Cell-Tak coating interferes with DNA-based normalization of metabolic flux data.

Metabolic flux investigations of cells and tissue samples are a rapidly advancing tool in diverse research areas. Reliable methods of data normalization are crucial for an adequate interpretation of results and to avoid a misinterpretation of experiments and incorrect conclusions. The most common methods for metabolic flux data normalization are to cell number, DNA and protein. Data normalization may be affected by a variety of factors, such as density, healthy state, adherence efficiency, or proportional seeding of cells. The mussel-derived adhesive Cell-Tak is often used to immobilize poorly adherent cells. Here we demonstrate that this coating strongly affects the fluorescent detection of DNA leading to an incorrect and highly variable normalization of metabolic flux data. Protein assays are much less affected and cell counting can virtually completely remove the effect of the coating. Cell-Tak coating also affects cell shape in a cell line-specific manner and may change cellular metabolism. Based on these observations we recommend cell counting as a gold standard normalization method for Seahorse metabolic flux measurements with protein content as a reasonable alternative.

Mitochondria-targeted compounds in the treatment of cancer.

Mitochondria are highly dynamic organelles involved in many cellular functions. Beyond their central role in metabolism, they also take a part in maintaining calcium homeostasis, cell death, immunity, and ROS production. Changes in these functions have been shown to be crucial for the adaptation and survival of cancer cells. Mitochondria, therefore, constitute a promising target for the development of novel anticancer agents. The triphenylphosphonium (TPP+) moiety has been widely used to target molecules into mitochondria. TPP+ derivatives of a variety of conventional cytostatic drugs, natural substances, metformin, antioxidants or a range of newly synthesized molecules have shown promising results against cancer cells. In this review, we discuss biochemical differences between cancer cells and normal cells with a specific focus on mitochondria, and how mitochondrially targeted molecules can be used to selectively affect mitochondrial function in normal and cancer cells. We summarize the published data on mitochondrially targeted anticancer agents and propose future research avenues.

Cytogenetic abnormalities predict treatment-free interval and response to therapy in previously untreated chronic lymphocytic leukemia patients.

We evaluated the prognostic impact of chromosomal abnormalities as detected by interphase fluorescence in situ hybridization (iFISH) in 86 chronic lymphocytic leukemia (CLL) patients. Overall, 39 of 86 (45%) patients displayed one (35%) or more (10%) chromosomal abnormalities, del13q (31%) being more frequently detected than trisomy 12 (19%) followed by del11q (17%), del17p (6%) and del6q (5%). Significant differences in the treatment free intervals (TFIs) were observed among individual cytogenetic subgroups (p=0.027) with the shortest mean TFIs in subgroups with del17p, del11q and trisomy 12 (10, 12 and 14 months, respectively) as compared to subgroups with normal cytogenetics (38 months) and del13q (68 months). Poor response to therapy was observed in subgroups with del11q (p=0.044) and trisomy 12 (p=0.047) while patients with normal cytogenetics had good response (p=0.003). Furthermore, del17p and del11q were associated with highest tumor burden and disease activity as reflected by corresponding laboratory data.

High-dose chemotherapy followed by autologous stem cell transplantation changes prognosis of IgD multiple myeloma.

Immunoglobulin D (IgD) multiple myeloma (MM) is a rare plasma cell disorder constituting less than 2% of all MM cases. Survival of patients with IgD MM is generally shorter than that of patients with other types of monoclonal (M-) protein. We have retrospectively analyzed patients with IgD MM participating in clinical trials of the Czech Myeloma Group. Twenty-six IgD MM patients treated between 1996 and 2006 were identified, 14 (54%) men and 12 (46%) women. The median age was 61 years (range: 37-79 years). Ten of 26 patients (39%) were treated with first-line high-dose chemotherapy (HDCT) using melphalan 200 mg/m(2) followed by autologous stem cell transplantation (ASCT). Thirteen of 26 patients (50%) received conventional chemotherapy (CHT), mostly melphalan and prednisone or a vincristine/doxorubicin/dexamethasone (VAD) regimen. Treatment responses were evaluable for 23 of 26 (89%) patients. All HDCT patients had treatment responses, including seven patients (70%) with complete responses and three patients (30%) with partial responses. The median progression-free survival was 18 months for HDCT patients and 20 months for CHT patients. The median overall survival (OS) for all patients was 34 months. The median OS for the HDCT group has not yet been reached (70% of the patients are still alive). In contrast, the median OS for CHT patients was only 16 months. The difference in OS between the two groups was statistically significant (P=0.005). In conclusion, the overall response rate for patients with IgD MM aged 65 years or less treated with HDCT and ASCT is similar to that seen in other MM types.

