Objective To assess the effect of suppression of insulin-like growth factor-1 receptor (IGF1R)in HO8910PM cell line by small interference RNA(siRNA).Methods Transfection of siRNA using liporectamine 2000 was conducted to silence IGF1R gene expression,the expression levels of IGF1R mRNA and protein were evaluated,and the effects on the cell cycles at 48 hours of transfection were assessed by real-time PCR,western blot and flow cytometry(FCM)assay respectively.The cell growth was detected by cell counting kit-8(CCK-8)at 24,48,72,96 hours of transfection.After 24 hours of transfection,the cells were cuhured with difierent concentrations of cisplatin(DDP)for 24 hours,the cell growth inhibition rate Was evaluated by CCK-8.Following incubation with 10μg/ml DDP for 24 hours after 24 hours of transfection,the apoptosis cells and the protein expression level of apoptosis-related gene,B cell leukemia/lymphoma 2(Bcl-2),were identified by FCM and western blot respectively.Resuits (1)Expression levels of IGF1R mRNA and protein were markedly decreased respectively at 48 hours of transfection IGF1R siRNA.(2)Suppression of IGF1R accompanied the reduction of cell growth at 48,72,96 hours of transfection with IGF1R siRNA,absorbance were 1.71±0.13,2.32±0.23,2.79±0.28 respectively (P＜0.01).(3)IGF1R siRNA induces arrest of G2 phase,the G2 phase rate of cells were 24.37%(P＜0.05).(4)Following treatment with 2.5,5,10,20μg/ml DDP for 24 hours after 24 hours of transfection,the cell growth inhibition rates were(25.94±0.08)%,(40.25±0.05)%,(59.48±0.03)%and(74.18±0.08)%respectively(P＜0.01).(5)Treatment with 10μg/ml DDP for 24 hours after 24 hours of transfection,induces 17.95%of cells apoptosis(P＜0.05),and decreases Bcl-2 protein level.Conclusion RNA interference of IGF1R gene induces the IGF1R silence in HO8910PM cell line significantly,inhibits cell growth in vitro, arrests the G2 phase, and enhances the chemosensitization to DDP.

The body fat measurements in old persons were carried out using two indirect methods; hydrostatic weighing and skinfold measurement.In comparison it was discovered that the skinfold measurement was significantly different from hydrostatic weighing method. Based on data of the circumference measurements which included forearm circumference (xl), arm circumference (x2), leg circumference(x3) thigh circumference(x4), abdomen circumference (x5) and buttock circumference(x6), two regression equations for the percentage of the body fat measurements were established as follows: male: F(%)=- 15.88 + 1.37BMI + 0.0102Y, female. F(%)= -34.9684 + 0.51BMI + 0.1469Y. Where Y = x1 + x2 + x3 + x4 + x5 + x6; BM1 (Body mass index) = weight(kg)/height(m)2Because the systematic error of skinfold measurements was bigger than those of circumference measurements, it was suggested that the above regression models could be used to estimate body fat in a simpler and easier way. At the same time the method of using percentage of body fat to classify obesity was compared with other two methods, excess body weight and BMI. The results showed that the rate of obesity based on BMI method was higher, and that based on excess body weight was lower than that of percentage of body fat measured by the water displacement method.