PEREIRA, JONATHAS X.SANTOS, SOFIA N. dosPEREIRA, THAIS C.CABANEL, MARIANACHAMMAS, ROGEROLIVEIRA, FELIPE L. deBERNARDES, EMERSON S.EL-CHEIKH, MARCIA C.2020-02-282020-02-282019PEREIRA, JONATHAS X.; SANTOS, SOFIA N. dos; PEREIRA, THAIS C.; CABANEL, MARIANA; CHAMMAS, ROGER; OLIVEIRA, FELIPE L. de; BERNARDES, EMERSON S.; EL-CHEIKH, MARCIA C. Galectin-3 regulates the expression of tumor glycosaminoglycans and increases the metastatic potential of breast cancer. <b>Journal of Oncology</b>, v. 2019, p. 1-15, 2019. DOI: <a href="https://dx.doi.org/10.1155/2019/9827147">10.1155/2019/9827147</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/30836.1687-8450http://repositorio.ipen.br/handle/123456789/30836Galectin-3 (Gal-3) is a multifunctional β-galactoside-binding lectin that once synthesized is expressed in the nucleus, cytoplasm, cell surface, and extracellular environment. Gal-3 plays an important role in breast cancer tumors due to its ability to promote interactions between cell-cell and cell-extracellular matrix (ECM) elements, increasing tumor survival and metastatic dissemination. Still, the mechanism by which Gal-3 interferes with tumor cell migration and metastasis formation is complex and not fully understood. Here, we showed that Gal-3 knockdown increased the migration ability of 4T1 murine breast cancer cells in vitro. Using the 4T1 orthotopic breast cancer spontaneous metastasis mouse model, we demonstrated that 4T1-derived tumors were significantly larger in the presence of Gal-3 (scramble) in comparison with Gal-3 knockdown 4T1-derived tumors. Nevertheless, Gal-3 knockdown 4T1 cells were outnumbered in the bone marrow in comparison with scramble 4T1 cells. Finally, we reported here a decrease in the content of cell-surface syndecan-1 and an increase in the levels of chondroitin sulfate proteoglycans such as versican in Gal-3 knockdown 4T1 cells both in vitro and in vivo. Overall, our findings establish that Gal-3 downregulation during breast cancer progression regulates cell-associated and tumor microenvironment glycosaminoglycans (GAGs)/proteoglycans (PG), thus enhancing the metastatic potential of tumor cells.1-15openAccesslectinstumor cellsextracellular spacemammary glandsneoplasmscell cyclecell culturesmetastasesArtigo de periódico201910.1155/2019/98271470000-0002-0029-7313https://orcid.org/0000-0002-0029-731322.74623.00