for Drug Control) when registering new drugs. It also allows evaluation of treatment outcomes outside clinical trials, for example within the CLSG prospective registry of patients with newly diagnosed lymphoma.

KEY WORDS

malignant lymphoma - computed tomography - positron emission tomography - staging - treatment responseThis work was supported by the grant Prvouk P27/2012 of the Third Faculty of Medicine, Charles University in Prague and by the grant of the Czech Lymphoma Study Group No. NT12193-5/2011.The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 24. 1. 2016Accepted: 16. 2. 2016.

[The Importance of MicroRNA Deregulation in the Molecular Pathogenesis and Histological Transformation of Follicular Lymphoma]

BACKGROUND

Molecular pathogenesis of follicular lymphoma (FL) is characterized by substantial dysregulation of epigenetic regulators. Many cases of FL are associated with the aberrant expression of non-coding regulatory RNAs, namely microRNAs (miRNA). Here we studied changes in miRNA expression and their association with histological transformation of FL to diffuse large B-cell lymphoma (DLBCL).

MATERIAL AND METHODS

To identify changes in miRNA levels during FL transformation we performed a global expression analysis of 377 miRNAs in 16 samples (8 pairs) from FL patients vs. transformed FL (tFL) (TLDA miRNA cards; Thermo Fisher Scientific). The association of miRNA expression with clinical-biological characteristics and target proteins were further analyzed in a cohort of 89 FL patients.

RESULTS

The miRNA expression profiling of paired FL-tFL samples revealed statistically significant changes in the expression of five miRNAs (p < 0.05). Four of them were down-regulated and one was up-regulated in tFL compared to FL. Lower levels of one of these miRNA were also associated with higher proliferation rate of FL cells (Ki-67 > 20%), higher FLIPI score ( 3) and shorter overall survival of FL patients. Furthermore, we found that this miRNA regulates the levels of FOXP1 protein in FL. The patients with high-level FOXP1 expression (> 70% positive cells) had significantly shorter overall survival in comparison to those with low-level FOXP1 expression (< 30% positive cells). Moreover, FOXP1 protein levels were higher in most tFL samples compared to FL before transformation.

CONCLUSION

We found miRNAs associated with the transformation of FL to a more aggressive DLBCL, and described that one of them could serve as a prognostic marker. We found that reduced expression of this tFL-associated miRNA results in increased levels of FOXP1 protein and we assume that the increased activity of FOXP1 proto-oncogene contributes to the histological transformation of FL.Key words: follicular lymphoma - microRNA - histological transformation This work was supported by Czech Ministry of Health registration No. 16-29622A. All rights reserved. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 5. 3. 2017Accepted: 26. 3. 2017.

Efficacy and safety of human mesenchymal stromal cells in healing of critical-size bone defects in immunodeficient rats

To evaluate the preclinical efficacy and safety of human mesenchymal stem cells (hMSC) rapidly expanded in growth medium for clinical use with human serum and recombinant growth factors, we conducted a controlled, randomized trial of plasma clots with hMSC vs. plasma clots only in critical segmental femoral defects in rnu/rnu immunodeficient rats. X-ray, microCT and histomorphometrical evaluation were performed at 8 and 16 weeks. MSC were obtained from healthy volunteers and patients with lymphoid malignancy. Human MSC survived in the defect for the entire duration of the trial. MSC from healthy volunteers, in contrast to hMSC from cancer patients, significantly improved bone healing at 8, but not 16 weeks. However, at 16 weeks, hMSC significantly improved vasculogenesis in residual defect. We conclude that hMSC from healthy donors significantly contributed to the healing of bone defects at 8 weeks and to the vascularisation of residual connective tissue for up to 16 weeks. We found the administration of hMSC to be safe, as no adverse reaction to human cells at the site of implantation and no evidence of migration of hMSC to distant organs was detected.

[Follicular Lymphoma]

Follicular lymphomas represent the second most frequent lymphoma subtype. Translocation t(14;18)(q32;q21) is a characteristic biologic hallmark. It is not sufficient to drive follicular lymphomas development and subsequent molecular defect appears which lead to follicular lymphomas development and progression. The microenvironment plays an important role. The disease is usually diagnosed in an advanced clinical stage. The course is mostly indolent, but there is a subgroup characterized by rapid progression. The outcome has been improved with median of progression free survival between 6-7 years and overall survival between 10 and 15 years. The outcome improvement was caused by introduction of immunotherapy - rituximab, both in induction as well as in maintenance therapy. Despite this improvement, subsequent relapses occur, they can be managed by a variety of approaches based on many factors. The most adverse event is histological transformation. The present review briefly summarizes understanding of biology, clinical course and management.

