miR-1307-3p promotes tumor growth and metastasis of hepatocellular carcinoma by repressing DAB2 interacting protein

Increasing studies provide evidence to support that microRNAs (miRNAs) play important roles in regulating hepatocellular carcinoma (HCC) initiation and progression. However, whether miR-1307-3p is aberrantly expressed in HCC and affects malignant behaviors of cancer cells remain unknown. In this study, we found that miR-1307-3p expression was obviously up-regulated in HCC compared to adjacent nontumor tissues. Moreover, miR-1307-3p expression was prominently higher in HCC cells compared with the normal hepatic cell line LO2. Patients with venous infiltration, tumor size >= 5 cm and advanced tumor stages (III + IV) had significant higher levels of miR-1307-3p in HCC tissues. Notably, the high level of miR-1307-3p predicted poor clinical outcomes of HCC patients. Functionally, miR-1307-3p knockdown inhibited the proliferation, migration and invasion of MHCC97H and HCCLM3 cells, and suppressed the in vivo growth and metastasis of HCCLM3 cells. Conversely, overexpression of miR-1307-3p facilitated Hep3B cell proliferation, migration and invasion. Mechanistically, DAB2 interacting protein (DAB2IP) was screened as a direct target of miR-1307-3p. The expression of DAB2IP mRNA was down-regulated and inversely correlated with miR-1307-3p level in HCC tissues. miR-1307-3p knockdown increased the level of DAB2IP in HCC cells. Luciferase reporter assay confirmed the direct interaction between miR-1307-3p and 3'UTR of DAB2IP. Importantly, DAB2IP overexpression significantly suppressed the proliferation, migration and invasion of HCCLM3 cells. DAB2IP knockdown rescued miR-1307-3p silencing-attenuated HCC cell proliferation, migration and invasion. Taken together, our findings suggest that miR-1307-3p plays a driving role in HCC progression by targeting DAB2IP. Our study may provide new therapeutic targets for HCC treatment.