title: Paclitaxel-resistant HeLa cells have up-regulated levels of reactive oxygen species and increased expression of taxol resistance gene 1.
abstract: This study is to establish a paclitaxel (PTX)-resistant human cervical carcinoma HeLa cell line (HeLa/PTX) and to investigate its redox characteristics and the expression of taxol resistance gene 1 (Txr1). HeLa cells were treated with PTX and effects of PTX on cell proliferation were detected through cell counting and the MTT assay. Levels of cellular reactive oxygen species (ROS), reduced glutathione (GSH), and oxidized glutathione (GSSG) as well as the ratio of GSH to GSSG were measured by the 2,7-difluorescein diacetate (DCFH-DA) method and the 5,5'dithiobis(2-nitrobenzoic acid) (DTNB) method. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined by the nitrite formation method, the molybdate colorimetric method, and the DTNB colorimetric method, respectively. The level of Txr1 mRNA was determined by real-time PCR. Compared with the regular HeLa cells, HeLa/PTX cells were larger in size and had more cytoplasmic granules. The population doubling time for HeLa/PTX cells was 1.32 times of that of HeLa cells (P<0.01). HeLa/PTX cells showed stronger resistance to PTX than HeLa cells with a resistance index of 122.69. HeLa/PTX cells had higher levels of ROS (P<0.01) and Txr1 mRNA (P<0.01), lower level of GSH (P < 0.05), and lower activities of SOD (P<0.01) and GPx (P < 0.05) than HeLa cells. HeLa/PTX cells, with higher levels of ROS and Txr1 mRNA expression, are more resistant to PTX than HeLa cells.
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, Shandong, PR China.
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Bi
authors.affiliation: Department of Obstetrics and Gynecology, Jinan Central Hospital, Shandong University, Jinan, Shandong, PR China.
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, Shandong, PR China.
authors.forename: Gaoying
authors.initials: G
authors.lastname: Sun
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, Shandong, PR China.
authors.forename: Xiaojin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynecology, Jinan Central Hospital, Shandong University, Jinan, Shandong, PR China.
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Obstetrics and Gynecology, Jinan Central Hospital, Shandong University, Jinan, Shandong, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Gynecology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, PR China.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Wang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D017239:Paclitaxel / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics*; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C513606:PRR13 protein, human; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D012097:Repressor Proteins; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione; D017239:Paclitaxel