asialo-gm1-ganglioside and Neoplasms

SeviL is a recently isolated lectin found to bind to the linear saccharides of the ganglioside GM1b (Neu5Ac[Formula: see text](2-3)Gal[Formula: see text](1-3)GalNAc[Formula: see text](1-4)Gal[Formula: see text](1-4)Glc) and its precursor, asialo-GM1 (Gal[Formula: see text](1-3)GalNAc[Formula: see text](1-4)Gal[Formula: see text](1-4)Glc). The crystal structures of recombinant SeviL have been determined in the presence and absence of ligand. The protein belongs to the [Formula: see text]-trefoil family, but shows only weak sequence similarity to known structures. SeviL forms a dimer in solution, with one binding site per subunit, close to the subunit interface. Molecular details of glycan recognition by SeviL in solution were analysed by ligand- and protein-based NMR techniques as well as ligand binding assays. SeviL shows no interaction with GM1 due to steric hindrance with the sialic acid branch that is absent from GM1b. This unusual specificity makes SeviL of great interest for the detection and control of certain cancer cells, and cells of the immune system, that display asialo-GM1.

Topics: Animals; Bivalvia; Carbohydrate Sequence; G(M1) Ganglioside; Gangliosides; Humans; Lectins; Neoplasms

Cancer progression involves carcinogenesis, an increase in tumour size, and metastasis. Here, we investigated the effect of overexpressed CXC chemokine ligand 14 (CXCL14) on these processes by using CXCL14/BRAK (CXCL14) transgenic (Tg) mice. The rate of AOM/DSS-induced colorectal carcinogenesis in these mice was significantly lower compared with that for isogenic wild type C57BL/6 (Wt) mice. When tumour cells were injected into these mice, the size of the tumours that developed and the number of metastatic nodules in the lungs of the animals were always significantly lower in the Tg mice than in the Wt ones. Injection of anti-asialo-GM1 antibodies to the mice before and after injection of tumour cells attenuated the suppressing effects of CXCL14 on the tumor growth and metastasis, suggesting that NK cell activity played an important role during CXCL14-mediated suppression of tumour growth and metastasis. The importance of NK cells on the metastasis was also supported when CXCL14 was expressed in B16 melanoma cells. Further, the survival rates after tumour cell injection were significantly increased for the Tg mice. As these Tg mice showed no obvious abnormality, we propose that CXCL14 to be a promising molecular target for cancer suppression/prevention.

Topics: Animals; Antigens, Ly; Autoantibodies; Cell Transformation, Neoplastic; Chemokines, CXC; Chronic Disease; Colitis; Disease Models, Animal; Female; G(M1) Ganglioside; Galactosylceramides; Killer Cells, Natural; Lung Neoplasms; Lymphocyte Depletion; Melanoma, Experimental; Mice; Mice, Transgenic; Neoplasms; NK Cell Lectin-Like Receptor Subfamily B; Tumor Burden

Hypoxia-inducible factor 1 alpha (HIF-1alpha), a component of HIF-1, is expressed in human tumors and renders cells able to survive and grow under hypoxic (low-oxygen) conditions. YC-1, 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole, an agent developed for circulatory disorders that inhibits platelet aggregation and vascular contraction, inhibits HIF-1 activity in vitro. We tested whether YC-1 inhibits HIF-1 and tumor growth in vivo.. Hep3B hepatoma, NCI-H87 stomach carcinoma, Caki-1 renal carcinoma, SiHa cervical carcinoma, and SK-N-MC neuroblastoma cells were grown as xenografts in immunodeficient mice (69 mice total). After the tumors were 100-150 mm(3), mice received daily intraperitoneal injections of vehicle or YC-1 (30 microg/g) for 2 weeks. HIF-1 alpha protein levels and vascularity in tumors were assessed by immunohistochemistry, and the expression of HIF-1-inducible genes (vascular endothelial growth factor, aldolase, and enolase) was assessed by reverse transcription-polymerase chain reaction. All statistical tests were two-sided.. Compared with tumors from vehicle-treated mice, tumors from YC-1-treated mice were statistically significantly smaller (P<.01 for all comparisons), expressed lower levels of HIF-1 alpha (P<.01 for all comparisons), were less vascularized (P<.01 for all comparisons), and expressed lower levels of HIF-1-inducible genes, regardless of tumor type.. The inhibition of HIF-1 alpha activity in tumors from YC-1-treated mice is associated with blocked angiogenesis and an inhibition of tumor growth. YC-1 has the potential to become the first antiangiogenic anticancer agent to target HIF-1 alpha.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Carcinoma; Carcinoma, Hepatocellular; Cell Hypoxia; Culture Media, Conditioned; Endothelial Growth Factors; Enzyme-Linked Immunosorbent Assay; Female; G(M1) Ganglioside; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunoblotting; Indazoles; Intercellular Signaling Peptides and Proteins; Kidney Neoplasms; Killer Cells, Natural; Liver Neoplasms; Lymphokines; Male; Mice; Mice, SCID; Neoplasms; Neovascularization, Pathologic; Neuroblastoma; Platelet Endothelial Cell Adhesion Molecule-1; Precipitin Tests; Rats; Reverse Transcriptase Polymerase Chain Reaction; Stomach Neoplasms; Transcription Factors; Transplantation, Heterologous; Tumor Cells, Cultured; Uterine Cervical Neoplasms; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

