CONICET | Buscador de Institutos y Recursos Humanos

CREB3L1 is a transcription factor, member of the CREB3 subfamily, that is expressed in a tissue specific manner. In some tissues CREB3L1 participates in cell differentiation processes regulating expression of tissue specific proteins, as well as proteins involved in the secretory pathway (transport factors). Moreover, CREB3L1 was described as a tumor suppressor factor that represses metastasis, migration and angiogenesis in breast cancer cell lines. We have previously described that CREB3L1 regulates the expression of proteins that contribute to the thyroid specific activity. However, the role of CREB3L1 in the differentiation process of thyroid cells is still unknown. Here, we aimed to study the role of CREB3L1 in normal thyroid cells by analyzing the effect of overexpression and inhibition of CREB3L1 on NIS, a thyroid specific protein, and transport factors. Moreover, we analyzed expression levels of CREB3L1, transport factors and NIS, in normal thyroid cells in comparison with BRAF/HRAS expressing cells. Our results show that CREB3L1 expression was able to increase NIS and transport factors. In addition, in cells silenced for CREB3L1 expression, NIS and transport factors levels were reduced relative to control cells. Furthermore, CREB3L1 immunofluorescence levels increase in cells expressing BRAF(V600E) or HRAS (G12V) in a time dependent manner (after 1, 3 and 5 days of induction). In the same conditions and in agreement with previous reports, NIS protein levels decreased until becoming undetectable after 5 days of oncogene induction. These results show a differential expression pattern of CREB3L1 and other proteins involved in the secretory pathway in an oncogenic context when compared to the expression of the same proteins under normal conditions. This could suggest a role of CREB3L1 in the progression of thyroid cancer, but further analyses will be required.