Imatinib mesylate in Philadelphia chromosome-positive, chronic-phase myeloid leukemia after failure of interferon alpha.

Imatinib mesylate (STI 571; Glivec) is a potent and selective tyrosine kinase inhibitor. The introduction of imatinib has chanced the philosophy of mechanisms of cancer therapy and already changed current management of patients with chronic myeloid leukemia (CML). A total of 49 patients with later chronic phase CML in whom previous therapy with interferon alpha had failed were treated with 400 mg of oral imatinib daily. Patients were evaluated for hematologic and cytogenetic responses. Time to progression, survival, and toxic effects were also evaluated. Complete hematologic responses were reported for 48 of 49 patients studied (98 percent). The median time to a complete hematologic response was 1.2 month; 89% of patients who had a response did so within 4 months. Imatinib induced major cytogenetic responses in 73%; 62% had a complete responses. After a median follow-up of 18 months, CML had not progressed to the accelerated or blast phases in an estimated 98% of patients, and 100 percent of the patients were alive. Grade 3 or 4 nonhematologic toxic effects were manageable. No one of patients discontinued treatment due to of drug-related adverse events, and no treatment-related deaths occurred. The results of current study indicate that imatinib has a significant therapy benefit in CML patients in whom treatment with IFN alpha had failed. Therefore, has favorably changed the prognosis for patients with chronic myelogenous leukemia.

[Relation between Bcl-2 protein expression and results of therapy in patients with acute myeloblastic leukemia]. / Vzt'ah medzi expresiou Bcl-2 proteínu a výsledkami liecby u chorých s akútnou myeloblastovou leukémiou.

Flow cytometric expression of Bcl-2 protein was analyzed in 67 newly diagnosed acute myeloblastic leukemia (AML) patients using an anti-Bcl-2 monoclonal antibody by direct immunofluorescence technique and result were correlated with FAB subtype, CD34 expression and clinical outcome. The number of Bcl-2+ cells in each sample was heterogenous (range, 19% to 96%), with mean of 81%. The percentage of Bcl-2+ cells was higher in M0 and M1 types according French-American-British classification. The mean fluorescence index (MFI), expressed as the ratio of sample channel: control mean channel was significantly higher (p < 0.01) in M0 (19.0) and M1 (17.6) than M4 (11.7) and M5 (8.9) cytotypes. In addition, Bcl-2 MFI significantly correlated both with CD34 positivity and with CD34 MFI. High percentage expression of Bcl-2 and MFI index of Bcl 2 was associated with a low complete remission rate after intensive chemotherapy (40.4% in cases with 20% and more positive cells vs 72% in cases with less than 20% positive cells). By statistical analysis we also demonstrated that both Bcl-2 high MFI (> 16) and CD34 expression are independent prognostic factors for achieving CR in AML.

Fludarabine combined with cyclophosphamid is highly effective in the treatment of chronic lymphocytic leukemia.

Combined treatment of fludarabine (FLU) with cyclophosphamide (CY) may increase the complete remission (CR) rate, decreased minimal residual disease (MRD) and, possibly, prolong survival in B-chronic lymphocytic leukemia patient's (B-CLL). The aim of study was to evaluate the activity and toxicity of FLU in combination with CY, the FLU-CY schedule, in patients with previously untreated B-CLL. From May 1999 to December 2002, 57 patients with advanced or progressive B-CLL received treatment with FLU at a dose of 30 mg/m2 for three consecutive days and CY at a dose of 300 mg/m2 for three days. The cycles were repeated at four week intervals or longer if severe myelosupression occurred. Guidelines for the evalution of response and toxicity were those developed by the National Cancer Institute Sponsored Working Group. Minimal residual disease (MRD) was detected by immunophenotyping only in patients with CR by standard criteria. In the analyzed group an overall response (OR) rate (CR+PR) of 89.5% (95% CI 80.6-94.7%) was achieved, including complete response in 29.8%. At the time of analysis 15 of 17 patients with CR are still in remission. Median duration of follow up in these is 12 (range 4-29.2) months. MRD was detected only in five out of 17(29.4%) patients with CR. Grade III/IV thrombocytopenia was seen in 3 (5.2%) patients and grade III/IV neutropenia in 6 (10.5%). Severe infections were noted in 14 (24%) patients. Two (3.5%) patients died, one due to sepsis, one as a result of disease progression. The FLU-CY regimen is highly effective combination in previously untreated CLL patients with acceptable toxicity. The efficacy of the regimen seems to be higher than that observed earlier after treatment with FLU alone.

