Down-regulation of bcl-2 is a potential marker of the efficacy of progestin therapy in the treatment of endometrial hyperplasia

Progestin Resistance and Corresponding Management of Abnormal Endometrial Hyperplasia and Endometrial Carcinoma

With a younger tendency in morbidity age, endometrial cancer (EC) incidence has grown year after year. Worse, even more commonly occurring is endometrial hyperplasia (EH), which is a precancerous endometrial proliferation. For young women with early EC and EH who want to preserve fertility, progestin therapy has been utilized as a routine fertility-preserving treatment approach. Nevertheless, progestin medication failure in some patients is mostly due to progestin resistance and side effects. In order to further analyze the potential mechanisms of progestin resistance in EH and EC, to provide theoretical support for effective therapeutic strategies, and to lay the groundwork for searching novel treatment approaches, this article reviews the current therapeutic effects of progestin in EH and EC, as well as the mechanisms and molecular biomarkers of progestin resistance, and systematically expounds on the potential therapeutic methods to overcome progestin resistance.

Expression levels of BCL2 and MKI67 in endometrial polyps in postmenopausal women and their correlation with obesity

Obesity is associated with numerous diseases, including endometrial disorders in postmenopausal women, such as adenocarcinoma, hyperplasias and endometrial polyps, and the risk of malignant transformation of these structures. The present study evaluated the influence of body mass index (BMI) on cell proliferation (BCL2 and MKI67) in endometrial polyps in postmenopausal women. A prospective cross-sectional study using immunohistochemical analysis of the expression of a cell proliferation marker (MKI67) and an anti-apoptotic gene (BCL2) in endometrial polyps in postmenopausal women was performed. The patients were divided into three groups depending on BMI: i) <24.9 kg/m² (normal); ii) >25 and <29.9 kg/m² (overweight); and iii) >30 kg/m² (obese). The present study analyzed the expression of these markers in relation to polyp size, histological type and time since menopause in 38 patients. The interpretation of MKI67 and BCL2 expression accounted for the percentage of positive cells (scores): 1 (weak), <5% of cells showed expression; 2 (moderate), between 5 and 50%; and 3 (intense), >50%. Statistical analysis was performed using GraphPad InStat version 3.00 software. ANOVA was used to analyze BCL2 and MKI67 expression. A significance level of P<0.05 was adopted for rejecting the null hypothesis. There was greater glandular expression of MKI67 in obese women than in normal weight women (P=0.02) and greater expression of BCL2 in the stroma of polyps >2 cm (P=0.03). Hyperplastic polyps exhibited hyperexpression of MKI67 (P=0.04) compared with atrophic polyps. No difference in MKI67 and BCL2 expression was identified in the glands and stroma of polyps when comparing overweight and obese postmenopausal patients. The present findings suggest that BMI has an influence on proliferation markers (MKI67) in the polyps of postmenopausal women and that polyps >2 cm exhibit hyperexpression of BCL2 in the stroma.

Progesterone ameliorates the endometrial polyp by modulating the signaling pathway of Wnt and β-catenin via regulating the expression of H19 and miR-152

BACKGROUND

MicroRNAs and long noncoding RNAs are believed to play important roles in the pathogenesis of various diseases. This study aimed to explore the potential mechanism of the involvement of H19 and miR-152 in an endometrial polyp.

METHODS

Luciferase assay was conducted to determine the effect of progesterone. Real-time polymerase chain reaction (PCR) and western blot were performed to detect the influence of progesterone on miR-152 and Wnt1. MTT assay and flow cytometry (FCM) were utilized to detect the effect of progesterone on cell proliferation and apoptosis. In silicon analysis, luciferase assay, real-time PCR, and immunohistochemistry (IHC) were performed to explore the regulatory relationship between H19 and miR-152 or miR-152 and Wnt1.

RESULTS

Progesterone dose-dependently increased the H19 expression level through driving the promoter efficiency of H19. Then, progesterone upregulated Wnt1 level and downregulated miR-152 in a dose-dependent manner in ECC1 and HEC1A cells. Administration of progesterone inhibited cell viability and promoted cell apoptosis. H19 negatively regulated miR-152 expression by binding to miR-152. Furthermore, Wnt1 was identified as a virtual target gene of miR-152 and was inhibited by miR-152. Progesterone receptors mRNA and miR-152 were lowly expressed in participants with an endometrial polyp, while the levels of H19 and Wnt1 were much higher in the endometrial polyp group compared with normal controls. H19 negatively regulated miR-152 and miR-152 negatively regulated Wnt1, with the negative correlation coefficients being -0.500 and -0.500, respectively. Using IHC, it was found that Wnt1 and Bcl-2 protein were highly expressed in the endometrial polyp group compared with normal controls.

