Artículo de revista
STAT3 inhibition by STA21 increases cell surface expression of MICB and the release of soluble MICB by gastric adenocarcinoma cells
Fecha
2017Registro en:
Immunobiology, 222 (2017): 1043–1051
10.1016/j.imbio.2017.05.009
Autor
Garrido Tapia, Macarena
Hernández González, Carolina
Ascui, Gabriel
Kramm, Karina
Morales Huber, Claudia
Garatea, Valentina
Zúniga, Roberto
Bustamante Zamorano, Marco
Aguillón Gutiérrez, Juan Carlos
Catalán Martina, Diego
Ribeiro, Carolina Hager
Molina Sampayo, María Carmen
Institución
Resumen
NKG2D is an activating receptor expressed on NK cells that binds to a variety of ligands, including MICA and MICB. These cell surface glycoproteins are overexpressed under cellular transformation, thus playing an important role in cell-mediated immune response to tumors. STAT3 is a transcription factor that is constitutively active in cancer. It negatively regulates MICA expression on target cells, while its inhibition enhances NK cell cytotoxicity against tumors. In this work, we aimed to describe the effect of STAT3 signaling inhibition by STA21 on the regulation of MICB expression in gastric adenocarcinoma cells and its effect on the cytotoxic function of NK cells. Treatment of gastric adenocarcinoma cells with STA21 induced an increase in MICB expression and soluble MICB secretion, as well as a variable pattern on effector cell degranulation. Soluble MICB secretion by gastric adenocarcinoma cells was not affected by metalloprotease inhibition. We also observed that primary gastric adenocarcinoma tissue released soluble MICB into the extracellular milieu. Recombinant MICB induced a significant decrease in the levels of NKG2D receptor on effector NK and CD8 + T cells, which correlated with an impaired cytotoxic function. Altogether, our data provide evidence that STAT3 signaling pathway regulates MICB expression on gastric adenocarcinoma cells and that recombinant soluble MICB compromises the cytolytic activity of NK cells.