ganglioside--gd1b and Neuroblastoma

The focus of this review is the ganglio-series of glycosphingolipids found in neuroblastoma (NB) and the myriad of unanswered questions associated with their possible role(s) in this cancer. NB is one of the more common solid malignancies of children. Five-year survival for those diagnosed with low risk NB is 90-95%, while that for children with high-risk NB is around 40-50%. Much of the survival rate reflects age of diagnosis with children under a year having a much better prognosis than those over two. Identification of expression of GD2 on the surface of most NB cells led to studies of the effectiveness and subsequent approval of anti-GD2 antibodies as a treatment modality. Despite much success, a subset of patients, possibly those whose tumors fail to express concentrations of gangliosides such as GD1b and GT1b found in tumors from patients with a good prognosis, have tumors refractory to treatment. These observations support discussion of what is known about control of ganglioside synthesis, and their actual functions in NB, as well as their possible relationship to treatment response.

Topics: Child; Disease-Free Survival; Gangliosides; Humans; Neuroblastoma; Risk Factors; Survival Rate

Low (< or = 35%) or absent expression of the complex 'b' pathway gangliosides GD1b, GT1b and GQ1b (CbG) correlates with an aggressive biological phenotype in human neuroblastoma tumors. To develop an in vitro model to probe mechanisms by which CbG may contribute to neuroblastoma behavior, we have comprehensively evaluated ganglioside expression in nine well-established human neuroblastoma cell lines, all derived from poor prognosis tumors. Total cellular ganglioside content ranged from 8 to 69 nmol/10(8) cells. High performance thin layer chromatography revealed that the simple disialoganglioside GD2 was prominent in eight of the cell lines (up to 60% of total gangliosides), whereas CbG were low (1-21%) in all nine cell lines. The structurally most complex 'b' pathway species, GQ1b, was not detected in any of the cell lines. The prominence of GD2 in neuroblastoma cell lines mirrors the high expression of GD2 that characterizes human neuroblastoma tumors, and the low CbG expression in the cell lines is analogous to that found in clinically and biologically unfavorable neuroblastoma tumors, thus establishing these neuroblastoma cell lines as valuable model systems for study of the role of CbG in the pathobiology of human neuroblastoma.

Topics: Cell Survival; Chromatography, Thin Layer; Gangliosides; Gene Expression Profiling; Humans; Neuroblastoma; Phenotype; Prognosis; Tumor Cells, Cultured

Recent findings link increased expression of the structurally complex 'b' pathway gangliosides GD1b, GT1b, GQ1b (CbG) to a favourable clinical and biological behaviour in human neuroblastoma (NB). Seeking a model to probe these observations, we evaluated four human NB cell lines. Very low CbG content (4-10%) in three of the four cell lines (LAN-5, LAN-1, SMS-KCNR) reflected the ganglioside pattern observed in the most aggressive NB tumours. Pharmacological alterations of complex ganglioside synthesis in vitro by a 5-7 day exposure to 5-10 microM retinoic acid, which is employed in maintenance therapy of disseminated NB, included markedly increased (i) relative expression of CbG (6.6+/-2.0-fold increase, P=0.037), (ii) relative expression of the analogous 'a' pathway gangliosides, termed CaG (6.4+/-1.4-fold increase in GM1a and GD1a; P=0.010), and (iii) total cellular ganglioside content (2.0-6.3-fold), which in turn amplified the accumulation of structurally complex gangliosides. Substantial increases (2.7-2.9-fold) in the activity of GD1b/GM1a synthase (beta-1,3-galactosyltransferase), which initiates the synthesis of CbG and CaG, accompanied the all-trans retinoic acid (ATRA)-induced ganglioside changes. Thus, increased CbG synthesis in NB cell lines is attributable to a specific effect of ATRA, namely induction of GD1b/GM1a synthase activity. Since the shift towards higher expression of CbG and CaG during retinoic acid-induced cellular differentiation reflects a ganglioside pattern found in clinically less-aggressive tumours, our studies suggest that complex gangliosides may play a role in the biological and clinical behaviour of NB.

Topics: Antineoplastic Agents; Cell Differentiation; Galactosyltransferases; Gangliosides; Glucosyltransferases; Humans; Neuroblastoma; Tretinoin; Tumor Cells, Cultured

Ganglioside metabolism has been linked to the clinical and biological behavior of human neuroblastoma. This study investigated the importance of differences in complex "b" ganglioside (GD1b, GT1b, and GQ1b; designated CbG) expression in this tumor. Gangliosides of 74 neuroblastomas were analyzed by high-performance TLC. Associations of CbG expression with known prognostic markers and with event-free survival (EFS) were evaluated. Higher CbG expression characterized nonprogressive versus progressive tumors (median 41% versus 18% of total gangliosides; P = 0.001) and completely accounted for the observed higher overall "b" pathway ganglioside expression (median 81% versus 68%; P = 0.003). In contrast, expression of the structurally simpler "b" pathway gangliosides (GD2 and GD3) did not differ (median 31% versus 35%; P = 0.4). Absolute CbG content differed even more (median 93 versus 29 nmol/g among nonprogressive versus progressive tumors; P = 0.02) and was most striking in the case of GQ1b content (8-fold higher in nonprogressive tumors). High CbG (> or =35% of total gangliosides) expression was strongly predictive of a favorable outcome in: (a) the entire study population (90% versus 60% EFS at 25 months; P = 0.001); and (b) among patients assigned a low-risk status by a either single genetic or biochemical tumor marker (MYCN, DNA, NSE, or ferritin), or by both unamplified MYCN and aneuploid DNA (22-28% difference in EFS at 25 months). These data suggest that high tumor CbG content may substratify "good prognosis" neuroblastoma patients, identifying patients at very low risk of relapse or death, and that the biological roles of CbG in neuroblastoma will be of importance to define.

