A selective serotonin 5-HT1B receptor inhibition suppresses cells proliferation and induces apoptosis in human uterine leiomyoma cells.

OBJECTIVE

Uterine leiomyomas (fibroids or myomas) are the most common pelvic tumor in women with about 70% lifetime incidence rate. Currently, the only definitive treatment is surgery, causing undesirable side effects and negative impact on women's quality of life, reproductive ability, and a substantial impact on healthcare costs. Therefore, curative medical treatments are needed to be developed. In this study, we investigated the impact of serotonin receptor 5-HT1B on cell proliferation and survival in human uterine leiomyoma cells (huLM).

STUDY

DESIGN

The impact of 5-HT1B receptor on cell proliferation, survival and apoptosis was investigated using a selective 5-HTR1B antagonist SB216641 in huLM cells, utilizing MTS, colony formation assay and Annexin V staining, respectively. Mechanisms of inhibition of cell proliferation, survival and induction of apoptosis were investigated by Western blot analysis after treatment with various doses of HT1B antagonist.

RESULTS

5-HT1B receptor inhibition leads to a significant decrease in proliferation and colony formation in huLM cells, reduction of cyclin D1 and alpha-smooth muscle actin (α-SMA) expressions and the activity of Mitogen Activated Protein Kinase (MAPK) ERK and Elongation Factor 2 kinase (EF2K) pathways. 5-HT1B receptor blockage also induces apoptotic cell death by inducing cleavage of caspase-8, -9, and -3 and PARP.

CONCLUSION

Our findings show for the first time that 5-HT1B receptor promotes uterine leiomyoma cell survival and proliferation and its inhibition may be a potential therapeutic approach for human uterine leiomyomas. Thus, 5-HT1B expression and antagonists should be further investigated in leiomyoma tumors.