中文摘要：

目的研究肝X受体（liver X receptors,LXRs）在乳腺癌中的表达及其对乳腺癌MCF-7细胞增殖的影响。方法采用免疫组化法检测LXRs在人乳腺癌组织中的蛋白表达;采用LXR激动剂T0901317处理人乳腺癌MCF-7细胞,流式细胞术检测BrdU标记MCF-7细胞的增殖情况。结果①LXRα和LXRβ在乳腺正常组织基本不表达,但LXRα在不同乳腺癌病变（导管原位癌和浸润性导管癌）中表达增高（P〈0.05）,在浸润性导管癌尤为明显;LXRβ在不同乳腺癌病变中不表达。②T0901317（10μM）处理明显抑制MCF-7细胞的增殖率（P〈0.05）。结论乳腺癌组织LXRα蛋白表达明显增高,激活LXRα能够显著抑制MCF-7细胞的增殖。

英文摘要：

【Objective】 To study the expression of liver X receptors（LXRs） in human breast cancer,and its effect on proliferation of breast cancer cell line MCF-7.【Methods】 The expression of LXRα and LXRβ in human breast cancer were examined by immunohistochemical technique,and the positive rates and the change of average gray value were analyzed by micro-image analysis system.Human breast cancer MCF-7 cells were treated with the LXR agonists T0901317（10 μM）,the proliferation assay was performed by FCM after 72 hours.【Results】 The proteins of LXRα and LXRβ were not obviously expressed in normal breast tissues,but positive expression ratio and intensity of LXRα has significantly increased in breast cancer tissues including ductal carcinoma in situ（DCIS） and invasive ductal carcinoma（IDC）,while LXRβ was no expressed in breast cancer tissues.The MCF-7 cells treated with LXR agonist T0901317 showed decreased proliferation compared with the control MCF-7 cells.【Conclusions】 The expression level of LXRα is increased in breast cancer,and activation of LXRα by T0901317 inhibits the proliferation of the MCF-7 cells.