Aim To investigate the potential impact of homocysteine(Hcy) on the expression of insulin-like growth factor-2(IGF-2) and H19 in vascular smooth muscle cells(VSMC),analyze its possible correlation with the proliferation of VSMC and its role in the pathogenesis of atherosclerosis(As). Methods Cultured human umbilical VSMC were divided into 0,50,100,200,500,1000 μmol/L Hcy group,and the 0 μmol/L Hcy group was the control.After the VSMC were treated with different concentrations of Hcy for 48 h,the cell viability was detected by MTT,the mRNA levels of H19 and IGF-2 were determined by reverse transcription polymerase chain reaction,and the protein expression of IGF-2 by Western Blotting. Results Compared with the 0 μmol/L Hcy groups,the viability of VSMC was increased in the Hcy groups,especially in 500 and 1000 μmol/L Hcy groups(P><0.05).The H19 expression of VSMC in Hcy groups was increased,and its levels in the 500 and 1000 μmol/L group(0.548 6±0.063 3 and 0.733 3±0.049 6)were significantly higher than that in the 0 μmol/L Hcy group(0.202 2±0.012 4)(P><0.05),while the IGF-2 mRNA and protein was down-expressed,which were also more significant in the 500 and 1 000 μmol/L group(mRNA: 0.258 8±0.024 8 and 0.168 9±0.069 6 vs 0.515 8±0.018 9,P><0.05;protein: 0.116 7± 0.015 5 and 0.083 7±0.018 0 vs 0.244 3±0.042 3,P><0.05). Conclusion Hcy harassesd the imprinting expression of IGF-2 and H19 in the VSMC.The expression of H19 was increased and that of IGF-2 decreased.The aberrant expression of IGF-2 and H19 possibly induced the proliferation of VSMC.