Lim Soo-Jeong, Choi Hyeon Gyeom, Jeon Chae Kyung, Kim So Hee
Department of Bioscience and Biotechnology, Sejong University, Seoul, Republic of Korea.
College of Natural Science, Hannam University, Daejeon, Republic of Korea.
Oncol Rep. 2015 Apr;33(4):2023-30. doi: 10.3892/or.2015.3775. Epub 2015 Feb 2.
The MCF10AT cell series of human breast epithelial cancer cells includes normal MCF10A (10A), premalignant MCF10AT (10AT) and MCF10ATG3B (10ATG3B), and fully malignant MCF10CA1a (10CA1a) cells. The series is a unique model system showing progressive tumorigenic potential with the same origin. The effects of paclitaxel, a microtubule inhibitor, were evaluated in this cell system. Paclitaxel inhibited cell proliferation in a time-dependent (24, 48 and 72 h) and concentration-dependent (0-10 nM) manners with less sensitivity in 10CA1a cells. Treatment with paclitaxel (10 nM) for 24 h induced apoptosis in 10A, 10AT, 10ATG3B and 10CA1a cells, with 23.6, 26.1, 25.2 and 8.96%, respectively, in the sub-G1 phase. Treatment with paclitaxel (0-10 nM) for 24 h, resulted in the appearance of DNA fragmentation (a hallmark of apoptosis) with less sensitivity in the 10CA1a tumor cells. Paclitaxel increased p53 protein expression in 10A, 10AT, 10ATG3B and 10CA1a cells, by 87, 102, 812 and 84%, respectively. The p21Waf1/Cip1 protein expression increased by 2.57-, 1.53- and 2.48-fold in 10A, 10AT and 10ATG3B cells, respectively, with negligible detection in the 10CA1a cells. Activation of the Akt signaling pathway was observed in the MCF10AT cell lineage and the protein expression of phospho-Akt (Ser473 and Thr308). The downstream targets of this pathway, phospho-p70S6K and phospho-S6RP, were also inhibited by paclitaxel in 10A, 10AT and 10ATG3B cells, but minimally inhibited in 10CA1a cells, suggestive of chemoresistance in 10CA1a cells. The effects of paclitaxel on the multidrug resistance 1 (MDR1), MRP1 and breast cancer resistance protein (BCRP) gene expression were not significant in the MCF10AT cell lineage. These results collectively indicated that paclitaxel inhibited cell proliferation and induced apoptosis in the MCF10AT cell lineage, with chemoresistance in 10CA1a tumor cells. The decreased responsiveness to paclitaxel observed in 10CA1a tumor cells was likely due, in part, to activation of the Akt signaling pathway and a high expression of wild-type p53 with lack of p21Waf1/Cip1.
人乳腺上皮癌细胞的MCF10AT细胞系包括正常的MCF10A（10A）、癌前的MCF10AT（10AT）和MCF10ATG3B（10ATG3B），以及完全恶性的MCF10CA1a（10CA1a）细胞。该细胞系是一个独特的模型系统，显示出具有相同起源的渐进性致瘤潜力。在这个细胞系统中评估了微管抑制剂紫杉醇的作用。紫杉醇以时间依赖性（24、48和72小时）和浓度依赖性（0 - 10 nM）方式抑制细胞增殖，10CA1a细胞的敏感性较低。用10 nM紫杉醇处理24小时可诱导10A、10AT、10ATG3B和10CA1a细胞凋亡，分别有23.6%、26.1%、25.2%和8.96%的细胞处于亚G1期。用0 - 10 nM紫杉醇处理24小时，导致DNA片段化（凋亡的标志）出现，10CA1a肿瘤细胞的敏感性较低。紫杉醇使10A、10AT、10ATG3B和10CA1a细胞中的p53蛋白表达分别增加87%、102%、812%和84%。p21Waf1/Cip1蛋白表达在10A、10AT和10ATG3B细胞中分别增加2.57倍、1.53倍和2.48倍，在10CA1a细胞中检测到的量可忽略不计。在MCF10AT细胞谱系中观察到Akt信号通路的激活以及磷酸化Akt（Ser473和Thr308）的蛋白表达。该通路的下游靶点磷酸化p70S6K和磷酸化S6RP在10A、10AT和10ATG3B细胞中也被紫杉醇抑制，但在10CA1a细胞中抑制作用最小，提示10CA1a细胞具有化疗耐药性。紫杉醇对多药耐药1（MDR1）、多药耐药相关蛋白1（MRP1）和乳腺癌耐药蛋白（BCRP）基因表达的影响在MCF10AT细胞谱系中不显著。这些结果共同表明，紫杉醇抑制MCF10AT细胞谱系中的细胞增殖并诱导凋亡，10CA1a肿瘤细胞具有化疗耐药性。在10CA1a肿瘤细胞中观察到的对紫杉醇反应性降低可能部分归因于Akt信号通路的激活以及野生型p53的高表达而缺乏p21Waf1/Cip1。
