[Primary mediastinal large B-cell lymphoma in pregnant women].

AIM: To elaborate a management tactic for pregnant women with primary mediastinal large B-cell lymphoma (PMLBL) and to assess the toxicity of its treatment to the mother and fetus. SUBJECTS AND METHODS: In 2004 to 2014, the Hematology Research Center, Ministry of Health of Russia, treated 94 patients with mediastinal large B-cell lymphoma, 7 (7.4%) of them developed the disease during pregnancy. Induction therapy was performed according to the VACOP-B or R-EPOCH program. For consolidation, polychemotherapy (PCT) was made after 3-4 weeks postpartum in accordance with the R+Dexa-BEAM program, followed by radiotherapy (RT) applied to a residual mediastinal mass in a total focal dose of 36 Gy. To assess the nature of the residual mass, positron emission tomography was carried out 1 month following the induction and consolidation cycles of PCT. RESULTS: PCT was performed in 5 and 2 of the 7 patients diagnosed with PMLBCL in the second and third trimesters according to the VACOP-B and R-EPOCH programs, respectively; for consolidation, PCT was done using the R+Dexa-BEAM regimen in 7 patients: 10 men and 29 women whose ages were 18 to 60 years (median age 30 years); in 5 of the 7 patients, RT was applied to the residual mediastinal region in a total focal dose of 36 Gy. After induction treatment, 4 of 5 the patients in the VACOP-B group achieved partial remission; one of the 5 patients was stated to have disease progression. In the R-EPOCH group, 2 of the 2 patients achieved partial remission. After performing the treatment protocol, an early recurrence was recorded in 1 of the 5 cases in the VACOP-B/Dexa-BEAM/RT group. Effective autologous stem cell transplantation was carried out in patients with disease progression and early recurrence. Seven children (3 boys and 4 girls) were born. Their median body weight was 2182 g (1700 to 3600 g); the median height was 47 cm (40 to 53 cm). Two neonatal infants born to women who had received CT using the R-EPOCH regimen were diagnosed as having intrauterine pneumonia resulting from respiratory distress syndrome, which might be associated with fetal prematurity and the use of rituximab. One baby born to a patient who had been included in the VACOP-B treatment protocol was stated to have superior vena cava at birth. The median follow-up of the patients and born infants was 35 months (15 to 64 months). CONCLUSION: Due to the elaborated algorithm for the treatment and management of pregnant women, all the patients are alive without tumor signs and their babies are healthy without signs of development defects and retardation.

[Eight-year experience in treating aggressive mediastinal large B-cell lymphomas].

AIM: To make a differential diagnosis of diffuse large B-cell lymphoma (DLBCL) with primary involvement of the mediastinal lymph nodes (LN) and primary mediastinal large B-cell lymphoma (PMLBCL); to evaluate the efficiency of a modified NHL-BFM-90 (M-NHL-BFM-90) program in the treatment of the above nosological entities. SUBJECTS AND METHODS: The investigation enrolled 60 patients with large B-cell lymphoma (LBCL) with primary involvement of mediastinal LN who had been treated at the Hematology Research Center, Ministry of Health of Russia, in 2004 to 2012. The diagnosis of PMLBCL and DLBCL with primary involvement of mediastinal LN was based on histological findings, the phenotype of tumor cells, and molecular evidence. Treatment was performed according to the M-NHL-BFM-90 program. Three pregnant women received predelivery polychemotherapy (PCT) according to the VACOP-B protocol and continued to have a DexaBEAM chemotherapy regimen 3-4 weeks postpartum. In case of a residual mass, all the patients underwent consolidation radiotherapy to the mediastinal area in a total focal dose of 36 Gy. RESULTS: The diagnosis of PMLBCL was established in 39 patients: 10 men and 29 women whose ages were 18 to 60 years (median age 30 years); DLBCL with primary involvement of mediastinal LN was verified in 21 patients: 8 men and 13 women whose age was 21 to 70 years (median age 30 years). After m-NHL-BFM-90 treatment protocol, 5-year overall survival rates in the patients with DLBCL with primary involvement of mediastinal LN and in those with PMLBCL were 95+/-5 and 86+/-6% and 5-year event-free survival rates were 95+/-5 and 78+/-7%, respectively. All the pregnant women diagnosed with PMLBCL who had received the VACOP-B --> delivery--> Dexa-BEAM PCT regimen during pregnancy achieved remission. The follow-up periods were 30, 36, and 42 weeks. CONCLUSION: The patients with new-onset LBCL and primary involvement of mediastinal LN are a heterogeneous group that includes patients having two different diagnoses: PMLBCL and DLBCL. The efficiency of high-dose PCT is different in the patients with DLBCL with primary involvement of mediastinal LN and in those with PMLBCL (in spite of their similar clinical features, similar epidemiological characteristics, and the presence of the same unfavorable prognostic factors at onset).

