HERG suppresses the malignant phenotypes of osteosarcoma via modulating NF-κB pathway / 国际肿瘤学杂志

ABSTRACT

Objective To detect the expression of HERG (human ether-à-go-go-related gene ) potassium channel in human osteosarcoma,and explore the effects of silencing HERG by small interfering RNA (siRNA)on the proliferation and apoptosis of osteosarcoma cells and the mechanisms responsible for HERG regulation.Methods The expressions of HERG in osteosarcoma MG-63 cells and tissues were detected by reverse transcription polymerase chain reaction (RT-PCR),Western blotting and immunohistochemistry.Next, osteosarcoma cells were divided into three groupsHERG-siRNA group,control-siRNA group and blank group. CCK-8,colony formation,flow cytometry and Tunel assay were used to measure the proliferation and apoptosis of the osteosarcoma cells.Finally,Western blotting analysis was performed to detect the expression of nuclear factor-κB (NF-κB)pathway in osteosarcoma cells treated with HERG siRNA.Results Osteosarcoma cells and tissues were found to highly express HERG.Inhibition of HERG in the osteosarcoma cells significantly inhibited the cell proliferation and induced cell apoptosis.Compared to control-siRNA group or blank group,HERG-siRNA could inhibit the proliferation of MG-63 cells significantly [HERG-siRNA group(75.34 ± 4.45)%;compared to control-siRNA group(100.60 ±5.31)%;t =3.64,P =0.007;compared to blank group(100.00 ±5.66)%;t =3.43,P =0.009].The similar results were obtained from colony formation assay (HERG-siRNA group134.30 ±11.82;compared to control-siRNA group225.30 ±11.56;t =5.51, P =0.002;compared to blank group232.80 ±12.21;t =5.80,P =0.001).HERG-siRNA transfected MG-63 cells demonstrated a significant increase of apoptotic rate compared to control-siRNA transfected cells or untreated cells [HERG-siRNA group(28.10 ±2.21 )%;compared to control-siRNA group(9.36 ± 2.42)%;t =5.72,P =0.005;compared to blank group(10.92 ±2.51)%;t =5.14,P =0.007].This resultwas further confirmed by Tunel assay.The cells transfected with HERG-siRNA (31.57 ±2.08)% dem-onstrated extensive apoptosis,compared with the control-siRNA group [(10.35 ±1.82)%;t =7.69,P =0.002)]or blank group [(7.96 ±0.88)%;t =10.48,P =0.001].Silencing HERG gene down-regulated the cIAP-1,XIAP,Bcl-2,Survivin,P-IκBαand NF-κB p65 expression,compared to the control groups. Conclusion HERG is highly expressed in osteosarcoma.HERG silencing can suppress osteosarcoma progres-sion through NF-κB pathway and suggest that HERG may be a novel molecular target for osteosarcoma therapy and diagnosis.