New considerations for the pathogenesis of endometriosis

The association between endometriosis and gynecological cancers and breast cancer: a review of epidemiological data

OBJECTIVE

This article critically reviews the literature on the association between endometriosis and gynecological cancers and breast cancer, based on epidemiologic data.

METHODS

Literature review of the English language literature based on searching in the MEDLINE (PubMed) database and additional collection of reports by systematically reviewing all references from retrieved papers.

RESULTS

Data from large cohort and case-control studies indicate that endometriosis patients only have an increased risk of ovarian cancer among the gynecological malignancies and breast cancer, although most of the observed associations are modest. Data on the association between endometriosis and breast cancer are inconsistent. Endometriosis patients have a reduced risk of cervical cancer, and there is no association between endometriosis and endometrial cancer. Endometriosis-associated ovarian cancer seems to be a distinct clinical entity; patients are younger, diagnosed in earlier stages, have lower grade lesions and a better survival. Further, endometriosis-associated ovarian cancers are predominantly clear cell and endometrioid histologic subtypes.

CONCLUSIONS

Endometriosis seems to be a precursor of epithelial ovarian cancer, especially clear cell and endometrioid adenocarcinomas. However, current evidence is insufficient to draw any definitive conclusions whether this association represents causality or the sharing of similar risk factors and/or antecedent mechanisms.

Effects of Chinese Materia Medica-Fubao Danggui Jiao on experimental endometriosis

The objective of this paper was to investigate the effects of a Chinese Materia Medica variant -Fubao Danggui Jiao (FDJ)-on experimental endometriosis. An endometriosis model was created by virtue of auto-transplantation of endometrial tissue onto rats' abdominal walls. The implants were allowed to grow for 30 days until the successful completion of the model. After that, forty endometriotic rats were randomly divided into four study groups and given different treatments: (1) negative control group (water, 2ml/kg, per os); (2) FDJ-A group (FDJ, 2ml/kg, per os); (3) FDJ-B group (FDJ, 4ml/kg, per os); (4) Danazol group (70mg/kg, per os). After 30 days with treatments, the volumes of endometriotic implants in each rat were measured. The implants and normal uterine horns were removed for routine histological examination. FDJ caused significant decreases in volumes of the surviving endometriotic implants, with two different doses having statistically equivalent effects. Upon histological examination, FDJ was observed to cause regression of epithelium and stroma of endometriotic implants. FDJ had revealed promising therapeutic effects on endometriosis.

[Effects of Quyu Jiedu Granule on expressions of tumor necrosis factor-alpha and interleukin-6 mRNAs in ovarian granulosa cells of endometriosis rats]

OBJECTIVE

To observe the effects of Quyu Jiedu Granule, a compound traditional Chinese herbal medicine for removing blood stasis and expelling superficial evils, on the quality of oocytes and the expressions of tumor necrosis factor-alpha (TNF-alpha)and interleukin-6 (IL-6) mRNAs in ovarian granulosa cells of endometriosis (EM) rats.

METHODS

Forty EM rats were randomly divided into two groups: experimental group and control group. There were 20 EM rats in each group. The uteri of another 20 SD rats were drawn in sham-operated group. The number and percentage of high quality oocytes and the levels of TNF-alpha and IL-6 mRNA expressions in the granulosa cells of EM rats were detected by using reverse transcription-polymerase chain reaction.

RESULTS

The number and percentage of high quality oocytes in the experimental group were significantly higher than those in the control group (P<0.05), and the levels of TNF-alpha and IL-6 mRNAs in granulose cells in the experimental group were significantly lower than those in the control group (P<0.05).

CONCLUSION

The increase of the TNF-alpha and IL-6 mRNA expressions in ovarian granulose cells of EM rats leads to the decrease of the oocyte quality. The mechanism of Quyu Jiedu Granule in improving the quality of oocytes may be related to the decrease of TNF-alpha and IL-6 mRNA expressions in ovarian granulosa cells.

