Search

PDF file, 654KB

B-cell chronic lymphocytic leukemia (B-CLL) is the most common human leukemia in the world. Deregulation of the TCL1 oncogene is a causal event in the pathogenesis of the aggressive form of this disease as was verified by using animal models. To study the mechanism of Tcl1 regulation in CLL, we carried out microRNA expression profiling of three types of CLL: indolent CLL, aggressive CLL, and aggressive CLL showing 11q deletion. We identified distinct microRNA signatures corresponding to each group of CLL. We further determined that Tcl1 expression is regulated by miR-29 and miR-181, two microRNAs differentially expressed in CLL. Expression levels of miR-29 and miR-181 generally inversely correlated with Tcl1 expression in the CLL samples we examined. Our results suggest that Tcl1 expression in CLL is, at least in part, regulated by miR-29 and miR-181 and that these microRNAs may be candidates for therapeutic agents in CLLs overexpressing Tcl1. (Cancer Res 2006; 66(24): 11590-3)

PDF file, 6KB

PDF file, 22KB

Electrocardiography (ECG) takes the lead in assessing the prevalence of coronary artery disease (CAD) in the population. ECG disorders, grouped in the Major (certain) and Minor (possible) categories, are prognostic markers of a high risk of cardiovascular diseases and sudden cardiac death. Unified assessing methods of ECG disorders prevalence and their associations with socio-demographic parameters have not previously been made in Russia.Aim. To study the prevalence of ECG parameters of certain and possible coronary artery disease among population of Russia, depending on the socio-demographic characteristics — age, sex, education and place of residence (city or country).Material and methods. We used 17504 ECGs from representative samples of population (25-64 years old), who participated in the epidemiological study “Epidemiology of cardiovascular diseases and their risk factors in the Russian Federation”. The analysis using Minnesota code was carried out among men and women of four age groups, two educational levels, among citizens and countrymen.Results. The highest prevalence was observed in the “Certain” (5,7%) and “Possible signs of CAD” (7,1%) categories, in the “Certain” (3,8%) and “Possible myocardial ischemia” groups (4,9%), the smallest is in the “Rhythm and conduction disorder” (0,7%) and “STT changes in left ventricular hypertrophy” (0,4%) groups. It was shown that the frequency of ECG disorders increases with age, has an sharp increase after 55 years, regardless of sex. In the age dynamics of categories, STT changes and atrial fibrillation have a decrease of gender differences. All groups of ECG disorders are detected more often among men than women, except for STT changes. With an increase in the level of education, the frequency of ECG pathologies decreases, with the exception of the groups of “major” and “minor Q (QS)”, “major rhythm and conduction disorders”. The prevalence of most ECG disorders does not depend on the place of residence. However, signs of major myocardial ischemia in men are more common in country than in the city (3,9% vs. 2,7%, pConclusion. The results confirm the patterns identified earlier. There is a steady association of ECG data with socio-demographic characteristics.

Aim . To analyze health care resource utilization and temporary disability in people of pre-retirement age in the Russian population. Material and methods . The analysis was carried out on the basis of the ESSE-RF study materials (13 regions of the RF). Standard epidemiological survey methods and evaluation criteria were used. The analysis included results of a survey of the ESSE-RF study participants about health care resource utilization and temporary disability (TD) during 12 months before the survey. The following characteristics were ascertained: a number and reasons of outpatient visits for medical assistance, hospital admissions (including duration of in-hospital treatment), emergency calls and temporary disability (a number of days and cases), their mean number per one study participant, mean number of cases and days of TD per 100 working participants, associations with social-demographic parameters, risk factors, chronic non-communicable diseases, stress and anxiety levels by the Hospital Anxiety and Depression Scale (HADS). Results . A total of 8334 people aged 50-64 years were examined: men – 2784 (33%) and women – 5550 (67%). A share of the hospitalized (at least one time) was 11% in the age group of 50-54 years, 12% – in the age group of 55-59 years and by the age of 60-64 this indicator increased to 15%. 20% of the participants at least one time were admitted to hospital and/or called an ambulance. A share of people who had utilized health care resources at least one time was increasing with age. Unemployed people were hospitalized more frequently than employed ones. Number of chronic non-communicable diseases correlated with the probability of hospitalization and/or emergency call. Categories 2 and 3 of disability, presence of diabetes mellitus, ischemic heart disease and hypertension were statistically significantly associated with the probability of hospitalization and/or emergency call. Smoking did not increase the probability of hospitalization and/or emergency call in comparison with absence of this risk factor, at that, people who had given up smoking were 1.3 times more likely to be hospitalized than non-smokers. People with low and moderate alcohol consumption were hospitalized and called an ambulance significantly less often than those who abstained from alcohol. Clinically significant anxiety increased the probability of hospital admission and/or emergency call as compared to people without this factor by the HADS. Subclinical and clinically significant anxiety, mean and high levels of stress were associated with the probability of hospitalization and/or emergency call. Number of TD days turned out to be rather low - 0.3 day per 1 working man and 0.4 day - per 1 working woman, this index did not significantly differ with age. Conclusion . So, pre-retirement age (50-64 years) is characterized by increase in health care resource utilization due to health state worsening. At the same time significant share of people of this age (40%) did not seek medical help. These 40% of pre-retirement age people can be possible reserve for health state improvement by means of their active involvement in preventive activity of primary health care system (the study had been conducted before the preventive medical examination program starting).