[Current Approaches in Cancer Immunotherapy]

Methods of cancer immunotherapy have finally entered clinical medicine after years of preclinical research. Currently, there are several methods, which have proven to be very effective even in cases of incurable cancer. Antitumor monoclonal antibodies are among major therapeutic anti-cancer drugs and have been successfully used for many ears. Novel group of antibodies are immunomodulatory antibodies which can break tumor -specific immune tolerance and induce regression of tumors by nonspecific activation of immune system. Bispecific antibodies represent a novel class of anticancer agents which can induce expansion of T cells in vivo, blinatumomab is an example of such agents and is currently available for the treatment of acute B -cell leukemia. Cellular immunotherapy is also very effective, especially the use of Chimeric receptor modified T-cells for the therapy of B- cell lymphoproliferative diseases. Although it is a very complicated and expensive method, it is highly effective approach which can induce remission even in previously hopeless conditions. The goal of this article is to explain the basic principles of cancer immunotherapy and summarize the newest findings in this field.

[Malignant Lymphomas - Past, Present and Future]

This review summarizes the key steps on the way to understanding lymphoma biology and management. The history of lymphomas started in 1832 when Thomas Hodgkin first presented lymphomas. Classification of lymphoproliferative tumors has changed almost every 10 years as a reflection of deeper knowledge of this disease. Systemic therapy has developed in several steps starting by monotherapy with different chemotherapeutic agents, followed by the era of combination chemotherapy and by the rituximab era, which significantly changed the treatment paradigm. Several years ago, we entered into the fourth era characterized by many different targeted treatments. Radiotherapy remains an important part of lymphoma management. Lymphoproliferative tumors incidence is growing but mortality has started to decline starting in the year 2000 as the reflection of targeted therapy based on biology and pathogenesis.

[Hodgkin´s Lymhoma - the Treatment Aproaches Development and Current Trends]

Hodgkins lymphoma is a relatively rare malignant disease, mostly affecting younger adults. It represents one of the most curable disease among all lymphomas and other malignant diseases of adult age, with curability more than 80%. The progress of curability and long term survival demonstrates the development of oncologic approach during the last few decades, depicted in this article, particularly by introduction of combined modality treatment (chemotherapy and radiotherapy), progress in radiotherapy technique, implementation of high intensity regimens for advanced stages and use of novel drugs as well. Because of high curability rate and young age of most of the patients, late toxic effects are of significant relevance. The ongoing clinical research is focused on better prognostic stratification offering the patients more individualized treatment by risk and response disease evaluation, aiming to reduce toxicity while maintaining high curability and introduction of novel, less toxic drugs and their use in early phases of treatment.

[Salvage Treatment and the Role of Transplantation in Lymphomas]

Despite achieving promising treatment results in patients with lymphoma, there is still a significant proportion of patients who relapse or have refractory disease. Salvage therapy followed by high dose treatment with autologous stem- cell transplantation is the standard of care in many of them. The role allogeneic stem- cell transplantation, especially after reduced intensity conditioning, is under extensive investigation. This review article presents current knowledge and recommendation in the salvage treatment of relapsed/ refractory lymphomas.

[Diffuse Large B cell Lymphoma - Modern Dia-gnostics and Molecularly Targeted Treatment]

BACKGROUND

Diffuse large B -cell lymphoma is a common label for a number of clinico pathological entities, which differ in molecular pathogenesis, clinical presentation and prognosis. Exact correlation between clinico pathological and molecular subtypes of diffuse large B -cell lymphoma was not optimally defined; however, key signal transduction pathways were identified; blockage of these pathways may be therapeutically significant.

AIM

The purpose of this review is to show current approach to dia-gnostics of diffuse large B -cell lymphoma on molecular levels, to summarize current firstline treatment options for newly diagnosed diffuse large B -cell lymphoma patients and to introduce new treatment possibilities, which are currently under investigation in clinical trials.

