照射时间延长对小鼠Lewis肺癌MMP-9和E-cad表达影响

EFFECT OF PROLONGED RADIOTHERAPY ON EXPRESSION OF MMP-9 AND E-cad OF Lewis PULMONARY CARCINOMA IN MOUSE

目的模拟调强适形放射治疗（IMRT）照射模式，观察照射时间延长对小鼠Lewis肺癌细胞转移相关基因基质金属蛋白酶-9（MMP-9）及E-钙黏附素（E-cad）表达的影响。方法荷Lewis肺癌C57BL／6雄性小鼠40只，随机分成4组：假照组、常规照射组（A组）、IMRT模拟1组（B1组）、IMRT模拟2组（B2组），各10只。A、B1、B2组照射剂量均为15Gy，24h后脱颈处死全部小鼠，用免疫组化法测细胞转移相关基因MMP-9及E-cad的表达。结果与假照组比较，A、B1、B2组MMP-9表达阳性率降低，E—cad表达阳性率升高，差异均有显著性（F=210．207、102．059，q=8．393-33．921，P〈O．01）；与A组比较，B1、B2组的MMP-9表达阳性率降低，E—cad表达阳性率升高，差异均有显著性（q=8．376～15．897，P〈0．01）；与B1组比较，B2组MMP-9表达阳性率降低，E—cad表达阳性率升高，差异均有显著性（q=2．957、4．044，P〈0．05）。结论在一定的范围内，照射时间延长可致MMP-9表达升高，E—cad表达降低。

Objective To investigate the effects of prolonged delivery time of intensity-modulated radiotherapy （IMRT） on the expressions of MMP-9 and E-cadherin of Lewis pulmonary carcinoma in mouse. Methods Forty male Lewis-lung-cancer （C57BL/ 6）-bearing mice were equally randomized to four groups： sham-radiotherapy group （SR group）, conventional radiotherapy group （group A） and two modeling IMRT groups （group B1 and group B2）. The mice in groups A, B1 and B2 were irradiated with 6 MV X-rays at a dose of 15 Gy and all the mice were killed 24 hours later. The expressions of MMP-9 and E-cadherin in tumor tissues were examined immunohistochemically. Results Compared with SR group, the expressions of MMP-9 in groups A, B1 and B2 decreased, that of E-eadherin increased （F=210.207,102.059;q=8.393-33.921;P〈0.01）. Compared with group A, the expressions of MMP-9 in groups B1 and B2 decreased, while that of E-cadherin increased （q = 8. 376-15. 897, P〈0. 01）. Compared with group B1, expression of MMP-9 in group B2 decreased, and that of E-cadherin increased （q=2. 957,4. 044;P〈0.05）. Conclusion Under given conditions, extention of exposure time may result in increasiong of expression of MMP-9 and decreasing of expression of E-cadherin.