转染B7-H3基因对前列腺癌细胞摄取^18F—FDG和^18F—FLT的影响

目的研究转染B7同系物3（B7-H3）基因对前列腺癌细胞摄取^18F—FDG和^18F-FLT的影响，并探讨抗B7-H3单克隆抗体（简称单抗）对前列腺癌细胞的作用。方法用细胞计数试剂盒（CCK）-8检测鼠源性前列腺癌RM1细胞和转染B7-H3基因RM1的同种细胞（RM1-B7-H3）培养后0．5、1、2、3、4和5d的吸光度（A）值，并用流式细胞仪测定2种细胞的生长周期。在不同糖浓度（0、5．5和11．0mmol／L）、不同细胞数（每孔5×10^4～5×10^6）、不同摄取时间（20～120min）的条件下，测定2种细胞的^18F—FDG摄取率；并在细胞数为1×10^6、反应时间为100min的条件下行^18F-FLT细胞摄取实验。最后测定给予抗B7-H3单抗4H7后RM1-B7-H3细胞的^18F—FDG细胞摄取率。数据比较行单因素方差分析和两样本t检验。结果RM1-B7-H3细胞培养1、2和3d时的A值分别为1．59±0．23、2．26±0．15和2．01±0．60，较RM1细胞（1．22±0．14、1．10±0．09和1．04±0．15）高（t=3．923、19．228和4．467，均P〈0．01）；其他时间点2组间差异无统计学意义（t=-0．094、0．858、2．000，均P〉0．05）。RM1-B7-H3细胞的G1、S、G2／M期比例分别为（32．96±2．56）％、（39．11±2．57）％和（27．94±0．21）％，S期比例较RM1细胞（32．76±1．90）％高（t=3．442，P〈0．05）。2种细胞^18F—FDG摄取率均随培养基糖浓度的增加而降低，随细胞数和摄取时间的增加而升高。在1．0×10^6细胞、摄取100min时，RM1-B7-H3和RM1细胞的^18F—FDG摄取率分别为（55．07±3．99）％和（44．16±3．60）％，^18F—FLT摄取率分别为（5．25±0．81）％和（3．33±0．64）％，差异均有统计学意义（t=4．977和4．567，均P〈0．01）。给予4H7单抗后RM1-B7。H3细胞的^18F—FDG细胞摄取率为（45．36±2．92）％，较未加单抗组^18F—FDG细胞摄取率低（F=10．001，P〈0．01）。结论转染B7-H3基因能增强前列腺癌细胞的代谢和增殖活性，并提高细胞对^18F—FDG和^18F-FLT的摄取；给予抗B7-H3单抗4H7后，RM1-B7-H3细胞的^18F—FDG细胞摄取率降低。

Effects of B7-H3 gene transfection on ^18F-FDG uptake and ^18F-FLT uptake in prostate cancer cells

Objective To evaluate the effects of B7-H3 gene transfection on ^18F-FDG uptake and ^18F-FLT uptake in prostate cancer cells. Methods The absorption （A） values of untransfected prostate cancer（RM1）cells and B7-H3 gene-transfected RM1 （RM1-B7-H3） cells were detected at different culturing time points （0.5, 1, 2, 3, 4 and 5 d） with cell counting kit-8 （CCK-8） test. Cell cycle phase distribution of RM1 and RM1-B7-H3 cells was measured with flow cytometry, ^18F-FDG uptake of RM1 and RM1-B7-H3 ceils was measured with γ counter and calculated under different conditions ： 5 × 10^4 - 5 × 10^6 cells ; 0-11.0 mmol/L glucose; 20-120 min incubation in 37 ℃. ^18F-FLT uptake of RM1 and RM1-B7-H3 cells was measured in 1×10^6 cells under incubation for 100 min at 37 ℃. After administering anti-B7-H3 monoclonal antibody 4H7, ^18F-FDG uptake of RM1-B7-H3 cells was measured. The data were analyzed using one-way analysis of variance and two-sample t test. Results The A values of RM1-B7-H3 cells after being incubated for 1, 2 and 3 d were higher than those of RM1 cells（ 1.59±0.23, 2.26±0.15 and 2.01±0.60 vs 1.22±0.14, 1.10±0. 09 and 1.04±0.15, t=3.923, 19.228, 4.467, all P〈0.01）. There was no statistical significance between the 2 groups at other time points （t=-0.094, 0.858, 2.000, all P〉0.05）. The ratios of RM1-B7-H3 cells in G1, S and G2/M phases were（32.96±2.56） %, （ 39.11 ±2.57） % and （ 27.94±0.21 ） %, respectively. The ratio of S phase in RM1-B7-H3 ceils was higher than that in RM1 cells （ （32.76±1.90）%, t=3.442, P〈 0. 05）. ^18F-FDG uptake of the both cell lines decreased with the increase of glucose concentrations, while the uptake went up with the increase of cell number and incubation time. With the cell number of 1.0× 10^6, incubation time of 100 min and temperature of 37 ℃, the ^18F-FDG uptake of RM1-B7-H3 and RM1 cells was （55.07±3.99）% vs （44.16±3.60）% （t=4.977, P〈0.01） ; and ^18F-FLT uptake of RM1-B7-H3 and RM1 cells was （5.25±0.81）% vs （3.33±0.64）% （t=4.567, P〈0.01）. After treated with antibody 4H7, ^18F- FDG uptake of RM1-B7-H3 cells （（45.36±2.92） %） was lower than that of untreated group （F= 10. 001, P〈 0.01 ）. Conclusion B7-H3 gene transfection may promote the metabolism and proliferation of prostate cancer cells, and thereby increase the ^18F-FDG uptake and ^18F-FLT uptake.