g(m2)-ganglioside and Neoplasms

Tumor-associated gangliosides have been investigated for their potential as antigenic targets for more than 35 years, culminating in the recent Food and Drug Administration approval of dinutuximab (Unituxin), an IgG antibody targeted against GD2, for the treatment of neuroblastoma in children. This review is focused on discoveries and development of therapeutic approaches involving human IgM antibodies directed against gangliosides, which occurred over the past 40 years at University of California-Los Angeles and the John Wayne Cancer Institute, where Dr. Donald Morton led the surgical oncology department until his death.

Topics: Antibodies, Monoclonal; Antigenic Variation; Antigens, Neoplasm; Cancer Vaccines; G(M2) Ganglioside; Gangliosides; Humans; Immunization, Passive; Immunoglobulin M; Immunotherapy; Molecular Targeted Therapy; Neoplasms

The factors involved in constructing vaccines for clinical testing are shown in Figure 3. The definition of melanoma antigens which are likely to be immunogenic is greatly facilitated by identification of reactive antibodies in sera or human hybridoma supernatants. It is also possible that antigens defined by murine monoclonal antibodies or extraction of melanoma specimens will be proven immunogenic with appropriately constructed vaccines, but this is unlikely unless immunohistologic testing and extraction of normal tissues show lack of expression on normal cells. With the use of purified antigens it has been possible to immunize with more antigen and to present the antigen in a more immunogenic fashion. On the other hand, the use of whole tumor cells or cell fractions provides the possibility of obtaining immune responses against antigens not previously known to be immunogenic, especially if linked with the production of human monoclonal antibodies. Experimental models for vaccine construction play a critical role in the selection of optimal adjuvants or vehicles for antigen presentation and for comparing different approaches to anti suppressor cell treatment. (Formula: see text). The ability to consistently induce high titer antibody responses against a single antigen, the ganglioside GM2, represents a foot in the door of active specific immunotherapy against malignant melanoma in man. When we are able to immunize as well against 2 or 3 additional melanoma antigens, the door will be open for testing the hypothesis that active specific immunotherapy can play a role in preventing recurrence or treating measurable cancer in man.

Topics: Adjuvants, Immunologic; Animals; Antigens, Neoplasm; Clinical Trials as Topic; Cyclophosphamide; G(M2) Ganglioside; Humans; Immunity, Active; Immunization; Immunotherapy; Melanoma; Mice; Neoplasms; Neoplasms, Experimental

The factors involved in constructing vaccines for clinical testing are shown in Figure 3. The definition of melanoma antigens which are likely to be immunogenic is greatly facilitated by identification of reactive antibodies in sera or human hybridoma supernatants. It is also possible that antigens defined by murine monoclonal antibodies or extraction of melanoma specimens will be proven immunogenic with appropriately constructed vaccines, but this is unlikely unless immunohistologic testing and extraction of normal tissues show lack of expression on normal cells. With the use of purified antigens it has been possible to immunize with more antigen and to present the antigen in a more immunogenic fashion. On the other hand, the use of whole tumor cells or cell fractions provides the possibility of obtaining immune responses against antigens not previously known to be immunogenic, especially if linked with the production of human monoclonal antibodies. Experimental models for vaccine construction play a critical role in the selection of optimal adjuvants or vehicles for antigen presentation and for comparing different approaches to anti suppressor cell treatment. (Formula: see text). The ability to consistently induce high titer antibody responses against a single antigen, the ganglioside GM2, represents a foot in the door of active specific immunotherapy against malignant melanoma in man. When we are able to immunize as well against 2 or 3 additional melanoma antigens, the door will be open for testing the hypothesis that active specific immunotherapy can play a role in preventing recurrence or treating measurable cancer in man.

Topics: Adjuvants, Immunologic; Animals; Antigens, Neoplasm; Clinical Trials as Topic; Cyclophosphamide; G(M2) Ganglioside; Humans; Immunity, Active; Immunization; Immunotherapy; Melanoma; Mice; Neoplasms; Neoplasms, Experimental

An efficient method was developed for the synthesis of a GM2 derivative suitable for the conjugation with various biomolecules. This GM2 derivative was covalently linked to keyhole limpet hemocyanin (KLH) and monophosphoryl lipid A (MPLA) to form novel therapeutic cancer vaccines. Immunological evaluations of the resultant conjugates in mice revealed that they elicited robust GM2-specific overall and IgG antibody responses. Moreover, the GM2-MPLA conjugate was disclosed to elicit strong immune responses without the use of an adjuvant, proving its self-adjuvant property. The antisera of both conjugates showed strong binding and mediated similarly effective complement-dependent cytotoxicity to GM2-expressing cancer cell line MCF-7. Based on these results, it was concluded that both GM2-MPLA and GM2-KLH are promising candidates as therapeutic cancer vaccines, whereas fully synthetic GM2-MPLA, which has homogeneous and well-defined structure and self-adjuvant property, deserves more attention and studies.

