title: Standard and quantitative analysis of cyclin E threshold by cyclin E/DNA multiparameter flow cytometry.
abstract: The threshold of cyclin E expression at G1/S boundary is a characteristic feature of cell cycle progressing. In this study, we tried to develop a quantitative approach to analyze cyclin E threshold by multiparameter flow cytometry. The expression of cyclin E in exponentially growing MOLT-4 cells was detected under different photomultiplier tube (PMT) voltages by cyclin E/DNA multiparameter flow cytometry. Additionally, cyclin E was detected in cells which were treated with caffeine and cycloheximide (CHX) under the same PMT voltage. Moreover, the expression of cyclin E in MOLT-4 cells was compared with that in JURKAT cells. Cyclin E threshold was quantified by formula B2/AxC (A, B, C indicates the minimum, threshold, and maximum of cyclin E fluorescence intensity, respectively). Results showed that in MOLT-4 cells, cyclin E threshold calculated by formula B2/AxC was invariable under different PMT settings. It was decreased in cells treated with caffeine and remained changeless in cells treated with cycloheximide. Cyclin E threshold in JURKAT cells was much lower than that in MOLT-4 cells. It was suggested that Formula B2/AxC we firstly set up could be used to analyze cyclin E expression threshold quantitatively.
authors.affiliation: The Cancer Research Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Daxing
authors.initials: D
authors.lastname: Xie
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Feng
authors.forename: Jianhong
authors.initials: J
authors.lastname: Wu
authors.forename: Shuangyou
authors.initials: S
authors.lastname: Liu
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Li
authors.forename: Deding
authors.initials: D
authors.lastname: Tao
authors.forename: Jianping
authors.initials: J
authors.lastname: Gong
mesh_terms: D002110:Caffeine / Q000494:pharmacology; D002453:Cell Cycle / Q000502:physiology*; D045744:Cell Line, Tumor; D019927:Cyclin E / Q000032:analysis*; D003513:Cycloheximide / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000032:analysis*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D019169:Jurkat Cells; D007945:Leukemia, Lymphoid / Q000473:pathology
chemical_list: D019927:Cyclin E; D004273:DNA, Neoplasm; D002110:Caffeine; D003513:Cycloheximide