摘要
目的研究受1,25二羟维生素D3调控的雌激素受体α表达载体联合他莫西芬对雌激素受体阴性乳腺癌细胞凋亡的影响及其机制。方法将本室构建的含有4个拷贝维生素D反应元件(VDRE)和胸苷激酶启动子(Tk)的VDRE-Tk-ERα表达载体转染到MDA-MB-231细胞中,利用免疫荧光法检测1,25二羟维生素D3对雌激素受体α(ERα)的诱导表达并通过末端原位法检测1,25二羟维生素D3联合他莫西芬诱导转染该表达质粒的MDA-MB-231凋亡诱导效应。用免疫印迹(Western blot)法检测细胞核因子κB(NFκB)P65活性亚单位表达以及核转位情况的变化。结果1,25二羟维生素D3能够有效诱导MDA-M-231VDRE-ERα细胞内ERα的表达,在此基础上与他莫西芬联合作用较对照和单独作用组能够有效诱导该乳腺癌细胞发生凋亡。与此同时,NFκB P65活性亚单位的表达以及核转位均受到不同程度的抑制。结论利用1,25二羟维生素D3可通过靶控外源性雌激素受体α的表达进而调控NFκB P65活性亚单位的表达及活性,从而诱导细胞发生凋亡并最终恢复乳腺癌细胞对他莫西芬的化疗敏感性。
Objective To study the pro-apoptotie effects of 1,25 dihydroxyvitamin D3 in combination with Tamoxifen on MDA-MB-231 cells transfected with ERα expression vector containing VDRE dements and .associated molecular mechanism. Methods To clone the 4 × VDRE-Tk sequence of VDRE-pGL3 reporter vector into ERα /pcDNA 3.1 ＋ vector and to transfect it into MDA-MB-231 breast cancer cells. Moreover, to treat MDA-MB-231^VDRE-ERα breast cancer cells with 1,25 dihydroxyvitamin D3 and Tamoxifen to observe their pro-apoptotic effects as detected by TUNEL and to explore the expression and nuclear translocation of NFκB P65 subunit by western blot assay. Results Compared with control group, the percentage of apoptotic cells increased remarkably after treatment with 1,25 dihydroxyvitamin D3 and Tamoxifen for 72h. Also, 1, 25 dihydroxyvitamin D3 and Tamoxifen synergistically inhibited the expression and nuclear translocation of NFκB P65 subunit as compared with control group. Conclusion ERa-negative breast cancer cells with exogenous VDRE-Tk-ERα vector cotdd effectively obtain responsiveness to Tamoxifen under the induction of 1,25 dihydroxyvitamin 133, which in combination with Tamoxifen could synergistically induce apootosis by influencing the ex0ression and activity of NFκB P65 subunit.
出处
《中国公共卫生》
CAS
CSCD
北大核心
2008年第4期435-437,共3页
Chinese Journal of Public Health
基金
国家自然科学基金(30371217)
