g(m3)-ganglioside and Brain-Neoplasms

GRP94 is an ATP-dependent chaperone able to regulate pro-oncogenic signaling pathways. Previous studies have shown a critical role of GRP94 in brain metastasis (BrM) pathogenesis and progression. In this work, an untargeted lipidomic analysis revealed that some lipid species were altered in GRP94-deficient cells, specially GM2 and GM3 gangliosides. The catalytic pathway of GM2 is affected by the low enzymatic activity of β-Hexosaminidase (HexA), responsible for the hydrolysis of GM2 to GM3. Moreover, a deficiency of the GM2-activator protein (GM2-AP), the cofactor of HexA, is observed without alteration of gene expression, indicating a post-transcriptional alteration of GM2-AP in the GRP94-ablated cells. One plausible explanation of these observations is that GM2-AP is a client of GRP94, resulting in defective GM2 catabolic processing and lysosomal accumulation of GM2 in GRP94-ablated cells. Overall, given the role of gangliosides in cell surface dynamics and signaling, their imbalance might be linked to modifications of cell behaviour acquired in BrM progression. This work indicates that GM2-AP could be an important factor in ganglioside balance maintenance. These findings highlight the relevance of GM3 and GM2 gangliosides in BrM and reveal GM2-AP as a promising diagnosis and therapeutic target in BrM research.

Topics: Animals; beta-Hexosaminidase alpha Chain; Brain Neoplasms; Carcinoma; Cell Line, Tumor; Culture Media, Conditioned; Down-Regulation; Female; G(M2) Activator Protein; G(M2) Ganglioside; G(M3) Ganglioside; Gene Expression Regulation, Neoplastic; Genes, Reporter; Humans; Lipidomics; Lysosomes; Membrane Glycoproteins; Mice; Neoplasm Proteins; RNA Interference; RNA, Small Interfering; Triple Negative Breast Neoplasms

GM3, the simplest ganglioside, modulates cell adhesion, proliferation and differentiation in the central nervous system and exogenously added GM3 regulates cell-cell and cell-extracellular matrix adhesion and induces apoptosis. To assess the anti-tumor action of exogenous GM3, we examined its effect on the proliferation and invasion of glioma cells. Its inhibitory effect on cell proliferation was demonstrated in vitro by 3-(4,5-dimethyl-2-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and in vitro in rats with meningeal gliomatosis whose survival was significantly prolonged by the intrathecal injection of GM3. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay revealed that GM3 induced glioma cell apoptosis in vitro and in vitro. In rat brain slice cultures, GM3 suppressed the invasion of glioma cells; this effect manifested earlier than the inhibition of cell proliferation and before apoptosis induction. Our results suggest exogenous GM3 as a potential therapeutic agent in patients with glioma requiring adjuvant therapy.

Topics: Animals; Apoptosis; Brain; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; G(M3) Ganglioside; Glioma; Humans; In Vitro Techniques; Neoplasm Invasiveness; Rats

The simple ganglioside GM3 inhibits proliferation and induces apoptosis in proliferating immature rodent CNS cells. To determine whether GM3 influenced the expansion of human neural tumors the effects of GM3 treatment on primary human brain tumors were assayed. Here we demonstrate that GM3 treatment dramatically reduces cell numbers in primary cultures of high-grade human glioblastoma multiforme (GBM) tumors and the rat 9L cell gliosarcoma cell line. By contrast, GM3 treatment had little effect on cell number in cultures of normal human brain. A single injection of GM3 3 days after intracranial implantation of 9L tumor cells in a murine xenograft model system resulted in a significant increase in the symptom-free survival period of host animals. The effects of GM3 were not restricted to GBMs and 9L cells. Cultures of high-grade ependymomas, mixed gliomas, astrocytomas, oligodendrogliomas, and gangliogliomas were all susceptible to GM3 treatment. These results suggest that GM3 may have considerable value as a selectively toxic chemotherapeutic agent for human high-grade gliomas.

