Direct inhibitory effects of 153Sm-DTPA-c(CGRRAGGSC) on human prostate cancer PC-3 cells / 中华核医学杂志

ABSTRACT

Objective To investigate the direct inhibitory effects of 153Sm- DTPA-c (Cys-Gly-Arg-Arg-Ala-Gly-Gly-Ser-Cys) NH2 ( 153 Sm-DTPA-c (CGRRAGGSC)) on human prostate cancer PC-3 cells. Methods 153Sm-DTPA-c(CGRRAGGSC) was synthesized by the reaction of 153SmCl3 with DTPA-c(CGRRAGGSC) using indirect synthesis method. PC-3 cells in vitro culture were divided into four study groups, groug A ( the control, with PBS only), group B with 1.5 mg/L c ( CGRRAGGSC), group C with 370 kBq 153 SmCl3 and group D with 370 kBq 153Sm-DTPA-c(CGRRAGGSC). PC-3 cell growth was assayed by 3-(4, 5-dimethylthiazol-2-yl ) -2, 5-diphenyltetrazolium bromide (MTT) method. Cell cycle and apoptosis were analyzed by flow cytometry. The expression changes of interleukin 11 (IL11 ) and IL11 receptor (IL1 1 R) in PC-3 cells were examined by Western Blot. One way analysis of variance (ANOVA) and paired-t test were applied for statistic analysis. Results The labeling yield of 153Sm-DTPA-c (CGRRAGGSC) was 85% and the radiochemical purity was 95.8%. The specific activity of 153Sm-DTPA-c(CGRRAGGSC) was 1.32 × 105 MBq/μmol. Significant inhibitory effects on the growth of PC-3 cells were found in both group C and D, with a time-dependent manner. However, no obvious inhibition was found either in group A or in group B. After 48 h,significant differences of sub-G1 peak area were found among groups, (0. 98 ± 0. 18)%, (0. 35 ±0. 10)%, (4.05 ±0.28)% and (13.38 ±0. 89)% for group A, B, C and D, respectively. Furthermore,sexpression of ILl 1R in group D was significantly lower than that in group B and C with absorbance values 0. 339 ~ 0.014, 0.338 ~ 0.019, 0.226 ~ 0. 015 for group B, C and D, respectively. Absorbance values in groups B and C were not significantly different after treatment, compared with those before treatment; however, there was difference between absorbance values after and before treatment in group D ( t = 0. 405,1. 163,135.989,P>0.05 >0.05, <0.05). Conchluion 153Sm-DTPA-c(CGRRAGGSC) can directly in hibit the cell growth and expression of human prostate cancer cells PC-3.