chondroitin-sulfates and Carcinoma--Lewis-Lung

Glycosaminoglycans, including chondroitin sulfate (CS), dermatan sulfate, and heparan sulfate, attached to proteoglycans at the surface of tumor cells play key roles in malignant transformation and metastasis. A Lewis lung carcinoma (LLC)-derived tumor cell line with high metastatic potential shows a higher proportion of E disaccharide units, d-glucuronic acid-GalNAc(4,6-O-disulfate), in CS chains than LLC cells with low metastatic potential, suggesting that E units in the CS chains contribute to the metastatic potential. In fact, the metastasis of LLC to mouse lungs is drastically inhibited by preadministration of CS-E or a phage display antibody specific for CS-E. However, the molecular mechanism underlying the pulmonary metastasis involving CS chains remained to be elucidated. Recently, receptor for advanced glycation end-products (RAGE), which is predominantly expressed in the lung, was identified as a functional receptor for CS chains containing E units. RAGE strongly interacted with not only CS-E but also heparan sulfate in vitro. The interaction with CS-E required a decasaccharide length and a cluster of basic amino acids. Intriguingly, antibody against RAGE robustly inhibited the pulmonary metastasis of not only LLC but also B16 melanoma cells, which also colonize mouse lungs after injection into a tail vein. Thus, CS chains containing E units are involved in the metastatic process, and RAGE is a critical receptor for glycosaminoglycan chains expressed at the tumor cell surface. Hence, RAGE and glycosaminoglycans are potential targets of drugs for pulmonary metastasis and a number of other pathological conditions involving RAGE in the pathogenetic mechanism.

Topics: Animals; Antibodies; Antineoplastic Agents; Carcinoma, Lewis Lung; Chondroitin Sulfates; Dermatan Sulfate; Glucuronic Acid; Humans; Ligands; Lung; Melanoma, Experimental; Mice; Neoplasm Metastasis; Protein Interaction Mapping; Receptor for Advanced Glycation End Products; Receptors, Immunologic

The low-molecular-weight fucosylated chondroitin sulfate (LFCS) was prepared from native fucosylated chondroitin sulfate (FCS), which was extracted and isolated from sea cucumber Cucumaria frondosa, and the anti-cancer mechanism of LFCS on mouse Lewis lung carcinoma (LLC) was investigated. The results showed that LFCS remarkably inhibited LLC growth and metastasis in a dose-dependent manner. LFCS induced cell cycle arrest by increasing p53/p21 expression and apoptosis through activation of caspase-3 activity in LLC cells. Meanwhile, LFCS suppressed the expression of vascular endothelial growth factor (VEGF), increased the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and downregulated the matrix metalloproteinases (MMPs) level. Furthermore, LFCS significantly suppressed the activation of ERK1/2/p38 MAPK/NF-κB pathway, which played a prime role in expression of MMPs. All of these data indicate LFCS may be used as anti-cancer drug candidates and deserve further study.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Lewis Lung; Cell Proliferation; Chondroitin Sulfates; Gene Expression Regulation, Neoplastic; Humans; Mice; Molecular Weight; Neoplasm Metastasis; Neoplasm Proteins; Sea Cucumbers; Signal Transduction

Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2CSA protein (rVAR2) derived from the malaria parasite, Plasmodium falciparum We demonstrate that ofCS plays a key role in tumor cell motility by affecting canonical integrin signaling pathways. Binding of rVAR2 to tumor cells inhibited the interaction of cells with extracellular matrix (ECM) components, which correlated with decreased phosphorylation of Src kinase. Moreover, rVAR2 binding decreased migration, invasion, and anchorage-independent growth of tumor cells in vitro Mass spectrometry of ofCS-modified proteoglycan complexes affinity purified from tumor cell lines on rVAR2 columns revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin-β1 (ITGB1) and integrin-α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core chondroitin sulfate synthesis enzymes β-1,3-glucuronyltransferase 1 (B3GAT1) and chondroitin sulfate N-acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and preincubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor cells in mice. This was associated with a significant increase in survival of the animals. These data functionally link ofCS modifications with cancer cell motility and further highlights ofCS as a novel therapeutic cancer target.. The cancer-specific expression of ofCS aids in metastatic phenotypes and is a candidate target for therapy. Mol Cancer Res; 14(12); 1288-99. ©2016 AACR.