Efficiency of in vivo purging with autologous stem cell transplantation and monoclonal antibody in B-cell lymphomas.

Elimination of tumor cells from hematopoietic stem cell products is a major goal of bone marow-suported high-dose cancer chemotherapy. In patients (pts) with low-grade lymphoma Gianni et al (2000) assessed the ability of Rituximab, given in combination with high-dose chemotherapy, to eradicate PCR-detectable disease and enable the harvesting of large amounts of uncontaminated circulating progenitor cells. Our study was conducted in 27 consecutive pts with untreated bcl2 positive NHL (follicular lymphoma--7, chronic lymphocytic leukemia--13 and NHL in leukemic phase--7), 14 pts received Rituximab. Patients received 4 courses of standard-dose chemotherapy (CHOP or FLU-CY), followed by one course of high-dose cyclophosphamid plus G-CSF. Patients allocated to Rituximab received i.v. infusions of 375 mg/m2 48 hours before stem cell collection and in 3 weekly doses after transplantation (R-CHT). Clinical response after transplantation was evaluated in 26 pts who completed the treatment. The complete response rate was in 100% in the Rituximab group (PCR negative in 79%) versus 50% of controls (p<0.01). Yield of purged CD34+ cells was with median 5.23x10(6)/kg in CHT and 8.76x10(6)/kg in R-CHT pts. Toxicity in the both arms was acceptated (no difference). No significant difference was observed between CHT and R-CHT group in the mean number of days spent with neutropenia and trombocytopenia. After a follow-up of 31 months, no patient relapsed. Aside from providing PCR-negative harvests, the chemoimmunotherapy treatment produced complete clinical (100%) and molecular remission in 79% of evaluable pts. We showed that Rituximab in combination with effective high-dose anti- lymphoma chemotherapy, allowed the harvesting of large amounts of tumor free progenitor cells in evaluable pts.

High expression of Bcl-2 protein in acute myeloid leukemia cells is associated with poor response to chemotherapy.

Flow cytometric expression of bcl-2 protein was analyzed in 67 newly diagnosed acute myeloblastic leukemia (AML) patients using an anti-bcl-2 monoclonal antibody by direct immunofluorescence technique and results were correlated with FAB subtype, CD34 expression and clinical outcome. The number of bcl-2+ cells in each sample was heterogenous (range, 19% to 96%), with a mean of 81%. The percentage of bcl-2+ cells was higher in M0 and M1 types according to French-American-British classification. The mean fluorescence index (MFI), expressed as the ratio of sample channel:control mean channel was significantly higher (p=0.01) in M0 (19.0) and M1 (17.6) than M4 (11.7) and M5 (8.9) cytotypes. In addition, bcl-2 MFI significantly correlated both with CD34 positivity and with CD34 MFI. High percentage expression of bcl-2 and MFI index of bcl-2 was associated with a low complete remission rate after intensive chemotherapy (40.4% in cases with 20% and more positive cells vs 72% in cases with less than 20% positive cells). By statistical analysis we also demonstrated that both bcl-2 high MFI (>16) and CD34 expression are independent prognostic factors for achieving CR in AML.

[Occurrence of autoimmune complications in patients with chronic myelocytic leukemia during treatment with interferon alfa]. / Výskyt autoimunitných komplikácií u chorých s chronickou myelocytovou leukémiou pocas liecby s interferónom alfa.