[Successful therapy for enteropathy-associated peripheral T-cell lymphoma using high-dose polychemotherapy and autologous hematopoietic stem cell transplantation].

Enteropathy-associated T-cell lymphoma (EATL) is a rare disease that accounts for not more than 1.4% of all lymphomas. It is most common in Europe, followed by North America and Asia. The disease is associated with gluten-sensitive celiac disease in 50% of cases and divided into types I and II. Mean-dose CHOP-like therapy is ineffective, with a median overall survival of 7-10 months. With high-dose therapy, 5-year survival rates can be 60%, but it can be used in not more than half of the cases. This is associated with the serious somatic status of most patients at diagnosis and with a median age of 57-64 years. The article presents a literature review and a case of successful therapy in a 58-year-old patient with type I EATL using the mNHL-BFM-90 protocol and autologous hematopoietic stem cell transplantation.

[The structure of the complexes of DNA with nonhistone chromosomal protein HMGB1 and the histone H1 in the presence of manganese ions. II. Vibrational circular dichroism spectroscopy].

Complexes of DNA with nonhistone chromosomal protein HMGB1 and histone H1 in the presence of manganese ions were studied using absorption and circular dichroism spectroscopy in infrared region. It was shown that the approach provides good results for solutions containing large particles, which cause light scattering in UV region. It was also shown that the manganese ions are able to coordinate to the chemical groups of DNA as well as to the carboxylic amino acid residues of the protein HMGB1. The latter stimulates DNA condensation and slightly weakens DNA-protein interactions in the complex.

[The structure of the complexes of DNA with chromosomal protein HMGB1 and histone H1 in the presence of manganese ions. I. Circular dicroism spectroscopy].

The mechanisms of interaction of the non-histone chromosomal protein HMGB1 and linker histone H1 with DNA have been studied using circular dichroism and absorption spectroscopy. Both of the proteins are located in the inter-nucleosomal regions of chromatin. It was demonstrated that properties of the DNA-protein complexes depend on the protein content and can not be considered as a simple summing up of the effects of individual protein components. Interaction of HMGB1 and H1 proteins is shown to be co-operative rather than competitive. Lysine-rich histone H1 facilitates the binding of the HMGB1 with DNA by screening the negatively charged groups of the sugar-phosphate backbone of DNA and dicarboxylic amino-acid residues in the C-terminal domain of the HMGB1 protein. The observed joint action of the and H1 proteins stimulates DNA condensation with formation of the anisotropic DNA-protein complexes with typical psi-type CD spectra. Structural organization of the complexes depends not only on the DNA-protein interactions, but also on the interaction between HMGB1 and H1 protein molecules bound to DNA. Manganese ions significantly modify the character of interactions between the components in the triple DNA-HMGB1-H1 complex. Binding of Mn2+ ions causes the weakening of the DNA-protein interactions and strengthening the protein-protein interactions, which promote DNA condensation and formation of large DNA-protein particles in solution.

[Conformational peculiarities of nuclear protein HMGB1 and specificity of its interaction with DNA].