The immunoconjugate "icon" targets aberrantly expressed endothelial tissue factor causing regression of endometriosis

Endometriosis is a major cause of chronic pain, infertility, medical and surgical interventions, and health care expenditures. Tissue factor (TF), the primary initiator of coagulation and a modulator of angiogenesis, is not normally expressed by the endothelium; however, prior studies have demonstrated that both blood vessels in solid tumors and choroidal tissue in macular degeneration express endothelial TF. The present study describes the anomalous expression of TF by endothelial cells in endometriotic lesions. The immunoconjugate molecule (Icon), which binds with high affinity and specificity to this aberrant endothelial TF, has been shown to induce a cytolytic immune response that eradicates tumor and choroidal blood vessels. Using an athymic mouse model of endometriosis, we now report that Icon largely destroys endometriotic implants by vascular disruption without apparent toxicity, reduced fertility, or subsequent teratogenic effects. Unlike antiangiogenic treatments that can only target developing angiogenesis, Icon eliminates pre-existing pathological vessels. Thus, Icon could serve as a novel, nontoxic, fertility-preserving, and effective treatment for endometriosis.

Disrupted cell cycle control in cultured endometrial cells from patients with endometriosis harboring the progesterone receptor polymorphism PROGINS

Presently, little is understood about how endometriosis is established or maintained, or how genetic factors can predispose women to the disease. Because of the crucial role that the progesterone receptor polymorphism PROGINS plays in predisposing women to the development of endometriosis, we hypothesized that this variant may influence critical steps during endometrial cell metabolism that are involved in the pathogenesis of endometriosis. Eutopic endometria were collected from three sources: women with endometriosis who had a single PROGINS allele (from the progesterone receptor gene); women with endometriosis who had the wild-type progesterone receptor allele; and women without endometriosis who had the wild-type allele. Cells prepared from the eutopic endometria of these women were stimulated with both estradiol and progesterone, and then examined for cell proliferation, viability, and apoptosis. The cells from women with endometriosis that carried the PROGINS allele demonstrated increased proliferation, greater viability, and decreased apoptosis following progesterone treatment. In general, these parameters were very different as compared with those of women with endometriosis but without the PROGINS allele and women in the control group. This result indicates there is a reduced level of progesterone responsiveness in women who carry the PROGINS polymorphism. Because progesterone responsiveness is known to be an important characteristic of women with endometriosis, these data support the contention that the PROGINS polymorphism enhances the endometriosis phenotype.

The relationship of endometriosis and ovarian malignancy: a review

OBJECTIVE

To review the malignant potential of endometriosis based on epidemiologic, histopathologic, and molecular data.

DESIGN

Literature review.

RESULT(S)

The pathogenesis of endometriosis remains unclear. The histopathologic development of endometriosis has undergone long-term investigation. Studies have confirmed histologic transition from benign endometriosis to ovarian malignancy, including malignant transformation of extraovarian endometriosis. The prevalence of endometriosis in patients with epithelial ovarian cancer, especially in endometrioid and clear cell types, has been confirmed to be higher than in the general population. Ovarian cancers and adjacent endometriotic lesions have shown common genetic alterations, such as PTEN, p53, and bcl gene mutations, suggesting a possible malignant genetic transition spectrum. Furthermore, endometriosis has been associated with a chronic inflammatory state leading to cytokine release. These cytokines act in a complex system in which they induce or repress their own synthesis and can cause unregulated mitotic division, growth and differentiation, and migration or apoptosis similar to malignant mechanisms.

CONCLUSION(S)

The malignant potential of endometriosis holds serious implications for management, such as the need for earlier and more meticulous surgical intervention for complete disease treatment.

Cytokine and immune cell levels in peritoneal fluid and peripheral blood of women with early- and late-staged endometriosis

OBJECTIVE

To investigate the level of cytokines and immune cells in the peripheral blood (PB) and peritoneal fluid (PF) of different stages of endometriosis.