The existing pruning shears and delimbers have many drawbacks that limit their widespread use in the production process. These are such disadvantages as large weight and dimensions, high power consumption, vibration and noise, low mobility due to being tied to an energy source. DC motors are used to drive the cutting blades. Their main disadvantage is the low operational reliability of such an element as electric brushes. The use of the kinematic transformation of the rotational motion of the electric motor into the reciprocating motion of the blades reduces the overall efficiency of the device and increases the consumption of electrical energy. The proposed linear electric motor for the delimber drive will increase the efficiency, operational reliability and reduce energy consumption for cutting tree branches. A feature of a linear electric motor is the use of two magnetizing coils, which are switched on alternately. The use of a thin element in the magnetic system makes it possible to redistribute the obtained magnetic flux towards the armature of the linear electric motor. The armature of the electric motor consists of magnetic and nonmagnetic bushings of a certain design. This allows you to obtain a magnetic flux, which, passing along the armature, creates an electromagnetic force that sets it in motion. The cutting blade is then anchored. This allows you to improve the characteristics of the proposed delimber. The main challenge in the design of the delimber is to create the maximum force on the cutting blade required to cut branches. For this, it is necessary to perform an improvement of the magnetic system of the linear electric motor. For this purpose, the simulation of the magnetic system was carried out in the ElCut program.

B-cell chronic lymphocytic leukemia (B-CLL), the most common leukemia in the Western world, occurs in two forms, aggressive (showing for the most part high ZAP-70 expression and unmutated IgH V H ) and indolent (showing low ZAP-70 expression and mutated IgH V H ). We found that miR-29a is up-regulated in indolent human B-CLL as compared with aggressive B-CLL and normal CD19 + B cells. To study the role of miR-29 in B-CLL, we generated Eμ- miR-29 transgenic mice overexpressing miR-29 in mouse B cells. Flow cytometric analysis revealed a markedly expanded CD5 + population in the spleen of these mice starting at 2 mo of age, with 85% (34/40) of miR-29 transgenic mice exhibiting expanded CD5 + B-cell populations, a characteristic of B-CLL. On average, 50% of B cells in these transgenic mice were CD5 positive. At 2 y of age the mice showed significantly enlarged spleens and an increase in the CD5 + B-cell population to ∼100%. Of 20 Eμ- miR-29 transgenic mice followed to 24–26 mo of age, 4 (20%) developed frank leukemia and died of the disease. These results suggest that dysregulation of miR-29 can contribute to the pathogenesis of indolent B-CLL.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common adult leukemia. Deregulation of the T-cell leukemia/lymphoma 1 (TCL1) oncogene in mouse B cells causes a CD5-positive leukemia similar to aggressive human B-CLLs. We recently reported that levels of TCL1 expression in B-CLL are regulated by miR-29 and miR-181 that target 3' UTR of TCL1. To determine whether treatment with microRNAs targeting TCL1 can inhibit B-CLL in mice, we generated TCL1 transgenic mice using a construct containing the 3' and 5' UTRs of TCL1 under B-cell-specific Emicro promoter (Emicro-TCL1FL). At the age of 16-20 months, these mice showed B-CLL-like disease. Immunophenotyping revealed accumulation of CD5+CD23+B220+ population in spleens and lymph nodes. Our results show that CD5+CD23+ B-cell populations from Emicro-TCL1FL mice actively proliferate and show significantly increased levels of phospho-Akt. Emicro-TCL1FL mice showed immunological abnormalities similar to human B-CLL, including hypoimmunoglobulinemia, abnormal levels of cytokines and impaired immune response. These findings revealed biochemical and immunological similarities between Tcl1-driven B-CLL in mice and human B-CLL.