CONCLUSION

The results suggested that H19 was associated with endometrial polyp via mediating cell proliferation and apoptosis.

Complete Histologic Regression of Endometrioid Adenocarcinoma on Endometrial Biopsy After Progestin Treatment Does Not Guarantee the Regression of an Invasive Carcinoma Within the Myometrium

Currently, the indications for progestin therapy are limited to endometrioid adenocarcinoma that are International Federation of Gynecology and Obstetrics (FIGO) grade 1, FIGO stage IA, and confined to the endometrium. However, there have been attempts to broaden the indications of progestin therapy to patients with higher FIGO grades and/or with superficial myometrial invasion. We experienced a case with myoinvasive endometrioid adenocarcinoma treated with oral progestin, whose follow-up endometrial curettage specimen showed an apparent complete histologic regression; however, the final hysterectomy specimen disclosed myoinvasive endometrioid adenocarcinoma within the superficial myometrium, with absence of residual tumor in the endometrium. We describe this case to demonstrate that complete histologic regression of the endometrial lesion in a follow-up curettage specimen after progestin treatment does not guarantee histologic regression of the carcinoma within the myometrium. Our case indicates that current indications for progestin treatment should not be broadened to patients with superficial myometrial invasion.

Predictive ability of estrogen receptor (ER), progesterone receptor (PR), COX-2, Mlh1, and Bcl-2 expressions for regression and relapse of endometrial hyperplasia treated with LNG-IUS: a prospective cohort study

OBJECTIVE

To test the predictive ability of immunohistochemical estrogen receptor(ER), progesterone receptor (PR), COX-2, Mlh1, and Bcl-2 expressions for predicting the outcomes of regression and relapse in women with endometrial hyperplasia treated with the Levonorgestrel-releasing intrauterine system (LNG-IUS).

METHODS

We recruited prospectively all women diagnosed with complex or atypical complex hyperplasia that underwent treatment with LNG-IUS from August 1998 until September 2008. Immunohistochemistry was performed with conventional methods and recorded using a semi-quantitative score (Q score) by two blinded assessors. Women were followed with endometrial biopsies to record regression and relapse. The biomarker predictive ability was analysed using the Cox proportional hazards model.

RESULTS

The median follow-up was 72.1 months (IQR 59.1-89.8). The Q score agreement between assessors was 82.6% (K statistic=0.801 ± 0.036). The majority of study participants initially regressed to normal endometrium following LNG-IUS therapy (n = 164 regressed; n = 10 persisted). From the 164 women that regressed with LNG-IUS we were able to assess 152 women for relapse from which 18 relapsed. We found a weak association for persisted endometrial hyperplasia with ER and PR expressions with Q score on the 5th and 10th centiles. No associations were found for COX-2, Mlh1 and Bcl-2 protein expressions for regression and for any of the biomarkers for relapse.

CONCLUSION

We found that poor expression of ER and PR is weakly associated with persisting endometrial hyperplasia and COX-2, Mlh1, and Bcl-2 expressions are not predictive. None of the biomarkers is predictive for relapse in women with endometrial hyperplasia treated with LNG-IUS.

Biomarkers of progestin therapy resistance and endometrial hyperplasia progression

OBJECTIVE

We sought to identify biomarkers associated with progestin therapy resistance and persistence/progression of endometrial hyperplasia.

STUDY DESIGN

We performed a nested case-control study among women with complex (n = 73) and atypical (n = 41) hyperplasia treated with oral progestin, followed up 2-6 months for persistence/progression. We evaluated index endometrial protein expression for progesterone receptor isoform A, progesterone receptor isoform B (PRB), PTEN, Pax-2, and Bcl-2. Odds ratios and 95% confidence intervals (CIs) were estimated.

RESULTS

Among women with atypical hyperplasia, high PRB expression was associated with 90% decreased risk of persistence/progression (95% CI, 0.01-0.8). High expression of progesterone receptor A and PRB suggested decreased risk of persistence/progression (odds ratio, 0.1; 95% CI, 0.02-1.0). These findings were not observed among women with complex hyperplasia. No associations were found with PTEN, Pax-2, and Bcl-2 protein expression.

CONCLUSION

PRB expression shows promise as a biomarker of progestin response. Further research is warranted to understand how PRB expression may guide treatment decisions.

