CEFYBO   02669
CENTRO DE ESTUDIOS FARMACOLOGICOS Y BOTANICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The thyroid status regulates the cytotoxic activity of natural killer cells modulating the growth of a solid tumor developed in mice.
Autor/es:
STERLE H.A.; KLECHA A.J.; PAULAZO M.A.; CREMASCHI G.A.; BARREIRO ARCOS M.L.
Lugar:
Foz do Iguazú
Reunión:
Congreso; XXXIX Reunión Anual de la Sociedad Brasilera de Bioquímica y Biología Molecular.; 2010
Institución organizadora:
Sociedad Brasilera de Bioquímica y Biología Molecular (SBBq).
Resumen:
We showed that thyroid hormones (HTs) are capable of regulating the proliferation of T cells. The results on the involvement of HTs in tumor development are controversial. We developed murine model of hyper- and hypothyroidism in C57BL/ Hep mice by oral administration of T4 or of the anti-thyroid agent PTU, respectively. Spleen cell from these animals were obtained and the activity of NK cells were measured through the lysis of radiolabeled YAC-1 cells. Hyperthyroid mice showed a lower cytotoxic activity than euthyroid or hypothyroid animals, while no differences were found between the last two groups. In vitro HTs were able to increase EL-4 cell proliferation, syngeneic with C57BL/Hep mice. To study the modulation of HTs on tumor progression EL-4 cells were sc inoculated in eu-, hypo- and hyperthyroid animals, giving rise to solid tumors at 13  ± 2 days. Hyperthyroid mice displayed a higher rate of tumor growth, increased tumor volume and reduced survival than euthyroid animals. By contrast, hypothyroid mice showed a lower tumor growth rate than controls. Additionally, marking tumor cells with CFSE showed a higher rate of cell division in hyperthyroid animals. By immunohistochemistry on tumor tissue sections from hyperthyroid animals showed a high percentage of cells expressing the Ki-67 cell division marker in the nucleus than control or hypothyroid animals. These results suggest that THs mediates the regulation of NK cell cytotoxic activity modulating the tumor developed in mice.