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The metastatic breast cancer cell line, 4T1, abundantly expresses the oligosaccharide sialylated Lewis x (sLe x ). SLe x oligosaccharide on tumor cells can be recognized by E-and P-selectin, contributing to tumor metastatic process. We observed that both selectins reacted with this cell line. However, contrary to the E-selectin reactivity, which was sLe x dependent, P-selectin reactivity with this cell line was sLe x -independent. The sLe x -Neg variant of the 4T1 cell line with markedly diminished expression of sLe x and lack of sLe a , provided a unique opportunity to characterize Pselectin ligands and their contribution to metastasis in the absence of overlapping selectin ligands and E-selectin binding. We observed that P-selectin binding was Ca 21-independent and sulfation-dependent. We found that P-selectin reacted primarily with cell surface chondroitin sulfate (CS) proteoglycans, which were abundantly and stably expressed on the surface of the 4T1 cell line. P-selectin binding to the 4T1 cells was inhibited by heparin and CS glycosaminoglycans (GAGs). Moreover, Heparin administration significantly inhibited experimental lung metastasis. In addition, the data suggest that surface CS GAG chains were involved in P-selectin mediated adhesion of the 4T1 cells to murine platelets and human umbilical vein endothelial cells. The data suggest that CS GAGs are also the major P-selectin-reactive ligands on the surface of human MDA-MET cells. The results warrant conducting clinical studies on the involvement of cell surface CS chains in breast cancer metastasis and evaluation of various CS types and their biosynthetic pathways as target for development of treatment strategies for antimetastatic therapy of this disease. ' 2006 Wiley-Liss, Inc.Key words: P-selectin; chondroitin sulfate; breast cancer; cell-cell adhesion Breast cancer metastasis represents a terrible milestone associated with a poor prognosis. The multistep process of metastasis includes release of malignant cells from the primary neoplasm, migration of cancer cells into the blood circulation, interaction with platelets and leukocytes in circulation, adhesion to the vascular endothelium in distant organs and growth of the disseminated cancer cells within the vessels or within the tissue following extravasation.1-3 Each step in this process requires different types of interactions between cancer cells and the host microenvironment.A widely accepted hypothesis is that cancer cells exploit the adhesion molecules used by hematopoietic cells to migrate into distant organs. 4 In particular, the selectin family of adhesion molecules whose ligands, sialyl Lewis x (sLe x ) and sialyl Lewis a (sLe a ), are expressed at elevated levels on various cancer cells of human and murine origin 5-9 and play a significant role in cancer metastasis. The oligosaccharides sLe x and sLe a are the prime ligands for P-and E-selectin and many published works underscore the relative importance of interactions between sLe x/a and these vascular receptors in the hematogenous spread ...

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Background V591 (TMV-083) is a live recombinant measles vector-based vaccine candidate expressing a pre-fusion stabilized SARS-CoV-2 spike protein. Methods We performed a randomized, placebo-controlled Phase I trial with an unblinded dose escalation and a double-blind treatment phase at 2 sites in France and Belgium to evaluate the safety and immunogenicity of V591. Ninety healthy SARS-CoV-2 sero-negative adults (18-55 years of age) were randomized into 3 cohorts, each comprising 24 vaccinees and 6 placebo recipients. Participants received two intramuscular injections of a low dose vaccine (1 × 10 5 median Tissue Culture Infectious Dose [TCID 50 ]), one or two injections of a high dose vaccine (1 × 10 6 TCID 50 ), or placebo with a 28 day interval. Safety was assessed by solicited and unsolicited adverse events. Immunogenicity was measured by SARS-CoV-2 spike protein-binding antibodies, neutralizing antibodies, spike-specific T cell responses, and anti-measles antibodies. ClinicalTrials.gov, NCT04497298. Findings Between Aug 10 and Oct 13, 2020, 148 volunteers were screened of whom 90 were randomized. V591 showed a good safety profile at both dose levels. No serious adverse events were reported. At least one treatment-related adverse event was reported by 15 (20.8%) participants receiving V591 vs. 6 (33.3%) of participants receiving placebo. Eighty-one percent of participants receiving two injections of V591 developed spike-binding antibodies after the second injection. However, neutralizing antibodies were detectable on day 56 only in 17% of participants receiving the low dose and 61% receiving the high dose (2 injections). Spike-specific T cell responses were not detected. Pre-existing anti-measles immunity had a statistically significant impact on the immune response to V591, which was in contrast to previous results with the measles vector-based chikungunya vaccine. Interpretation While V591 was generally well tolerated, the immunogenicity was not sufficient to support further development.

The selective targeting of tumor-associated carbohydrate Ags by the induction of serum Abs that trigger apoptosis of tumor cells as a means to reduce circulating tumor cells and micrometastases would be an advantage in cancer vaccine development. Some plant lectins like Griffonia simplicifolia lectin I and wheat germ agglutinin mediate the apoptosis of tumor cells. We investigated the possibility of using these lectins as templates to select peptide mimotopes of tumor-associated carbohydrate Ags as immunogens to generate cross-reactive Abs capable of mediating apoptosis of tumor cells. In this study, we show that immunization with a mimotope selected based on its reactivity with Griffonia simplicifolia lectin I and wheat germ agglutinin induced serum IgM Abs in mice that mediated the apoptosis of murine 4T1 and human MCF7 cell lines in vitro, paralleling the apoptotic activity of the lectins. Vaccine-induced anti-carbohydrate Abs reduced the outgrowth of micrometastases in the 4T1 spontaneous tumor model, significantly increasing survival time of tumor-bearing animals. This finding parallels suggestions that carbohydrate-reactive IgM with apoptotic activity may have merit in the adjuvant setting if the right carbohydrate-associated targets are identified.

Aberrant glycosylation is a universal feature of cancer cells, and certain glycan structures are well-known markers for tumor progression. Availability and composition of sugars in the microenvironment may affect cell glycosylation. Recent studies of human breast tumor cell lines indicate their ability to take up and utilize fructose. Here we tested the hypothesis that adding fructose to culture as a carbon source induces phenotypic changes in cultured human breast tumor cells that are associated with metastatic disease. MDA-MB-468 cells were adapted to culture media in which fructose was substituted for glucose. Changes in cell surface glycan structures, expression of genes related to glycan assembly, cytoskeleton F-actin, migration, adhesion and invasion were determined. Cells cultured in fructose expressed distinct cell-surface glycans. The addition of fructose affected sialylation and fucosylation patterns. Fructose feeding also increased binding of leukoagglutinating Phaseolus vulgaris isolectin, suggesting a possible rise in expression of branching β-1, 6 GlcNAc structures. Rhodamine-phalloidin staining revealed an altered F-actin cytoskeletal system. Fructose accelerated cellular migration and increased invasion. These data suggest that changing the carbon source of the less aggressive MDA-MB-468 cell line induced characteristics associated with more aggressive phenotypes. These data could be of fundamental importance due to the markedly increased consumption of sweeteners containing free fructose in recent years, as they suggest that the presence of fructose in nutritional micro-environment of tumor cells may negatively affect the outcome for some breast cancer patients.