Changes in the secondary structure of DNA and non-histone chromosomal protein HMGB1 were studied by circular dichroism and UV spectroscopy. We have demonstrated that the HMGBI protein is able to change its secondary structure upon binding to DNA. We estimated the proportion of bound protein on the assumption that there were two spectrally distinguishable forms of the HMGB1 in solution. The bound protein fraction decreases with increasing protein to DNA ratios (r) from 0.48 at r = 0.13 to 0.06 at r = 2.43. It has been shown that HMGB1 is able to induce considerable changes in DNA structure even when the amount of the protein directly associated with DNA is low.

[The interaction of DNA with sperm-specific histones of the H1 family].

We have studied the interactions of DNA with sperm-specific histones of the H1 family of sea urchin Strongylocentrotus intermedius, sea starfish Aphelasterias japonica and bivalve mollusk Chlamis islandicus using circular dichroism and DNA melting analysis. It was shown that echinoderm's sperm H1 protein has additional alpha-helical domains in its C-terminus and it demonstrates stronger DNA compaction. The differential melting curves of DNA-protein complexes have two peaks. The low temperature peak characterized the melting temperature of free DNA within the complex. The higher temperature peak characterizes the melting temperature of DNA bond to protein. DNA is found to be in the most stable state in the complexes with mollusk sperm H1 protein.

[Diffuse large B-cell lymphoma with primary involvement of mediastinal lymph nodes: diagnosis and treatment].

AIM: To diagnose diffuse large B-cell lymphosarcoma (DLBCLS) with primary involvement of the mediastinal lymph nodes (LN) and to evaluate the efficiency of aggressive polychemotherapy (PCT). SUBJECTS AND METHODS: The study included 15 patients (6 men and 9 women aged 18 to 70 years; median 38 years) followed up at the Hematology Research Center, Russian Academy of Medical Sciences, in 2004 to 2009. Three and 12 patients had Stages II and IE DLBCLS, respectively. B symptoms were found in 14 (93.4%) patients. Increased lactate dehydrogenase (LDH) concentrations were detectable in 14 (93.4%) patients; tumors of 10 cm or more (bulky disease) were seen in 11 (73.3%). Enlarged cervical, supraclavicular, and axillary lymph nodes were found in 9 (60%) patients; lung involvement via extension in 9 (60%), and invasion into the pericardium in 5 (33.3%) and soft tissues of the anterior thoracic wall in (13.3%). There were no signs of involvement of extranodal organs at the moment of diagnosis. All the 15 patients received PCT according to the modified NHL-BFM-90 program: 4 to 6 courses depending on the response to the therapy; 10 (66.6%) and 5 (33.3%) patients had 4 and 6 courses, respectively; for consolidating purpose, 11 (78.5%) patients were prescribed radiotherapy applied to the mediastinum in a cumulative dose of 36 Gy due to the fact that they had a residual mass. RESULTS: Thirteen (86.6%) patients achieved a complete remission (CR). Primary PCT resistance was confirmed in one case. Another patient was stated to have near-complete remission. No recurrences were notified during the follow-up. The mean CR duration was 24.5 (range 2-49) months. CONCLUSION: DLBCLS with primary LN involvement is an individual nosological entity to be differentiated from primary mediastinal large B-cell lymphosarcoma. In most cases, DLBCLS shows signs of a poor prognosis, which makes it necessary to perform aggressive PCT.

[Diagnosis of cryptococcal encephalitis in a patient with mature B-cell lymphoblastic leukemia].

Fungal meningoencephalitides are one of the most menacing infectious complications in hematologic cancer patients in the presence of myelotoxic agranulocytosis. Due to diagnostic difficulties, mortality in these cases can be as high as 100%. The causative agent of cryptococcosis is Cryptococcus neoformans; damage to the brain arachnoid membranes and substance is diagnosed in 70-90% of cases. Unlike bacterial meningitis, the meningeal symptoms typical of cryptococcal meningoencephalitis are not characteristic. The paper gives a case of successful treatment for cryptococcal meningoencephalitis in the presence of agranulocytosis, the diagnosis of which is based on the detection of abnormal MR signal foci by magnetic resonance imaging and identification of the cryptococcal antigen-glucuronoxylomannan in spinal fluid.