Topics: Animals; Brain Neoplasms; Cell Death; Cell Division; Cell Survival; Child, Preschool; Drug Screening Assays, Antitumor; G(M3) Ganglioside; Glioblastoma; Glioma; Humans; Male; Mice; Rats; Transplantation, Heterologous; Tumor Cells, Cultured

We studied ganglioside expression in 12 human metastatic brain tumors metastasized from colon (4), renal (3), lung (2), esophagus (1), pancreas (1), and mammary (1) carcinomas. GM3 was the major common ganglioside expressed in brain metastatic tumor tissues, and GT1b was also present in all the metastatic brain tumor tissues. The latter was identified by TLC-immunostaining and characterized structurally by secondary ion mass spectrometry combined with 'Far-Eastern blot'. The immunohistochemical analysis of frozen tissue sections confirmed localization of GT1b in the tumor cell membrane or cytosol. GT1b was shown to be expressed both in the primary colon carcinoma and the metastasis of a single patient by immunohistochemical procedure. In systemic carcinomas without brain metastasis, GM3 was a common major component, but no GT1b was detected. These findings indicate that GT1b is a brain metastasis-associated ganglioside. We speculate that the presence of GT1b would be a useful marker for estimating metastatic potentials to the brain.

Topics: Adenocarcinoma; Biomarkers, Tumor; Brain Neoplasms; Chromatography, Thin Layer; Colonic Neoplasms; Frozen Sections; G(M3) Ganglioside; Gangliosides; Humans; Immunohistochemistry; Kidney Neoplasms; Mass Spectrometry; Neoplasm Metastasis

A procedure was developed to analyze glycosphingolipids (GSLs) in tumor-infiltrating macrophages (TIMs). The procedure entailed dissociating tumors into single cell suspensions with a concurrent metabolic labeling of GSLs using [14C]galactose. TIMs were then separated from tumor cells and other host cells by magnetic activated cell sorting and CD11b (Mac-1) microbeads. Gangliosides and neutral glycosphingolipids were analyzed in the TIM-enriched and TIM-depleted fractions in two different murine brain tumors (EPEN and CT-2A). The TIM gangliosides consisted of over 30 structures as assessed by two-dimensional high performance thin-layer chromatography. GSLs enriched in TIMs, relative to the tumors, included Gg4Cer (asialo GM1), GM1b, and GD1alpha. TIM GSLs were similar in EPEN and CT-2A despite their differences in growth and morphology. TIM GSLs were similar whether TIMs were isolated from tumors grown intracranially or subcutaneously. TIM GSLs were also similar to activated peritoneal macrophage GSLs, although differences in the ceramide structure were observed. Knowledge of TIM GSLs will be important in determining the function of these molecules in macrophage-tumor interactions. In addition, these methods will be helpful in determining the cellular origin of human brain tumor GSLs and in identifying tumor-associated GSLs for immunotherapy.

Topics: Animals; Brain Neoplasms; Cell Separation; Chromatography, Thin Layer; G(M3) Ganglioside; Glycosphingolipids; Leukemic Infiltration; Macrophage-1 Antigen; Mice; Mice, Inbred C57BL; Receptors, Fc

Previous findings with various murine tumor cell lines suggest an association between ganglioside GM3 and cell cohesive properties. The influence of GM3 on cohesion was studied in two mouse brain tumor cell lines: ependymoblastoma (EPEN) and CT-2A. In culture, the EPEN cells grow as islands and contain GM3 as the only ganglioside, whereas the CT-2A cells grow as a fusiform cell monolayer and contain GM2, GM1, and GD1a as major gangliosides and low amounts of GM3. To examine the role of GM3 in cohesion, both cell lines were treated with 1) C. perfringens neuraminidase, 2) anti-GM3 monoclonal antibody (mAb DH2), or 3) were grown in serum-free medium. All three treatments caused a significant increase in the number of non-cohesive and protoplasmic process-bearing cells for the EPEN, but had no effect on the morphology of the CT-2A cells. The neuraminidase treatment removed GM3 from both cell lines and caused a significant accumulation of GM1 in the CT-2A cells. EPEN cell cohesion and GM3 content returned to control levels after removal of neuraminidase. EPEN cell cohesion was restored in serum-free medium with added high density lipoprotein (HDL). The HDL effect on the EPEN cell cohesion was dose-dependent and was not seen with other lipoproteins. We suggest that EPEN cell cohesion could involve an interaction between extracellular HDL, acting as a bridge, and GM3 molecules on opposing cell surfaces.

