Hideo Honjo

Endometriosis: the pathophysiology as an estrogen-dependent disease.

Endometriosis, defined as the presence of endometrial glands and stroma outside of the uterine cavity, develops mostly in women of reproductive age and regresses after menopause or ovariectomy, suggesting that the growth is estrogen-dependent. Indeed, the lesions contain estrogen receptors (ER) as well as aromatase, an enzyme that catalyses the conversion of androgens to estrogens, suggesting that local estrogen production may stimulate the growth of lesions. The expression patterns of ER and progesterone receptors in endometriotic lesions are different from those in the eutopic endometrium. Moreover, estrogen metabolism, including the expression pattern of aromatase and the regulation of 17 beta-hydroxysteroid dehydrogenase type 2 (an enzyme responsible for the inactivation of estradiol to estrone), is altered in the eutopic endometrium of women with endometriosis, adenomyosis, and/or leiomyomas compared to that in the eutopic endometrium of women without disease. Immunostaining for P450arom in endometrial biopsy specimens diagnosed these diseases with sensitivity and specificity of 91 and 100%, respectively. This is applicable to the clinical diagnosis of endometriosis. The polymorphisms in the ER-alpha gene, the CYP19 gene encoding aromatase, and several other genes are associated with the risk of endometriosis. Studies of these will lead to better understandings of the etiology and pathophysiology of endometriosis.

IL-15 Expression at Human Endometrium and Decidua

Abstract A large number of natural killer (NK) cells appear in human uterine mucosa during the secretory phase and first trimester pregnancy. We investigated the expression of interleukin (IL)-15, a possible stimulator for these NK cells, in human endometrium and first trimester decidua. Semiquantitative reverse transcriptase-polymerase chain reaction revealed that IL-15 mRNA expression was stronger during the secretory phase and first trimester pregnancy than during the proliferative phase. Immunohistochemistry revealed that immunoreactivity for anti-IL-15 was higher during the secretory phase than it was during the proliferative phase. This was prominent in the perivascular stromal cells around invading spiral arteries during the mid- to late-secretory phase. In first trimester decidua, endothelial cells were also stained as strongly as stromal cells. A membrane-bound IL-15 molecule was detected on the surface of first trimester decidual cells by flow cytometry. Progesterone stimulated the release of soluble IL-15 in the supernatant of cultured decidual cells. These results suggest that IL-15 expression in human uterine mucosa corresponds to the fluctuation of uterine NK cells and that its production is hormonally controlled, especially by progesterone.

Detection of aromatase cytochrome P-450 in endometrial biopsy specimens as a diagnostic test for endometriosis

OBJECTIVE To evaluate the clinical usefulness of examining endometrial biopsy specimens for aromatase cytochrome P-450 as a diagnostic test for endometriosis. DESIGN Retrospective, case-controlled study. SETTING Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Kyoto, Japan. PATIENT(S) One hundred five women of reproductive age with normal menstrual cycles underwent endometrial biopsy laparotomy or laparoscopy, and examination of their tissue revealed endometriosis, adenomyosis, and/or leiomyomas. Patients who had cervical carcinoma in situ but no other gynecologic disease were considered to be disease-free. INTERVENTION(S) Endometrial biopsy specimens were collected. MAIN OUTCOME MEASURE(S) The expression of aromatase cytochrome P-450 was examined by reverse transcription-polymerase chain reaction and immunohistochemical analysis. The distribution and intensity of the immunostaining was assessed using a semiquantitative index designed H-score. RESULT(S) Immunostaining for aromatase cytochrome P-450 was detected in biopsy specimens obtained from patients with endometriosis, adenomyosis, and/or leiomyomas but not in specimens obtained from disease-free patients (H-score <20), with a sensitivity and specificity of 91% and 100%, respectively. CONCLUSION(S) The expression of aromatase cytochrome P-450 in biopsy specimens of eutopic endometrium distinguishes between disease-free women and women with endometriosis, adenomyosis, and/or leiomyomas. This technique can be used at outpatient infertility clinics as an initial screening procedure to rule out the presence of estrogen-dependent disease.