RESULTS

Current molecular dia-gnostics of diffuse large B -cell lymphoma is evolving in two main directions. One direction is classification according to gene expression or protein levels. According to these studies, patients may be divided into subgroups according to the cell of origin or according their stromal signature. Most frequently used is classification accord-ing cell of origin (COO), which divides diffuse large B-cell lymphomas into GCB subtype (germinal B-cell like) or ABC subtype (activated B-cell like). Second direction is studying genetic information on DNA level, where genetic mutations, deletions, amplifications and losses of heterozygozity are identified, which may be specific for subgroups defined by gene expression analysis, but may go across them. Both these directions aim at identifying signaling pathways important for survival and proliferation of tumor cells and in these, to identify targets for pharmacological block-age. Currently, standard of first-line treatment for all patients is antracyclinebased regimen with rituximab, which improved prognosis in both cell of origin subtypes, even if patients in the ABC subgroup have still inferior outcome. There is a number of new drugs with promising effectivity, which are studied in different phases of clinical trials (lenalidomide, bortezomib, idelalisib, venetoclax), but their possible effectivity will be limited only for precisely defined molecular subtypes of diffuse large B -cell lymphoma.

CONCLUSION

The advent of new targeted drugs for diffuse large B- cell lymphoma is still awaited. For their effective use, besides the proof of their effectivity in randomized studies, also the extension of use of molecular methods in routine diagnostics and ensuring their wide availability will be necessary.

[Mantle Cell Lymphoma - Cutting edge Dia-gnostics and Treatment Approaches]

BACKGROUND

Mantle cell lymphoma represents a specific subtype of B -cell non-Hodgkin lymphoma characterized on the molecular level by translocation t(11;14)(q13;q32) leading to aberrant overexpression of cyclin D1 and deregulation of the cell cycle. Despite sporadic indolent forms of mantle cell lymphoma, majority of patients present with advanced aggressive disease that requires immediate treatment. Despite chemosensitive nature of mantle cell lymphoma, approximately 10% patients present with a refractory disease, and the vast majority of patients who initially respond to therapy, relapse sooner or later. The course of mantle cell lymphoma thus represents a chronically relapsing malignancy requiring further and further lines of therapies. Prognosis of relapsed or refractory (R/ R) mantle cell lymphoma is dismal.

AIM

The goal of this article is to provide a cutting -edge review of currently used diagnostic and treatment approaches for mantle cell lymphoma.

RESULTS

Several key modifications of the therapeutic algorithm of mantle cell lymphoma treatment implemented in the past 10 years resulted in significantly improved prognosis of patients. The milestones in the therapy of mantle cell lymphoma include incorporation of anti-CD20 monoclonal antibody rituximab into induction therapy, intensification of polychemotherapeutic regimen including implementation of high-dose cytarabine, consolidation of response with high-dose therapy and autologous stem cell transplantation (HDT ASCT) in younger fit patients, and maintenance therapy with rituximab in the elderly patients. Besides such "optimization" of frontline therapy, introduction of novel antilymphoma agents into therapy of R/ R mantle cell lymphoma also contributed (and will contribute in the future) to improved prognosis of mantle cell lymphoma. Among these agents, there is a new cytostatic drug bendamustine, Bruton tyrosine- kinase inhibitor ibrutinib, immunomodulatory agent lenalidomide, mTOR inhibitor temsirolimus and proteasome inhibitor bortezomib.

CONCLUSION

The overall survival of mantle cell lymphoma virtually doubled in the recent 10 years as a result of two key factors: 1. optimization of frontline therapy with "conventional" antilymphoma agents, and 2. brand new possibilities of therapy for R/ R mantle cell lymphoma thanks to the introduction of novel antilymphoma agents. Combinatorial approaches using most efficacious combinations of novel and "conventional" anti-mantle cell lymphoma agents will definitely lead to further improvements of survival parameters in mantle cell lymphoma patients in near future.

[Hepatic involvement in patients with non-Hodgkins lymphoma]

Non-Hodgkins lymphoma (NHL) represent the most frequent hematological malignancy with frequent extranodal involvement. We have identified 79 pts (4.6%) out of 1,712 patients with NHL, who were diagnosed in our center between 1999-2010. Five cases were primary extranodal lymphomas and we have observed one primary hepatic lymphoma (0.015%). The most frequent (61.3%) NHL subtype in our cohort was diffuse large B-cell lymphoma. B-NHL formed 92.4% of all lymphomas. We have observed high number of HBsAg positive patients (10%). The whole group have poor prognostic features with high number of patients (85%) with intermediate-high and high risk according to international prognostic index. The patients were treated with chemotherapy in 95%, B-NHL patients recieved immunochemotherapy with rituximab in 77%. The median progression free survival, resp. overall survival 4.6, resp. 8.4 years in the whole group and 1.4, resp. 8.4 years in diffuse large B-cell lymphoma were observed with median follow-up 4.5 years. The outcome of T-NHL patients was significantly worse with overall survival median 1.2 vs 8.4 years (p < 0.033). The patients with B-NHL treated by immunochemoterapy with rituximab had significant death risk reduction (HR 0.44, p = 0.03) compared to the patients treated with chemotherapy.

