Molecular genetics and racial disparities of uterine leiomyomas

Efficacy and tolerability of CDB-2914 treatment for symptomatic uterine fibroids: a randomized, double-blind, placebo-controlled, phase IIb study

OBJECTIVE

To evaluate the efficacy and tolerability of the P receptor modulator CDB-2914 (Ulipristal, CDB).

DESIGN

Randomized, placebo-controlled double-blind clinical trial.

SETTING

Clinical research center.

PATIENT(S)

Premenopausal women with symptomatic uterine fibroids.

INTERVENTION(S)

Once-daily oral CDB (10 or 20 mg) or placebo (PLC) for 12 weeks (treatment 1). A second 3-month treatment with CDB (treatment 2) was offered. A computer-generated blocked randomization was used.

MAIN OUTCOME MEASURE(S)

Magnetic resonance imaging (MRI)-determined total fibroid volume (TFV) change was the primary outcome; amenorrhea and quality of life (QOL) were secondary end points.

RESULT(S)

Treatment 1 TFV increased 7% in the PLC group, but decreased 17% and 24% in the CDB10 and CDB20 groups. The TFV decreased further in treatment 2 (-11%). Amenorrhea occurred in 20/26 women taking CDB and none on PLC. Ovulation resumed after CDB. Hemoglobin improved only with CDB (11.9 ± 1.5 to 12.9 ± 1.0 g/dL) as did the Fibroid QOL Questionnaire symptom severity, energy/mood, and concern subscores, and overall QOL scores. The CDB was well tolerated, with no serious adverse events. Adverse events were unchanged during treatments.

CONCLUSION(S)

Administration of CDB-2914 for 3-6 months controls bleeding, reduces fibroid size, and improves QOL.

Vitamin D inhibits proliferation of human uterine leiomyoma cells via catechol-O-methyltransferase

OBJECTIVE

To evaluate the effects and mechanisms of action of vitamin D on human uterine leiomyoma (HuLM) cell proliferation in vitro.

DESIGN

Laboratory study.

SETTING

University hospitals.

PATIENTS(S)

Not applicable.

INTERVENTIONS(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

HuLM cells were treated with 1,25-dihydroxyvitamin D3 (vitamin D), and cell proliferation was assayed by the methylthiazolyl tetrazolium technique. proliferating cell nuclear antigen (PCNA), BCL-2, BCL-w, cyclin-dependent kinase (CDK) 1, and catechol-O-methyltransferase (COMT) protein levels were analyzed by Western blotting. COMT mRNA and enzyme activity were assayed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and high-performance liquid chromatography analysis, respectively. The role of COMT was evaluated in stable HuLM cells by silencing COMT expression.

RESULT(S)

Vitamin D inhibited the growth of HuLM cells by 47±0.03% at 1 μM and by 38±0.02% at 0.1 μM compared with control cells at 120 hours of treatment. Vitamin D inhibited extracellular signal-regulated kinase activation and down-regulated the expression of BCL-2, BCL-w, CDK1, and PCNA. Western blot, RT-PCR, and enzyme assay of COMT demonstrated inhibitory effects of vitamin D on COMT expression and enzyme activity. Silencing endogenous COMT expression abolished vitamin D-mediated inhibition of HuLM cell proliferation.

CONCLUSION(S)

Vitamin D inhibits growth of HuLM cells through the down-regulation of PCNA, CDK1, and BCL-2 and suppresses COMT expression and activity in HuLM cells. Thus, hypovitaminosis D appears to be a risk factor for uterine fibroids.

Racial and ethnic disparities in benign gynecologic conditions and associated surgeries

Common gynecologic conditions and surgeries may vary significantly by race or ethnicity. Uterine fibroid tumors are more prevalent in black women, and black women may have larger, more numerous fibroid tumors that cause worse symptoms and greater myomectomy complications. Some, but not all, studies have found a higher prevalence of endometriosis among Asian women. Race and ethnicity are also associated with hysterectomy rate, route, and complications. Overall, the current literature has significant deficits in the identification of racial and ethnic disparities in the incidence of fibroid tumors, endometriosis, and hysterectomy. Further research is needed to better define racial and ethnic differences in these conditions and to examine the complex mechanisms that may result in associated health disparities.

Green tea extract inhibits proliferation of uterine leiomyoma cells in vitro and in nude mice

OBJECTIVE

The purpose of this study was to investigate the effect of epigallocatechin gallate (EGCG) on rat leiomyoma (ELT3) cells in vitro and in a nude mice model.

