Tadayuki Kasai

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.

Successful treatment of a symptomatic uterine leiomyoma in a perimenopausal woman with a nonsteroidal aromatase inhibitor.

OBJECTIVE To assess the management of symptomatic leiomyomas using a nonsteroidal aromatase inhibitor in perimenopausal women. DESIGN Case report. SETTING Academic clinical practice. PATIENT(S) A 53-year-old woman suffering from recurrent urinary retention secondary to a uterine leiomyoma. INTERVENTION(S) Fadrozole, orally, 2 mg daily for 8 weeks and then 1 mg daily for 4 weeks. MAIN OUTCOME MEASURE(S) Measurements of leiomyoma volume, and levels of serum E(2), LH, and FSH. RESULT(S) Urinary retention resolved after 2 weeks of treatment and did not recur. Leiomyoma volume estimated by ultrasonography revealed a 71% reduction after 8 weeks of treatment. CONCLUSION(S) Fadrozole was useful for the management of a symptomatic leiomyoma without transient deterioration of symptoms. Clinical trials are warranted.

Aromatase Expression in Stromal Cells of Endometrioid Endometrial Cancer Correlates with Poor Survival

Purpose and Experimental Design: To assess the prognostic significance of intratumoral aromatase in endometrioid endometrial cancer, sections from 55 patients with endometrial cancer were evaluated for expression of aromatase using immunohistochemistry, and the correlation between aromatase expression and clinicopathologic parameters were analyzed. Results: Immunohistochemical staining for aromatase was positive for 32 (58%), 20 (36%), and 19 (34%) patients in cancer epithelial cells, stromal cells, and myometrial cells around the flank invasion, respectively. In situ hybridization also detected aromatase mRNA in all three types of cells. RT-PCR analysis revealed that aromatase mRNA was 2.5 ± 1.0 amol/μg total RNA (mean ± SE; n = 7) in tumor tissue. Western blot analysis detected the expected aromatase protein size of 58 kDa in cancer tissues more abundantly than in cancer-free endometrium (n = 3). The immunoreactivity in stromal cells correlated positively with advanced surgical stage and poor survival. Survival analysis revealed that the immunoreactivity of stromal cells was a significant prognostic factor, independent of histologic grade, muscular invasion, and lymph node metastasis, but dependent on surgical stage. By contrast, the immunoreactivity of aromatase both in cancer epithelial cells and myometrial cells did not correlate with prognosis. Conclusions: To the best of our knowledge, this is the first evidence associating intratumoral aromatase expression in stromal cells and poor survival in endometrioid endometrial cancer. This positive linkage indicates that local expression of aromatase plays a role in tumor progression through the formation of in situ estrogens. In situ expression of aromatase may offer a potential target for management of endometrial cancers.

Decreased Expression of Early Growth Response-1 and Its Role in Uterine Leiomyoma Growth

Expression of early growth response (Egr)-1, a transcriptional factor implicated in growth regulation, is suppressed in several malignant tumors. The present study investigated the expression of Egr-1 and related genes in uterine leiomyoma and normal myometrium to determine possible contributions of Egr-1 to neoplastic growth in leiomyoma cells. Levels of Egr-1 transcripts were decreased in all leiomyomas (n = 20) to approximately 10% of levels in corresponding myometrium, where basal expression was high. Preoperative leuprorelin acetate therapy increased levels of Egr-1 mRNA in normal myometrium only. Northern blot analysis using additional sample sets (n = 5) revealed the full-length Egr-1 transcript. Western blot analysis (n = 5) confirmed decreased expression of Egr-1 protein. Southern blot analysis of the Egr-1 gene and microsatellite analysis of the chromosomal location at 5q31 (D5S414, D5S500, and D5S476) revealed neither DNA recombination nor loss of heterozygosity in leiomyomas. Moreover, Egr-1 retained identical responsiveness to phorbol 12-myristate 13-acetate in primary cultures derived from both leiomyoma and normal tissues. Electrophoretic mobility shift analysis revealed that phorbol 12-myristate 13-acetate-induced Egr-1 in leiomyoma cells retained DNA binding ability. Egr-1 thus appears functionally intact in leiomyoma cells. Finally, consistent with the role of Egr-1 in growth inhibition, transfection of Egr-1 expression vector into a myometrial cell line (KW) that expresses low levels of Egr-1 and displays rapid growth inhibited thymidine uptake in these cells. Egr-1 may display tumor-suppressing activity and offers a potential target for leiomyoma management.

