Relationship between RSUME and HIF-1α/VEGF-A with invasion of pituitary adenoma

Abstract

The RWD-containing sumoylation enhancer (RSUME) can stabilize hypoxia-inducible factor-1α (HIF-1α) which promotes vascular endothelial growth factor-A (VEGF-A) expression. RSUME plays an important role in promoting the invasion of pituitary adenoma. In this study, we compared the mRNA and protein levels of RSUME, HIF-1α, and VEGF-A in pituitary adenoma tissue and analyzed the correlation. We found that the expression levels of RSUME, HIF-1α, and VEGF-A in invasive pituitary adenoma were significantly higher than in noninvasive pituitary adenoma. Moreover, a positive correlation was found between RSUME and HIF-1α/VEGF pathways. RSUME and HIF-1α were treated with hypoxia-mimicking CoCl2 and transfected into AtT-20 and GT1.1 cell lines to determine the relationship between them. It was found that RSUME effects post-transcriptional expression of HIF-1α regulated VEGF-A secretion. Reducing RSUME expression using siRNA transfection resulted in a decrease of the invasion inhibition rate of AtT-20 cells, as determined using Transwell and MTT assays. Together, we found that RSUME silencing can inhibit the invasion of pituitary adenoma cells.