Steroid hormones and hormone antagonists regulate the neural marker neurotrimin in uterine leiomyoma.

OBJECTIVE

To characterize the role of steroid hormone and antihormone exposure on neurotrimin (NTM) expression in human leiomyoma and myometrial tissue and cells.

DESIGN

Laboratory study of placebo and ulipristal acetate (UPA)-treated patient tissue. In vitro assessment of immortalized myometrial and leiomyoma cell lines after hormone and antihormone exposure.

SETTING

Academic research center.

PATIENT(S): Not applicable.

INTERVENTIONS(S): Exposure of leiomyoma cell lines to 17β-E2, medroxyprogesterone acetate (MPA), UPA, and fulvestrant.

MAIN OUTCOME MEASURE(S): Messenger RNA expression quantified with the use of RNASeq analysis and quantitative real-time polymerase chain reaction (qRT-PCR). Protein levels quantified by means of Western blot analysis. Immunohistochemistry (IHC) on placebo- and UPA-treated patient uterine tissue specimens.

RESULT(S): Expression of NTM in human uterine leiomyoma specimens according to RNASeq was increased compared with myometrium (5.22 ± 0.57-fold), which was confirmed with the use of qRT-PCR (1.95 ± 0.05). Furthermore, NTM protein was elevated in leiomyoma tissue compared with matched myometrium (2.799 ± 0.575). IHC revealed increased staining intensity in leiomyoma surgical specimens compared with matched myometrium of placebo patients. Western blot analysis in immortalized leiomyoma cell lines demonstrated an up-regulation of NTM protein expression (2.4 ± 0.04). Treatment of leiomyoma cell lines with 17β-E2 yielded a 1.98 ± 0.11-fold increase in NTM protein expression; however, treatment with fulvestrant showed no significant change compared with control. Leiomyoma cell lines demonstrated a 1.91 ± 0.97-fold increase in NTM protein expression after progesterone treatment. RNASeq analysis demonstrated a reduced expression in patient leiomyoma after UPA treatment (0.75 ± 0.14). Treatment of leiomyoma cells with UPA demonstrated a reduced total NTM protein amount (0.54 ± 0.31) in patients, which was confirmed with the use of IHC (UPA10 147.2 ± 9.40, UPA20 182.8 ± 8.98). In vitro studies with UPA treatment revealed a concentration-dependent effect that supported these findings.

CONCLUSION(S): NTM, a neural cell adhesion molecule, is increased in leiomyoma compared with myometrium in patient tissue and in vitro models after estrogen and progesterone treatment. Down-regulation of expression occurs after UPA treatment, but not after fulvestrant exposure.

CLINICAL TRIAL REGISTRATION NUMBER: NCT00290251.