低剂量辐射对小鼠S180肉瘤组织EPO和VEGF表达影响

THE EFFECT OF LOW-DOSE RADIATION ON EPO AND VEGF OF TUMOR IN S180 SARCOMA-BEARING MICE

目的观察低剂量照射(LDR)对荷S180肉瘤小鼠一般状态的影响,探讨其抑瘤机制及对肿瘤组织中促红细胞生成素(EPO)、血管内皮生成因子(VEGF)的影响。方法昆明小鼠皮下接种S180肉瘤细胞,待肿瘤形成后第12天,将小鼠随机分为假照(A)组及LDR组。对LDR组小鼠一次性给予75mGy60Co射线全身照射,A组行无射线假照射。A组于照射后6h处死,LDR组分别于照射后6h(B组)、12h(C组)、24h(D组)、48h(E组)及72h(F组)处死。分别取瘤称瘤质量,免疫组化方法检测两组肿瘤组织中EPO及VEGF的表达情况。结果E、F组与A组小鼠的瘤质量比较,差异有显著性(F=3.90,q=4.525、4.551,P<0.05)。A组肿瘤组织中EPO的阳性率与E、F组比较,差异有显著性(F=16.26,q=6.600、7.554,P<0.01)。LDR各组肿瘤组织中VEGF的阳性率与A组比较差异亦有显著性(F=47.27,q=2.777～14.668,P<0.05)。结论LDR可降低小鼠的瘤质量,说明其在一定程度上抑制肿瘤的生长;LDR可降低VEGF、EPO表达,从而抗血管生成,抑制肿瘤生长和转移。

Objective To observe the effect of low-dose radiation （LDR） on general condition of sarcoma-bearing mice and investigate its effect on EPO and VEGF as well as its tumor inhibition. Methods Subcutaneous inoculation with S180 sarcoma cells was done in Kunming mice,which were randomized to sham radiation （SR） group and LDR group on day 12 after tumor formation. The mice in LDR group were given 75 mGy total-body γ-ray radiation, and those in SD group received no ray radiation. The mice in SD group were sacrificed six hours after the radiation, and those in LDR group killed at 6h （group B）, 12 h （group C）, 24 h （group D）, 48 h （group E） and 72 h （group F）, respectively. The tumor weight was measured, and the expressions of EPO and VEGF were detected immunohistochemically. Results The tumor weight of mice in groups E and F was statistically differ ent compared to that in group A （F=3.90;q=4. 525,4. 551 ;P〈0.05）. A comparison between the positive EPO in tumor of group A and that of groups E and F showed significant difference （F= 16.26;q= 6. 600,7. 554;P〈0.01） ; the VEGF expressions in LDR groups were different as compared with that in group A （F=47.27,q=2. 777-14. 668,P〈0.05）. Conclusion LDR can lower the weight of tumor, indicating that LDR, in some extent, inhibit the expressions of EPO and VEGF, thus restrain angiogenesis, the growth and metastasis of the tumor.