Gonadotropin-releasing hormone agonist and danazol normalize aromatase cytochrome P450 expression in eutopic endometrium from women with endometriosis, adenomyosis, or leiomyomas

OBJECTIVE To investigate whether GnRH agonists or danazol therapy normalizes estrogen metabolism in the eutopic endometrium of women with endometriosis, adenomyosis, or leiomyomas. DESIGN Prospective clinical study. SETTING University hospital. PATIENT(S) Fifty-three women with endometriosis, adenomyosis, or leiomyomas. INTERVENTION(S) Patients received GnRH agonist or danazol. Biopsy samples of the endometrium were obtained before and after endocrine therapy. Nontreated endometrial explants were cultured in the presence of either drug. MAIN OUTCOME MEASURE(S) Reverse transcription polymerase chain reaction-Southern blot and immunohistochemical analyses of the endometrial expression of aromatase cytochrome P450, estrogen receptor, progesterone receptor, and Ki-67. Nontreated endometrial explants were cultured in the presence of either drug. RESULT(S) Messenger RNA and protein of aromatase cytochrome P450 were greatly reduced in the eutopic endometrium of patients treated with GnRH agonist for 2 months or more or with danazol for 1 month or more. Culture of endometrial explants with GnRH agonist (10(-9)-10(-7) M) did not change the amount of aromatase cytochrome P450, whereas danazol (10(-7)-10(-6) M) efficiently reduced aromatase cytochrome P450 expression. CONCLUSION(S) Therapy with GnRH agonist or danazol decreases expression of aromatase cytochrome P450 in diseased eutopic endometrium. Endocrine therapy normalized in part the impaired hormonal expression of the eutopic endometrium. GnRH agonist reduced aromatase cytochrome P450 expression mainly by promoting a hypoestrogenic state, whereas danazol reduced aromatase cytochrome P450 in part by direct action on the eutopic endometrium.

Estrogen as a growth factor to central nervous cells. Estrogen treatment promotes development of acetylcholinesterase-positive basal forebrain neurons transplanted in the anterior eye chamber.

In a previous report, we demonstrated in vivo ameliorating effects of conjugated estrogen in women suffering from senile dementia-Alzheimers type. To investigate the effects of estrogen on the growth of cholinergic neurons, the present study was performed using rat cholinergic tissue implanted into the anterior chamber of the eye. Fetal diagonal band tissue containing cholinergic neurons was grafted into the anterior eye chamber of adult female rats that had either been treated or not with 2 mg estradiol valerate injected every 3 days after oophorectomy. Two and four weeks after transplantation, the axonal and/or dendritic growth of cholinergic neurons in the graft was studied using acetylcholinesterase histochemistry. At both times, acetylcholinesterase positive processes were densely distributed in the grafts of estradiol valerate treated rats, while in rats without estradiol valerate treatment acetylcholinesterase positive reaction was essentially localized only on the cell bodies. These findings were more obvious at 2 weeks after transplantation than at 4 weeks. These results suggest that estrogen acts on cholinergic neurons as a growth factor.

Estrogen productivity of endometrium and endometrial cancer tissue; influence of aromatase on proliferation of endometrial cancer cells.

Aromatase, estrone (E1) sulfatase and E1 sulfotransferase activities were examined in endometrium and endometrial cancer tissue preparations. Aromatase and E1 sulfatase activities in endometrial cancer tissues were found to be significantly higher than in normal endometrial tissues. However, E1 sulfotransferase activity did not differ between benign and malignant tissue. We also examined the effect of testosterone (T) on aromatase activity and tritiated thymidine uptake (DNA synthesis) in various cultured cervical or corpus endometrial cancer cell lines (OMC-4, HHUA, Ishikawa, HEC-59). The results demonstrated that only the HEC-59 cell line had high aromatase activity and increased its DNA synthesis in response to T. This increase of DNA synthesis by T was not suppressed by simultaneous addition of cyproterone acetate, but was by tamoxifen. These data suggest that in situ estrogen production in endometrial cancer tissue is biologically important and that aromatase in cancer cells may contribute partially to cell proliferation if androgen substrate is provided.