[Interaction between non-histone chromatin protein HMGB1 and linker histone H1].

The fundamental possibility of interaction between non-histone chromatin protein HMGB1 and linker histone H1 was studied in the solutions with different ionic strength by intrinsic UV-fluorescence, far and near-UV CD and spectrophotometry. The obtained data allow us to assume that the increase of histone H1 content in the HMGB1 solutions in a low ionic strength is accompanied by the destruction of HMGB1 associates. The interaction between proteins of HMGB1 and H1 causes the increase in the number of ordered regions in the protein molecules and the minor changes in their tertiary structure.

[Structural organization of DNA complexes with proteins HMGB1 and HMGB1-(A+B)].

The interaction between DNA and the nonhistone proteins HMGB1 and HMGB1-(A+B) has been studied using circular dichroism and scanning force microscopy. The recombinant protein HMGB1-(A+B) has no negatively charged C-terminal domain characteristic for HMGB1. Our earlier suggestion about the structural interaction of tandem HMGB1-domains of the recombinant protein with DNA was confirmed. It was shown that the C-terminal part modulates the interactions of HMGB1-domains with DNA. Without the C-terminal sequence, the HMGB1-(A+B) protein forms DNA-protein complexes with the ordered supramolecular structure.

The effect of manganese(II) on the structure of DNA/HMGB1/H1 complexes: electronic and vibrational circular dichroism studies.

The interactions were studied of DNA with the nonhistone chromatin protein HMGB1 and histone H1 in the presence of manganese(II) ions at different protein to DNA and manganese to DNA phosphate ratios by using absorption and optical activity spectroscopy in the electronic [ultraviolet (UV) and electronic circular dichroism ECD)] and vibrational [infrared (IR) and vibrational circular dichroism (VCD)] regions. In the presence of Mn2+, the protein-DNA interactions differ from those without the ions and cause prominent DNA compaction and formation of large intermolecular complexes. At the same time, the presence of HMGB1 and H1 also changed the mode of interaction of Mn2+ with DNA, which now takes place mostly in the major groove of DNA involving N7(G), whereas interactions between Mn2+ and DNA phosphate groups are weakened by histone molecules. Considerable interactions were also detected of Mn2+ ions with aspartic and glutamic amino acid residues of the proteins.

[Cationic oligopeptides modified with lipophilic fragments: use for DNA delivery to cells].

Cationic oligopeptides, including the amphipathic alpha-helical peptides, are applied to the targeted delivery of DNA to eukaryotic cells due to their DNA-compacting properties and the ability to destabilize the cell lipid bilayer in some cases. We synthesized the peptides differing in the number and location of residues of decanoic acid covalently attached to Lys residues in order to combine the DNA-binding and the membrane activities in a single molecule. We chose peptide structures that assisted in the formation of alpha-helices. The DNA-binding ability of the peptides and the membrane activity of their complexes with DNA were shown to depend on the structure. The study of erythrocyte hemolysis by complexes with DNA of the pCMV LacZ plasmid and the peculiarities of transfection of these complexes revealed a correlation between the hemolytic activity and the expression level of the lacZ gene in the cells.

[The structure of the complexes of DNA with non-histone chromosomal protein HMGB1 in the presence of manganese ions]. / Struktura kompleksov DNK s negistonovym khromosomnym belkom HMGB1 v prisutstvii ionov margantsa.