The helix-loop-helix transcription factor Tal1 is required for blood cell development and its activation is a frequent event in T-cell acute lymphoblastic leukemia. The Akt (protein kinase B) kinase is a key player in transduction of antiapoptotic and proliferative signals in T cells. Because Tal1 has a putative Akt phosphorylation site at Thr90, we investigated whether Akt regulates Tal1. Our results show that Akt specifically phosphorylates Thr90 of the Tal1 protein within its transactivation domain in vitro and in vivo. Coimmunoprecipitation experiments showed the presence of Tal1 in Akt immune complexes, suggesting that Tal1 and Akt physically interact. We further showed that phosphorylation of Tal1 by Akt causes redistribution of Tal1 within the nucleus. Using luciferase assay, we showed that phosphorylation of Tal1 by Akt decreased repressor activity of Tal1 on EpB42 (P4.2) promoter. Thus, these data indicate that Akt interacts with Tal1 and regulates Tal1 by phosphorylation at Thr90 in a phosphatidylinositol 3-kinase–dependent manner.

T-cell leukemia/lymphoma 1 (TCL1) is an oncogene overexpressed in T-cell prolymphocytic leukemia and in B-cell malignancies including B-cell chronic lymphocytic leukemia and lymphomas. To date, only a limited number of Tcl1-interacting proteins that regulate its oncogenic function have been identified. Prior studies used a proteomic approach to identify a novel interaction between Tcl1 with Ataxia Telangiectasia Mutated. The association of Tcl1 and Ataxia Telangiectasia Mutated leads to activation of the NF-κB pathway. Here, we demonstrate that Tcl1 also interacts with heat shock protein (Hsp) 70. The Tcl1-Hsp70 complex was validated by coimmunoprecipitation experiments. In addition, we report that Hsp70, a protein that plays a critical role in the folding and maturation of several oncogenic proteins, associates with Tcl1 protein and stabilizes its expression. The inhibition of the ATPase activity of Hsp70 results in ubiquitination and proteasome-dependent degradation of Tcl1. The inhibition of Hsp70 significantly reduced the growth of lymphoma xenografts in vivo and down-regulated the expression of Tcl1 protein. Our findings reveal a functional interaction between Tcl1 and Hsp70 and identify Tcl1 as a novel Hsp70 client protein. These findings suggest that inhibition of Hsp70 may represent an alternative effective therapy for chronic lymphocytic leukemia and lymphomas via its ability to inhibit the oncogenic functions of Tcl1.

TAL1 oncogene encodes a helix-loop-helix transcription factor, Tal1, which is required for blood cell development, and its activation is a frequent event in T-cell acute lymphoblastic leukemia. Tal1 interacts and inhibits other helix-loop-helix factors such as E47 and HEB. To investigate the function of Tal1 in B cells, we generated Eμ-TAL1 transgenic mouse line, expressing Tal1 in mouse B-cell lineage. Fluorescence-activated cell sorting (FACS) analysis of lymphocytes isolated from spleens of five out of five founders reveals complete absence of IgM- or CD19-expressing cells. Only 2% to 3% of these cells were B220+ and 100% of B220+ cells were CD43+, indicating that these mice were able to make pro-B cells. Similarly, FACS analysis of bone marrow cells in Eμ-TAL1 mice revealed complete absence of B220+IgM+ and B220+CD19+ cells. Analysis of the recombination status of IgH genes revealed the presence of D-J but absence or drastic reduction of V-D-J rearrangements. Our results suggest that Tal1 overexpression in B cells results in a phenotype similar to that of B cells of E47/E2A knockout animals. This represents first in vivo evidence that Tal1 can completely inhibit E47/E2A function. (Cancer Res 2006; 66(12): 6014-7)