[Advances in the treatment of chronic lymphocytic leukaemia]

Chronic lymphocytic leukemia (CLL) is the most common forms of leukemia in the western world and is characterized by a highly variable clinical course. Some patients live for many years without treatment, whereas other have disease with rapid progression. The treatment of chronic lymphocytic leukemia has achieved extraordinary progress over the last years with the incorporation of monoclonal antibodies and combined chemoimmunotherapy. Despite these therapeutic successes, CLL is still considered to be an incurable disease. Only the allogenic transplantation is potentially curative but it is feasible only for selected group of younger patients without comorbidities. However, elderly and comorbid patients, who represent the majority of CLL population, are not usually able to undergo intensive treatment. The search for new treatment options is therefore still relevant. This review summerizes the current treatment options and newly tested drugs in CLL.

In vivo growth of mantle cell lymphoma xenografts in immunodeficient mice is positively regulated by VEGF and associated with significant up-regulation of CD31/PECAM1

Mantle cell lymphoma (MCL) is an aggressive lymphoma subtype with dismal prognosis. New treatments are needed to improve outcome of relapsed/ refractory disease. Recently, several drugs targeting at least partially the process of angiogenesis have been successfully tested in the therapy of MCL. Molecular mechanisms that regulate MCL-induced angiogenesis and that might represent potential new druggable targets remain, however, incompletely understood. We established two mouse models of human MCL by subcutaneous xenotransplantation of JEKO-1 and HBL-2 cell lines into immunodeficient mice. Histological analyses of xenografts confirmed their neovascularization. The growth of xenografts was significantly suppressed by single-agent therapy with bevacizumab, monoclonal antibody targeting vascular endothelial growth factor (VEGF). Subsequently, we analysed expression of 94 angiogenesis related genes in ex vivo isolated JEKO-1 and HBL-2 cells compared to in vitro growing cells using TaqMan low-density arrays. The most up-regulated genes in both JEKO-1 and HBL-2 xenografts were genes encoding platelet/endothelial cell-adhesion molecule (CD31/PECAM1), VEGF receptor 1 (FLT1), hepatocyte growth factor (HGF), angiogenin (ANG) and transcription factor PROX1. The most downregulated genes in both JEKO-1 and HBL-2 xenografts were midkine (MDK) and ephrine B2 (EPHB2). In summary, our results demonstrate an important role of angiogenesis in the biology of MCL and provide preclinical evidence of potent anti-MCL activity of bevacizumab. In addition, gene expression profiling of 94 angiogenesis-related targets revealed several in vivo up-regulated and down-regulated transcripts. The most differentially expressed target in both MCL tumours was CD31/PECAM1. Whether any of these molecules might represent a potential druggable target in MCL patients remains to be elucidated.

[The role of radiotherapy in the treatment of malignant lymphomas - recommendations of the Czech Lymphoma Study Group]

BACKGROUND

Indication of radiotherapy in lymphoma treatment is an important strategic decision requiring comprehensive expertise. It also calls for a better definition of the position of radiotherapy in clinical practice.

DESIGN

This position paper represents a consensus between hematooncologists and radiation oncologists on the role of RT in treatment of different histological types and stages of malignant lymphomas. The discussion was underway within professional societies of both specializations (Czech Lymphoma Study Group for the hematooncologists and the Society of Radiation Oncology, Biology and Physics for the radiation oncologists).

RESULTS

The consensus presented here was reached in early 2012 and draws on evidence-based medicine and clinical practice. Besides defining the role of radiotherapy in lymphoma treatment, this paper also gives specific recommendations on total doses of radiotherapy in lymphoma treatment.

CONCLUSION

These recommendations will supplement 7th edition of "Diagnostic and treatment guidelines in patients with malignant lymphoma" scheduled for publication in 2013.

Xenogeneic protein-free cultivation of mesenchymal stromal cells - towards clinical applications