Topics: Animals; Antigens, Protozoan; Carcinoma, Lewis Lung; Cell Line, Tumor; Chondroitin Sulfates; Humans; Integrins; Melanoma, Experimental; Mice; Neoplasm Metastasis; Neoplasms; Pancreatic Neoplasms; Signal Transduction

Chondroitin sulfate (CS) containing E-disaccharide units, glucuronic acid-N-acetylgalactosamine(4, 6-O-disulfate), at surfaces of tumor cells plays a key role in tumor metastasis. However, the molecular mechanism of the metastasis involving the CS chain-containing E-units is not fully understood. In this study, to clarify the role of E-units in the metastasis and to search for potential molecular targets for anticancer drugs, the isolation and characterization of Lewis lung carcinoma (LLC) cells stably downregulated by the knockdown for the gene encoding N-acetylgalactosamine 4-O-sulfate 6-O-sulfotransferase (GalNAc4S-6ST), which is responsible for the formation of E-units in CS chains, were performed. Knockdown of GalNAc4S-6ST in LLC cells resulted in a reduction in the proportion of E-units, in adhesiveness to extracellular matrix adhesion molecules and in proliferation in vitro. Furthermore, the stable downregulation of GalNAc4S-6ST expression in LLC cells markedly inhibited the colonization of the lungs by inoculated LLC cells and invasive capacity of LLC cells. These results provide clear evidence that CS chain-containing E-units and/or GalNAc4S-6ST play a crucial role in pulmonary metastasis at least through the increased adhesion and the invasive capacity of LLC cells and also provides insights into future drug targets for anticancer treatment.

Topics: Animals; Carcinoma, Lewis Lung; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Chondroitin Sulfates; Down-Regulation; Extracellular Matrix; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Lung Neoplasms; Mice; Molecular Targeted Therapy; Neoplasm Invasiveness; Sulfotransferases

The altered expression of cell surface chondroitin sulfate (CS) and dermatan sulfate (DS) in cancer cells has been demonstrated to play a key role in malignant transformation and tumor metastasis. However, the functional highly sulfated structures in CS/DS chains and their involvement in the process have not been well documented. In the present study, a structural analysis of CS/DS from two mouse Lewis lung carcinoma (3LL)-derived cell lines with different metastatic potentials revealed a higher proportion of Delta(4,5)HexUA-GalNAc(4,6-O-disulfate) generated from E-units (GlcUA-GalNAc(4, 6-O-disulfate)) in highly metastatic LM66-H11 cells than in low metastatic P29 cells, although much less CS/DS is expressed by LM66-H11 than P29 cells. This key finding prompted us to study the role of CS-E-like structures in experimental lung metastasis. The metastasis of LM66-H11 cells to lungs was effectively inhibited by enzymatic removal of tumor cell surface CS or by preadministration of CS-E rich in E-units in a dose-dependent manner. In addition, immunocytochemical analysis showed that LM66-H11 rather than P29 cells expressed more strongly the CS-E epitope, which was specifically recognized by the phage display antibody GD3G7. More importantly, this antibody and a CS-E decasaccharide fraction, the minimal structure recognized by GD3G7, strongly inhibited the metastasis of LM66-H11 cells probably by modifying the proliferative and invading behavior of the metastatic tumor cells. These results suggest that the E-unit-containing epitopes are involved in the metastatic process and a potential target for the diagnosis and treatment of malignant tumors.

Topics: Animals; Carcinoma, Lewis Lung; Cell Line, Tumor; Cell Membrane; Cell Proliferation; Chondroitin Sulfates; Disaccharides; Dose-Response Relationship, Drug; Glycosaminoglycans; Immunohistochemistry; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Neoplasm Metastasis; Tissue Distribution