Gambogic acid(GA) is a natural substance with a good antitumor effect, but it is too lipophilic to be metabolized and excreted, thus accumulating in the body. Gemcitabine(GEM), one of the first-line antitumor drugs, h...Gambogic acid(GA) is a natural substance with a good antitumor effect, but it is too lipophilic to be metabolized and excreted, thus accumulating in the body. Gemcitabine(GEM), one of the first-line antitumor drugs, has high hydrophilicity, which greatly shortens its half-life in vivo. We previously reported a compound named N-gamboyl gemcitabine(GAG), derived from the condensation of GEM and GA, whose hydrophilicity is better than GA and stability is better than GEM. Here, the antitumor performance of GAG was investigated for the first time by using several common tumor cell lines as tumor models. The results of in vitro study showed that GAG significantly inhibited the proliferation and migration of the tumor cells. The IC50 values of GAG for the tumor cells were lower than those of GEM and GA. The present study suggests that GAG has a promising potential to be developed into a broad-spectrum antitumor drug.展开更多
基金Science&Technology Commission of Shanghai MunicipalityChina (No.20DZ2254900)+3 种基金Municipal Public Welfare Research Project from JiaxingZhejiang ProvinceChina (No.2022AY10001)Open Project Program of Jiaxing Key Laboratory of Virus-Related Infectious Diseases。
文摘Gambogic acid(GA) is a natural substance with a good antitumor effect, but it is too lipophilic to be metabolized and excreted, thus accumulating in the body. Gemcitabine(GEM), one of the first-line antitumor drugs, has high hydrophilicity, which greatly shortens its half-life in vivo. We previously reported a compound named N-gamboyl gemcitabine(GAG), derived from the condensation of GEM and GA, whose hydrophilicity is better than GA and stability is better than GEM. Here, the antitumor performance of GAG was investigated for the first time by using several common tumor cell lines as tumor models. The results of in vitro study showed that GAG significantly inhibited the proliferation and migration of the tumor cells. The IC50 values of GAG for the tumor cells were lower than those of GEM and GA. The present study suggests that GAG has a promising potential to be developed into a broad-spectrum antitumor drug.
文摘具有混合记忆的自步对比学习(Self-paced Contrastive Learning,SpCL)通过集群聚类生成不同级别的伪标签来训练网络,取得了较好的识别效果,然而该方法从源域和目标域中捕获的行人数据之间存在典型的分布差异,使得训练出的网络不能准确区别目标域和源域数据域特征。针对此问题,提出了双分支动态辅助对比学习(Dynamic Auxiliary Contrastive Learning,DACL)框架。该方法首先通过动态减小源域和目标域之间的局部最大平均差异(Local Maximum Mean Discrepancy,LMMD),以有效地学习目标域的域不变特征;其次,引入广义均值(Generalized Mean,GeM)池化策略,在特征提取后再进行特征聚合,使提出的网络能够自适应地聚合图像的重要特征;最后,在3个经典行人重识别数据集上进行了仿真实验,提出的DACL与性能次之的无监督域自适应行人重识别方法相比,mAP和rank-1在Market1501数据集上分别增加了6.0个百分点和2.2个百分点,在MSMT17数据集上分别增加了2.8个百分点和3.6个百分点,在Duke数据集上分别增加了1.7个百分点和2.1个百分点。