STUDY DESIGN

ELT3 cells were treated with various concentrations of EGCG. Cell proliferation, proliferation cell nuclear antigen (PCNA), and cyclin-dependent kinase 4 (Cdk4) protein levels were evaluated. ELT3 cells were inoculated subcutaneously in female athymic nude mice. Animals were fed 1.25 mg EGCG (in drinking water)/mouse/day. Tumors were collected and evaluated at 4 and 8 weeks after the treatment.

RESULTS

Inhibitory effect of EGCG (200 micromol/L) on ELT3 cells was observed after 24 hours of treatment (P < .05). At > or = 50 micromol/L, EGCG significantly decreased PCNA and Cdk4 protein levels (P < .05). In vivo, EGCG treatment dramatically reduced the volume and weight of tumors at 4 and 8 weeks after the treatment (P < .05). The PCNA and Cdk4 protein levels were significantly reduced in the EGCG-treated group (P < .05).

CONCLUSION

EGCG effectively inhibits proliferation and induces apoptosis in rat ELT3 uterine leiomyoma cells in vitro and in vivo.

Antiproliferative and proapoptotic effects of epigallocatechin gallate on human leiomyoma cells

OBJECTIVE

To investigate the effects of epigallocatechin gallate (EGCG), an extract of green tea on cultured human leiomyoma cells (HuLM).

DESIGN

Laboratory study.

SETTING

University hospitals.

PATIENT(S)

Not applicable.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

The HuLM cells were treated with various EGCG concentrations. Cell proliferation was assayed using Hoechst 33258 dye, and apoptosis by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Total RNA was isolated, and gene expression profiling was performed on 84 key genes related to 18 different signal transduction pathways. The protein levels of PCNA, CDK4, BCL2, and BAX were examined by Western blot analysis.

RESULT(S)

The HuLM cells treated with EGCG showed a dose-dependent and time-dependent inhibition of cell proliferation. The TUNEL staining indicated a significant increase in apoptosis in HuLM cells treated with 100 μM of EGCG compared with untreated control. Gene expression profiling indicated that EGCG treatment up-regulated representative genes from the transforming growth factor β (TGF-β) and stress pathways, while inhibiting the survival pathway and NFκB-dependent inflammatory pathway. Western blot analysis confirmed that EGCG at ≥50 μM significantly decreased the expression of PCNA, CDK4, and BCL2 as well as increased the expression of the proapoptotic BAX in a dose-dependent manner.

CONCLUSION(S)

Epigallocatechin gallate inhibits the proliferation of HuLM cells and induces apoptosis. These results suggest that EGCG may be a potential anti-uterine fibroid agent acting through multiple signal transduction pathways.

High aromatase expression in uterine leiomyoma tissues of African-American women

CONTEXT

Symptomatic uterine leiomyoma is associated with irregular uterine bleeding, anemia, and recurrent pregnancy loss. African-American women develop uterine leiomyomas at an earlier age and with higher frequency compared with Caucasian-American women or other races; however, the underlying mechanism for this discrepancy is unknown.

OBJECTIVE

Our objective was to determine whether gene targets of emerging leiomyoma therapeutics such as aromatase inhibitors and antiprogestins, which reduce tumor size and symptoms, are differentially expressed in tissues of African-American (n = 31), Caucasian-American (n = 34), and Japanese women (n = 36).

RESULTS

We found strikingly higher aromatase mRNA levels in leiomyoma compared with adjacent myometrium in African-American (83 fold), Caucasian-American (38 fold), and Japanese women (33 fold). Among the four major promoters that regulate aromatase expression in leiomyoma, the proximal promoter II accounted for higher aromatase mRNA levels in tissues from African-American women. Estrogen receptor subtype alpha mRNA levels were significantly, and 1.8- to 2.6-fold, higher in leiomyoma compared with adjacent myometrium in all groups, whereas leiomyoma estrogen receptor subtype beta mRNA levels were significantly elevated only in Japanese women. Leiomyoma progesterone receptor mRNA levels were significantly higher in Japanese women compared with African-American or Caucasian-American women.

CONCLUSIONS

Leiomyoma tissues from African-American women contained the highest level of aromatase expression, which may result in elevated tissue concentrations of estrogen, and account for the higher prevalence and earlier incidence. Analysis of leiomyoma tissue for biomarkers may predict the response to hormonal treatments such as aromatase inhibitors.