[A comparative study of sphingolipids in transplanted melanomas with high and low metastatic activity].

The content of sphingolipids in M3 and B16/F10 melanomas with a high metastatic potential and in Claudman's and B16/F1 melanomas with a low metastatic potential was studied. It was shown that the content of total lipid-bound sialic acids and ganglioside GM3 in melanomas with a high metastatic potential is considerably higher than that in melanomas with a low metastatic potential. On the other hand, the ceramide to glucosylceramide molar ratio is higher in melanomas with a low metastatic potential. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2008, vol. 34, no. 2; see also http://www.maik.ru.

[Glycosphingolipids and antitumor immunity]. / Glikosfingolipidy i protivoopukholevyi immunitet.

Glycosphingolipids are immunogenic components of cell surface whose composition and structure change during the cell transformation. The contemporary state of the question about the influence of glycosphingolipids on specific and non-specific antitumour immunity is considered. The available information about shedding of glycosphingolipids from the tumour cell surface, about the change of the ganglioside content in blood serum of the tumour host and about the effect of glycolipids on immunocompetent cells is analyzed. The results obtained by the authors in studies of the influence of glycosphingolipids on effector cells of the body natural resistance system to tumour are discussed.

[The relationship between the biological functions of sphingolipids and their chemical structure]. / Sviaz' biologicheskikh funktsii sfingolipidov s ikh khimicheslkoi strukturoi.

The interrelation between the bioeffector functions of sphingolipids and their chemical structure is reviewed. The effects of modifications of sphingoid functional groups on the bioregulatory properties of sphingolipids in cell proliferation, differentiation, and apoptosis are discussed.

[Sphingolipids and cancer]. / Sfingolipidy i rak.

The qualitative and quantitative changes in sphingolipids (ceramides, sphingomyelins, glycosphingolipids) occurring under tumor growth are considered. The influence of these changes on cell functions and immunity as well as the role of dietary sphingolipids in cancer and "sphingolipid" therapy of tumors are discussed.

[Biologically effective sphingolipids devoid of 4-trans-double bond in the sphingoid hydrocarbon chain]. / Bioéffektornye svoistva sfingolipidov v otsutstvie 4-trans-dvoinoi sviazi v uglevodorodnoi tsepi sfingoida.

The bioregulatory functions of sphingolipids devoid of 4E-double bond in the sphingoid chain are discussed; the sphingolipids are shown to be biologically active. The English version of the paper.

[Bioeffector sphingolipids as stimulators of cell growth and survival]. / Bioéffektornye sfingolipidy kak stimuliatory rosta i vyzhivaemosti kletok.

The effects of various bioactive sphingolipids (sphingosine 1-phosphate, sphingosine 1-phosphocholine, ceramide 1-phosphate, ceramide beta-glucoside and beta-lactoside, and gangliosides) on cell proliferation and apoptosis are reviewed. It is concluded that the balance between the bioeffector sphingolipids determines their overall effect on cell. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 3; see also http://www.maik.ru.

[The changes in the sphingenine/sphinganine ratio in sphingolipids of transplantable rat tumors depends on a transplantation organ]. / Izmenenie otnosheniia sfingenin/sfinganin v sfingolipidakh perevivaemykh opukholei krys v zavisimosti ot organa transplantatsii.

The content of sphingenine (sphingosine) and sphinganine was determined in the total pool of sphingomyelin and ceramide in the rat tumors transplanted subcutaneously and intrahepatically. The sphingenine/sphinganine ratio in the subcutaneously transplanted sarcoma M1 and cholangiocellular carcinoma RS1 was lower than that in the sphingolipids of the intrahepatically transplanted tumors. However, the sphingenine/sphinganine ratio in the subcutaneously transplanted rat hepatoma 27 was higher than in the intrahepatically transplanted hepatoma. These observations indicate that the sphingenine/sphinganine ratio in sphingolipids of tumors depends on the tumor type and its cellular microenvironment.

[Analysis of the NeuAc-LacCer ganglioside structure and its analogs by mass spectrometry with bombardment with accelerated atoms]. / Analiz struktury gangliozida NeuAc-LacCer i ego analogov metodom mass-spectrometrii s bombardirovkoi uskorennymi atomami.

Gangliosides NeuAc-LacCer, NeuGc-LacCer, NeuLac-Sph and NeuAc-LacSphAc were analysed by FAB mass spectrometry in the negative ion mode. It is shown that this method gives valuable information on the structure of carbohydrate chains and fatty acid residues of the ganglioside molecules taking only micrograms of substances.

[Chromatographic-mass spectrometric analysis of sialic acids of disialosyllactosylceramides from the calf thymus]. / Khromatomass-spektrometricheskii analiz sialovykh kislot disialozillaktoziltseramidov timusa telenka.

Gas-liquid chromatography/mass spectrometry of the compounds obtained on methanolysis and deuterioacetylation of the permethylated gangliosides has demonstrated that disialosyllactosyl ceramides of calf thymus contain three components - NeuAc alpha 2----8NeuAc alpha 2----LacCer, NeuAc alpha 2----8NeuGc alpha 2----LacCer and NeuGc alpha 2----8NeuGc alpha 2----LacCer.

[Ganglioside GM3 derivatives and their immunomodulating effect]. / Proizvodnye gangliozida GM3 i ikh immunomoduliruiushchii éffekt.

