瘦素受体在脑胶质瘤中的表达及外源性瘦素对人胶质瘤细胞系U251的作用

Expression of leptin receptor in gliomas and the effect of exogenous leptin on human glioma U251 cell line

目的检测正常脑组织及脑胶质瘤组织中瘦素和瘦素受体的表达，探讨外源性瘦素对人胶质瘤细胞系U251细胞增殖、迁移及侵袭生物学行为的影响。方法采用免疫组织化学染色检测50例不同级别的脑胶质瘤组织及20例正常脑组织中瘦素与瘦素受体的表达情况；使用MTT法、细胞划痕实验、Transwell侵袭实验检测外源性瘦素对U251细胞增殖、迁移及侵袭的影响。结果（1）胶质瘤组织中瘦素和瘦素受体的阳性表达率分别为50．0％和92．O％。（2）增殖活性：0ng/ml、10ng/ml、50ng／ml的瘦素对U251细胞的增殖能力影响无显著差别（吸光度分别为：0．263±0．015、0．273±0．017、0．277±0．006），100ng/ml的瘦素对U251细胞的增殖具有显著影响（吸光度为：0．315±0．005，P〈0．05）。（3）迁移能力：不同浓度瘦素处理的U251细胞随着时间的推移迁移率明显增加，浓度100ng／ml时迁移率最显著[（93．313±3．080）％]，且各组差异有统计学意义（P〈0．05）。（4）侵袭能力：随瘦素处理浓度的增高及作用时间的延长，U251细胞的侵袭能力增强，浓度为100ng／ml时的瘦素作用U251细胞时穿出细胞个数最多[（135±2）个]。结论瘦素和瘦素受体参与了脑胶质瘤的发生，且瘦素促进U251细胞增殖、迁移及侵袭能力具有时间和剂量依从性。

Objective To clarify the expression of leptin and leptin receptor in normal brain tissues and gliomas and investigate the effect of exogenous leptin on the proliferation, migration and invasion of human glioma U251 cell line. Methods Immunohistoehemieal staining was used to detect the expression of leptin and leptin receptor in 50 cases of different grades of glioma tissues and 20 cases of normal brain tissues.The effects of exogenous leptin on proliferation,migration and invasion of U251 cells were detected by MTT assay, cell scratch assay and Transwell invasion assay. Results （ 1 ） The positive expression rates of leptin and leptin receptors in glioma tissues were 50.0% and 92.0%, respectively. （2）Proliferation activity： leptin concentrations of 0 ng/ml, 10 ng/ml, and 50 ng/ml had no significant difference in the proliferation of U251 cells （absorbanee：0.263±0.015,0.273±0.017 and 0.277±0.006,respectively） ,and the leptin concentration of 100 ng/ml had a significant effect on the proliferation of U251 cells （absorbance：0.315±0.005,P〈 0.05 ）. （3）Migration ability：the migration rate of U251 cells treated with different concentrations of leptin increased significantly with the passage of time, and the migration rate was most significant at the concentration of 100 ng/ml （ （ 93.313±3.080） % ）, and the difference was statistically significant （P〈0.05）. （4） Invasive ability ： with the increase of leptin concentration and the prolongation of the action time, the invasive ability of U251 cells was enhanced.When leptin was used at a concentration of 100 ng/ml,the number of penetrating cells were the biggest（135±2）. Conclusion Leptin and leptin reeeptors are involved in the oecurrence of gliomas; and exogenous leptin promotes the proliferation of U251 cells and has time and dose dependability on the migration and invasion of 15251 cells.