MARA DE SOUZA JUNQUEIRA
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina
LIM/43 - Laboratório de Medicina Nuclear, Hospital das Clínicas, Faculdade de Medicina
LIM/24 - Laboratório de Oncologia Experimental, Hospital das Clínicas, Faculdade de Medicina
LIM/43 - Laboratório de Medicina Nuclear, Hospital das Clínicas, Faculdade de Medicina
LIM/24 - Laboratório de Oncologia Experimental, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
Agora exibindo 1 - 2 de 2
- O-glycan sialylation alters galectin-3 subcellular localization and decreases chemotherapy sensitivity in gastric cancer(2016) SANTOS, Sofia N.; JUNQUEIRA, Mara S.; FRANCISCO, Guilherme; VILANOVA, Manuel; MAGALHAES, Ana; BARUFFI, Marcelo Dias; CHAMMAS, Roger; HARRIS, Adrian L.; REIS, Celso A.; BERNARDES, Emerson S.ST6GalNAc-I, the sialyltransferase responsible for sialyl-Tn (sTn) synthesis, has been previously reported to be positively associated with cancer aggressiveness. Here we describe a novel sTn-dependent mechanism for chemotherapeutic resistance. We show that sTn protects cancer cells against chemotherapeutic-induced cell death by decreasing the interaction of cell surface glycan receptors with galectin-3 and increasing its intracellular accumulation. Moreover, exogenously added galectin-3 potentiated the chemotherapeutics-induced cytotoxicity in sTn non-expressing cells, while sTn overexpressing cells were protected. We also found that the expression of sTn was associated with a reduction in galectin-3-binding sites in human gastric samples tumors. ST6GalNAc-I knockdown restored galectin-3-binding sites on the cell surface and chemotherapeutics sensibility. Our results clearly demonstrate that an interruption of O-glycans extension caused by ST6GalNAc-I enzymatic activity leads to tumor cells resistance to chemotherapeutic drugs, highlighting the need for the development of novel strategies to target galectin-3 and/or ST6GalNAc-I.
- Nanoradiopharmaceuticals for breast cancer imaging: development, characterization, and imaging in inducted animals(2016) SARCINELLI, Michelle Alvares; ALBERNAZ, Marta de Souza; SZWED, Marzena; ISCAIFE, Alexandre; LEITE, Katia Ramos Moreira; JUNQUEIRA, Mara de Souza; BERNARDES, Emerson Soares; SILVA, Emerson Oliveira da; TAVARES, Maria Ines Bruno; SANTOS-OLIVEIRA, RalphMonoclonal antibodies as polymeric nanoparticles are quite interesting and endow this new drug category with many advantages, especially by reducing the number of adverse reactions and, in the case of radiopharmaceuticals, also reducing the amount of radiation (dose) administered to the patient. In this study, a nanoradiopharmaceutical was developed using polylactic acid (PLA)/polyvinyl alcohol (PVA)/montmorillonite (MMT)/trastuzumab nanoparticles labeled with technetium-99m (99mTc) for breast cancer imaging. In order to confirm the nanoparticle formation, atomic force microscopy and dynamic light scattering were performed. Cytotoxicity of the nanoparticle and biodistribution with 99mTc in healthy and inducted animals were also measured. The results from atomic force microscopy showed that the nanoparticles were spherical, with a size range of similar to 200-500 nm. The dynamic light scattering analysis demonstrated that over 90% of the nanoparticles produced had a size of 287 nm with a zeta potential of -14,6 mV. The cytotoxicity results demonstrated that the nanoparticles were capable of reaching breast cancer cells. The biodistribution data demonstrated that the PLA/PVA/MMT/trastuzumab nanoparticles labeled with 99mTc have great renal clearance and also a high uptake by the lesion, as similar to 45% of the PLA/PVA/MMT/trastuzumab nanoparticles injected were taken up by the lesion. The data support PLA/PVA/MMT/trastuzumab labeled with 99mTc nanoparticles as nanoradiopharmaceuticals for breast cancer imaging.