UNLABELLED: Several prospective randomized studies have shown that the treatment of chronic myeloid leukemia with interferon alfa (IFN alpha) prolongs the survival by comparison with conventional chemotherapy. However, long-term treatment with Interferon alfa (IFN alpha) can produce or exacerbate immune-mediated complications (IMC). The purpose of this study was to analyze the experience with IMC in patients with chronic myelogenous leukemia (CML) undergoing IFN alpha treatment. PATIENTS AND METHODS: The occurrence of IMC was evaluated in 76 patients (47 male; 29 female) with Philadelphia chromosome (Ph)-positive CML. The median of age was 45 years and the duration of disease was 3.9 years. Diagnostic criteria of IMC were performed in patients with sign and symptoms suggestive of particular disorders. RESULTS: Well-documented and clinically evident complications developed in 7 patients after a median of 19 months (range 1-84) of IFN alpha treatment. These included 9.2% patients with Ph-positive CML treated with IFN alpha-containing regimens. Hypothyroidism (H) occurred in 1 patient (1.3%), immune-mediated hemolysis (HEM) in 2 patients (2.6%) and connective tissue disorders (CTD) in 4 patients (5.3%) [2-SLE, 1-Raynad's syndrome and 1-mixed connective tissue syndrome (MCTS)]. IFN alpha was discontinued in 3 patients and the dose was reduced in 2 patients. Five of 7 patients (75%) with immune-mediated complications had some degree of cytogenetic response at the time of the event. The association with female sex was strong and significant (86% vs 33.6%, x2; 48; p = 0.02). CONCLUSION: The frequency of IMC of clinical relevance with interferon alfa therapy in CML increased (long-term therapy). The patients treated with interferon alfa should be monitored for sign and symptoms of autoimmunity.

Immune-mediated complications during interferon alpha therapy in chronic myelogenous leukemia.

Several prospective randomized studies have shown that the treatment of chronic myeloid leukemia with interferon alpha (IFNalpha) prolongs the survival by comparison with conventional chemotherapy. However, long-term treatment with Interferon alpha can produce or exacerbate immune-mediated complications (IMC). The purpose of this study was to analyze the experience with IMC in patients with chronic myelogenous leukemia (CML) undergoing IFNalpha treatment. The occurrence of IMC was evaluated in 76 patients (47 male; 29 female) with Philadelphia chromosome (Ph)-positive CML. Diagnostic criteria of IMC were performed in patients with symptoms suggestive of particular disorders. Well-documented and clinically evident complications developed in 7 patients after a median of 19 months (range 1-84) of IFNalpha treatment. These included 9.2% patients with Ph-positive CML treated with IFNalpha-containing regimens. Hypothyroidism (H) occurred in 1 patient (1.3%), immune-mediated hemolysis (HEM) in 2 patients (2.6%) and connective tissue disorders (CTD) in 4 patients (5.3%) (2 systemic lupus erythematosus--SLE, 1 Raynaud's phenomena and 1 mixed connective tissue disease--MCTD). IFNalpha was discontinued in 3 patients and the dose was reduced in 2 patients. Five of 7 patients (75%) with immune-mediated complications had some degree of cytogenetic response at the time of the event. The association with female sex was strong and significant (86% vs 33.6%, x2; 48; p = 0.02). The frequency of IMC of clinical relevance with interferon alpha therapy in CML increased (long-term therapy). The patients treated with interferon alpha should be monitored for signs and symptoms of autoimmunity.

Leukemic transformation of polycythemia vera after treatment with hydroxyurea with abnormalities of chromosome 17.

The leukemogenic risk attributed to therapy of polycythemia vera with radiophosphorus and alkylating drugs has led, over the last 20 years, to the increased use of myelosupressive nonmutagenic drugs, especially hydroxyurea. But there exist reports, which showed the development of polycythemia vera into acute leukemia not only in patients treated with alkylating agents and radiophosphorus but also with single hydroxyurea. In this article we present two cases of polycythemia vera, in which the development to acute myeloblastic leukemia occurred after long-term treatment with hydroxyurea. Significant is the fact, that in both presented cases cytogenetic and FISH analysis showed abnormalities of chromosome 17, in the one of case fullfilled criteria for "17p-syndrome". Due to the possibility of leukemogenic potential in the time of hydroxyurea treatment, it is necessary to be careful especially in young patients. The dynamic follow up of cytogenetic analysis is necessary, especially, in those, where long-term hydroxyurea therapy is supposed.

