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.

Increasing evidence shows that eukaryotic initiation factor subunit (EIF3C) plays a crucial role in development of tumors. However, the underlying roles of EIF3Cin the development of pancreatic cancer (PC) remain unknown. In this study, we examined the expression of EIF3C in PC tissues, their adjacent normal tissues and 3 cell lines (SW1990, PANC-1 and AsPC-1). Moreover, the EIF3C-shRNA lentivirus was constructed to suppress EIF3C expression. Following this, the cell colony formation assay was employed to evaluate proliferation ability of PC cells. Meanwhile, the cell cycle and apoptotic assays were also performed by flow cytometry. We found that level of EIF3C in PC tissues was significantly increased compared with that in adjacent normal tissues. Furthermore, the knockdown of EIF3C can significantly reduce cell proliferation, block cell cycle in G2/M and induce apoptosis in both SW1990 and PANC-1 cells. Our findings suggest that EIF3C plays a crucial role in the progression of PC and may be a potential target in the treatment of PC.