The derivatives of ganglioside GM3-NeuLacCer. NeuLacSph and NeuAcLacSphAc-were obtained and their immunomodulating properties studied. These substances are shown to inhibit lymphocyte blast-transformation independently of their ceramide structure. On the contrary, the stimulation by the above GM3-derivatives of Con A-induced T-suppressor activity depends significantly on the structure of their ceramide moiety.

[The role of glycosphingolipids in the immune process]. / Rol' glikosfingolipidov v immunologicheskom protsesse.

The paper deals with the role of glycosphingolipids as antigens and receptors of immunocompetent cells as well as modulators of the immune response. Glycosphingolipids are shown to be markers of different immunocompetent cells, serve as receptors of the factor inhibiting the migration of macrophages on their surface, inhibit or stimulate the lymphocyte differentiation, inhibit the cytotoxic-action of natural killers. A possible effect of glycosphingolipids on the immune response during tumour growth is discussed.

[Isolation and identification of products of accumulation in Fabry disease]. / Vydelenie i identifikatsiia produktov nakopleniia pri bolezni Fabri.

Three fractions of glycolipids--monohexosylceramide, dihexosylceramide (DHC) and trihexosylceramide (THC) were isolated from kidney of patient with Fabry disease. As compared with normal state amount of DHC and THC was increased in the patient kidney 9-19-fold and 15-26-fold, respectively. Gas liquid chromatography showed that the DHC fraction consisted in digalactosylceramide, while the THC fraction--a mixture of digalactosylglucosylceramide (90%) and trigalactosylceramide (10%). Presence of the latter glycolipid was not early found in human body both in normal state and in Fabry disease. Accumulation of DHC and THC was also detected in urine precipitates of the patients using thin-layer chromatography, whereas these substances were not found in urine of one of the patients daughter, who was heterozygote gene carrier of Fabry disease. The data obtained corroborate the Fabry disease presence, which have been predetermined by means of clinical diagnosis as well as basing on deficiency of alpha-D-galactosidase in blood plasma and leukocytes.

[Ceramides and gangliosides in benign and malignant human ovarian tumors]. / Tseramidy i gangliozidy dobrokachestvennykh i zlokachestvennykh opukholei cheloveka.

Composition and content of ceramides and gangliosides from different kinds of human ovary benign and malignant epithelial tumours were studied. The ceramide content was shown to decrease significantly in the tumours, especially in malignant tumours, in comparison with the normal ovary tissue. In the tumour ceramides a sphingosine base composition changes: sphinganine was found along with sphingenine, which is characteristic for normal ceramides. The fatty acid composition changes also. Main tumour gangliosides were shown to be GM3 and GD3. Their content decreases in malignant ovary tumours, especially the amount of ganglioside GD3. As a result of these changes the molar ratio Cer/Sia decreases. It can appears stimulates a tumour growth.

[Ganglioside (GD3) in serum of cancer patients]. / Gangliozid (GD3) v syvorotke krovi rakovykh bol'nykh.

Gangliosides were studied in blood serum of healthy volunteers and of patients with cancer of mammary gland and stomach. Blood serum of the majority of patients with cancer and only 15% of healthy persons were shown to contain ganglioside GD3 which was detected in blood of patients with some other tumors.

[Inhibition of the cytotoxic activity of natural killer cells by glycosphingolipids. Effect of the structure of carbohydrate chains]. / Ingibirovanie tsitotoksicheskoi aktivnosti estestvennykh killerov glikosfingolipidami. Vliianie struktury oligosakharidnykh tsepei.

The ability of various glycosphingolipids to inhibit the cytotoxic activity of natural killer (NK) cells was studied. The inhibitory effect was found to depend on the structure and concentration of the glycosphingolipids. Gangliosides SiaLacCer inhibited the NK activity most effectively and their inhibitory effect depended on the structure of sialic acids: the N-acetyl form was more active than the N-glycoloyl form. Elongation of the carbohydrate chain decreased the inhibitory effect and monosialogangliosides NeuGcGgOse3Cer and NeuAcGgOse4Cer were practically inactive. The inhibitory ability of disialogangliosides depended on the structure of the carbohydrate chain as well as on the structure and attachment site of the sialic acids. Previously it was found that ganglioside (NeuAc)2LacCer, which is absent or very low in normal blood, is produced by a number of tumors and alongside with NeuAcLacCer is present in elevated amounts in the blood of tumor-bearing subjects. Elevated concentration of these gangliosides in the blood of tumor hosts may inhibit apparently the NK activity and thus contribute to the escape of tumor cells from host immune surveillance.

[Changes in the activity of neutral and acidic isoforms of sphingomyelinase in hepatoma-22, regenerating and ischemic liver]. / Izmenenie aktivnosti neitral'noi i kisloi izoform sfingomielinazy v gepatome-22, v regeneriruiushchei i ishemizirovannoi pecheni.

Activity of neutral and acidic sphingomyelinases (N- and A-SMases) were studied in regenerating liver after partial hepatectomy (during 48 hrs after operation), in ischemic liver during 15, 30 min and 1 and 2 hrs ischemia and during following reperfusion (from 5 min up to 2 hrs), in hepatoma- 22 after 15 days of transplantation and in liver of tumor bearing animals. It was shown that activity of N-SMase is increased in hepatoma-22 and in regenerating liver and it is decreased in ischemic liver. Following reperfusion of ischemic liver area activity of enzyme was found to have returned to baseline in dependence on time of ischemia and reperfusion. Activity of A-SMase is decreased in tumor, is not changed in regenerating liver and increased after long time of ischemia. It was supposed that N-SMase is involved in cell proliferation, but A-SMase is connected with cell damage.