P-glycoprotein expression in adult acute myeloid leukemia: correlation with induction treatment outcome.

Drug resistance has become a major cause of the treatment failure in patients with acute leukemia. P-glycoprotein (P-gp), which is associated with multidrug resistance (MDR) phenotype, has been reported to be an important predictor of the treatment outcome. The aim of this study was to analyze the value of P-gp expression in bone marrow cells as a predictor of the response to remission induction chemotherapy, as well as duration of remission in adult patients with newly diagnosed acute myeloid leukemia (AML). We examined the expression of P-gp in 31 patients using the monoclonal antibody UIC2. Direct immunofluorescent labeling was performed and samples were analyzed by flow cytomery. Kolmogorov-Smirnov test (D-value) was used to estimate UIC2 staining. A D > or = 0.3 for labeling of gated leukaemic blasts as compared to that of the isotypic control was defined positive (+) and compared to clinical data. P-gp expression was found in 14/31 (45.6%) patients, 17/31 (54.8%) of the samples were found P-gp negative(-). No correlation was found regarding age, sex and FAB subtype, altough 6/14 (43%) cases with more than 50% of cells having P-gp expression, were CD34+/CD7+. Complete remission rates were significantly lower in UIC2+ patients than in UIC2- cases (70% vs 35%, p < 0.01). Complete remission duration was also shorter in UIC2+ patients (6 vs 12.4 months). Our data indicate, that P-gp expression is a reliable marker of resistance to induction treatment in patients with de novo AML and can help to identify patients who may require alternative regimens designed to overcome therapy resistance.

[Hematologic and cytogenetic response to treatment in patients with chronic myeloid leukemia]. / Hematologická a cytogenetická odpoved na liecbu u chorých s chronickou myeloickou leukémiou.

BACKGROUND: The Interferon alpha therapy increases the number of cytogenetic responses in patients with chronic myeloic leukaemia. The addition of cytarabine can reduce the number of Ph positive metaphases. The achievement of cytogenetic response is connected with longer survival of patients with chronic myeloic leukaemia. The aim of the study was the evaluation of the achievement of hematologic and cytogenetic response as well as adverse effects of the treatment in chronic myeloic leukaemia patients. METHODS AND RESULTS: The followed was the group of 87 previously untreated CML Ph positive patients. 34 patients with the median age of 44.6 years were treated with hydroxyurea, 42 patients were treated with single interferon alpha and 11 patients with the median age of 41.3 years with the combined interferon plus cytarabine therapy. The complete hematologic remission occurred in only 17.5% of patients treated with hydroxyurea, but in 35.7% treated with interferon and in 54.5% patients treated with the combined therapy. The cytogenetic response we have not found in any of hydroxyurea treated patients, in the group of interferon alpha in 38%. The highest number of cytogenetic responses was in the group treated with interferon plus cytarabine. As we have expected, the addition of cytarabine increased hematotoxicity and gastrotoxicity. CONCLUSION: Based on the published date, that show a better survival of patients with the achieved cytogenetic response as well as the higher number of cytogenetic responses in the group of interferon plus cytarabine therapy from our observation, we believe, that combined therapy should be suitable as a front-line therapy of chronic myeloic leukaemia patients.

Hematological and cytogenetic response of interferon alpha 2b alone and combined interferon alpha plus cytarabine as a first-line treatment in chronic myeloid leukemia.

Treatment with interferon-alpha (IFNalpha) prolongs survival in chronic myeloid leukemia (CML). Additionally, cytarabine (AraC) can reduce the number of Ph + metaphases. Fortythree previously untreated patients with CML in chronic phase were randomly assigned to receive either. IFNalpha 2b (5 MU sqm/daily) or IFNalpha 2b in the same dosages plus monthly courses of low-dose AraC. The aim were complete hematologic remission at 6 months and cytogenetic response at 12 months. A complete hematologic remission occurred in 60.4% patients with single IFNalpha 2b in 76.2% patients with combination therapy. A cytogenetic response was present in 13.9% (major in 2 patients) with IFN therapy and in 38.1% patients with combination therapy. Two of 21 patients treated with IFNalpha/AraC therapy achieved major (9.52%), 4 partial (19.04%) and 2 minor (9.52%) cytogenetic response. Major side effects were cytopenia (20.1%), flu-like syndromes (42.4%) and increase of hepatic transaminases (3.4%). The side effects were more significant in the group receiving combination therapy. Based on published data that show a survival advantage for patients who achieved any cytogenetic response, and high rate of cytogenetic response which we observed in our study we believe that IFN plus AraC regimen could be a front-line therapy for CML.