METHODS

A prospective study was conducted to include 97 women with (n 60) and without (n 37) histopathologically confirmed endometriosis. Based on rASRM classification, stage I/II and stage III/IV were categorized as early-and late-staged endometriosis. Prior to surgery, 10 ml of blood was withdrawn from antecubital vein and serum was obtained. Aliquots were made and stored at -70 degrees C until assayed for cytokines. PF was aspirated from the pouch of Douglas. Peripheral and PF samples were analyzed by ELISA in terms of IL-2, IL-4, IL-10 and IFN-gamma. Determinations of T helper, T suppressor, NK, and B cells were assessed by using cluster determinant-3 (CD-3), CD4, CD8, CD25, CD28, CD45, CD16, CD23 and antibodies against early T cell activation antigens such as CD45RA/CD45RO, CD-69 and late activation antigens such as HLA-DR. A multiparameter flow cytometry was applied to detect the cell activation antigen expression.

RESULTS

In terms of cytokine levels in PB and PF's of control group and early- and late-staged endometriosis cases, no significant difference was depicted in the cytokine levels (p > 0.05). Levels of immune cells did not differ between three groups (p > 0.05).

CONCLUSIONS

The result of this study did not show any significant difference in PB and PF cytokine and lymphocyte subgroups between normal and early- and late-staged endometriosis.

Elevated ghrelin levels in the peritoneal fluid of patients with endometriosis: associations with vascular endothelial growth factor (VEGF) and inflammatory cytokines

OBJECTIVE

To study ghrelin concentrations in the peritoneal fluid of women with endometriosis and of control women without pelvic pathology and its associations with the levels of proinflammatory cytokines and vascular endothelial growth factor (VEGF).

DESIGN

Case-control study.

SETTING

University research institution and hospital.

PATIENT(S)

Forty-six nonobese women with laparoscopically and histopathologically confirmed endometriosis and 20 control women without pelvic pathology.

INTERVENTION(S)

Peritoneal fluid was aspirated during routine diagnostic laparoscopic examination.

MAIN OUTCOME MEASURE(S)

Concentrations of ghrelin and inflammatory cytokines (interleukin [IL]-1 beta, IL-6, tumor necrosis factor [TNF], and VEGF) in the peritoneal fluid were evaluated by specific enzyme immunoassay and enzyme-linked immunosorbent assays, respectively.

RESULT(S)

Ghrelin concentrations in the peritoneal fluid of women with endometriosis were significantly increased as compared with control subjects. Peritoneal ghrelin levels in patients with endometriosis were strongly positively associated with VEGF (r(s) = 0.625). There was no correlation between ghrelin and IL-1 beta, IL-6, or TNF.

CONCLUSION(S)

The results of the present study show that endometriosis is associated with increased peritoneal ghrelin levels. The association between ghrelin and endometriotic lesion vascularization remains to be elucidated.

Salivary cortisol concentrations, stress and quality of life in women with endometriosis and chronic pelvic pain

The objective of this study was to evaluate the perceived stress index, quality of life, and hypothalamus-pituitary-adrenal axis activity in women with endometriosis and chronic pelvic pain. For the study, 93 women with endometriosis and 82 healthy women volunteered. The visual analogue scale (VAS) (0=no pain; 10=severe pain) was used to determine pain intensity; the perceived stress questionnaire (PSQ) defined stress index, and the health-related quality-of-life (HRQOL)-SF-36 questionnaire was used to evaluate quality of life. Salivary cortisol was measured at 0800, 1600, and 2000 h and the awakening cortisol response was assessed to evaluate the hypothalamus-pituitary-adrenal axis activity. The results show that women with endometriosis and chronic pelvic pain of moderate intensity (4.1+/-0.58, mean+/-SEM) have higher levels of perceived stress (0.55+/-0.01 versus 0.42+/-0.01, p<0.05), a poorer quality of life expressed as lower scores for all items of the inventory and hypocortisolism. Lower levels of salivary cortisol were observed in all three samples collected, as well as in the awakening cortisol response, for women with endometriosis (0.19+/-0.09 microg/dl) when compared with controls (0.78+/-0.08 microg/dl, p<0.05 l), and it was independent of pain intensity and Mental health (MH) scores in SF-36. We concluded that women with endometriosis and chronic pelvic pain show low concentrations of salivary cortisol and a high level of perceived stress, associated with a poor quality of life. Whether the hypocortisolism was an adaptive response to the aversive symptoms of the disorder or a feature related to the etiology of endometriosis remains to be elucidated.

