[Growth of breast cancer cells is inhibited in vitro by cyclin E-siRNA].
OBJECTIVE
To investigate the changes of biological characteristics of breast cancer cell line by cyclin E expression.


METHODS
Human breast cancer cell line MCF-7 was transfected with cyclin E siRNA vector pEGFP/CCNE2. siRNA-induced silencing of cyclin E was determined by RT-PCR at RNA level and Western blot at protein level. The proliferation of MCF-7 cells and their sensitivity to chemotherapy was measured by CCK-8 assay. The cells were examined by FCM. The cell line was injected into nude mice and the tumor size was measured.


RESULTS
The expression of cyclin E was inhibited in the MCF-7 cells. The relative expression level of cyclin E mRNA was 0.23 +/- 0.05, and that of cyclin E protein was 0.24 +/- 0.05. The cell growth was inhibited by 68.56% +/- 0.08%, and their sensitivity to chemotherapy was increased. Most cells were blocked at G(1) (77.38%), their tumorigenic ability in nude mice was reduced, and the size of tumor formed in mice of the experimental group was decreased than that of controls.


CONCLUSIONS
Inhibition of cyclin E expression in breast cancer cells can block their cell cycle at G(1) phase, reduce their cell growth, differentiation and proliferation, and increase their sensitivity to chemotherapy.
He
Wen-shan
WS
Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Huang
Tao
T
Ren
Jing-hua
JH
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019927:Cyclin E / Q000235:genetics / Q000378:metabolism*; D004317:Doxorubicin / Q000494:pharmacology; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D017239:Paclitaxel / Q000494:pharmacology; D010957:Plasmids; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D014162:Transfection; D047368:Tumor Burden
D000903:Antibiotics, Antineoplastic; D000964:Antimetabolites, Antineoplastic; D000972:Antineoplastic Agents, Phytogenic; D019927:Cyclin E; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D004317:Doxorubicin; D017239:Paclitaxel; D005472:Fluorouracil