Programmed cell death 4 (Pdcd4) is a tumor suppressor protein that interacts with eukaryotic initiation factor 4A and inhibits protein synthesis. Pdcd4 also suppresses the transactivation of activator protein-1 (AP-1)–responsive promoters by c-Jun. The Akt (protein kinase B) serine/threonine kinase is a key mediator of phosphoinositide 3-kinase pathway involved in the regulation of cell proliferation, survival, and growth. Because Pdcd4 has two putative Akt phosphorylation sites at Ser67 and Ser457, we investigated whether Akt phosphorylates and regulates Pdcd4. Our results show that Akt specifically phosphorylates Ser67 and Ser457 residues of Pdcd4 in vitro and in vivo. We further show that phosphorylation of Pdcd4 by Akt causes nuclear translocation of Pdcd4. Using luciferase assay, we show that phosphorylation of Pdcd4 by Akt also causes a significant decrease of the ability of Pdcd4 to interfere with the transactivation of AP-1–responsive promoter by c-Jun. (Cancer Res 2005; 65(24): 11282-6)

T-cell acute lymphoblastic leukemia (T-ALL) is a neoplasia of thymocytes characterized by the rapid accumulation of the precursors of T lymphocytes. HMGA2 (high-mobility group AT-hook 2) gene expression is extremely low in normal adult tissues, but it is overexpressed in many tumors. To identify the biological function of HMGA2, we generated transgenic mice carrying the human HMGA2 gene under control of the VH promoter/Eμ enhancer. Approximately 90% of Eμ-HMGA2 transgenic mice became visibly sick between 4 and 8 months due to the onset and progression of a T-ALL-like disease. Characteristic features included severe alopecia (30% of mice); enlarged lymph nodes and spleen; and profound immunological abnormalities (altered cytokine levels, hypoimmunoglobulinemia) leading to reduced immune responsiveness. Immunophenotyping showed accumulation of CD5+CD4+, CD5+CD8+ or CD5+CD8+CD4+ T-cell populations in the spleens and bone marrow of sick animals. These findings show that HMGA2-driven leukemia in mice closely resembles spontaneous human T-ALL, indicating that HMGA2 transgenic mice should serve as an important model for investigating basic mechanisms and potential new therapies of relevance to human T-ALL.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in the western world. Human B-CLL occurs in two forms: aggressive (showing high ZAP-70 expression and unmutated IgH VH) and indolent (showing low ZAP-70 expression and mutated IgH VH). We found that miR-29a is upregulated in indolent human B-CLL compared to aggressive B-CLL and normal CD19+ B-cells. To study the role of miR-29 in B-CLL, we generated Eµ-miR-29 transgenic mice overexpressing miR-29 in mouse B-cells. Flow cytometric analysis revealed a markedly expanded CD5+ population in the spleen of these mice starting at 2 months of age. Over 80% of miR-29 transgenic mice exhibited an expanded population of CD5+ B-cells, a characteristic of the B-CLL phenotype. An average of 56% of the B-cell population in these transgenics were CD5 positive. At the age of 2 years these mice showed significantly enlarged spleens and an increase in CD5+ B-cell population of up to 100% of B-cells. Over 8% (3/36) of Eµ-miR-29 transgenic mice developed frank leukemia and prematurely died from the disease at the age of 24-26 months. The expanded CD5+ B-cell population was found to be proliferative, with an increased number of cells in the S-phase of the cell cycle, compared to wild type CD19+ B-cells. These results suggest that deregulation of miR-29 can cause, or at least significantly contribute to the pathogenesis of indolent B-CLL. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-352.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common human leukemia. Deregulation of the T-cell leukemia/lymphoma 1 (TCL1) oncogene in mouse B-cells causes a CD5 positive leukemia similar to aggressive human B-CLLs. We recently reported that TCL1 expression in B-CLL is regulated by miR29 and miR181. To determine whether treatment with microRNAs can inhibit B-CLL in mice by targeting TCL1 we generated TCL1 transgenic mice using a construct containing 3’ and 5’ UTRs of TCL1 under B-cell specific Eμ promoter (Eμ-TCL1fl). At the age of 12-18 months these mice showed B-CLL like disease. Immunophenotyping revealed accumulation of CD5+CD23+B220+ population in spleens and lymph nodes. Our results show that CD5+CD23+ B-cell populations from Eμ-TCL1fl mice actively proliferate and display significantly increased levels of phospho-Akt. Eμ-TCL1fl mice showed immunological abnormalities similar to human B-CLL, including hypoimmunoglobulinemia, abnormal levels of cytokines, and impaired immune response. These findings revealed biochemical and immunological similarities between Tcl1 driven B-CLL in mice and human B-CLL. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 401.