A number of studies have been shown that retiniods can inhibit malignant cell growth including certain breast carcinoma cells. Its inhibitory effort is observed only in ER-positive but not in ER-negative breast cancer...A number of studies have been shown that retiniods can inhibit malignant cell growth including certain breast carcinoma cells. Its inhibitory effort is observed only in ER-positive but not in ER-negative breast cancer cells. We examined retinoic acid receptors (RARs) and retinoids X receptors (RXRs) levels in 6 breast carcinoma cell lines and 18 breast cancer biopsy specimens. We found that RAR-α mRNA level was significantly higher in ER positive cell lines and samples. RAR-γ mRNA was expressed at relatively high levels in majority of tumor samples independent of the ER-status while RAR-β mRNA was expressed at low levels. We also found high RXR-α mRNA levels in all of the tumor samples examined while RXR-γ mRNA could not be detected. Our study suggests a possibility that retinoids inhibit tumor cell growth through RAR-a and RAR-α levels may serve as a potential marker to determine responsiveness of patients to retinoids therapy.展开更多
类视黄醇X受体(retinoid X receptors,RXRs)属于配体依赖性核受体家族成员。以往的许多研究揭示了RXRs在季节性发情和发情周期中的重要性,但由于RXRs必须与自身或者其他核受体形成二聚体才能发挥作用,且每种二聚体发挥的作用不同,使其...类视黄醇X受体(retinoid X receptors,RXRs)属于配体依赖性核受体家族成员。以往的许多研究揭示了RXRs在季节性发情和发情周期中的重要性,但由于RXRs必须与自身或者其他核受体形成二聚体才能发挥作用,且每种二聚体发挥的作用不同,使其在繁殖中的分子机制研究变成了难题。前人研究表明,RXRs在季节性发情动物下丘脑-垂体-性腺(HPG)轴组织中有不同水平的表达,THRs/RXRs、RARs/RXRs和PPARs/RXRs等二聚体能刺激下丘脑GnRH的释放达到调控季节性发情作用,同时参与调节卵巢颗粒细胞的增殖、卵巢血管组织重塑和类固醇生成从而影响动物发情周期中时期转换。本文总结了目前关于RXRs及其二聚体在动物季节性发情和发情周期不同繁殖活动中的作用,以期为后续研究提供参考依据。展开更多
目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXR...目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXRα)表达的关系。方法用鹅去氧胆酸(chenodeoxycholic ac id,CDCA)或苯巴比妥(phenobarb ital,PB)分别刺激培养的肝癌细胞HepG2并建立DBL阻塞性胆汁淤积大鼠模型后,分别抽提HepG2细胞总蛋白、核蛋白和大鼠肝脏细胞膜蛋白和核蛋白,W estern b lot方法检测MRP3和RXRα蛋白表达水平的变化。结果在细胞水平,CDCA和PB可诱导HepG2细胞膜MRP3蛋白表达增高,并抑制细胞核RXRα蛋白表达;在动物体内,BDL大鼠肝脏MRP3明显增加,同时RXRα表达明显下降。结论肝细胞膜蛋白MRP3表达的上调可能与核受体RXRα表达抑制有关。展开更多
文摘A number of studies have been shown that retiniods can inhibit malignant cell growth including certain breast carcinoma cells. Its inhibitory effort is observed only in ER-positive but not in ER-negative breast cancer cells. We examined retinoic acid receptors (RARs) and retinoids X receptors (RXRs) levels in 6 breast carcinoma cell lines and 18 breast cancer biopsy specimens. We found that RAR-α mRNA level was significantly higher in ER positive cell lines and samples. RAR-γ mRNA was expressed at relatively high levels in majority of tumor samples independent of the ER-status while RAR-β mRNA was expressed at low levels. We also found high RXR-α mRNA levels in all of the tumor samples examined while RXR-γ mRNA could not be detected. Our study suggests a possibility that retinoids inhibit tumor cell growth through RAR-a and RAR-α levels may serve as a potential marker to determine responsiveness of patients to retinoids therapy.
文摘类视黄醇X受体(retinoid X receptors,RXRs)属于配体依赖性核受体家族成员。以往的许多研究揭示了RXRs在季节性发情和发情周期中的重要性,但由于RXRs必须与自身或者其他核受体形成二聚体才能发挥作用,且每种二聚体发挥的作用不同,使其在繁殖中的分子机制研究变成了难题。前人研究表明,RXRs在季节性发情动物下丘脑-垂体-性腺(HPG)轴组织中有不同水平的表达,THRs/RXRs、RARs/RXRs和PPARs/RXRs等二聚体能刺激下丘脑GnRH的释放达到调控季节性发情作用,同时参与调节卵巢颗粒细胞的增殖、卵巢血管组织重塑和类固醇生成从而影响动物发情周期中时期转换。本文总结了目前关于RXRs及其二聚体在动物季节性发情和发情周期不同繁殖活动中的作用,以期为后续研究提供参考依据。
文摘目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXRα)表达的关系。方法用鹅去氧胆酸(chenodeoxycholic ac id,CDCA)或苯巴比妥(phenobarb ital,PB)分别刺激培养的肝癌细胞HepG2并建立DBL阻塞性胆汁淤积大鼠模型后,分别抽提HepG2细胞总蛋白、核蛋白和大鼠肝脏细胞膜蛋白和核蛋白,W estern b lot方法检测MRP3和RXRα蛋白表达水平的变化。结果在细胞水平,CDCA和PB可诱导HepG2细胞膜MRP3蛋白表达增高,并抑制细胞核RXRα蛋白表达;在动物体内,BDL大鼠肝脏MRP3明显增加,同时RXRα表达明显下降。结论肝细胞膜蛋白MRP3表达的上调可能与核受体RXRα表达抑制有关。