Insulin-Like Growth Factor I Enhances the Expression of Aromatase P450 by Inhibiting Autophagy

Aromatase, a key enzyme of estrogen biosynthesis, is transcriptionally regulated by many growth factors. IGF-I enhances aromatase activity in a variety of cells, but the mechanism of action has not been determined. We herein report our finding of a novel mechanism of action for IGF-I. IGF-I enhanced the dexamethasone (DEX)-induced aromatase activity by 30% in serum-starved THP-1 cells. The increase was associated with a corresponding increase in the level of aromatase protein but not with any change in the mRNA level. Metabolic labeling experiments revealed that IGF-I inhibited the degradation of aromatase. We identified pepstatin A as the most effective inhibitor of aromatase degradation by in vitro assay. Using a nontoxic concentration of pepstatin A, we examined IGF-Is action on aromatase distribution in microsomes and lysosomes. In the presence of pepstatin A, DEX caused an increase in the amount of aromatase in both microsomes and lysosomes, and IGF-I attenuated the DEX-induced accumulation of aromatase in lysosomes and, conversely, enhanced its accumulation in the microsomes. The addition of serum abolished the IGF-I-induced changes. The transport from microsome to lysosome was fluorescently traced in cells using a recombinant aromatase. IGF-I selectively reduced the aromatase signal in the lysosomes. Finally, we observed that IGF-I enhanced the aromatase activity by 50% as early as 1 h after treatment; furthermore, rapamycin, an enhancer of autophagy, completely negated the effect of IGF-I on the enzyme. These results indicate that IGF-I enhances aromatase by the inhibition of autophagy.

Early growth response gene-1 plays a pivotal role in down-regulation of a cohort of genes in uterine leiomyoma

Microarray studies have identified many genes that are down-regulated in uterine leiomyoma compared with myometrium, including early growth response gene-1 (EGR1). However, the mechanisms underlying coordinated down-regulation of this gene cohort remain unknown. To address the transcriptional role of EGR1 in leiomyoma, EGR1 binding to promoter sequences on target genes was assessed by chromatin immunoprecipitation (ChIP) assay in leiomyoma tissues and myometrium-derived KW cells. Computer analysis demonstrated that 50 out of 135 genes listed as down-regulated in array reports possessed potential binding sites for EGR1 within 1 kb promoter sequence. ChIP assay was performed for a random selection of 13 genes possessing potential binding sites for EGR1 (Group A), 3 genes known as EGR1 targets in other tissues (Group B), and 4 control genes. Decreased EGR1 bindings were significant for 11 out of 16 genes (Group A+B) in leiomyoma tissues compared with myometrium, and mRNA levels in tissue samples were actually decreased for 7 out of the 11 genes. ChIP analyses performed on KW cells showed induction of EGR1 binding to the promoter region of all genes except one Group A+B gene, but for none of the control genes. These results indicate that EGR1 is a key player in coordinated down-regulation of genes in leiomyoma. Application of ChIP-quantitative PCR assay with the aid of computer-assisted analysis of genome databases appears useful for the comprehensive interpretation of array data.

Ultrasound‐guided culdotomy for vaginal ovarian cystectomy using a renal balloon dilator catheter

To evaluate the feasibility and utility of performing ultrasound‐guided culdotomy using a renal balloon dilator catheter for transvaginal ovarian cystectomies.

Use of laparoscopic support to avoid laparotomy in vaginal ovarian cystectomy.

The objective of our study was to evaluate the use of a procedure for vaginal ovarian cystectomy that is supported by the option to convert to laparoscopy. The ovarian cystectomy was initially approached transvaginally, and then if impossible, completed laparoscopically. We applied this operation system to 38 patients with benign ovarian cysts. Preoperative characteristics of patients, outcomes of colpotomy and vaginal ovarian cystectomy, conversion rate from a vaginal approach to a laparoscopic procedure or a laparotomy, completion rate, operating time, blood loss, complications, and postoperative outcomes were examined. Colpotomy was successfully performed in 37 (97%) of 38 cases and vaginal ovarian cystectomy was accomplished in 35 (92%) cases. Three (8%) cases, including 1 case of failed posterior colpotomy and 2 cases of intrapelvic adhesions, were converted from a vaginal approach to a laparoscopic procedure. In all (100%) cases, cystectomy was successful without laparotomy. Support by laparoscopy preserves the minimal invasiveness of vaginal ovarian cystectomy in cases that would normally require conversion to laparotomy. Thus, this operation system is an alternative procedure to an exclusively vaginal ovarian cystectomy.