[Expressions of cyclins A, B1, D3, and E in asynchronous and synchronous MOLT-4 cells of G1 phase].
OBJECTIVE
We have testified expression imbalance of Cyclins A, B1, D3, and E in MOLT-4 cells, which were synchronized by "double thymidine blocks", with flow cytometry (FCM). However, comparisons of Cyclins expressions between synchronized cells and asynchronized cells haven't been performed at that time because of technique limitations. This study was to compare expressions of Cyclins A, B1, D3, and E in G(1) phase of asynchronized and synchronized cells by newly established "postsorting Western blot", and to conform the unreasonableness of using double thymidine blocks to synchronize cells to analyze normal cell cycles.


METHODS
MOLT-4 cells were synchronized at G(1) phase by double thymidine blocks, asynchronous cells of G(1) phase were sorted by FCM. Western blot and double parameters analysis of DNA/Cyclins were performed to detect Cyclins A, B1, D3, and E expressions in asynchronous and synchronous MOLT-4 cells of G(1) phase.


RESULTS
There were almost no expressions of Cyclins A, B1 in asynchronous MOLT-4 cells of G(1) phase, and obvious expressions in synchronized cells of G(1) phase. Expressions of Cyclins D3, E in synchronous MOLT-4 cells of G(1) phase were higher than those in asynchronous cells of G(1) phase. The FCM results were accordant with Western blot results.


CONCLUSIONS
The expressions of Cyclins in synchronized cells obtained through "double thymidine blocks" can't represent their expressions in normal cells. Thus, synchronous cells produced by "double thymidine blocks" are not ideal experimental models for analyzing normal cell cycles.
Yu
Chun-Zhao
CZ
Department of General Surgery/ Cancer Research Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei, 430030, P. R. China.
Feng
Yong-Dong
YD
Tao
De-Ding
DD
Yu
Yuan
Y
Wu
Jian-Hong
JH
Gong
Jian-Ping
JP
D002453:Cell Cycle; D045744:Cell Line, Tumor; D019925:Cyclin A / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D056743:Cyclin D3; D019927:Cyclin E / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism*; D005434:Flow Cytometry; D016193:G1 Phase / Q000187:drug effects; D006801:Humans; D015458:Leukemia, T-Cell / Q000378:metabolism* / Q000473:pathology; D013936:Thymidine / Q000494:pharmacology
C534699:CCNB1 protein, human; C534696:CCND3 protein, human; D019925:Cyclin A; D019926:Cyclin B; D056744:Cyclin B1; D056743:Cyclin D3; D019927:Cyclin E; D016213:Cyclins; D013936:Thymidine