Frequency of bcl-2/IgH translocation in patients with non-Hodgkin's lymphoma and chronic hepatitis C virus infection.

AIM: It has been previously suggested that t(14;18) translocation of bcl-2 to the immuno-globulin heavy chain (IgH) locus may contribute to pathogenesis of lymphoproliferative disorders related to hepatitis C virus (HCV) infection, including type II mixed cryoglobulinemia (MC). METHODS: In this study, the presence or absence of t(14;18) translocation was determined in tumor biopsy specimens and peripheral blood mononuclear cells (PBMCs) for 48 NHL patients with chronic HCV infection. RESULTS: In tumor biopsy specimens from 32 HCV-positive NHL patients, bcl-2/IgH translocation was detected in 1 of 13 patients with MC syndrome (7.7%) and 3 of 19 patients without MC syndrome (15.8%). In PBMCs from 23 HCV-positive NHL patients, this translocation was observed in 3 of 6 patients with MC syndrome (50%) and 4 of 17 patients without MC syndrome (23.5%). Interestingly, bcl-2/IgH translocation was found in 2 extranodal marginal zone B-cell lymphoma tissues from HCV-infected patients. CONCLUSIONS: However, additional studies are required to better clarify the relationship between this translocation and extranodal marginal zone B-cell lymphoma development. Although the frequency of bcl-2/IgH translocation in PBMCs from patients with chronic HCV infection is higher than that of other NHL patients, this increased translocation rate remains to be elucidated.

Bovine seminal RNase induces apoptosis in normal proliferating lymphocytes.

Bovine seminal ribonuclease is a member of the RISBAses (ribonucleases with special biological actions) family. It exerts specific anti-tumor, embryotoxic, aspermatogenic and immunosuppressive activities. The cytotoxic effect of bovine seminal ribonuclease on tumor cells is accompanied by the induction of apoptosis. We provide ultrastructural and flow cytometry evidence of apoptotic death following bovine seminal ribonuclease treatment, in normal cells and phytohemagglutinin-stimulated lymphocytes. Transmission and scanning electron microscopy, which were fully supported by flow cytometry data, showed typical features of apoptosis, such as decreased cell size, chromatin condensation, fragmentation in micronuclei, and the presence of apoptotic bodies.

[Action of retinol on viable cell recovery and clonogenic potential of HTC cells after in vitro hyperthermia]. / Azione del retinolo sul recupero di cellule vitali e sul potenziale clonogenico di cellule HTC ipertermizzate in vitro.

The aim of this study was to investigate if the association of both hyperthermic and Retinol treatment of HTC hepatoma cells could be useful in antitumor therapy. Treatment with 5 microM Retinol was carried out before or after hyperthermia (42 degrees C or 44 degrees C, one hour; in the latter case it was performed in cells already thermo-selected. We took into consideration two parameters, i.e. the number of the collected vital cells (evaluated by the trypan blue-exclusion test) and the clonal efficiency of these cells (calculated as number of colonies obtained from 250 cells cultured for 5 days). Thermal treatment alone caused a decrease of the number of the collected vital cells and of their clonal efficiency only in the cell cultures incubated at 44 degrees C. Instead the control thermo-selected cells, both at 42 degrees C and at 44 degrees C, showed both decreased clonal efficiency and yield of the vital cells. Compared with the control cultures treated with 0.1% Ethanol, used as vitamin A solvent, only cell cultures treated with Retinol before hyperthermia showed a decreased number of collected viable cells, nevertheless their clonal efficiency was unchanged.

[Effect of hyperthermia and retinol treatment in vitro on HTC cell adhesiveness to laminin and fibronectin]. / Azione dell'ipertermia e del trattamento con retinolo in vitro sull'adesivita' alla laminina ed alla fibronectina delle cellule HTC.

Since cell adhesiveness is very important in the metastatic process and because both hyperthermia and treatment with Retinol can modify the fluidity of the lipid components of the plasma membrane (and therefore its receptor distribution), we investigated if a hyperthermic treatment (at 42 degrees C or 44 degrees C, for one hour) of HTC hepatoma cells, preceded or followed by treatment with 5 microM Retinol, could alter cell adhesiveness to Laminin or to Fibronectin-coated substrata. Hepatoma cells, after such treatments, were collected and processed by Auerbach's method. In the control cells thermal treatment alone caused a decrease of adhesiveness to Laminin but no change in that to Fibronectin. When treatment with Retinol was carried out before hyperthermia, the cells showed an increased adhesiveness to Laminin and a decreased adhesiveness to Fibronectin. Instead, when treatment with Retinol was performed in cells previously thermo-selected, a decrease of adhesiveness to both tested ligands was observed.

[Actions of retinol and retinoic acid on hepatoma H4 cultures]. / Azione del retinolo e dell'acido retinoico su colture di epatoma H4.

The amount of vital cells recovered, their morphology (studied by SEM) and some of their biochemical aspects concerning the differentiation processes (aerobic glycolysis, cell production of cAMP and CEA) were investigated in a strain of H4 hepatoma cultured for 8 days in the presence of 5 microM retinol (R) or retinoic Acid (RA). Vital cell recovery is slightly reduced either by R or RA treatment. Flattening of the cell shape and reduction of the plasma membrane prolongations and of intercellular bonds are observed in the R-treated cells but to a greater extent in those treated with RA. Aerobic glycolysis is decreased in the R-treated cells but increased in those treated with RA. Such events could be related to the regressive processes observed in the RA-treated cells. cAMP cell content is increased to a greater extent in the R-treated cells than in those treated with RA. CEA cell content is greatly decreased in the RA-treated cells but only slightly in those treated with R. Therefore, the treatment of HA hepatoma cells with 5 microM R or RA, while reducing cell growth only slightly, does not cause evident and unequivocal morphological and biochemical events related to cell redifferentiation.

