The effects of microRNA-1224-5p on hepatocellular carcinoma tumor endothelial cells

The aim of this study was to investigate the effect of microRNA-1224-5p (miR-1224-5p) on tumor endothelial cells (TECs) of human hepatocellular carcinoma (HCC).

Oligonucleotides were chemically synthesized and transfected into TECs using Lipofectamine 2000. TECs were divided into three groups, namely a control (CON) group without transfection, a negative control (NC) group transfected with negative control oligonucleotides and green fluorescent protein (GFP), and a micro-up (MU) group transfected with miR-1224-5p mimic and GFP. The expression of miR-1224-5p was quantified via quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The proliferation of TECs was detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the optical density value at 490 nm was measured after every 24 h. Apoptosis was detected via flow cytometry using a 7-aminoactinomycin/APC Annexin V kit. The migration and invasion of TECs were detected using transwell assay. The tube formation ability was evaluated using the tube formation assay.

Oligonucleotides were successfully transduced into TECs, and the expression of miR-1224-5p was specifically upregulated. The results of qRT-PCR analysis showed that the expression of miR-1224-5p was significantly upregulated in the MU group (2^-ΔΔCt = 3.27 ± 0.15) than in the CON group (2^-ΔΔCt = 1) and NC group (2^-ΔΔCt = 1.08 ± 0.11) (P < 0.01). The results of MTT assay showed that the cell proliferation was significantly inhibited in the MU group at four time points than in the CON and NC groups (P < 0.01). Flow cytometry analysis revealed the significant increase in apoptosis of cells from the MU group (19.29% ± 0.95%) than those from the CON (8.73% ± 0.64%) and NC (9.51% ± 0.56%) (P < 0.01) groups. The migration ability was significantly inhibited in MU group (51.0 ± 3.6) as compared with CON (77.7 ± 2.5) and NC (79.2 ± 3.5) groups (P < 0.01). The invasion ability of TECs was significantly inhibited in MU group (9.8 ± 1.3) than in CON (15.8 ± 0.8) and NC (15.4 ± 0.9) groups (P < 0.01). The ability of tube formation of TECs was completely inhibited in MU group but remained unaffected in CON and NC groups.

miR-1224-5p may serve as a potential tumor suppressor in HCC. Upregulation in miR-1224-5p expression may decrease proliferation, induce apoptosis, inhibit migration and invasion, and suppress tube formation in TECs of human HCC.