A relationship between increased peritoneal leptin levels and infertility in endometriosis

Endometriosis is a common, complex and chronic disease related to ectopic implantation and growth of endometrial tissue that may manifest by pelvic pain, and accounts for over 20% of all cases of infertility in women. Endometriosis may be associated with increased levels of leptin in peritoneal fluid. However, the association of leptin with infertility has not been definitely documented. Therefore, the aim of the present study was to search for a relationship between concentrations of peritoneal-fluid leptin and patients' clinical status. The study included 56 patients being diagnosed for infertility and/or pelvic pain. Peritoneal fluid was aspirated during routine laparoscopic examination. Concentrations of leptin in peritoneal fluid were evaluated by a specific enzyme-linked immunosorbent assay. The results revealed that the levels of peritoneal-fluid leptin did not correlate with different stage of endometriosis. However, they correlated with body mass index. Leptin levels were significantly higher in infertile patients than in patients with pelvic pain (p = 0.0023 by Mann-Whitney U test or p = 0.0045 by analysis of variance). It may suggest that increased leptin levels in the peritoneal fluid may play a role in pathogenesis of infertility.

Endometriosis and tissue factor

Tissue factor (TF), is a cellular receptor that binds the ligand factor VII/VIIa to initiate the blood coagulation cascade. In addition to its role as the initiator of the hemostatic cascade, TF is known to be involved in angiogenesis via an interaction with factor VIIa and protease-activated receptor-2 (PAR-2). In this article we review previous studies from our laboratory demonstrating that the pattern and level of TF expression is altered in multiple cell types derived from eutopic and ectopic endometrium from women with endometriosis compared with normal endometrium. We posit that the inflammatory environment that occurs in ectopic and eutopic endometrium from patients with disease results in high TF expression that in turn, signals via PAR-2 to further produce inflammatory cytokine or chemokine production and macrophage recruitment. Thus, our studies suggest that TF might be an ideal target for therapeutic intervention in endometriosis.

Gene expression profiling of the rat endometriosis model

PROBLEM

To investigate the molecular mechanism of endometriosis, gene expression profiling was analyzed in a rat endometriosis model.

METHOD OF STUDY

An endometriosis model was induced by uterine autotransplantation in the peritoneal cavity on a female-SD rat (8 weeks old). As control samples, the normal uterine tissues were used. The gene expression was compared between endometriotic lesions and normal uterine tissues by cDNA microarray analysis, quantitative real time RT-PCR and immunohistochemistry.

RESULTS

The expression of 71 genes was upregulated and that of 45 genes was downregulated in the endometriotic lesions compared to normal uterine tissues. The upregulated genes included genes encoding cytokines, chemokines, growth factors and cell adhesion molecules. The levels of transcripts of osteopontin, Lyn, Vav1, Runx1, and l-selectin in the endometriotic lesions were 130, 10, 10, 12 and 46-fold higher than the respective levels in the eutopic endometrial samples.

CONCLUSION

The results suggest that osteopontin, Lyn, Vav1, Runx1, and l-selectin play important roles in the pathogenesis of endometriosis.