The complexes of DNA - HMGB1 protein - manganese ions have been studied using circular dichroism (CD) technique. It was shown that in such three-component system the interactions of both the protein and metal ions with DNA differ from those in two-component complexes. The manganese ions do not affect the CD spectrum of free HMGB1 protein. However, Mn2+ ions induce considerable changes in the CD spectrum of free DNA in the spectral range of 260-290 nm. The presence of Mn2+ ions prevents formation of the ordered supramolecular structures specific for the HMGB1-DNA complexes. The interaction of manganese ions with DNA has a marked influence on the local DNA structure changing the properties of protein-binding sites. This results in the serious decrease in cooperativity of the DNA-protein binding. Such changes in the mode of the DNA-protein interactions occur at concentrations as small as 0.01 mM Mn2+. Moreover, the changes in local DNA structure induced by manganese ions promote the appearance of new HMGB1 binding sites on the DNA double helix. At the same time interactions with HMGB1 protein induce alterations in the structure of the DNA double helix which increase with a growth of the protein/DNA ratio. These alterations make the DNA/protein complex especially sensitive to manganese ions. Under these conditions the Mn2+ ions strongly affect the DNA structure that reflects in abrupt changes of the CD spectra of DNA in the complex in the range of 260-290 nm. Thus, structural changes of the DNA double helix in the three-component DNA-HMGB1-Mn2+ complexes come as a result of the combined and interdependent interactions of DNA with Mn2+ ions and the molecules of HMGB1.

[The effect of Ca2+ ions on DNA compaction in the complex with non-histone chromosomal protein HMGB1]. / Vliianie ionov Ca2+ na kompaktizatsiiu DNK v komplekse s negistonovym khromosomnym belkov HMGB1.

The analysis of absorption and circular dichroism spectra in UV and IR regions showed that Ca2+ ions interact both with the phosphate groups of DNA and with the HMGB1 protein. Not only negatively charged C-terminal part of the protein molecule participates in interaction with metal ions but also its DNA-binding domains. The latter fact leads to the change of the mode of protein-DNA interaction. The presence of Ca2+ ions prevents formation of ordered supramolecular structures, specific for the HMGB1-DNA complexes, though promotes intermolecular aggregation. The structure of the complexes between DNA and the protein HMGB1 lacking C-terminal tail appears to be the most sensitive to the presence of Ca2+ ions. The data obtained allow to conclude that Ca2+ ions do not play a structural role in the HMGB1/DNA complexes and the presence of these ions is not necessary to DNA compaction in such systems.

[Dissociation action of cationic peptides with hydrophobic radicals on functional coupling between serpentine type receptors and GTP-binding proteins]. / Razobshchaiushchee vliianie kationnykh peptidov, soderzhashchikh gidrofobnye radikaly, na funktsional'noe sopriazhenie retseptorov serpantinnogo tipa s GTF-sviazyvaiushchimi belkami.

The coupling of hormone-activated receptor and heterotrimeric G protein is an important step of the signal transduction through adenylyl cyclase signal system (ACS). The numerous literature data and own results show that G protein-interacting regions, that are localized in cytoplasmic loops of receptors, have considerable positive charge, can form amphiphilic alpha-helices and are tightly associated with the membrane. We studied the influence of model cationic peptides on both basal and stimulated by hormones and nonhormonal agents adenylyl cyclase (AC) activity and on GTP binding activity of heterotrimeric G proteins in skeletal muscles of rats and smooth muscles of mollusc Anodonta cygnea. Peptides with hydrophobic radicals of caprinoyl acid (C10): Lys(C10)-His-Glu-Lys-Lys-(C10)-His-Glu-Lys-Lys(C10)-His-Glu-Lys-Lys(C10)- His-Glu-Lys-Ala-amide (peptide I), Cys-Lys(C10)-X-Tyr-Lys-Ala-Lys7-Trp-Lys-amide (II), Cys-X-Trp-Lys-Lys(C10)-Lys2-Lys(C10)-Lys3-Lys(C10)-Tyr-Lys-Lys(C10)-Lys-Lys- amide (III), where X--epsilon-aminocaproyl acid residue, were synthesized by solid-phase methodology. IC50 values for inhibiting the influence of peptides on serotonin-(molluscs) and isoproterenol-stimulated (rats) AC activity were: for peptide I--56 and 70 mkM, for peptide II--32 and 47 mkM, for peptide III--22 and 28 mkM, respectively. At the same time the peptides weakly decreased AC activity stimulated by nonhormonal agents (NaF, Gpp[NH]p, forskolin). Peptides I--III stimulated basal activity of the enzyme in both investigated tissues. The maximum stimulating effects (28--52%) of the peptides were observed at their concentration 10 mkM. Peptides (10--100 mkM) increased Gpp[NH]p binding in plasma membranes of mollusc and rat muscles and strongly decreased the influence of the hormones on the binding. Based on the obtained data we supposed that cationic peptides with hydrophobic radicals mimic G protein-binding regions of the receptors and can be involved in the regulation of functional coupling between the receptors and G proteins.

The effect of manganese(II) on DNA structure: electronic and vibrational circular dichroism studies.

The interaction of DNA with Mn2+ was studied in absorbance and optical activity in the electronic and vibrational regions. Based on the data, several stages of the interaction were identified. Con formational transition towards the C-form of DNA was observed in solution at the molar ratio Mn2+/DNA-phosphates between 0.1 and 1.5. The exact ratio depended on the ionic strength and increased with increasing NaCl concentration. Although manganese interacted with the phosphates and bases of DNA at higher metal concentrations, it is unlikely that direct chelation occurred. A model for the interaction between manganese ions and DNA mediated by water is suggested destabilizing the double helix and partially breaking the hydrogen bonds between the base pairs. At high Mn2+ concentrations DNA aggregation was observed.

[Molecular mechanisms of action of dendrons, containing 48-60 sequence of HIV-1 TAT-protein, on the functional activity of the adenylyl cyclase signaling systems]. / Molekuliarnye mekhanizmy vliianiia zvezdoobraznykh polikationnykh peptidov, soderzhashchikh posledovatel'nost' 48-60 TAT-belka VICH-1, na funktsional'nuiu aktivnost' adenilattsiklaznoi signal'noi sistemy.

For the aims of studying molecular mechanisms of functioning of adenylyl cyclase signaling systems (ACS), we investigated the influence of synthetic polycationic peptides of the star-like structure (dendrons), containing 48-60 sequence of HIV-1 TAT-protein, on the functional activity of ACS components in smooth muscles of the mollusc Anodonta cygnea and in rat skeletal muscles. It has been shown that the following peptides (Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-Pro-Pro-Gln)2-Lys-epsilonAhx(= epsilon-aminohexanoic acid)-Cys(Acm), referred to as peptide I, (Gly-Arg-Gly-Asp-Ser-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-Pro-Pro-Gln)2-Lys-epsilonAhx-Cys(Acm) (peptide II), [(Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-Pro-Pro-Gln)2-Lys-epsilonAhx-Cys]2 (peptide III), and [(Gly-Arg-Gly-Asp-Ser-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-Pro-Pro-Gln)2-Lys-epsilonAhx-Cys]2 (peptide IV) inhibit in a dose-dependent manner the adenylyl cyclase (AC) activity stimulated by both nonhormanal agents (GppNHp and forskolin) and hormones, such as serotonin (mollusc) and isoproterenol (rat). Peptides III and IV (tetrameric dendrons) were most effective in comparison with peptides I and II (dimeric dendrons). The AC activity stimulated by hormones and forskolin was most sensitive to the action of dendrons. All dendrons stimulated GTP-binding activity of G-proteins: dimeric dendrons were most effective at 10(-5) M concentration, whereas tetrameric dendrons at 10(-6) M. In the presence of dendrons, the affinity of beta-antagonist [3H]-dihydroalprenolol to P-adrenergic receptor in rat muscle mem- branes was unchanged. At the same time, the affinity of beta-agonist isoproterenol to the receptor decreased, and no shift to the right was observed on the curve of isoproterenol-induced [3H]-dihydroalprenolol displacement in the presence of GTP. The obtained data show the disturbance of the coupling between the receptor and G-protein, which is the main reason of dendron inhibitory action on AC stimulation by hormones. Besides, these data demonstrated that hormones could disturb the functional activity of AC, i.e. a catalytic component of ACS.