Estrone sulfate and sulfatase activity in human breast cancer and endometrial cancer

Estrone sulfate (E1-S) in the serum and tissues of patients with breast cancer or endometrial cancer was measured by a direct radioimmunoassay without hydrolysis. The concentration of E1-S in breast cancer tissue was 1.64 +/- 0.28 ng/g wet wt (+/- SE), lower than in surrounding normal breast tissue (4.46 +/- 1.23). Estradiol-17 beta(E2)/E1-S was higher in endometrial cancer tissue than normal endometrial tissue. Estrone sulfatase activity in breast cancer tissue was 0.81 +/- 0.23 nmol/h/mg protein, higher than in surrounding normal breast tissue (0.35 +/- 0.11). These results suggest that E1-S, which is abundant in the peripheral circulation, is hydrolyzed by sulfatase in breast cancer tissue or endometrial cancer tissue and liberates free estrogens, which may stimulate the growth of these malignant tumors.

Estrogen protects neuronal cells from amyloid β-induced apoptotic cell death

Accumulating studies have shown that estrogen replacement therapy reduces the risk of Alzheimers disease. In this study, we clarified that 17β-estradiol (E2) significantly rescues PC12 neuronal cells from amyloid β protein (Aβ)-induced cell death. We found that the amino acid residues of 25 to 35 (Aβ25-35) were more cytotoxic than the full length protein (Aβ1-40) and these residues induced DNA fragmentation typical for apopto- sis. In addition, E2 was confirmed to inhibit calcium influx and cytochrome c release induced by Aβ25-35. Since these sequential events cause apoptosis, the protective effect of E2 may be exerted not by the direct interaction with Aβ, but by the blockade of the mitochondrial apoptotic pathway induced by Aβ.

Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in women with or without gynecologic cancer.

Objective: To detect the level of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) which is an oxygen‐radical‐forming agent, in the urine of patients with (n = 18) or without (n = 10) carcinoma of the female genitalia. None of the patients had been receiving any treatment before their urinary 8‐OHdG levels were measured.

Different expression patterns of KIT, EGFR, and HER-2 (c-erbB-2) oncoproteins between epithelial and mesenchymal components in uterine carcinosarcoma

Uterine carcinosarcoma histologically comprises the components of epithelial and mesenchymal malignancies, and is known to be clinically highly aggressive. To reveal the significance of the expression of tyrosine‐kinase‐receptor‐type oncoproteins in this tumor type, the incidence and distribution of the KIT, EGFR, and HER‐2 (c‐erbB‐2) oncoproteins were immunohistochemically examined in 16 surgically resected cases. For 6 cases, the EGFR and HER‐2 amplifications were also examined by fluorescence in situ hybridization (FISH). In the epithelial component, overexpressions of KIT, EGFR, and HER‐2 were detected in 4 (25%), 5 (31%), and 9 (56%) cases, respectively, whereas these overexpressions in the mesenchymal component were detected in 6 (38%), 8 (50%), and 1 (6%) cases, respectively. KIT and EGFR were co‐overexpressed in the mesenchymal component of 4 cases and in the epithelial component of 2 cases. However, HER‐2 overexpression was mostly detected in the epithelial component only, and tended to occur independently of KIT and/or EGFR overexpression. By FISH, one of the 4 cases with HER‐2 overexpression showed low‐level gene amplification. In two cases with EGFR overexpression, the gain of EGFR alleles and/or polyploidization of chromosome 7 had occurred. The expression patterns of KIT, EGFR, and HER‐2 differed between the epithelial and mesenchymal components, and the regulation of their expression appeared important in the acquisition of mesenchymal metaplasia in uterine carcinosarcoma. Structural and/or numerical alterations of chromosomes might be in part involved in EGFR and/or HER‐2 overexpression in this tumor type.