Topics: Adjuvants, Immunologic; Animals; Antibody-Dependent Cell Cytotoxicity; Cancer Vaccines; Complement System Proteins; Disease Models, Animal; Female; G(M2) Ganglioside; Lipid A; Mice; Molecular Structure; Neoplasms; Vaccines, Synthetic; Xenograft Model Antitumor Assays

The development of carbohydrate-based antitumor vaccines is an attractive approach towards tumor prevention and treatment. Herein, we focused on the ganglioside GM2 tumor-associated carbohydrate antigen (TACA), which is overexpressed in a wide range of tumor cells. GM2 was synthesized chemically and conjugated with a virus-like particle derived from bacteriophage Qβ. Although the copper-catalyzed azide-alkyne cycloaddition reaction efficiently introduced 237 copies of GM2 per Qβ, this construct failed to induce significant amounts of anti-GM2 antibodies compared to the Qβ control. In contrast, GM2 immobilized on Qβ through a thiourea linker elicited high titers of IgG antibodies that recognized GM2-positive tumor cells and effectively induced cell lysis through complement-mediated cytotoxicity. Thus, bacteriophage Qβ is a suitable platform to boost antibody responses towards GM2, a representative member of an important class of TACA: the ganglioside.

Topics: Allolevivirus; Animals; Antibodies, Monoclonal; Cancer Vaccines; Carbohydrate Sequence; Cell Line, Tumor; Enzyme-Linked Immunosorbent Assay; G(M2) Ganglioside; Mice; Molecular Sequence Data; Neoplasms

The definitive role of ganglioside GM2 in mediating tumor-induced growth and progression is still unknown. Here we report a novel role of ganglioside GM2 in mediating tumor cell migration and uncovered its mechanism. Data shows differential expression levels of GM2-synthase as well as GM2 in different human cancer cells. siRNA mediated knockdown of GM2-synthase in CCF52, A549 and SK-RC-26B cells resulted in significant inhibition of tumor cell migration as well as invasion in vitro without affecting cellular proliferation. Over-expression of GM2-synthase in low-GM2 expressing SK-RC-45 cells resulted in a consequent increase in migration thus confirming the potential role GM2 and its downstream partners play in tumor cell migration and motility. Further, treatment of SK-RC-45 cells with exogenous GM2 resulted in a dramatic increase in migratory and invasive capacity with no change in proliferative capacity, thereby confirming the role of GM2 in tumorigenesis specifically by mediating tumor migration and invasion. Gene expression profiling of GM2-synthase silenced cells revealed altered expression of several genes involved in cell migration primarily those controlling the integrin mediated signaling. GM2-synthase knockdown resulted in decreased phosphorylation of FAK, Src as well as Erk, while over-expression and/or exogenous GM2 treatment caused increased FAK and Erk phosphorylation respectively. Again, GM2 mediated invasion and Erk phosphorylation is blocked in integrin knockdown SK-RC-45 cells, thus confirming that GM2 mediated migration and phosphorylation of Erk is integrin dependent. Finally, confocal microscopy suggested co-localization while co-immunoprecipitation and surface plasmon resonance (SPR) confirmed direct interaction of membrane bound ganglioside, GM2 with the integrin receptor.

Topics: Cell Line, Tumor; Cell Movement; Dose-Response Relationship, Drug; Extracellular Signal-Regulated MAP Kinases; Focal Adhesion Kinase 1; G(M2) Ganglioside; Gene Expression Profiling; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Gene Regulatory Networks; Humans; Immunoprecipitation; Integrin beta1; Kinetics; Microscopy, Confocal; N-Acetylgalactosaminyltransferases; Neoplasm Invasiveness; Neoplasms; Phosphorylation; Protein Binding; Protein Interaction Mapping; RNA Interference; Signal Transduction; src-Family Kinases; Surface Plasmon Resonance; Time Factors; Transfection

GM1 and GM2 gangliosides are important components of the cell membrane and play an integral role in cell signaling and metabolism. In this conceptual overview, we discuss recent developments in our understanding of the basic biological functions of GM1 and GM2 and their involvement in several diseases. In addition to a well-established spectrum of disorders known as gangliosidoses, such as Tay-Sachs disease, more and more evidence points at an involvement of GM1 in Alzheimer's and Parkinson's diseases. New emerging methodologies spanning from single-molecule imaging in vivo to simulations in silico have complemented standard studies based on ganglioside extraction.