[The 6M 12M trial--study of the effectivess and tolerance of treatment in chronic myeloid leukaemia with a combination of interferon alfa and cytarabine]. / Stúdia 6M 12M--Ucinnost' a tolerancia liecby chronickej myeloickej leukémie kombináciou interferonu alfa s cytosinarabinosidom.

OBJECTIVE: Comparing the conventional treatment after the interferon alpha treatment the number of hematologic as well as cytogenetic responses increases. With the cytogenetic response is associated a longer survival. Today is interferon alpha considered to be the first line treatment in those patients with chronic myeloic leukaemia, who are not candidates for alogenic bone marrow transplantation. The combination with cytosinarabinoside can reduce the number of Ph positive metaphases. DESIGN AND METHODS: Forty-three previously untreated patients with CML in chronic phase were randomly assigned to receive either IFN alpha 2 b (5MU sqm/daily) or IFN alpha 2 b in the same dosage plus monthly courses of low-dose AraC. The aim were complete hematologic remission at 6 months and cytogenetic response at 12 months. RESULTS: A complete hematologic remission occured in 61.9% patients with single IFN alpha 2 b and in 78.9% patients with combination therapy. A cytogenetic response was present in 28.5% and in 42.2% patients with combination therapy. One of 21 patients treated with IFNalpha/AraC therapy achieved complete (5.2%), 4 partial (21%) and 3 minor (16%) cytogenetic response. The side effects were more significant in the group receiving combination therapy. CONCLUSIONS: Based on published data that shows a survival advantage for patients who achieved any cytogenetic response and high rate of cytogenetic response which we observed in our population we believe that IFN plus AraC regimen could be a front-line therapy for CML.

[Leukemic transformation of polycythemia vera after treatment with hydroxyurea and chromosome 17 abnormalities]. / Leukemická transformácia polycytemia vera po liecbe s hydroxyureou s abnormalitami chromozómu c. 17.

The authors present two patients with polycythemia vera where they recorded after several years' treatment with hydroxyurea development of acute myeloblastic leukaemia. In both instances they found, associated with leukaemia, abnormalities of chromosome no.17, in one case meeting criteria of the so-called 17p-syndrome. Progression of polycythemia vera into acute leukaemia is explained by the possible association with the long-term use of the drug and loss of chromosomal material (short arm of chromosome 17), the part where genes important in the process of leukaemogenesis are located. The authors draw attention to contemplated long-term administration of hydroxyurea to young patients with polycythemia vera. As cytogenetic analysis is a suitable method for evidence of progressing polycythemia vera into acute leukaemia, dynamic follow up of chromosomal changes is necessary, in particular in patients where long-term treatment with hydroxyurea is assumed.

[Recombinant interferon alfa in the treatment of essential thrombocythemia]. / Rekombinantný interferón alfa v liecbe esenciálnej trombocytémie.

Essential thrombocythaemia, a clonal myeloproliferative disease characterized by a persisting increase of the number of thrombocytes, their abnormal morphology and function, is a special clinical and therapeutic problem which calls for a comprehensive approach. Based on a group of their own patients and on data from the literature, the authors discuss the asset of interferon alpha in the treatment of essential thrombocythaemia.

[Interferon alpha in the treatment of chronic myeloid leukemia]. / Interferon alfa v liecbe chronickej myeloickej leukémie.

The authors present their results assembled in patients with chronic myeloid leukaemia (CML) to whom they administered interferon alpha (IFN) in the chronic stage of the disease. They evaluated the survival of patients and the haematological and cytogenetic response. They recorded a favourable haematological response in patients with CML to IFN treatment comparable with data reported in the literature. They assume that the smaller number of cytogenetic responses is due to the smaller percentage of patients in the early chronic stage and short period of hydroxyurea administration at the onset of treatment. They consider interferon alpha, similarly as other authors, a successful drug in the treatment of the chronic stage of chronic myeloid leukaemia.