Ontogeny of progesterone receptor expression in the subplate of fetal and neonatal rat cortex

The progesterone receptor (PR) is transiently expressed in the rat cortex during development and its expression is initiated in the developmentally critical layer, the subplate. As subplate neurons pioneer thalamocortical and corticofugal connectivity, the expression of PR in this layer suggests an important function for PR in cortical development. Using immunocytochemistry for PR, the present study determined the precise ontogeny of PR expression in subplate neurons. The number of cells containing PR immunoreactivity (PRir) within the subplate was quantified from embryonic day (E) 17 through postnatal day (P) 14. The subplate was positively identified by the marker calretinin and by BrDU birthdating. The results demonstrate that PRir is undetectable in fetal cortex on E17, but is first observed in the subplate on E18. The number of PRir cells peaks on P2 and then steadily declines, until PRir is once again not detectable in subplate by P14. This developmental window of PR expression within the subplate coincides with establishment of early cortical circuitry and the gradual demise of subplate cells, suggesting that PR may play a critical role in mediating these fundamental developmental processes.

Aberrant survivin expression in endometrial hyperplasia: another mechanism of progestin resistance

Up to 30% of failure rate in endometrial hyperplasia patients treated by progestin urges more detailed understanding of the mechanisms involved in progestin resistance. Survivin is a key regulator in the antiapoptotic network, and overexpression of survivin has been reported in endometrial hyperplasia and cancer. This study investigated the role of survivin in progestin resistance in endometrial hyperplasia. Pre- and post-treatment endometrial hyperplasia tissue samples from 23 women were examined for changes in survivin expression related to the administration of progestins. The impact of continuous or intermittent progestin treatment on survivin expression in Ishikawa cells was examined by the western blot. Survivin immunoreactivity was present in epithelial compartment of all pre-progestin-treated endometrial hyperplasia samples with mean nuclear indices 78 and cytoplasmic indices 114. In the 15 progestin responders, an average of 19.5-fold decrease of survivin expression was seen in epithelial nuclei (P<0.001) and 8-fold decrease in epithelial cytoplasm (P<0.001). In the eight non-responders, no significant changes in survivin expression were detected. With in vitro Ishikawa cells, survivin expression was effectively inhibited by either 72-h continuous treatment with 10 muM medroxyprogesterone acetate or 72 h after medroxyprogesterone acetate withdrawal. Our results indicated that dysregulation of survivin expression in hyperplastic endometrium may be part of the molecular mechanisms for progestin resistance. Intermittent, rather than continuous, progestin treatment may be more effective clinically for the treatment of endometrial hyperplasia.

Expression of Bcl-2 and Ki-67 in Tamoxifen-Associated Endometrial Polyps: Comparison with Postmenopausal Polyps

BACKGROUND

The aim of this study was to evaluate the expression of Bcl-2 and Ki-67 in tamoxifen (TAM)-associated endometrial polyps and postmenopausal polyps.

MATERIAL AND METHODS

For this purpose, a retrospective analysis of paraffin-embedded specimens was carried out. Polyps of 20 postmenopausal and 14 TAM-treated patients, 11 simple endometrial hyperplasia, 10 atypical complex endometrial hyperplasia and 8 endometrial adenocarcinoma specimens were included in the study. Hematoxylin/eosin-stained sections were evaluated. Immunohistochemical staining was performed to investigate the expression of Bcl-2 protein and the Ki-67 proliferation index.

RESULTS

There was no statistically significant difference between the 5 groups with regard to Bcl- 2 staining (p > 0.05). However, Bcl-2 expression in TAM-associated polyps was higher (86%) than in the postmenopausal control group (80%). Positive Ki-67 was highest in the endometrial adenocarcinoma specimens, followed by the atypical complex endometrial hyperplasia group (p < 0.0001). Compared to these 2 groups, Ki- 67 expression was lower in TAM-associated polyps, but Ki-67 indexes were significantly higher in the TAM-associated group than in the control group (p < 0.0001).

CONCLUSION

Since TAM-associated polyps tend to have higher proliferation indexes and Ki-67 ratios than control groups, we suggest that they are likely to have a higher malignant potential.