Topics: Animals; Antibodies, Monoclonal; Brain Neoplasms; Carbohydrate Sequence; Cell Adhesion; Cell Membrane; Culture Media, Serum-Free; G(M3) Ganglioside; Glycosphingolipids; Lipoproteins, HDL; Mice; Molecular Sequence Data; Neuraminidase; Tumor Cells, Cultured

Limitations of classification schemes for brain tumors based solely on morphology have stimulated searches for molecular markers of nosologic and prognostic value. Gangliosides are logical candidates because there are high concentrations of them in the nervous system, there is evidence of their roles in regulation of growth and differentiation, and data from small series suggest correlations between ganglioside composition and glioma type.. Ganglioside compositions were determined for 70 primary human brain tumors: 16 low grade astrocytomas (LG), 12 anaplastic astrocytomas (AA), 34 glioblastoma multiformes (GBM), and 8 primitive neuroectodermal tumors (PNET). This method involved identification and quantitation of specific gangliosides using chemical analysis and immunoanalysis.. Among all tumor types, histologic grade correlated with a progressive loss of 1b gangliosides (P < 0.0001). GQ1b was higher in LGs than in AAs (P < 0.001). Both GT1b and GD1b were higher in AAs than GBMs (P < 0.01 and 0.05, respectively) and lower in PNETs than in GBMs (P < 0.05). GM3 was higher in PNETs than in any astrocytoma group and higher in GBMs than in either AAs or LGs. There was a significant difference in the content of 3'-LM1 among all groups (P < 0.005), between AAs and GBMs (P < 0.05), and between low grade ordinary and juvenile pilocytic astrocyomas (P < 0.01). The lacto-series ganglioside 3'-isoLM1 was present in all groups except PNET.. These results indicate that patterns of gangliosides could be of considerable value in refining the classification and diagnosis of primary human brain tumors.

Topics: Adult; Aged; Astrocytoma; Biomarkers, Tumor; Brain Neoplasms; Female; G(M1) Ganglioside; G(M3) Ganglioside; Gangliosides; Glioblastoma; Humans; Male; Middle Aged; Nerve Growth Factors; Neuroectodermal Tumors, Primitive, Peripheral

The serum concentration and composition of gangliosides were examined in 80 humans including 10 normal subjects. A significant increase was found in the total gangliosides of serum in 7 patients with cerebral astrocytomas. There was also an increased percentage of serum gangliosides with simpler structure, particularly GM3. The serum of patients with other intracranial tumors, including pituitary adenomas, ependymoma, teratoma, and metastases, did not show an increase in total ganglioside; however the pattern of simplification was found in these and in a few patients with extracranial tumors as well. The findings suggest that astrocytoma tumors shed sialoglycolipids into the circulation, and their assay may be useful in monitoring oncological therapy.

Topics: Astrocytoma; Brain Diseases; Brain Neoplasms; Chromatography, Thin Layer; G(M3) Ganglioside; Gangliosides; Humans; Neoplasms; Pons

By silica gel chromatography we have studied the various glycolipids of six established lines derived from human brain tumors. Among the glycolipids, the GM3 ganglioside appeared as one of the major components in the three lines rejected by athymic nude Mice. On the contrary, GM3 was absent, or present in trace, in the three tumorigenic lines.

Topics: Animals; Brain Neoplasms; Cell Line; Chromatography, Gel; G(M3) Ganglioside; Glycolipids; Graft Rejection; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Transplantation, Heterologous