We have studied a rapid cultivation method for human mesenchymal stromal cells based on CellGroTM medium and human serum, supplemented with insulin, ascorbic acid, dexamethasone, epidermal growth factor, platelet-derived growth factor BB, macrophage colony-stimulating factor and fibroblast growth factor 2. This study has shown that rapid expansion of human multipotent mesenchymal stromal cells using human serum could not be achieved without addition of growth factors. Furthermore, we have found that insulin and, quite probably, epidermal growth factor may be omitted from our formula without loss of colony-forming capacity or total cell yield. On the other hand, dexamethasone, ascorbic acid and fibroblast growth factor 2 were necessary for the growth and colony-forming capacity of multipotent mesenchymal stromal cells, while platelet-derived growth factor BB prevented their differentiation into adipogenic lineage. Moreover, multipotent mesenchymal stromal cells cultivated in our system expressed higher levels of bone morphogenetic protein 2, but not bone morphogenetic protein 7, than cells cultivated in α-MEM with foetal bovine serum. This shows that our system promotes differentiation of mesenchymal cells towards osteogenic and chondrogenic lineages, making them more suitable for bone and cartilage engineering than cells grown in conventional media. Furthermore, we have proved that these cells may be conveniently cultivated in a closed system, in vessels certified for clinical use (RoboFlaskTM), making the transfer of our cultivation technology to good clinical practice easier and more convenient.

Retrospective analysis of the results of high-dose chemotherapy with the support of autologous blood stem cells in patients with multiple myeloma. The experience of a single centre

Despite new medical products introduced in multiple myeloma therapy, autologous stem cell transplant (ASCT) remains a standard procedure in younger patients with symptomatic disease. We analyzed a group of 190 patients who underwent ASCT at our clinic for multiple myeloma as primary therapy in years 1995-2008. The total number of transplants performed in this group was 291. 110 patients underwent one ASCT, 59 patients had double transplant, out of which 51 patients underwent tandem transplant, 21 patients underwent triple ASCT, out of which 15 patients were transplanted front-line throughout a clinical trial and 6 patients underwent follow-up transplants due to disease progression. The assessment of the best therapeutic effect of ASCT showed the total rates of patients with complete remission--22%, very good partial remission (VGPR)--8%, partial remission--63%, stabilized disease--6% and progression--1%. The transplant related mortality (TRM) was 4.1%. With the median follow-up of surviving patients 2.6 years, the median progression-free survival (PFS) and overall survival (OS) were 21 and 54 months, respectively; the likelihood of a 7-year overall survival was 28%. Comparing tandem versus single transplants, there was a significant increase in the median PFS (25.8 versus 20.8 months, respectively); however, there was no difference in overall survivals. The IVE mobilization regimen was found to be more efficacious for PBPC collection than high-dosed cyclophosphamide.

Advanced rai stage in patients with chronic lymphocytic leukaemia correlates with simultaneous hypermethylation of plural tumour suppressor genes

Hypermethylation of CpG islands within gene promoters is one of various mechanisms of gene silencing involved in the pathogenesis of human cancer. By using methylation-specific polymerase chain reaction we explored aberrant promoter methylation of five tumour suppressor genes in 29 patients with chronic lymphocytic leukaemia. Aberrant methylation of DLC1, SHP1, p15 and p16 occurred, respectively, in 89.7 %, 70 %, 62.1 % and 31 % of patients at diagnosis. Lamin A/C was unmethylated in all the samples. Hypermethylation of at least one gene was detected in 96.6 % of patients. Concurrent methylation of two or more genes correlated with Rai stage at diagnosis.

Dendritic cells and T lymphocyte interactions in patients with lymphoid malignancies

Dendritic cell (DC) vaccination is an attractive approach to the treatment of patients with lymphoid tumors. To evaluate its feasibility, we have tested the functional properties of DC and T-lymphocytes in patients with treated and untreated chronic lymphocytic leukemia (CLL) and follicular lymphoma (FL). Healthy volunteers were used both as controls and as a source of cells for allogeneic mixed leukocyte reaction (MLR). In these reactions, dendritic cells from both untreated and treated patients were comparable to dendritic cells from healthy volunteers. In all the untreated patients studied, autologous dendritic cells promoted the survival and proliferation of both CD4 and CD8 lymphocytes (though the proliferation response was much better in the CD4 subset), whereas only 3 out of 5 treated patients were able to mount this response with CD4 lymphocytes and 4 out of 5 with CD8 lymphocytes. In 3 out of 5 untreated patients, pulsing of DCs with tetanus toxoid promoted a better CD4 response than was achieved with unpulsed DCs, while none of 5 treated patients had an additional response after pulsing with tetanus toxoid. None of patients studied, either treated or untreated, had a better CD8 response to pulsed DCs than to unpulsed ones. During CD4 lymphocyte proliferation, more CD4(+)CD25(hi) lymphocytes were generated in both treated and untreated patients than in healthy controls. Poor proliferation of cytotoxic cells and preferential proliferation of CD4(+)CD25(hi) T-regulatory cells in response to self and/or foreign antigens might be one of the mechanisms responsible for immunosuppression and impaired tumor surveillance in patients with lymphoid malignancies.