Abstract
The underlying molecular mechanisms of pancreatic neuroendocrine tumor (pNET) development have not yet been clearly identified. The present study revealed that thrombospondin 2 (THBS2) was downregulated in pNET tissues and cells. Forced expression of THBS2 inhibited the proliferation and migration of pNET cells in vitro. MicroRNA(miR)-744-5p was indicated to be a direct regulator of THBS2. Upregulation of miR-744-5p potentially caused THBS2 repression. Furthermore, THBS2 inhibited the production of matrix metalloproteinase (MMP) MMP9 through suppressing the transcriptional activity of CUT-like homeobox 1 (CUX1). CUX1 and MMP9 mediated the effect of THBS2 on pNET proliferation and migration, respectively. The results of the present study revealed a mechanistic role for THBS2 in pNET proliferation and migration, indicating that THBS2 was downregulated by miR-744-5p and further affected the CUX1/MMP9 cascade, which promoted the development of pNET.