The effect of long-term use of progesterone therapy on proliferation and apoptosis in simple endometrial hyperplasia without atypia

The aim of this study was to evaluate the effect of long-term use of progesterone treatment on proliferation and apoptosis in simple endometrial hyperplasia without atypia. In this prospective control study, endometrial tissue samples of 19 patients with simple endometrial hyperplasia without atypia (group 1), posttreatment biopsy materials of the patients after 3 months of cyclic progesterone treatment with noretisterone for 10 days (group 2), and 18 endometrial biopsy materials of the control group (group 3) were examined for proliferative and apoptotic activities. There was a statistically significant difference between the median values of the proliferative index of the three groups (P = 0.000). The proliferative index was significantly higher in the endometrial hyperplasia group than in posttreatment group (P = 0.000). But there was no significant difference between posttreatment group and control group. The median value of apoptotic activity was significantly different between three groups (P = 0.000). Apoptotic index was highest in hyperplasia group. A significant decrease in apoptosis was observed after the progesterone treatment (P = 0.002). The lowest apoptotic activity was detected in the control group. In conclusion, 3 months of cyclic progesterone treatment reduces both proliferative and apoptotic activities in endometrial tissue with simple hyperplasia.

Bcl-2, BAX, and apoptosis in endometrial hyperplasia after high dose gestagen therapy

OBJECTIVES

The aim of the study was to investigate apoptosis as a growth regulatory mechanism of gestagen in endometrial precancers and to compare differences in the apoptotic cascade after high and low dose gestagen regimens.

METHOD

Pre- and post-treatment paraffin-embedded endometrial hyperplasia specimens from women treated with levonorgestrel intrauterine device (n = 26) and women treated with 10 mg medroxyprogesterone for 10 days per cycle (n = 31) were examined for changes in the expression of Bcl-2 and BAX and the extent of apoptosis after 3 months of treatment. Immunohistochemical expression in tissue specimens for Bcl-2 and BAX was evaluated by H-score. Average number of apoptotic cells per hundred cells within ten different high power field (40 x) was evaluated for each section after in situ apoptosis detection (TUNEL method). A second group of patients with endometrial hyperplasia was examined after 1 week treatment with levonorgestrel IUD (n = 6) or medroxyprogesterone (n = 5) to determine early effects on expression of Bcl-2 and BAX and the extent of apoptosis.

RESULTS

All the patients in the IUD group (n = 31) but only about half of the patients in per oral group (16 of 26) responded to treatment. The glandular reduction in Bcl-2 expression was markedly greater for the IUD patients than for the patients who received oral gestagen. The decrease in BAX expression after IUD treatment was less than the reduction of Bcl-2. Decrease in glandular Bcl-2 after 3 months of treatment was coincident with a significant increase in the measurable amount of apoptosis. In stromal cells, the increase in expression of Bcl-2 and BAX was found after gestagen treatment, the response being much more marked for the IUD group. The non- responders to per oral gestagen had no Bcl-2 expression in stroma after 3 months of therapy whereas an increase was observed for the responders. After 1 week, glandular Bcl-2 expression was significantly reduced after treatment in the IUD group. As for the rest, no changes were detected in either of the groups.

CONCLUSION

Our results indicate that proteins in the apoptotic cascade are regulated by gestagen therapy in human endometrial precancers. Expression of these proteins is shown to be dependent on administration form and/or type of gestagen. Stromal Bcl-2 expression appears to be a potential biomarker which can separate responders of gestagen treatment from non-responders after oral administration.

Clinical and pathological responses of progestin therapy for non-atypical endometrial hyperplasia: A prospective study

AIMS

To evaluate the clinical and pathological responses and factors predicting non-responders to various progestins currently prescribed for the treatment of non-atypical endometrial hyperplasia.

METHODS

A prospective observational study was conducted in the Gynecologic Endocrinology Unit, Faculty of Medicine, Siriraj Hospital, Thailand, from 1998 to 2003. A 6-month course of progestin therapy was offered to all patients. The clinical response was evaluated from the vaginal bleeding pattern during the first 4 months of treatment. The pathological response was evaluated from the histopathology of the endometrium after completion of the 6-month therapy.

RESULTS

Of 250 registered patients, the number of cases qualified for the evaluation of the clinical and pathological response were 198 and 134 cases, respectively, revealing the overall clinical and pathological response rates of 93.4% and 92.5%, respectively. Among 13 clinical non-responders, 84.6% might have associated pelvic pathology. Among 10 pathological non-responders, three had surgical treatment, and progressive disease was found in one case. Significant factors predicting clinical non-responders included a history of prior bleeding (odds ratio [OR] = 8.79, 95% confidence interval [CI] = 1.63, 47.53), the presence of associated pelvic pathology (OR = 25.52, 95% CI = 3.21, 203.01), and treatment using progestins other than medroxyprogesterone acetate. Factors predicting pathological non-responders were not statistically significant.

CONCLUSIONS

The current regimens of progestin therapy for non-atypical endometrial hyperplasia have high response rates. Patients who fail to have a clinical response should be evaluated for associated pelvic pathology. Follow-up endometrial biopsy should be offered to the patients, because 7.5% have persistent or progressive lesions, necessitating aggressive treatment.

Molecular markers in the endometrium at baseline of postmenopausal patients with early breast cancer in the ATAC (Arimidex, tamoxifen, alone, or in combination) trial

OBJECTIVE

This study was undertaken to assess baseline endometrial molecular events in the ATAC (Arimidex, tamoxifen, alone, or in combination) trial of breast cancer adjuvant therapy.

STUDY DESIGN

Estrogen receptor (ER) and progesterone receptor (PR) levels and markers of cell proliferation (Ki67) and apoptosis ( Bcl -2) were assessed in 93 patients at baseline.

RESULTS

An inactive/atrophic endometrium was found in 63 patients, 5 had a proliferative endometrium, and 12 had a secretory endometrium. Thirteen endometrial polyps were analyzed. Inactive endometrium showed high levels of ER in the glandular epithelium, whereas in more than 50% of samples, PR expression was negative or low (+) in the glandular epithelium, and stroma. Ki67 expression was low in both the glandular epithelium and the stroma of the inactive endometrium, whereas Bcl -2 expression was mostly high or very high (+++/++++) in the glandular epithelium. Bcl -2 was strongly expressed (+++/++++) in the glandular epithelium of polyps.

CONCLUSION

Although all patients were asymptomatic, some had endometrial pathology.

Endometrial Hyperplasia: A Review

Endometrial hyperplasia is a precursor to the most common gynecologic cancer diagnosed in women: endometrial cancer of endometrioid histology. It is most often diagnosed in postmenopausal women, but women at any age with unopposed estrogen from any source are at an increased risk for developing endometrial hyperplasia. Hyperplasia with cytologic atypia represents the greatest risk for progression to endometrial carcinoma and the presence of concomitant carcinoma in women with endometrial hyperplasia. Abnormal uterine bleeding is the most common presenting symptom of endometrial hyperplasia. Specific Pap smear findings and endometrial thickness per ultrasound could also suggest the diagnosis. Unopposed estrogen in women taking hormone replacement therapy increases the risk of endometrial hyperplasia. Tamoxifen has demonstrated its efficacy in treating women at risk for breast cancer, but it increases the risk of endometrial hyperplasia. The choice of treatment for endometrial hyperplasia is dependent on patient age, the presence of cytologic atypia, the desire for future childbearing, and surgical risk. Endometrial hyperplasia without atypia responds well to progestins. However, women with atypical hyperplasia should be treated with hysterectomy unless other factors preclude surgery.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to describe the definition and classification of endometrial hyperplasia, to outline the clinical features of a patient with endometrial hyperplasia, to point out the natural history of endometrial hyperplasia, and to summarize the diagnostic options for patients with endometrial hyperplasia.

Involution of PTEN-null endometrial glands with progestin therapy

OBJECTIVES

Loss of PTEN tumor suppressor gene function characterizes most (63%) endometrial precancerous lesions (endometrial intraepithelial neoplasia, EIN) and up to 83% of endometrioid endometrial cancers. Because systemic progestins are known to promote involution of precancerous endometrial lesions, we tested the hypothesis that this therapy preferentially leads to clearance of immunohistochemically detected PTEN-null endometrial glands in a variety of histopathologic settings.

METHODS

PTEN immunohistochemistry of pre and postprogestin-treated endometria was successfully performed on 17 women presenting with an intake endometrial biopsy diagnosis of "hyperplasia". Intake biopsies were rediagnosed using EIN criteria as 5 normal (proliferative or secretory), 4 anovulatory, 3 polyps, and 5 EIN endometria. The persistence of PTEN-null glands in progestin-treated patients was compared to that seen previously in rebiopsied normal proliferative endometrium of endogenously cycling premenopausal women.

RESULTS

Ten of 17 women prehormonal therapy had PTEN-null glands in the initial biopsy, and 90% (9/10) of these disappeared in the postprogestin sample. This contrasts with only 17% (2/12) involution in the endometria of normal cycling women (Fishers exact test P=0.002, Odds Ratio 45).

CONCLUSIONS

We conclude that progestin therapy promotes involution, or disappearance, of PTEN-null endometrial glands relative to the persistence rate seen for normal cycling women. This effect occurs among PTEN-null glands having a variety of histopathologic presentations.

Fas-mediated pathway and apoptosis in normal, hyperplastic, and neoplastic endometrium

OBJECTIVES

Abnormalities in the control of cell proliferation and apoptosis have been suggested to contribute to the development and progression of neoplasia. There are at least two pathways that activate apoptosis. The first is a mitochondria-dependent route governed by bcl-2 family proteins. The second is a parallel mechanism which involves the activation of a group of tumor necrosis factor (TNF) receptors, such as Fas.

METHODS

The aim of this study was to examine the distribution and interrelation between the expression patterns of apoptosis-related proteins such as Fas, caspase-3 (CPP32), and M30, and to investigate the role of Fas-mediated apoptosis in the pathogenesis and progression of endometrial neoplasms.

RESULTS

Using specific antibodies for Fas, caspase-3, and M30, we examined protein expressions in 29 endometrial carcinomas, 30 endometrial hyperplasias, and 21 normal cyclic endometria. The results of immunostaining for Fas and caspase-3 were analyzed semiquantitatively by using an immunohistochemical scoring system (HSCORE) that incorporated both the intensity and the distribution of specific staining. For M30, positive staining cells and extracellular particles were analyzed semiquantitatively per 10 high-power fields.HSCOREs of Fas and caspase-3 were slightly higher in the secretory endometria than in the proliferative endometria. Similarly, M30 reactivity seemed to increase in the late secretory phase of the cycle. HSCOREs of Fas and caspase-3 and the reactivity of M30 were significantly higher in the carcinoma group than in the simple hyperplasia group (P < 0.05). Complex hyperplasias, however, expressed quite similar HSCOREs of Fas and caspase-3 as carcinomas. M30 reactivity was also significantly higher in complex hyperplasias than in simple hyperplasias, and in carcinomas positivity increased significantly (P < 0.05) as the grade progressed.

CONCLUSIONS

The significant increase observed in Fas, caspase-3, and M30 expression in carcinomas as compared with simple hyperplasias may suggest that the Fas-related apoptotic pathway is also involved in the regulation of apoptosis in the endometrial tissue and promotes the development and progression of endometrial neoplasia.

Mechanisms involved in the evolution of progestin resistance in human endometrial hyperplasia--precursor of endometrial cancer

BACKGROUND

Successful treatment of endometrial hyperplasia with progestins is commonly accompanied by the finding of an inactive or suppressed endometrium after therapy. However, approximately 30% of the endometrial hyperplasia cases do not respond to progestins and hyperplastic glands persist. The Fas/FasL system is known to play a role in tissue remodeling as a result of changes in menstrual hormone levels. The aims of this study are to examine Fas/FasL expression in endometrial hyperplasia of pre- and postprogestin treatment samples and to study the Fas/FasL regulation in vitro with Ishikawa cells after progestin stimulation.

DESIGN

Pre- and posttreatment paraffin-embedded endometrial hyperplasia tissue samples from 26 women were examined by immunohistochemistry for changes in Fas/FasL expression related to the administration of progestins. Among 26 patients, 18 were successfully treated with progestins and 8 failed treatment. Fas/ FasL positivity was defined by the presence of 10% or more immunoreactive epithelial cells in each specimen. In positive cases, a percentage or an immunoscore of immunoreactive cells was given by counting 500 cells. Cell viability was evaluated by the MTT assay. The in vitro effects of progesterone on Fas/FasL expression and apoptosis in Ishikawa cells were examined by using Western blot and TUNEL assays, respectively.

RESULTS

Fas immunoreactivity was present in 4/26 (15%) preprogestin cases with an average of 16% of the epithelial cells expressing Fas. FasL was expressed in 21/26 (80%) pretreatment cases with an average of 42% of the hyperplastic glandular cells being positive. In postprogestin cases, an increase of Fas expression (14/18, 77%) with an average of 47% stained cells was seen in responders (P < 0.001), while FasL was found in 16/18 (89%) responders with an average of 65% of cells positive (P = 0.587). In nonresponders, no significant changes in Fas/FasL expression were detected compared to pretreatment samples. With in vitro Ishikawa cells, a slight increase (10-20%) of Fas and FasL protein expression was detected after 24 h of progesterone treatment, but a more significant increase (220-343%) of both Fas and FasL expression was found after 48 h of withdrawing progesterone, which parallels apoptotic activity.

CONCLUSIONS

The Fas/FasL system may be involved in the development of endometrial hyperplasia. Part of the molecular mechanisms of progestin therapy for endometrial hyperplasia is through upregulation of Fas/FasL expression. Dysregulation of Fas/FasL expression in hyperplastic endometrium may be part of the molecular mechanisms for nonresponders to progestin treatment. Intermittent, rather than continuous, progestin treatment may be more effective clinically for the treatment of endometrial hyperplasia.

Systemic therapy for gynecological neoplasms: ovary, cervix and endometrium

Early-stage endometrial carcinomas should be treated by total abdominal hysterectomy and bilateral salpingo-oophorectomy. In a small subset of patients, who wish to have children, conservative treatment (hormonal therapy) could be considered. The most effective agents for palliation of advanced disease are doxorubicin plus cisplatin.

Apoptosis-related proteins and steroid hormone receptors in normal, hyperplastic, and neoplastic endometrium

The purpose of this study was to evaluate the distribution and frequency of apoptosis-related proteins and their correlation with estrogen, progesterone, and androgen receptors in endometrial tissues. Immunohistochemical analyses of bcl-2, bax, bcl-x, and steroid receptors were performed in 22 endometrial carcinomas, 26 endometrial hyperplasias, and 19 cases of normal cyclical endometrium. Bcl-2 was expressed in 45.4% of carcinomas and 92.3% of hyperplasias. Bax immunostaining was found in 90.9% of carcinomas and 76.9% of hyperplasias. Bcl-x positivity was similar in carcinomas (68.1%) and endometrial hyperplasias (76.9%). In normal cyclical endometria, bcl-2 staining was intense and diffuse in the proliferative phase, but decreased dramatically in the early and mid-secretory phase to reappear in the late secretory phase. Bax was expressed throughout the menstrual cycle but more strongly in the secretory phase. Bcl-x displayed a similar degree of expression in proliferative and secretory endometria. Nineteen carcinomas (86.3%), 25 hyperplasias (96.1%), and 18 normal cyclical endometria (94.7%) were positive for estrogen receptor (ER). Progesterone receptor (PR) was observed in 20 carcinomas (90.9%), all hyperplasias (100%), and 18 normal cyclical endometria (94.7%). Androgen receptor (AR) positivity was seen in 7 carcinomas (31.8%), 6 hyperplasias (23.0%), and 3 normal cyclical endometria (15.7%). There was a statistically positive correlation between bcl-x and ER and a tendency toward significant correlation between bcl-x and PR and between ER and PR in carcinomas. In hyperplasias, there was a significant positive correlation between bcl-2 and PR and between bcl-2 and bax and a negative correlation between ER and bax. There was a statistically significant difference for bcl-2 (p = 0.001) and bax (p = 0.001) between the hyperplasia and carcinoma groups. There was increased expression of bax, decreased expression of bcl-2, and persistence of bcl-x protein in advanced endometrial carcinomas. Our findings show that ovarian hormones have a regulatory role on bcl-2 protein and that there is a correlation between other members of the bcl-2 family (bcl-x and bax) and steroid hormone receptors. Bax/bcl-x may be the major control mechanisms of apoptosis in advanced carcinomas; other members of the bcl-2 family may also be under hormonal control.

Dissociated expression of Bcl-2 and Ki-67 in endometrial lesions: diagnostic and histogenetic implications

The objective of the present study was to analyze the expression of the proliferation marker, Ki-67, and the anti-apoptotic protein, bcl-2, in various endometrial lesions. Ki-67 and bcl-2 expressions were studied in 194 specimens of endometrial hyperplasia, polyps, carcinomas, and cyclic endometrium from a defined geographic area. Results were statistically analyzed with respect to marker expression, localization to the stromal or glandular component, and intraglandular topography. The lowest glandular Ki-67 expression was seen in secretory endometrium, in polyps, and in atypical hyperplasia. The Ki-67 score was significantly higher and less heterogeneous in endometrial carcinomas than in hyperplasia (p<0.001). Endometrial hyperplasia of all types was characterized by a markedly heterogeneous glandular expression of Ki-67. The glandular expression of bcl-2 was highest in proliferative endometrium and polyps. Bcl-2 expression was significantly lower in adenocarcinomas than in hyperplastic lesions (p=0.002). Ki-67 and bcl-2 expression showed a significant association in proliferative endometrium (p=0.003). Endometrial polyps demonstrated a unique pattern of very low expression of Ki-67 and high bcl-2 expression in both stroma and glands. Our findings indicate that an imbalance between proliferation and apoptosis may be an important factor in the development of different endometrial lesions, benign as well as malignant. The specific finding of inter- and intraglandular Ki-67 heterogeneity may be valuable as an adjunct to morphology in the differential diagnosis of endometrial hyperplasia.

Reversal by medical treatment of endometrial hyperplasia caused by estrogen replacement therapy

OBJECTIVE

Endometrial hyperplasia, an entity considered a precursor to endometrial carcinoma, frequently develops in women receiving unopposed estrogens. Progestins used concomitantly with estrogens can largely prevent endometrial hyperplasia and carcinoma. However, the ability of progestins to reverse endometrial hyperplasia induced by estrogens is less well recognized. The purpose of this study was to assess the medical reversal rate of endometrial hyperplasia that develops in women receiving unopposed estrogen replacement therapy (ERT).