We have examined the antitumor and antimetastatic effects of native-type, glycosylated recombinant lymphotoxin (LT) on human and murine tumors transplanted in mice. The results reported here are as follows: (a) The in vivo antitumor spectrum of LT is not coincident with the in vitro study, and it has a wide antitumor spectrum and substantially inhibits the growth of human solid tumors, (b) When both syngeneic and nude mice are transplanted with Meth A tumor, the significant growth-inhibitory effect of LT is obtained in syngeneic mice, but the effect is quite small in nude mice regardless of the routes; LT attains the same degree of effectiveness as that in syngeneic mice, but at an 8 to 16 times higher dose. Furthermore, the pretreatment with anti-asialo-GM1 antibody inhibits the antitumor effects of LT in syngeneic mice, (c) In the pulmonary metastasis model induced by i.v. injection of Meth A cells, a high preventive effect of LT is obtained by systemic administration in syngeneic mice, but not in nude mice. In addition, the pretreatment with anti-asialo-GM1 antibody completely prevents the antimetastatic effect of LT, but also blocks that effect of control mice without LT treatment. In conclusion, LT appears to be a potent cytokine against tumor growth and metastasis in vivo. The differences between nude and syngeneic mice suggest the involvement of host immunity in the expression of LT function.

Topics: Animals; Female; G(M1) Ganglioside; Glycosphingolipids; Glycosylation; Humans; Immunization, Passive; Lung Neoplasms; Lymphotoxin-alpha; Mammary Neoplasms, Experimental; Melanoma, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms; Recombinant Proteins; Sarcoma, Experimental; Tumor Cells, Cultured

The present study was performed to further evaluate the possible in vivo involvement of natural killer (NK) cells in host resistance against tumors. Selective depression of NK activity in Wistar Furth rats was induced by i.p. or i.v. injection of rabbit anti-asialo GM1. This antiserum has previously been shown to produce a decrease in NK activity and a parallel increase in tumor growth in mice. In the present study, rats treated with this antibody showed a parallel decrease in NK activity and in the frequency of large granular lymphocytes (LGL) in the spleen and peripheral blood, indicating that the antiserum-induced depression of NK activity in these sites was probably caused by an elimination of most effector cells. To further determine the possible role of rat LGL in tumor rejection in vivo, we studied LGL involvement in the rapid clearance of radiolabeled tumor cells from the lungs, an assay previously shown to correlate well with in vitro NK activity. Animals treated with anti-asialo GM1 antiserum were found to have a substantial decrease in the in vivo rate of clearance of tumor cells from the lungs. Furthermore, the adoptive transfer of a highly enriched population of LGL into NK-depressed animals 2 hr before tumor challenge, partially restored their cytotoxic activity against established cell lines in vitro and their ability to eliminate radiolabeled cells from the lungs. These results provide direct support for the hypothesis that NK cells are involved in in vivo resistance to tumors, particularly in the elimination of potentially metastatic tumor cells from the circulation and capillary beds.

Topics: Animals; Antibodies; Cytotoxicity, Immunologic; Female; G(M1) Ganglioside; Glycosphingolipids; Killer Cells, Natural; Lymphocytes; Male; Neoplasms; Rats

Topics: Animals; G(M1) Ganglioside; Glycosphingolipids; Humans; Immune Sera; Immunity, Innate; Killer Cells, Natural; Mice; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms; Neoplasms, Experimental; Transplantation, Heterologous