Effects of vitamin A in the presence of vitamins D3, E, K1 on red cell membrane structure.

The incubation of erythrocyte ghosts with mixtures of vitamins A+D3, A+E, A+K1 produces decrease or increase of fluorescence anisotropy r of the DPH probe, depending on the vitamin/vitamin ratio. We found a correlation between the order parameter S and cell fusion phenomena observed by phase contrast microscopy.

Effect of lipophilic vitamins on the erythrocyte membrane. 31P NMR and fluorescence studies.

Structural changes induced by the fat-soluble vitamins A, D3, E and K1 in natural membranes were studied by 31P NMR and fluorescence anisotropy on erythrocyte ghosts; the occurrence of cell fusion following vitamin addition was detected by optical microscopy of intact cells. Vitamins A, E and K1, which produce cell fusion, also induce the formation of configurational phases other than the bilayer and increase, at a different extent for the different vitamins, membrane fluidity. Vitamin D3, on the contrary, induces aggregation without fusion, paralleled by bilayer phase stabilization and microviscosity increase. A correlation between fusion phenomena and structural variations in the bilayer organization is therefore suggested.

[Biochemical and ultrastructural research on the antagonism between vitamins A and D at the leve of the erythrocyte membrane]. / Ricerche biochimiche ed ultrastrutturali sull'antagonismo tra le vitamine A e D a livello della membrana degli eritrociti.

The reason for the antagonistic action between retinol and cholecalciferol on cellular membranes was investigated "in vitro" on human erythrocytes, by testing their lipoperoxide production, the amount of membrane-bound retinol and the morphology of these cells by scanning electron microscope. Lipoperoxides were assayed by TBA-test; the membrane-bound retinol was tested by the Karr-Price method on lipids extracted from red blood cells by the Folch method and vitamin D-deprived by TCL chromatography; the morphological changes of these cells treated with vitamin A, or D, or A+D, were tested by scanning electron microscope. In our experimental system both retinol and cholecalciferol increase the lipoperoxide production from the erythrocytes; nevertheless no synergism of action can be demonstrated between the two vitamins. Cholecalciferol decreases the amount of membrane-bo und retinol as well as the changes produced by vitamin A in red blood cell surface. These results are in good agreement with our previous observations obtained by nuclear magnetic resonance, using the same experimental system.

[Effect of vitamin D on cellularity and mechanical fragility of lysosomes: experiments on carrageenan granuloma cells]. / Azione della vitamina D sulla cellularita' e sulla fragilita' meccanica dei lisosomi: esperienze su cellule di granulomi da carragenina.

In rats daily treated with vitamin D3 (5 micrograms/g of body weight/d for 5 d), the subcutaneous charrageenan granuloma shows reduced cellularity, mesenchimal cells degenerative process, increased mechanical fragility of lysosomes, oedema and modified fibrillogenesis of stroma. These effects are related to vitamin D3 action on cytomembranes.

[Role of erythrocyte membrane lipids in the antagonism between vitamin A and D3]. / Ruolo dei lipidi eritrocitari nell'antagonismo tra le vitamine A e D3.

The "in vitro" lytic effect of retinol (35 microM) on various animal species erythrocytes is partially inhibited by cholecalcipherol. The inhibition observed is not related with reduction of retinol bound by erythrocytes membranes while it can be related with the amount of glycolipids not gangliosides of these cells. Instead, we have observed that the amount of retinol molecules bound to erythrocytes membranes and their haemolysis can be related with the gangliosides contents of red cells membranes.

[Effect of vitamin D and vitamin E on the erythrocyte membrane. I. Effect on in vitro osmolar resistance and lysis]. / Azione delle vitamine D ed E sulla membrana eritrocitaria. Nota I. - Azione sulla resistenza globulare e sulla lisi eritrocitaria "in vitro".

As in the case of retinol, low doses of cholecalcipherol and alpha-tocopherol "in vitro" increase the osmotic resistance of red blood cells, while high doses have a lytic effect on the erythrocytes of various animal species (e.g.: man, sheep, rabbit, guinea-pig, mouse, rat) with the exception of the chicken. The haemolytic effect of cholecalcipherol is less intense than that of retinol; alpha-tochopherol, while causing even less haemolysis than cholecalcipherol, involves a remarkable loss of K+ from the red cells. Besides these quantitative differences, the mechanism of action of the three vitamins seems somewhat different, as shown by modifications of the suspension medium (e.g.: pH, temperature, presence of proteins and reducing substances) or by treatment of the red cells with trypsin. Our results therefore essentially confirm the hypothesis of Dingle and Lucy of common mechanism of action of liposoluble vitamins on biological membranes.

[Action of vitamin D and E on the erythrocyte membrane. II. Morphological changes in the erythrocytes studied by transmission electron microscopy]. / Azione delle vitamine D ed E sulla membrana eritrocitaria. Nota II. Modificazioni morfologiche degli eritrociti studiate al microscopio elettronico a trasmissione.

Man, rabbit, guinea-pig erythrocytes treated "in vitro" with high doses of cholecalcipherol or alpha-tocopherol release K+ and haemoglobin and show ultrastructural damages. These damages consist in a change of the red cells profile as well as in the desappearance of the glycocalix, in alterations of the membrane and of the cortical cytoplasm structure. These ultrastructural alterations are of a different degree, depending on the animal species; they partly resemble the erythrocyte changes induced by retinol. Our results are in partial agreement with the Dingle and Lucy's hypothesis on the common action of liposoluble vitamines on the erythrocyte membrane.