Levonorgestrel inhibits proliferation and induces apoptosis in uterine leiomyoma cells.
BACKGROUND
The levonorgestrel intrauterine system (LNG-IUS) is a widely recognized intrauterine anti-fertility system, which can alleviate symptoms of uterine leiomyoma. This study aims to evaluate leimyoma cell growth inhibition induced by high concentrations of LNG.


METHODS
After treatment with LNG, the growth rate of the cultured primary uterine leiomyoma cells was studied with methyl thiazolyl tetrazolium (MTT) assay. Cell apoptosis rate was determined by morphological changes and flow cytometry. Reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were performed to measure the differential mRNA and protein expression levels.


RESULTS
The proliferation rate of uterine leiomyoma cells was suppressed after treatment with LNG at a minimum concentration of 10 mcg/mL. The inhibitive effect was positively correlated with the LNG concentration and with the incubation time. Flow cytometry showed that the apoptosis rate was increased with the LNG concentration. The mRNA levels of IGF-1, Bcl-2 and survivin were down-regulated significantly after treatment with 10 mcg/mL LNG. Western blot analysis confirmed that the expression of Bcl-2 and survivin was decreased significantly, and the p38 phosphorylation level was increased and caspase 3 was activated remarkably 72 h after treatment with 10 and 20 mcg/mL LNG.


CONCLUSIONS
This study demonstrated that LNG may suppress the proliferation and induce apoptosis of the uterine leiomyoma cells.
Xu
Qing
Q
Department of Obstetrics and Gynecology, Nanjing Maternity and Child Health Hospital of Nanjing Medical University, Nanjing, Jiangsu, China. xu88njmu@163.com
Qiu
Lili
L
Zhu
Liqun
L
Luo
Li
L
Xu
Changfen
C
D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D005260:Female; D005562:Formazans / Q000737:chemistry; D006651:Histocytochemistry; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000235:genetics; D007889:Leiomyoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D016912:Levonorgestrel / Q000008:administration & dosage*; D046529:Microscopy, Electron, Transmission; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis / Q000235:genetics; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077022:Survivin; D013778:Tetrazolium Salts / Q000737:chemistry; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology
C107489:BIRC5 protein, human; D003271:Contraceptive Agents, Female; D005562:Formazans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012334:RNA, Neoplasm; D000077022:Survivin; D013778:Tetrazolium Salts; C079782:MTT formazan; D016912:Levonorgestrel; D007334:Insulin-Like Growth Factor I