Insulin-like growth factor II mRNA binding protein 3 regulates proliferation, invasion and migration of neuroendocrine cancer cells

This study aimed to investigate the role of insulin-like growth factor II mRNA binding protein 3 (IMP3) in neuroendocrine tumor (NET). Mouse NET STC-1 cell line was chosen as the experimental model and three IMP3-targeting siRNAs and a non-specific scramble siRNA were transfected into STC-1 cells. The efficiency of IMP3 siRNA to knockdown IMP3 was evaluated by immunocytochemical staining. Cell proliferation was detected by MTT assay. Cell migration and invasion was analyzed with Transwell chamber assay. Protein expression was detected by Western blot analysis. We found that IMP3 silencing inhibited the proliferation of STC-1 cells potentially by down-regulating the expression of cell proliferation associated proteins EGFR and Ki67. Furthermore, IMP3 silencing inhibited the migration and invasion of STC-1 cells potentially by downregulating the expression of metastasis associated proteins IGF1R, MMP2 and MMP9. In conclusion, this study provides the first evidence that IMP3 plays an oncogenic role in Net and is a promising therapeutic target for NET.