Topics: Amyloid beta-Peptides; Cell Membrane; Diabetes Mellitus; G(M1) Ganglioside; G(M2) Ganglioside; Humans; Neoplasms; Neurodegenerative Diseases; Virus Diseases

Our previous studies have described a rare type of antibody that spontaneously binds to itself, or homodimerizes. This self-binding, or autophilic antibody provides stronger protection against bacterial infection than a non-self-binding antibody with identical specificity and affinity, due to an increase of polymeric avidity. Furthermore, we have shown that a peptide derived from the self-binding domain of the autophilic T15 antibody can be crosslinked to the Fc carbohydrate of monoclonal antibodies specific for the B-cell receptor of B-cell tumors. These peptide-crosslinked antibodies can exert self-binding properties, leading to an increase in binding efficiency to the target cells as well as an increase in potential to induce apoptosis. Herein, we report a novel finding that crosslinking of the autophilic T15 peptide rescues a loss-of-function chimerized (ch) anti-GM2 antibody. The parental antibody demonstrates in vivo anti-tumor activity against melanoma xenografts. The T15 peptide-conjugated antibody shows the ability to bind to itself, as well as an increased binding to its antigen, ganglioside GM2. Moreover, the peptide-conjugated antibody also demonstrates an increased ability to bind to two GM2-positive tumor cell lines and notably important, restores its ability to induce apoptosis in two types of tumor cells. These results provide strong support for the clinical potential of the autophilic technology.

Topics: Antibodies, Monoclonal; Antibody Specificity; Apoptosis; Autoantibodies; Chimera; Dimerization; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; G(M2) Ganglioside; HeLa Cells; Humans; Jurkat Cells; Neoplasms

Understanding the distribution of tumor-associated antigens on cancers and normal tissues is essential for selection of targets for cancer immunotherapy. Seven carbohydrate antigens, potential targets for immunotherapy, were studied using a panel of well-characterized MAbs by immunohistochemistry on cryostat-cut tissue sections of 13 types of cancers and 18 normal tissues. GD2 and GD3 were present on most cancers of neuroectodermal origin and GD2 was also present on B cell lymphomas. 9-O-acetyl-GD3 was detected only on melanoma while fucosyl GM1 was detected only on small cell lung cancers (SCLC). Surprisingly, GM2 was strongly expressed on all tested tumors, including cancers of neuroectodermal origin and cancers of epithelial origin. Polysialic acid was primarily expressed on SCLC and neuroblastomas. Globo H was present on most cancers of epithelial origin. These antigens were also identified in normal tissues. Fucosyl GM1 was not expressed significantly on any of the normal tissues analyzed. GD3, GD2, GM2 and polysialic acid were detected in normal brain to varying degrees. GM2 and Globo H were expressed on the luminal surface of epithelia of a variety of organs. The unexpected expression of GM2 on a broad range of cancers and normal epithelial tissues was confirmed by loss after methanol fixation and by immune thin layer chromatography.

Topics: Animals; Antibodies, Monoclonal; Antigens, Neoplasm; G(M2) Ganglioside; Gangliosides; Humans; Immunohistochemistry; Mice; Neoplasms

Using beta 1,4-N-acetylgalactosaminyltransferase (EC 2.4.1.92) complementary DNA, the correlation of gene expression, enzyme activity, and expression of ganglioside antigens was analyzed in 20 human tumor cell lines. In many lines, GM2 and/or GD2 were the most complex structures examined. Northern blot analysis revealed 5.2- and 3.0-kilobase mRNAs in almost all cell lines expressing GD2 and/or GM2. Some melanoma lines, however, showed no bands although they expressed fairly high levels of GD2. These cell lines expressed very high levels of alpha 2,8-sialyltransferase and the resulting product, GD3. Semiquantitative RT-PCR demonstrated that even cell lines with no bands in Northern blot contained 0.4-2.5% of mRNA level in the highest expressing cell line. These results indicate that GD2 expression on individual cell lines is regulated not only by the expression level of the N-acetylgalactosaminyl transferase but also by the amount of its precursor structure (GD3) and alpha 2,8-sialyltransferase present in the cells. beta 1,4-N-acetylgalactosaminyltransferase activities and mRNA levels generally correlated quite closely. A few lines, however, showed lower enzyme activities than expected from their mRNA levels, indicating the possibility that the enzyme is being regulated by translational or posttranslational modification such as phosphorylation and glycosylation as well as by transcriptional regulation. Depending on their patterns of ganglioside synthesis and expression, the lines examined were classified into 6 groups which were characteristic of different tumor cell types.

Topics: Antibodies, Monoclonal; Base Sequence; Blotting, Southern; G(M2) Ganglioside; G(M3) Ganglioside; Galactosyltransferases; Gangliosides; Humans; Molecular Sequence Data; N-Acetylgalactosaminyltransferases; Neoplasms; Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured