Bcl-2 and Fas expression in eutopic and ectopic human endometrium during the menstrual cycle in relation to endometrial cell apoptosis

Potential Mechanisms of Guizhi Fuling Wan in Treating Endometriosis: An Analysis Based on TCMSP and DisGeNET Databases

ETHNOPHARMACOLOGICAL RELEVANCE

Guizhi Fuling Wan (GFW), is a traditional Chinese herbal formula that consists of Cinnamomi Ramulus (Guizhi), Poria Cocos(Schw.) Wolf. (Fuling), Persicae Semen (Taoren), Radix Paeoniae Rubra (Chishao), and Cortex Moutan (Mudanpi). This formula has been used in traditional Chinese medicine for more than 1800 years to treat disorders caused by stagnation of circulation and qi (air).

AIM OF THE STUDY

Based on pre-clinical and clinical studies, this review aimed to reveal the potential mechanisms of GFW in inhibiting endometriosis. The enhancement of therapeutic effects of western medications on endometriosis by GFW was also shown.

MATERIALS AND METHODS

A bibliographic assessment of publications on "Guizhi Fuling Wan" and "endometriosis" indexed in PubMed, Science Direct, and China National Knowledge Infrastructure (CNKI) was conducted. Five pre-clinical studies and 13 clinical studies were selected for this review. Moreover, the targeted molecules of each herb were first extracted from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database and Analysis Platform followed by obtaining the endometriosis-related genes from DisGeNET. Subsequently, pathway and gene ontology analyses using David Bioinformatics Resources explored the potential mechanisms of therapeutic effects of GFW in treating endometriosis.

RESULTS

Pre-clinical and clinical studies showed that GFW might inhibit the growth of endometriotic lesion through the modulation of immunity, apoptosis-regulating molecules, and angiogenesis-associated factors, while enhancing the therapeutic effects of western medications in treating endometriosis. Furthermore, pathway and gene ontology analyses demonstrated that GFW might attenuate the disease primarily by affecting AGE-RAGE signaling pathway in diabetic complications (hsa04933) as well as pathways involved in Kaposi sarcoma-associated herpesvirus infection (hsa05167), human cytomegalovirus infection (has05163), and fluid shear stress and atherosclerosis (hsa05418). These pathways were all involved in the regulation of inflammation, angiogenesis, and apoptosis and commonly affected by all herbs.

CONCLUSIONS

The current review revealed that endometriosis is highly associated with aberrant inflammatory, angiogenic, and apoptotic activities. The therapeutic effects of GFW on endometriosis are likely to act through regulating these activities.

Roles of microRNAs in Regulating Apoptosis in the Pathogenesis of Endometriosis

Endometriosis is a gynecologic disorder characterized by the presence of endometrial tissues outside the uterine cavity affecting reproductive-aged women. Previous studies have shown that microRNAs and their target mRNAs are expressed differently in endometriosis, suggesting that this molecule may play a role in the development and persistence of endometriotic lesions. microRNA (miRNA), a small non-coding RNA fragment, regulates cellular functions such as cell proliferation, differentiation, and apoptosis by the post-transcriptional modulation of gene expression. In this review, we focused on the dysregulated miRNAs in women with endometriosis and their roles in the regulation of apoptosis. The dysregulated miRNAs and their target genes in this pathophysiology were highlighted. Circulating miRNAs as potential biomarkers for the diagnosis of endometriosis have also been identified. As shown by various studies, miRNAs were reported to be a potent regulator of gene expression in endometriosis; thus, identifying the dysregulated miRNAs and their target genes could help discover new therapeutic targets for treating this disease. The goal of this review is to draw attention to the functions that miRNAs play in the pathophysiology of endometriosis, particularly those that govern cell death.

Structural equation modelling analysis determining causal role among methyltransferases, methylation, and apoptosis during human pregnancy and abortion

The human implantation failure during first trimester leads to spontaneous abortions. Spontaneous abortions are consecutive and occur twice or thrice (with or without prior live births) due to factors which are either maternal or fetal. However, it also constitutes of unknown etiology; known as unexplained recurrent spontaneous abortions (URSA). In this study, the medical terminated human normal early pregnancies (NEP) of the first trimester were taken as control samples, the normal decidual sample whose molecular and epigenetic changes were compared with that of decidua of human URSA subjects. Apoptosis-related genes reported in consecutive recurrent pregnancy loss became the basis for this study. So, in this study, we evaluated the hypothesis that "p53 methylation level through methyltransferases (G9aMT and DNMT1) implicates the fate of embryo towards sustenance or cessation of pregnancy". Further, the interaction between P53, BAX, BCL-2, CASPASE-6, G9aMT, DNMT-1, and methylated p53 expression level(s) during the first trimester of both URSA and NEP are included in this study. The degree of p53 methylation during the first trimester is found to be significant and positively correlated with that of G9aMT (p < 0.05), BCL-2 (p < 0.001), and DNMT1 (p < 0.001) at both transcript and protein level. A significant and negative correlation (with p-value < 0.001) between the degree of p53 methylation during the first trimester and that of the expression level of TUNEL assay (Apoptosis), P53, BAX, and CASPASE-6 are also observed in the present study. A positive correlation between apoptosis and a higher level of p53 expression (which is possibly due to low degree of p53 methylation) is observed both at the transcript and protein level in URSA which is in line with our findings. The analysis performed using structural equation modelling (SEM) further throws light on the causal relationship between sustenance of pregnancy or URSA during the first trimester of a human pregnancy and degree of methylation of p53 which is closely correlated with the interaction between G9aMT, DNMT1, BCL-2, BAX, P53, CASPASE-6, and apoptosis.

Apoptotic functions of microRNAs in pathogenesis, diagnosis, and treatment of endometriosis

MicroRNAs or miRNAs are a component of the non-coding RNAs family which is engaged in many cellular functions such as cell proliferation, apoptosis, gene expression, signaling pathways, angiogenesis, and etc. Endometriosis is a malignant gynecologic disorder occurring in women before menopausal age. Pathogenesis of this illness is still a discussion subject between the scientists but in our knowledge, microRNAs can be one of the possible involved factors. The purpose of this paper is to investigate the role of apoptotic activities of miRNAs in endometriosis. Accumulative evidence has demonstrated the role of cell proliferation, apoptosis, and invasion in the progression of these diseases. In this review, we looked into the specific role of apoptosis and its related genes and pathways in endometriosis and tied to present an explanation of how miRNAs can affect endometriosis by their apoptotic activities. What we found is that a great extent of miRNAs is involved in this illness and they are responsible for repressing apoptosis and progression of the disease. As a result, miRNAs have two different usages in endometriosis: biomarkers and potential therapeutic targets. In this review we gathered a great amount of evidence to inquire into the role of micro RNAs in inducing apoptosis and how this mechanism can be exerted for therapeutic purposes for endometriosis.

Hepatocyte nuclear factor-1 beta protects endometriotic cells against apoptotic cell death by up-regulating the expression of antiapoptotic genes†

The overexpression of hepatocyte nuclear factor-1 beta (HNF1β) in endometriotic lesion has been demonstrated. However, the role of HNF1β in endometriosis remains largely unknown. Human endometriotic 12Z cells showed higher level of HNF1β when compared with normal endometrial HES cells. In human endometriotic 12Z cells, HNF1β knockdown increased susceptibility to apoptotic cell death by oxidative stress, while HNF1β overexpression suppressed apoptosis. In addition, HNF1β knockdown and overexpression significantly decreased and increased, respectively, the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-dependent antiapoptotic genes. Knockdown of the antiapoptotic genes significantly reduced the HNF1β-induced resistance against oxidative stress in 12Z cells. Furthermore, HNF1β regulated the transcriptional activity of NF-κB, and an NF-κB inhibitor suppressed the HNF1β-enhanced NF-κB-dependent antiapoptotic gene expression and the resistance of the 12Z cells against cell death. Taken together, these data suggest that HNF1β overexpression may protect endometriotic cells against oxidative damage by augmenting antiapoptotic gene expression.

Effects of WD‑3 on tumor growth and the expression of integrin αvβ3 and ERK1/2 in mice bearing human gastric cancer using the 18F‑RGD PET/CT imaging system

Activation of the vitronectin receptor α_vβ₃ and the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 are critical events during tumor development and progression. The aim of the present study was to investigate the effects of WD-3, a formula used in traditional Chinese medicine, on integrin α_vβ₃ and ERK1/2 expression in vivo using a nude mouse-human gastric cancer xenograft model combined with non-invasive, real-time ¹⁸F-Arg-Gly-Asp (RGD) positron emission tomography (PET)/computerized tomography (CT) imaging methods. SGC-7901 human gastric cancer cells were subcutaneously injected into BALB/c nude mice. Following tumor development, animals were randomly assigned into the following 4 groups (n=6 mice/group): Control group (CG), Chinese medicine group (CMG), Western medicine group (WMG) and Chinese and Western medicine combination group (CMG + WMG). Mice in the CG and CMG received daily intragastric injections of 0.5 ml saline and 0.5 ml WD-3, respectively. Mice in the WMG received an intravenous injection of albumin-bound paclitaxel (25 mg/kg) on days 0, 2 and 4 Mice in the CMG + WMG received combination therapy of WD-3 and albumin-bound paclitaxel. Tumor growth was monitored using standard caliper technique and via PET imaging. ¹⁸F-RGD PET/CT analysis was performed on days 3, 7, 18 and 24 following drug administration. Radioactivity uptake was measured and expressed as the percentage of injected dose (ID) per tissue weight (%ID/g) and the standardized uptake value (SUV). Animals were sacrificed at 30 days following treatment and tumor weight was measured. Immunohistochemistry was used to detect the expression of phosphorylated (p)-ERK1/2 protein in tumor tissue samples. No statistically significant differences were observed in %ID/g and SUV among the various groups prior to treatment. At the end of treatment, mice in the CMG, WMG and CMG + WMG exhibited significantly reduced tumor mass when compared with mice in the CG. In addition, mice in the CMG and CMG + WMG demonstrated reduced %ID/g and SUV when compared with mice in the CG. Conversely, mice in the WMG exhibited no significant difference in %ID/g and SUV compared with the CG. Furthermore, p-ERK1/2 expression was significantly reduced in mice from all treatment groups when compared with those in the CG. The results of the present study suggest that the traditional Chinese formula WD-3 may inhibit gastric tumor growth, potentially via the downregulation of integrin α_vβ₃ and the inhibition of ERK1/2 phosphorylation in vivo.

Elevated Serum CD95/FAS and HIF-1α Levels, but Not Tie-2 Levels, May Be Biomarkers in Patients With Severe Endometriosis: A Preliminary Report

STUDY OBJECTIVE

To evaluate serum values of cluster of differentiation 95 (CD95/FAS), hypoxia-inducible factor 1-alpha (HIF-1α), and tyrosine kinase receptor 2 (Tie-2) as possible biomarkers of disease presence and severity in women with endometriosis, and to characterize the changes in these values in women with stage I/II and stage III/IV endometriosis.

DESIGN

Prospective study (Canadian Task Force classification I).

SETTING

University hospital.

PATIENTS

Thirty women with endometriosis and 30 healthy women without endometriosis.

INTERVENTION

For the diagnosis of endometriosis and prediction of its severity, we measured the serum levels of CD95/FAS, which assess apoptotic conditions, and of HIF-1α and Tie-2, which assess angiogenesis. Endometriosis was diagnosed and staged through surgical laparoscopy and later confirmed histologically. During the surgery, the patients with endometriosis were divided into 2 groups based on disease stage. Eleven patients had stage I/II endometriosis, and 19 had stage III/IV endometriosis.

MEASUREMENTS AND MAIN RESULTS

Endometriosis was associated with increased serum CD95/FAS and HIF-1α levels, but not Tie-2 levels. We also determined that stage III/IV endometriosis was associated with higher serum CD95/FAS and HIF-1α levels, but not Tie-2 levels, compared with stage I/II endometriosis.

CONCLUSION

Endometriosis, in accordance with its severity, increases serum CD95/FAS and HIF-1α levels, but not Tie-2 levels. These biomarkers may be useful for reproductive surgeons to improve the quality of counseling women about the presence and severity of endometriosis.

Deep Invasive Endometriosis Lesions of the Rectosigmoid May Be Related to Alterations in Cell Kinetics

OBJECTIVES

The aim of this study was to analyze cell kinetics through expression and apoptosis of topoisomerase 2-α (TOP2A), p53, and c-erb2 in rectosigmoid endometriotic lesions and in healthy endometrial tissue and to establish correlations between such findings and clinical data in patients with rectosigmoid endometriosis.

METHODS

Sixty patients with rectosigmoid endometriosis and 20 control women without endometriosis were included. Immunohistochemical assays were used to measure expression of TOP2A, p53, and c-erB-2. Apoptosis was quantified by directly counting the apoptotic bodies.

FINDINGS

The number of lesions was positively correlated with expression of TOP2A in the lesion. There was also significant correlation between the lesions' size and number and cell turnover index. Apoptosis index (AI) was the same for endometriosis lesions and eutopic endometrium. Expression of TOP2A was significantly lower in the endometriosis group compared to the controls.

CONCLUSIONS

Changes in cell proliferation but not in the AI in rectosigmoid endometriosis are indicative of an imbalance in cell kinetics that may lead to the development of the disease.

Oestrous cycle-dependent expression of Fas and Bcl2 family gene products in normal canine endometrium

During the oestrous cycle canine endometrium undergoes cyclical cellular proliferation, apoptosis and differentiation. To study the regulation of endometrial apoptosis and proliferation events the expression of apoptosis-related genes was analysed by real-time polymerase chain reaction and cellular expression of their proteins was identified through immunohistochemistry. Cellular apoptosis and proliferation events were detected by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and proliferation marker Ki67 immunostaining, respectively. The highest proliferative index was observed in the follicular phase (all endometrial cellular components) and at early dioestrus (basal glands). This was associated with a low apoptotic index and a strong expression of anti- (Bcl2) and pro-apoptotic proteins (Fas, FasL, Bax). Subsequently (Days 11-45 of dioestrus), basal glandular epithelium experienced the highest apoptotic index, coincidental with a decrease of Bcl2 expression and a low ratio of Bcl2/Bax transcription. An increase in the apoptotic index of crypts, stromal and endothelial cells was observed at late dioestrus and the beginning of anoestrus. These results indicate that pro- and anti-apoptotic proteins regulate the balance between cell proliferation and death in the canine endometrium during the oestrous cycle. High Bcl2 expression in both the follicular and early dioestrous phases stimulate glandular proliferation and prevent apoptosis but, in the non-pregnant uterus, a decrease in Bcl2 expression together with an increase in pro-apoptotic proteins induces apoptosis of basal glandular epithelium cells.

Inhibitor of apoptosis proteins (IAPs) may be effective therapeutic targets for treating endometriosis

STUDY QUESTION

What is the role of the inhibitor of apoptosis proteins (IAPs) in human endometriotic tissues and a mouse model of endometriosis?

SUMMARY ANSWER

Four IAP proteins were expressed in endometriotic tissue indicating IAPs may be a key factor in the pathogenesis and progression of endometriosis.

WHAT IS KNOWN ALREADY

Overexpression of IAPs protects against a number of proapoptotic stimuli. IAPs (c-IAP1, c-IAP2, XIAP and Survivin) are expressed in human ectopic endometrial stromal cells (ESCs) from ovarian endometriomas.

STUDY DESIGN, SIZE, DURATION

Forty-eight women with or without ovarian endometrioma are included in this study. BALB/c mice (n = 24) were used for the mouse endometriosis model. Mice with surgically induced endometriosis were treated with an IAP antagonist (BV6) for 4 weeks.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Human ectopic endometrial tissues from chocolate cysts and eutopic endometrial tissue were collected. ESCs were enzymatically isolated from these tissues. ESC proliferation was examined by 5-bromo-2'-deoxyuridine-enzyme-linked immunosorbent assay. IAPs expression in tissue derived from eutopic endometria and chocolate cysts was evaluated using real-time RT-PCR and immunohistochemistry. A homologous mouse endometriosis model was established by transplanting donor mouse uterine tissue into the abdominal cavities of recipient mice. After treating the mice with BV6 (i.p. 10 mg/ml), the extent of endometriosis-like lesions in mice was measured and proliferative activity assessed by Ki67 staining. All experiments were repeated a minimum of three times.

MAIN RESULTS AND THE ROLE OF CHANCE

IAP (c-IAP1, c-IAP2, XIAP and Survivin) mRNA and protein in human ectopic endometrial tissues were expressed at higher levels than in eutopic endometrial tissues (P < 0.05). All four IAPs proteins were expressed in mouse endometriosis-like implants. BV6 inhibited BrdU incorporation of human ESCs (P < 0.05 versus control). BV6 also decreased the total number, weight, surface area and Ki67 positive cells in the endometriosis-like lesions in the mice (P < 0.05 versus control).

LIMITATIONS, REASONS FOR CAUTION

Endometriotic lesions were surgically induced in mice by transplanting mouse uterine tissue only, not human pathological endometriotic tissue. Furthermore, the effects of BV6 on human ESCs and mouse endometriosis-like lesions may differ between the species.

WIDER IMPLICATIONS OF THE FINDINGS

Our data support the hypothesis that IAPs are involved in the development of endometriosis, and therefore an inhibitor of IAPs has potential as a novel treatment for endometriosis.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by KAKENHI (Japan Society for the Promotion of Science, Grant-in-Aid: to F.T.; 21592098 and to T.H.; 24659731) and Yamaguchi Endocrine Research Foundation. The authors have no conflicts of interest to disclose.

Growth mechanisms of endometriotic cells in implanted places: a review

Endometriosis is a common gynecological disease defined by extrauterine growth of endometrial glands and stroma. A variety of theories have been proposed to account for the pathogenesis of this disease, including retrograde transplantation theory, metaplasia of coelomic epithelium, hematogenic and lymphogenic spread, and remnants of the Mŭllerian duct. However, the etiopathology of endometriosis is still obscure. In this article, we aim to summarize recent researches concerning the growth mechanisms of endometriotic cells in implanted sites systematically, including the adhesion, invasion, angiogenesis, proliferation, apoptosis of endometriotic cells, variations of the immune molecules and endometriotic cells themselves, which may provide clues for future researches in the pathogenesis of endometriosis.

Apoptosis resistance in endometriosis

INTRODUCTION

In a cytological analysis of endometriotic lesions neither granulocytes nor cytotoxic T-cells appear in an appreciable number. Based on this observation we aimed to know, whether programmed cell death plays an essential role in the destruction of dystopic endometrium. Disturbances of the physiological mechanisms of apoptosis, a persistence of endometrial tissue could explain the disease. Another aspect of this consideration is the proliferation competence of the dystopic mucous membrane.

METHODS

Endometriotic lesions of 15 patients were examined through a combined measurement of apoptosis activity with the TUNEL technique (terminal deoxyribosyltransferase mediated dUTP Nick End Labeling) and the proliferation activity (with the help of the Ki-67-Antigens using the monoclonal antibody Ki-S5).

RESULTS

Twelve out of 15 women studied showed a positive apoptotic activity of 3-47% with a proliferation activity of 2-25% of epithelial cells. Therefore we concluded that the persistence of dystopic endometrium requires proliferative epithelial cells from middle to lower endometrial layers.

CONCLUSION

A dystopia misalignment of the epithelia of the upper layers of the functionalism can be rapidly eliminated by apoptotic procedures.

Apoptosis is increased and cell proliferation is decreased in out-of-phase endometria from infertile and recurrent abortion patients

BACKGROUND

Various endometrial abnormalities have been associated with luteal phase deficiency: a significant dyssynchrony in the maturation of the glandular epithelium and the stroma and a prevalence of out-of-phase endometrial biopsy specimens. Out-of phase endometrium is a controversial disorder related to failed implantation, infertility and early pregnancy loss. Given that the regulation of the apoptotic process in endometrium of luteal phase deficiency is still unknown, the aim of this study was to evaluate cell proliferation, apoptosis and the levels of the main effector caspase, caspase-3 in the luteal in-phase and out-of-phase endometrium.

METHODS

Thirty-seven endometrial samples from sterile or recurrent abortion patients were included in this study: 21 in-phase samples (controls) and 16 samples with out-of-phase endometrium. Biopsy specimens of eutopic endometrium were obtained from all subjects during days 21-25 of the menstrual cycle. The endometrium with endometrial maturity of cycle day 25 or less at the time of menstruation was considered out-of phase. Endometrial tissues were fixed in 10% buffered formaldehyde. For apoptosis quantification, sections were processed for in situ immunohistochemical localization of nuclei exhibiting DNA fragmentation, by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP digoxygenin nick-end labeling (TUNEL) technique. Expressions of Proliferating Cell Nuclear Antigen (PCNA) as a marker of cell proliferation, and of cleaved caspase-3 as a marker of apoptosis, were assessed by immunohistochemistry in the luteal in-phase and out-of-phase endometrium from infertile and recurrent abortion patients.

RESULTS

Luteal out-of-phase endometrium had increased apoptosis levels compared to in-phase endometrium (p < 0.05). Caspase-3 evaluation confirmed these results: the luteal out-of-phase endometrium showed augmented cleaved caspase-3 expression (p < 0.005). As well, our data demonstrated that the luteal out-of-phase endometrium expresses decreased PCNA levels (p < 0.05), showing that cell proliferation is diminished in this tissue.

CONCLUSIONS

this study represents the first report describing variations at the cell proliferation and cell death levels in the out-of-phase endometrium in comparison with in-phase endometrium from infertile and recurrent abortion patients. Further studies are needed to elucidate a potential role of these alterations in the physiopathology of luteal phase deficiency.

Effects of the levonorgestrel-releasing intrauterine system on cell proliferation, Fas expression and steroid receptors in endometriosis lesions and normal endometrium

BACKGROUND

The objectives of this study were: (i) to evaluate the effects of the levonorgestrel-releasing intrauterine system (LNG-IUS) on both proliferation and apoptosis markers and hormone receptors of the eutopic and ectopic endometrium of women experiencing pain related to endometriosis and (ii) to compare the results with those obtained with GnRH agonist (GnRHa) injections.

METHODS

Pre- and post-treatment endometrium and endometriosis specimens were obtained from 22 women experiencing pain related to endometriosis who were treated with LNG-IUS (n = 11) or GnRHa (n = 11) for 6 months. Changes in the expression of proliferating cell nuclear antigen, Fas, progesterone receptor (PRA) and estrogen receptor alpha (ER-alpha) were analyzed by immunohistochemistry.

RESULTS

The cell proliferation index was significantly reduced in the epithelium and stroma of both the eutopic and the ectopic endometrium after treatment with the LNG-IUS and GnRHa. Only LNG-IUS users showed an increased H-score for Fas in the epithelium of the eutopic and ectopic endometrium (P < 0.05). Expression of ER-alpha and PRA by the glandular epithelium was lower in the eutopic endometrium after both treatments, but this reduction was noted in the ectopic endometrium only after LNG-IUS treatments (P < 0.05). No difference was detected between groups for any of the markers.

CONCLUSIONS

LNG-IUS reduced both cell proliferation and the expression of PRA and ER-alpha and increased Fas expression in the eutopic and ectopic endometrium of patients with endometriosis. Some of these actions were not observed with GnRHa.

MicroRNA signature and regulatory functions in the endometrium during normal and disease states

During the menstrual cycle, human endometrium undergoes extensive cyclic morphologic and biochemical modifications in preparation for embryo implantation. These processes are highly regulated by ovarian steroids and various locally expressed gene products and involve inflammatory reaction, apoptosis, cell proliferation, angiogenesis, differentiation (tissue formation), and tissue remodeling. MicroRNAs (miRNAs) have emerged as key regulators of gene expression, and their altered and/or aberrant expression has been associated with establishment and progression of various disorders, including tumorigenesis. This review highlights the endometrial expression of miRNAs and their potential regulatory functions under normal and pathologic conditions such as endometriosis, dysfunctional uterine bleeding, and endometrial cancer. Given the key regulatory function of miRNAs on gene expression stability, understanding the underlying mechanisms of how endometrial miRNAs are regulated and identifying their specific target genes and their functions might lead to the development of preventive and therapeutic strategies by regulating specific target genes associated with such reproductive disorders.

Immunohistochemical expression of PTEN in normal, hyperplastic and malignant endometrium and its correlation with hormone receptors, bcl-2, bax, and apoptotic index

PTEN is a tumor suppressor gene that is frequently mutated in type I endometrioid endometrial carcinomas (EECs), and is involved in the control of cell proliferation, differentiation, and apoptosis. In this study, we aimed to assess the relationship between PTEN expression and estrogen, progesterone receptors (PRs), other apoptosis-related proteins, such as bcl-2 and bax, and apoptotic index (AI) in EEC, its precursor lesion hyperplasia, and cyclical endometrium. We also evaluated the relationship between PTEN expression and clinicopathologic parameters. PTEN, estrogen receptor (ER), PR, and bcl-2 and bax expressions were evaluated immunohistochemically, and AI was evaluated in hematoxylin and eosin (HE)-stained slides in 23 cyclical and 37 hyperplastic endometria and in 35 EECs. PTEN expression was higher in cyclical endometrium than in the carcinomas (p<0.05). The PTEN expression level was significantly higher in non-atypical hyperplasias than in EEC, but there were no differences between atypical complex hyperplasia (ACH) and EEC and between hyperplasias. In the carcinomas, there was a negative correlation between grade and PTEN expression (r=-0.338, p=0.047). In conclusion, we presume that PTEN is involved in the early phases of endometrial tumorigenesis, and it can be speculated that decreased PTEN expression with loss of differentiation in carcinoma can contribute to the emergence of tumors with a more aggressive phenotype.

Endometriosis: epidemiology and aetiological factors

Estimates of the frequency of endometriosis vary widely. Based on the few reliable data, the prevalence of the condition can reasonably be assumed to be around 10%. Although no consistent information is available on the incidence of the disease, temporal trends suggest an increase among women of reproductive age. This could be explained-at least in part-by changing reproductive habits. Numerous epidemiological studies have indicated that nulliparous women and women reporting short and heavy menstrual cycles are at increased risk of developing endometriosis; data on other risk factors are less consistent. These epidemiological findings strongly support the menstrual reflux hypothesis. Additional evidence in favour of this theory includes the demonstration of viable endometrial cells in the menstrual effluent and peritoneal fluid, experimental implantation and growth of endometrium within the peritoneal cavity, observation of some degree of retrograde menstruation in most women undergoing laparoscopy during menses, and an association between obstructed menstrual outflow and endometriosis.

Nuclear factor-kappab (NF-kappaB): an unsuspected major culprit in the pathogenesis of endometriosis that is still at large?

Endometriosis, defined as the ectopic presence of endometrial glandular and stromal cells outside the uterine cavity, is a common benign gynecological disorder with an enigmatic pathogenesis. Many genes and gene products have been reported to be altered in endometriosis, yet some of them may not be major culprits but merely unwitting accomplices or even innocent bystanders. Therefore, the identification and apprehension of major culprits in the pathogenesis of endometriosis are crucial to the understanding of the pathogenesis and would help to develop better therapeutics for endometriosis. Although so far NF-kappaB only has left few traces of incriminating fingerprints, several lines of investigation suggest that NF-kappaB, a pivotal pro-inflammatory transcription factor, could promote and maintain endometriosis. Various inflammatory agents, growth factors, and oxidative stress activate NF-kappaB. NF-kappaB proteins themselves and proteins regulated by them have been linked to cellular transformation, proliferation, apoptosis, angiogenesis, and invasion. Interestingly, all existing and nearly all investigational medications for endometriosis appear to act through suppression of NF-kappaB activation. In endometriotic cells, NF-kappaB appears to be constitutively activated, and suppression of NF-kappaB activity by NF-kappaB inhibitors or proteasome inhibitors suppresses proliferation in vitro. Viewing NF-kappaB as a major culprit, an autoregulatory loop model can be postulated, which is consistent with existing data and, more importantly, can explain several puzzling phenomena that are otherwise difficult to interpret based on prevailing theories. This view has immediate and important implications for novel ways to treat endometriosis. Further research is warranted to precisely delineate the roles of NF-kappaB in the pathogenesis of endometriosis and to indict and convict its aiders and abettors.

Effect of GnRH analogues on apoptosis and expression of Bcl-2, Bax, Fas and FasL proteins in endometrial epithelial cell cultures from patients with endometriosis and controls

BACKGROUND

Our purpose was to evaluate the effect of the GnRH agonist (GnRHa), leuprolide acetate (LA), and the GnRH antagonist (GnRHant), Antide, on apoptosis and expression of apoptosis-related proteins in endometrial epithelial cell (EEC) cultures from patients with endometriosis and controls (infertile women without endometriosis).

METHODS

Biopsy specimens of eutopic endometrium were obtained from 22 patients with endometriosis and from 14 women that served as controls. Apoptosis was examined in EEC after incubation with LA and Antide. Bax, Bcl-2, Fas and FasL expression was evaluated after exposure to LA, Antide or a combination of both. The percentage of apoptotic cells (%ApC) was assessed by the acridine orange-ethidium bromide technique, and protein expression was evaluated by western blot and immunocytochemistry.

RESULTS

LA 100 and 1000 ng/ml increased the %ApC in EEC from patients with endometriosis (both P < 0.05) and controls (p < 0.05 and P < 0.01, respectively). Antide 10(-5) M increased the %ApC in EEC from patients with endometriosis and controls (P < 0.01). In EEC from women with endometriosis, Bax expression increased after treatment with LA, Antide and LA + Antide (P < 0.05, P < 0.001 and P < 0.001), whereas Bcl-2 expression decreased after exposure to LA and Antide (P < 0.001 and P < 0.01). FasL expression increased after LA, Antide and LA + Antide treatments (P < 0.01, P < 0.001 and P < 0.01). No significant changes were observed on Fas expression.

CONCLUSIONS

GnRH analogues enhanced apoptosis in EEC, and this was accompanied by an increase in expression of the pro-apoptotic proteins Bax and FasL and a decrease in expression of the anti-apoptotic protein Bcl-2.

Inhibition of proliferation of endometrial stromal cells by trichostatin A, RU486, CDB-2914, N-acetylcysteine, and ICI 182780

BACKGROUND

All current major medications in treating endometriosis are effective in treating pain, most likely through suppression of proliferation of the implants, yet their effectiveness is relatively short term and they all have many undesirable, and sometimes severe, side effects. There is pressing need for novel, more effective medications in treating endometriosis with less and/or milder side effects.

METHODS

Using a recently established immortalized endometrial stromal cell line, we carried out cell proliferation assays for cells treated with trichostatin A (TSA), RU486, CDB-2914, and N-acetylcysteine, and ICI 182780. Gene expression levels for PR-A, PR-B, AR, Fas and FasL were measured. Protein expression levels for ERalpha, ERbeta, and AR were also measured.

RESULTS

Cell proliferation assay results for NAC, H2O2, CDB, and RU486 were nearly identical or similar to what have been reported based on primary cell cultures or in vivo studies. TSA, CDB, RU486 and NAC all had various antiproliferative effects. TSA had a more potent and longer lasting antiproliferative effect than CDB and NAC, even in the presence of an oxidant, H2O2. Its antiproliferative effect was concentration-dependent. ICI did not have a significant antiproliferative effect. PR-A, PR-B, AR, and FasL expression were all increased as compared with untreated cells.

CONCLUSIONS

The cell line appears to be an adequate model for stromal components of endometriotic implants. That ICI has no inhibitory effect on endometrial proliferation may explain why a phase II clinical trial on its use to treat endometriosis did not advance to later stages. The upregulation of PR-B and AR may be responsible for antiproliferative effects induced by TSA, a histone deacetylase inhibitor (HDACI). HDACIs may be promising therapeutics in treating endometriosis due to their antiproliferative effects as well as the potential to restore gene dysregulation through chromatin remodeling.

Bufalin induces apoptosis and the G0/G1 cell cycle arrest of endometriotic stromal cells: a promising agent for the treatment of endometriosis

Most of the current medical treatments for endometriosis aim to down-regulate the estrogen activity. However, a high recurrence rate after medical treatments has been the most significant problem. Bufalin is a major digoxin-like immunoreactive component isolated from the skin and parotid venom glands of toad and is considered an apoptosis-inducing agent. To apply bufalin to the medical treatment of endometriosis, we investigated the effects of this agent on the cell proliferation and apoptosis of cultured ovarian endometriotic cyst stromal cells (ECSC) by a modified methylthiazoletetrazolium (MTT) assay, a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and internucleosomal DNA fragmentation assays. The effect of bufalin on the cell cycle of ECSC was also determined by flow cytometry. The expression of apoptosis- and cell cycle-related molecules was also examined in ECSC using Western blot analysis. Bufalin significantly inhibited the cell proliferation and DNA synthesis of ECSC and induced apoptosis and the G0/G1 phase cell cycle arrest of these cells. The down-regulation of the cyclin A, Bcl-2, and Bcl-X(L) expression with the simultaneous up-regulation of the p21 and Bax expression, and caspase-9 activation was observed in ECSC after bufalin treatment. It is suggested that bufalin induces apoptosis of ECSC by simultaneously suppressing anti-apoptotic proteins and inducing pro-apoptotic proteins. Caspase-9-mediated cascade is involved in this mechanism. Therefore, bufalin could be used as a therapeutic agent for the treatment of endometriosis.

Expression of apoptosis-related proteins in peritoneal, ovarian and colorectal endometriosis

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterus. Apoptosis, a physiological process by which multicellular organisms eliminate superfluous cells, is altered in tumor tissue. Here we studied the expression of the apoptosis-related proteins p53, bcl-2, bax, p21 and fas in proliferative (n=9) and secretory (n=9) endometrium, and in peritoneal (n=11), ovarian (n=20) and colorectal (n=20) endometriosis, by qualitative and semi-quantitative immunohistochemical methods using the percentage of positive cells and HSCORE analysis. In endometrium, p53, p21 and fas expression was low, whereas bax and bcl-2 expression was elevated. Using HSCORE analysis, only bcl-2 expression varied during the menstrual cycle (48.9+/-34.2% in the proliferative phase, 11.5+/-24.7% in the secretory phase, p=0.01). Using HSCORE analysis, p53 expression was higher in ovarian endometriosis than in peritoneal (p<0.0001) and colorectal endometriosis (p=0.03). P21 expression was higher in ovarian endometriosis than in peritoneal (p=0.01) and colorectal endometriosis (p=0.01). Bcl-2 expression was lower in ovarian endometriosis than in peritoneal (p=0.0002) and colorectal endometriosis (p<0.0001). Fas expression was higher in peritoneal endometriosis than in ovarian (p=0.02) and colorectal endometriosis (p=0.008). In conclusion, these results confirm the involvement of apoptosis in the pathogenesis of endometriosis. Moreover, expression of apoptosis-related proteins varies according to the location of endometriosis suggesting the involvement of different apoptotic pathways.

Apoptosis and expression of Bcl-2 in human endometrium in natural and artificial cycles

Apoptosis plays a significant role in differentiation of many organs and helps to maintain homeostasis. The occurrence of apoptosis (using the apoptotic index) and expression of regulation protein Bcl-2 in the human endometrium was evaluated within the secretory phase of both the natural cycle, and an artificial one. Oral hormonal substitution used in this design induced similar, but more marked dynamic changes in Bcl-2 expression in the mid-secretory endometrium as were observed in the natural cycle, primarily in the surface and glandular epithelium of the endometrium. The apoptosis revealed similar a trend, but not significantly different.

Reduced thymic output, increased spontaneous apoptosis and oligoclonal B cells in polyethylene glycol-adenosine deaminase-treated patients

Impairment of purine metabolism due to adenosine deaminase (ADA) deficiency is associated with a severe combined immunodeficiency (SCID). Polyethylene glycol-modified ADA (PEG-ADA) has provided noncurative, life-saving treatment for these patients, but full immune recovery is not achieved with this therapy. Since ADA-SCID is perhaps the most difficult form of SCID to handle clinically, understanding the benefits and limitations of PEG-ADA therapy may be relevant for treatment selection. To this purpose, we analyzed the rate of thymic output, T and B cell repertoires, number of T cell divisions, IFN-gamma and IL-4 production, and the extent of cell death in five ADA-SCID patients following a prolonged period of treatment with PEG-ADA. We found that thymic output was low in these patients. However, their T cell repertoire was heterogeneous, and their T lymphocytes produced cytokines upon activation and responded to mitogen stimulation, although with different kinetics. Furthermore, a high number of peripheral T lymphocytes were committed to apoptosis. Anomalies were also observed in the B cell compartment, with oligoclonal expansions of B cell clonotypes in two patients. Our data indicate that decreased thymic function, B cell oligoclonality, and increased spontaneous apoptosis may be the mechanisms by which the immunodeficiency of ADA-SCID patients persists in spite of treatment with PEG-ADA.

Effect of mifepristone on proliferation and apoptosis of Ishikawa endometrial adenocarcinoma cells

OBJECTIVE

To determine the mechanism by which mifepristone improves breakthrough bleeding, the effects of mifepristone on proliferation and apoptosis of Ishikawa endometrial carcinoma cells were evaluated in the presence and absence of progestin.

DESIGN

Prospective basic research study.

SETTING

Research laboratories for reproductive health at a university medical school.

PATIENT(S)

None.

INTERVENTION(S)

Ishikawa cells were cultured in vitro. Mifepristone and/or medroxyprogesterone acetate at various concentrations were added to the cells.

MAIN OUTCOME MEASURE(S)

Determination of cell proliferation and apoptosis.

RESULT(S)

Colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and bromodeoxyuridine (BrdU) labeling analysis demonstrated that mifepristone inhibited the growth of Ishikawa cells and percentage of BrdU-labeled cells in a time- and dose-dependent manner. Flow cytometry analysis demonstrated that mifepristone at 100 micromol/L, which completely inhibited cell proliferation, increased the proportion of cells in the S phase and diminished the cells in the G2/M phase. Apoptosis was identified by annexin-V-fluorescein isothiocyanate binding and caspase-3 activation. Immunofluorescent double labeling of Ishikawa cells in the absence or presence of mifepristone revealed that BAX protein expression increased and translocated from cytosol to mitochondria.

CONCLUSION(S)

Mifepristone inhibited cell growth by arresting cell cycle progression at S phase, induced apoptosis through caspase-3 activation, and modulated apoptosis regulatory genes BCL2/BAX and FAS/FASLG in Ishikawa cells. Together, these data imply that the improvement in breakthrough bleeding observed with mifepristone might be due to diminished volume of endometrial tissue similar to that seen with endometrial atrophy.

Endometriotic cells are resistant to interferon-gamma-induced cell growth inhibition and apoptosis: a possible mechanism involved in the pathogenesis of endometriosis

In order to evaluate the involvement of cell proliferation and apoptosis in the pathogenesis of endometriosis, we investigated the effects of interferon-gamma (IFN-gamma) on cell growth inhibition and apoptosis of cultured ovarian endometriotic cyst stromal cells (ECSC), eutopic endometrial stromal cells with endometriosis (ESCwE) and normal endometrial stromal cells (NESC) by modified methylthiazoletetrazolium assay, 5-bromo-2'-deoxyuridine incorporation assay and internucleosomal DNA fragmentation assay. The expression of apoptosis-related molecules and IFN-gamma receptor 1 was also examined in ECSC, ESCwE and NESC using western blot analysis. IFN-gamma significantly inhibited cell proliferation and DNA synthesis of ESCwE and NESC, and induced apoptosis of these cells. In contrast, IFN-gamma did not show apparent effects on the viable cell number, DNA synthesis, or apoptosis of ECSC. An up-regulated expression of Bcl-2 and Bcl-X(L) proteins was observed in ECSC in comparison with ESCwE and NESC, whereas the levels of Bax, Bad, Fas and Fas ligand proteins in ECSC were similar to those in ESCwE and NESC. IFN-gamma receptor 1 expression was detected in ECSC, ESCwE and NESC. Enhanced expression of anti-apoptotic molecules in the ectopic endometrial cells may contribute to the development of endometriosis by conferring resistance to cytokine-induced apoptosis and increasing the chance that these cells will survive and implant outside the uterus. Further investigations on the regulation of cell proliferation in both the endometriotic and the normal endometrium may be important for the elucidation of the pathogenesis of endometriosis.

Fas, FasL, Bcl-2, and Bax in the endometrium of rhesus monkey during the menstrual cycle

To study possible role and regulation of apoptosis occurred in primate endometrium, the expression of apoptosis-related molecules, Fas, FasL, B cell lymphoma/leukaemia-2 (Bcl-2), and Bax were analyzed in relation to occurrence of apoptosis and proliferation in the cycling endometrium of the rhesus monkey using immunohistochemistry and Western blot. The cell apoptosis and proliferation were evaluated by means of in situ 3'-end labeling and Ki67 immunostaining, respectively. The results showed that the expressions of Fas, Fas ligand (FasL), Bcl-2, and Bax were co-localized predominantly in the epithelial cells of the endometrium. Modest Fas staining with no obvious change was detected throughout the menstrual cycle, while the levels of FasL and Bax protein in the epithelial cells increased in the secretory phase when apoptosis was most prevalent. In contrast, epithelial immunostaining for Bcl-2 was maximal during the proliferative phase and decreased in the secretory phase. Bcl-2 immunoreactivity was also detected in some immunocytes. The coordinated expression of Fas, FasL, Bcl-2, and Bax in the cycling endometrium of the rhesus monkey suggests that the cyclic changes in endometrial growth and regression may be regulated by the balance of these factors under the action of ovary steroids.

Endocrine-Immune Interactions in Human Endometrium

The immune system is a complex entity designed to eliminate foreign intruding antigens and is influenced by and, in turn, influences the function of the reproductive system. Despite the widespread associations between immunology and reproductive medicine, the study of system interactions remains in its infancy. Many diverse facts are accumulating, and pieces of the puzzle are becoming available to provide a clearer picture. In this review article, we focus on the interactions between endocrine and immune systems in the human endometrium. Understanding the molecular pathways in endocrine-immune interactions in the human endometrium is crucial to understand events such as menstrual bleeding, tissue repair and regeneration, inflammation, angiogenesis, blastocyst implantation, and progression of pregnancy. These events require a balanced regulation of endometrial differentiation, proliferation, cell survival, leukocyte recruitment, apoptosis, and angiogenesis by sex steroids. In this review, we first outline the role of survival factors such as phosphoinositol 3-kinase/protein kinase B, PTEN, NFkappaB, and apoptotic molecules (Fas-FasL, Bcl-2). We then discuss their regulation by estrogen and progesterone in the endometrium. We present evidence for direct and/or indirect roles of steroid hormones on the expression of chemotactic cytokines (interleukin-8 and monocyte chemotactic protein-1) and on the survival versus apoptosis of resident endometrial cells (stromal, epithelial, and endothelial cells) and nonresident cells (leukocytes).

Ubiquitin is associated with the survival of ectopic stromal cells in endometriosis

Background

Endometriosis is a condition that affects women of reproductive age, where the glandular and/or stromal tissues from the eutopic endometrium implant in ectopic locations. It is well established that the survival of ectopic implants is due to lower levels of apoptosis, but no consensus exists as to which pathway/s this is mediated by. The ubiquitin protein shares a similar sequence homology to an anti-apoptotic protein called BAG-1 and is expressed in the normal endometrium. Currently, no studies have been conducted to determine ubiquitin expression and its possible anti-apoptotic effects in endometriosis.

Methods

Archived endometrial tissues from endometriosis patients and women undergoing laparoscopic diagnosis (controls) from January 2000 to July 2003 at Westmead Hospital were examined, where 14 cases of endometriosis and 55 controls were included in the study.

Results

Both the ubiquitin protein and apoptosis were expressed in both glandular and stromal cells throughout the menstrual cycle of the eutopic endometrium, in which ubiquitin exhibited a cyclic expression, reaching a peak in late proliferative phase. In contrast, ubiquitin was predominantly expressed in cells of stromal origin in endometriosis, was no longer regulated by a cyclic pattern and was associated with an aberrant level of cell survival.

Conclusions

For the first time, this study shows that ubiquitin is expressed in endometriotic cells and may contribute to a reduced sensitivity of ectopic endometrial tissue to apoptosis. These findings also suggest that stromal cells contribute differentially to the development of ectopic endometrial tissue.

Expression of Apoptosis-Related Proteins in Adenomyotic Uteri Treated with Danazol and GnRH Agonists

The biologic properties of adenomyosis and the effects of therapeutic agents on adenomyosis were evaluated with immunohistochemistry, terminal deoxy-nucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method, transmission electron microscopy, and analysis of genomic abnormality. In the adenomyotic endometrium, estrogen receptor (ER) expression was more intense than in the eutopic endometrium during the secretory phase, and bcl-2 was constantly expressed throughout the menstrual cycle. The expression of ER and bcl-2 was weaker in the adenomyotic endometrium treated with danazol than in that treated with gonadotro-pin-releasing hormone agonist (GnRHa), whereas bcl-2 phosphorylated on serine-87 was more intensely expressed in danazol-treated adenomyotic endometrium than in the GnRHa-treated one. The number of TUNEL-positive cells increased in the adenomyotic endometrium treated with danazol or GnRHa. Ultrastructurally, most of the adenomyotic endometrial cells treated with danazol underwent postapoptotic necrosis and formed a cluster of dead cells. In contrast, cells treated with GnRHa underwent typical apoptosis and were sparsely distributed in the adenomyotic endometrium. Analysis of several cancer-related genes showed no microsatellite instability or loss of heterozygosity in adenomyotic tissues. Therefore, we conclude that the occurrence of adenomyosis is correlated to bcl-2 expression regulated by estrogen and ER rather than genetic mutation.

Reduction of apoptosis and proliferation in endometriosis

OBJECTIVE

To evaluate whether endometriosis could be related to an impaired balance between apoptosis and proliferation, two processes which could be modulated by hormonal status.

DESIGN

Immunohistochemical study.

SETTING

Academic research laboratory.

INTERVENTION(S)

Endometriotic samples obtained from peritoneum of women aged 26-40 years who were undergoing laparoscopy for pain or infertility.

MAIN OUTCOME MEASURE(S)

Apoptotic cells were detected with the use of the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. The production of p53 and bcl-2, estrogen and Progesterone (P) receptors, and cellular proliferation were assessed by immunohistochemistry in eutopic and ectopic endometria from 30 patients with endometriosis throughout the menstrual cycle. Results were compared with those from normal endometria from 15 fertile patients.

RESULT(S)

Endometriotic lesions were characterized by reduced TUNEL and p53 stainings and by enhanced bcl-2 staining. No correlation between apoptosis and estrogen receptor or P receptor levels was found. A lower amount of steroid receptor was found in endometriotic tissues, without cyclic modulation, compared with the eutopic endometrium.

CONCLUSION(S)

Our results suggest that when endometrial tissue is located at ectopic locations, it differs from eutopic endometrium by its proliferation rate, steroid hormone levels, and markers of apoptosis. A reduced sensitivity of endometriotic cells to apoptosis could promote the dissemination and implantation of these cells to ectopic sites.

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.

Genetics of endometriosis

Endometriosis long has been recognized as showing heritable tendencies, with recurrence risks of 5% to 7% for first-degree relatives. The risk indicates that polygenic and multifactorial etiology is far more likely to be the cause than mendelian inheritance. The current task is to determine the number and location of genes responsible for endometriosis. Molecular advances of the past decade make identification and elucidation of these genes a reality. The authors review the basis for concluding that endometriosis is a genetic disorder of polygenic/multifactorial inheritance. Genome-wide strategies for identifying causative genes are considered and available data on association or linkage to putative candidate genes systematically reviewed.

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.