Breast cancer is the most common malignancy in women worldwide.Triplenegative breast cancer(TNBC),refers breast cancer negative for estrogen receptor,progesterone receptor and human epidermal growth factor receptor 2,...Breast cancer is the most common malignancy in women worldwide.Triplenegative breast cancer(TNBC),refers breast cancer negative for estrogen receptor,progesterone receptor and human epidermal growth factor receptor 2,characterized by high drug resistance,high metastasis and high recurrence,treatment of which is a difficult problem in the clinical treatment of breast cancer.In order to better treat TNBC clinically,it is a very urgent task to explore the mechanism of TNBC resistance in basic breast cancer research.Pregnane X receptor(PXR)is a nuclear receptor whose main biological function is to participate in the metabolism,transport and clearance of allobiological agents in PXR.PXR plays an important role in drug metabolism and clearance,and PXR is highly expressed in tumor tissues of TNBC patients,which is related to the prognosis of breast cancer patients.This reviews synthesized the important role of PXR in the process of high drug resistance to TNBC chemotherapeutic drugs and related research progress.展开更多
葡糖醛酸C5-差向异构酶(C5-epi)是肝素/硫酸乙酰肝素生物合成的关键酶之一,本文通过无缝克隆技术将人源C5-epi基因克隆至p Fast Bac1质粒构建重组载体,转化至含杆状病毒穿梭载体和辅助载体的DH10αBac感受态细胞并发生位点特异性转座,...葡糖醛酸C5-差向异构酶(C5-epi)是肝素/硫酸乙酰肝素生物合成的关键酶之一,本文通过无缝克隆技术将人源C5-epi基因克隆至p Fast Bac1质粒构建重组载体,转化至含杆状病毒穿梭载体和辅助载体的DH10αBac感受态细胞并发生位点特异性转座,经抗性和蓝白斑筛选获得重组穿梭质粒Bacmid-C5-epi;在脂质体介导下将穿梭质粒转染昆虫细胞Sf9产生重组病毒,扩增病毒感染昆虫细胞Sf9进行蛋白表达;采用Western blotting鉴定Sf9培养上清中C5-epi的表达情况,以合成的肝素五糖为底物测定C5-epi酶的活力;采用Reed-Muench两氏计算法和TCID50计算病毒滴度并优化表达条件;采用Ni-NTA亲和层析柱纯化上清液。结果表明,Western blotting表明重组C5-epi以分泌蛋白的形式在昆虫细胞Sf9中正确表达,且具有C5异构化酶活性;采用感染复数(MOI)为1、感染时间(TOI)为72 h,重组活性酶在昆虫细胞Sf9中的表达达到峰值;纯化后的C5-epi的酶比活达118.57 U/μg,是大肠杆菌表达的酶活27.32倍。因此,在Sf9昆虫细胞中表达得到活性高的重组人源C5-epi酶,适合用于肝素/硫酸乙酰肝素寡糖的高效合成和规模化制备。展开更多
基金Supported by Science project of Hunan Provincial Health Commission,No.B202304089304.
文摘Breast cancer is the most common malignancy in women worldwide.Triplenegative breast cancer(TNBC),refers breast cancer negative for estrogen receptor,progesterone receptor and human epidermal growth factor receptor 2,characterized by high drug resistance,high metastasis and high recurrence,treatment of which is a difficult problem in the clinical treatment of breast cancer.In order to better treat TNBC clinically,it is a very urgent task to explore the mechanism of TNBC resistance in basic breast cancer research.Pregnane X receptor(PXR)is a nuclear receptor whose main biological function is to participate in the metabolism,transport and clearance of allobiological agents in PXR.PXR plays an important role in drug metabolism and clearance,and PXR is highly expressed in tumor tissues of TNBC patients,which is related to the prognosis of breast cancer patients.This reviews synthesized the important role of PXR in the process of high drug resistance to TNBC chemotherapeutic drugs and related research progress.