Topics: Carbohydrate Sequence; Cohort Studies; Gangliosides; Humans; Infant; Molecular Sequence Data; Neoplasm Staging; Neuroblastoma; Prognosis; Risk Factors

It was reported recently by our group that the transfection of GD3 synthase cDNA into Neuro2a cells, a neuroblastoma cell line, caused cell differentiation with neurite sprouting (Kojima et al., 1994; J. Biol. Chem., 269, 30451-30456). To further explore this phenomenon in detail, we applied tetracycline-regulated system to control the expression of GD3 synthase cDNA in Neuro2a cells. Under this system, the process of Neuro2a cell differentiation was rather slow, about 3 weeks of cell culturing in the absence of tetracycline was required for most cells to extend the neurite-like structures. The RNase protection assay indicated that the mRNA of GD3 synthase gene was first detected between 4 h and 8 h after the gene was activated and kept at approximately the same level through the process. Furthermore, time-course analysis of total ganglioside expressions has shown that GD3 and GT1b gangliosides appeared on the cell surface early in the process and reached the maximum level around day 6. We also found that the amounts of GD3 and GT1b on the cell surface started to decrease after day 6 and returned gradually to the basal values after 3 weeks. On the other hand, GQ1b and GD1b were started to be synthesized at early stage and the amounts were continuously to increase through the whole Neuro2a morphological change process. In addition, time-course analysis by flow cytometry method for GD3 and GQ1b suggested that the conversions of simple gangliosides to more complex gangliosides may be required to induce the Neuro2a differentiation. Our results indicated that the combination of cDNA transfection and regulated gene expression is a powerful tool to study the function of glycolipids and should have a general application to the glycobiology field.

Topics: Animals; Cell Differentiation; DNA, Complementary; Flow Cytometry; Gangliosides; Gene Expression Regulation; Kinetics; Mice; Neuroblastoma; RNA, Messenger; Sialyltransferases; Tetracycline; Transfection; Tumor Cells, Cultured

A serum containing a monoclonal IgM lambda with anti-GM1 and anti-GD1b activity was obtained from a patient with upper motor neuron syndrome. By indirect immunocytochemical techniques with double staining, the patient's IgM strongly stained membranes of neurons in primary cultures of fetal central and peripheral nervous system. It was cytotoxic for neurons in two human neuroblastoma established cell lines in a complement-dependent chromium release assay. These results are in keeping with the hypothesis of a direct pathogenetic role of such monoclonal anti-GM1 and GD1b IgM antibodies.

Topics: Antibodies, Monoclonal; Cells, Cultured; Female; G(M1) Ganglioside; Gangliosides; Humans; Immunoglobulin M; Neuroblastoma; Neurons; Pregnancy; Tumor Cells, Cultured

An abnormal circulating ganglioside was found in patients with neuroblastoma. This ganglioside appeared as a single band by resorcinol-HCl staining of thin-layer chromatograms of purified total gangliosides isolated from as little as 1 ml of patient plasma. It is a major ganglioside of neuroblastoma tumour tissue and was present (250-1500 pmol lipid-bound sialic acid/ml) in the plasma of five patients with widespread neuroblastoma. In contrast, the ganglioside was not detected (less than 50 pmol/ml) in plasma samples of six patients in complete remission, nor in plasma samples of seventeen healthy children and adults. Measurement of this circulating tumour-associated ganglioside should be clinically useful in neuroblastoma, offering a new approach to the detection of tumour and the evaluation of therapy.

Topics: Adolescent; Adult; Child; Child, Preschool; Chromatography, Thin Layer; Female; G(M1) Ganglioside; G(M3) Ganglioside; Gangliosides; Humans; Male; Middle Aged; Neuroblastoma

Individual ganglioside species (possessing the gangliotetrose oligosaccharide) were purified from bovine brain gray matter and applied in varying concentrations to the culture medium of mouse neuroblastoma cells (N2A) in vitro. After 48 hr of incubation, the cells were stained, and the neuritogenic response quantitated with a video analysis system, employing a program to measure three parameters of neuroblastoma differentiation: neurites per cell (sprouting), neurite length (extension), and degree of neurite branching (arborization). All the individual gangliosides tested promoted neurite extension in a dose-dependent fashion. Asialogangliosides ("neutral" glycosphingolipids) were without effect, which suggests that sialic acid (N-acetylneuraminic acid) is necessary to elicit this cellular response. With increasing concentrations of GM1 (5 to 500 micrograms/ml), the average cellular neurite length increased significantly, whereas the number of neurites per cell decreased. With the trisialoganglioside GT1b, neurite length did not increase to the extent seen with GM1, but an increase in the number of neurites per cell (sprouting) and branch points per neurite (arborization) was observed. These results suggest that the in vitro neuronal response to exogenous gangliosides may combine specific responses to individual species making up the total.

Topics: Animals; Cell Line; G(M1) Ganglioside; Gangliosides; Glycosphingolipids; Mice; Neuroblastoma; Neurons