DESIGN

Review of recent literature (1990-2000).

RESULTS

Based on four large series, more than 90% of endometrial hyperplasia caused by ERT can be reversed by medical treatment. Discontinuation of estrogen and oral administration of 10 mg/day of medroxyprogesterone acetate continuously for 6 weeks or cyclically for 3 months (2 weeks of each month) are the two regimens most widely used. Other progestins also have been shown to be effective.

CONCLUSIONS

Progestins are highly successful in reversing endometrial hyperplasia caused by ERT.

Apoptosis may be an early event of progestin therapy for endometrial hyperplasia

OBJECTIVE

The aim of this study was to investigate the role of apoptosis during progestin therapy for the treatment of endometrial hyperplasia.

METHODS

Pre- and posttreatment paraffin-embedded endometrial tissue samples from 19 women with endometrial hyperplasia were examined for changes in glandular cellularity and apoptotic activity related to the administration of progestins. Twelve patients were successfully treated with progestin therapy and 7 patients failed treatment. Glandular cellularity was assessed based on calculating the average number of cells per gland obtained on histologic examination of hematoxylin and eosin stained tissue sections. Apoptotic activity was assessed on the same tissue sections by counting the average number of apoptotic cells per 10 high power fields (hpf) using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay. The effects of progesterone on apoptotic activity in a low-grade endometrial adenocarcinoma cell line (Ishikawa cells) was also examined using an ELISA cell death detection kit.

RESULTS

Glandular cellularity significantly decreased with progestin therapy in both treatment outcome groups. The reduction in cells per gland was significantly greater in the group of successfully treated cases compared to the treatment failures (P = 0.005). However, within the successfully treated group, in situ detection of apoptotic cells using the TUNEL assay showed no statistical difference between pre- and posttreatment endometrial samples. Interestingly, a significant decrease in apoptosis was found in posttreatment samples of the group with persistent hyperplasia. The average number of apoptotic cells detected in 10 hpf was reduced from 7.9 prior to treatment to 3.1 after progestin therapy (P = 0.03). In the progesterone-treated Ishikawa cell line, an increase in apoptotic activity started at 24 h, reached a peak at 48 h, and continued up to 72 h of hormone treatment. At 48 h, apoptotic activity was 42.6% greater than in the untreated control (P = 0.04). By 72 h of progesterone treatment, apoptosis was 37.2% greater in the treated cells compared to the noninoculated cells (P = 0.04).

CONCLUSIONS

Progestin-induced apoptosis may occur during the early period of treatment for endometrial hyperplasia. Compared to the fully responsive group, persistent endometrial hyperplasia may have intrinsically different molecular mechanisms in response to progestin therapy.

The patterns of expression of an apoptosis-related CK18 neoepitope, the bcl-2 proto-oncogene, and the Ki67 proliferation marker in normal, hyperplastic, and malignant endometrium

Expression of a neoepitope on cytokeratin 18, recognized by the monoclonal antibody M30, is an early indicator of apoptosis in epithelial cells. The aim of this study was to determine the equilibrium between apoptosis (M30), anti-apoptosis (bcl-2), and proliferation (Ki-67) in different endometrial conditions. Paraffin-embedded samples (n = 107), representing proliferative endometrium (18), secretory endometrium (19), postmenopausal endometrium (15), disordered proliferative endometrium (6), simple hyperplasia (12), complex hyperplasia (8), and endometrial adenocarcinoma (29), were evaluated immunohistochemically. The indirect streptavidin-biotin-horseradish peroxidase technique, with 3-amino-9-ethylcarbazole as the chromogen, was used to visualize the reactions. Proliferative endometrium showed high bcl-2 and Ki-67 expression levels with no M30. In the secretory phase, the balance was tipped in favor of M30 with a decrease of bcl-2 and Ki-67. Postmenopausal endometrium revealed high Ki-67 and bcl-2 expression levels and no M30. In complex hyperplasia, M30, bcl-2, and Ki-67 showed increased expression. In endometrial carcinoma, an increasing reactivity for M30 and Ki-67 was seen as the grade progressed. bcl-2 reacted weakly and only in grade 1 cancer. Immunohistochemistry facilitates the study of the expression of proteins related to cyclic endometrial activity. Interruption of these cyclic events is associated with specific disturbances in the expression patterns of these proteins.