Application of the nuclear factor-kappaB inhibitor BAY 11-7085 for the treatment of endometriosis: an in vitro study

Most of the current medical treatments for endometriosis aim to downregulate estrogen activity. However, a high recurrence rate after medical treatment has been the most significant problem. BAY 11-7085, a soluble inhibitor of NK-kappaB activation, has been shown to inhibit cell proliferation and induce apoptosis of a variety of cells. To examine the potential application of BAY 11-7085 in the treatment of endometriosis, we investigated the effects of this agent on the cell proliferation and apoptosis of cultured ovarian endometriotic cyst stromal cells (ECSCs) by a modified methylthiazole tetrazolium assay, a 5-bromo-2'-deoxyuridine incorporation assay, and internucleosomal DNA fragmentation assays. The effect of BAY 11-7085 on the cell cycle of ECSCs was also determined by flow cytometry. The expression of apoptosis-related molecules was examined in ECSCs with Western blot analysis. BAY 11-7085 significantly inhibited the cell proliferation and DNA synthesis of ECSCs and induced apoptosis and the G0/G1 phase cell cycle arrest of these cells. Additionally, downregulation of the B-cell lymphoma/leukemia-2 (Bcl-2) and Bcl-X(L) expression with simultaneous activation of caspase-3, -8, and -9 was observed in ECSCs after treatment with BAY 11-7085. These results suggest that BAY 11-7085 induces apoptosis of ECSCs by suppressing antiapoptotic proteins, and that caspase-3-, -8-, and -9-mediated cascades are involved in this mechanism. Therefore, BAY 11-7085 could be used as a therapeutic agent for the treatment of endometriosis.

Immunohistochemical detection of heparanase-1 expression in eutopic and ectopic endometrium from women with endometriosis

OBJECTIVE

To investigate the expression of heparanase-1, an endoglycosidase that degrades heparan sulfate proteoglycans, in eutopic and ectopic endometrial tissues from women with endometriosis.

DESIGN

An immunohistochemical study.

SETTING

Academic research laboratory and a private infertility clinic affiliated with a university medical center.

PATIENT(S)

Premenopausal women undergoing laparoscopy for endometriosis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Expression of heparanase-1 analyzed by immunohistochemical staining in 91 eutopic and 14 ectopic endometrial specimens.

RESULT(S)

We found that 17% (4/24) of the eutopic endometrial specimens in the early proliferative phase and 32% (9/28) of the samples in the midproliferative phase were heparanase-1 positive. However, >or=80% of eutopic endometrial specimens at late proliferate phase and at luteal phase were heparanase-1 positive. Twelve of 14 ectopic endometriotic specimens stained heparanase-1 positive. Comparison of heparanase-1 expression in paired eutopic and ectopic endometrial tissues revealed that 5 of 6 ectopic specimens in the early proliferative phase were heparanase-1 positive, whereas only 1 eutopic specimen was heparanase-1 positive. In comparison with our recent study of heparanase-1 expression in normal endometrium, we found that there was no significant difference in heparanase-1 expression in the eutopic endometrium from women with or without endometriosis.

CONCLUSION(S)

Heparanase-1 was differentially expressed in the eutopic endometrium in the different menstrual phases. Heparanase-1 was highly expressed in the ectopic endometriotic lesions regardless of their menstrual phases, suggesting that the local environment is responsible for increased heparanase-1 expression.

Endometriosis among women exposed to polybrominated biphenyls

PURPOSE

We examined the association between endometriosis and exposure to polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) among women inadvertently exposed to PBBs in 1973.

METHODS

Serum PBBs and PCBs were measured in the late 1970s. Women self-reported endometriosis at interview in 1997. We constructed Cox models to estimate the relative incidence of endometriosis in relation to PBB and PCB levels.

RESULTS

Seventy-nine of 943 women (9%) reported endometriosis. Compared with women with low PBB exposure (<or=1 parts per billion [ppb]), women with moderate PBB (1-4 ppb) (hazard ratio [HR] = 0.72; 95% confidence interval [CI], 0.39-1.31) and high PBB (>or=4 ppb) (HR = 0.90; 95% CI, 0.51-1.59) exposure did not have increased incidence of endometriosis. Increased incidence of endometriosis was suggested among women exposed to moderate PCB (5-8 ppb) (HR = 1.67; 95% CI, 0.91-3.10) and high PCB (>or=8 ppb) (HR = 1.68; 95% CI, 0.95-2.98) levels compared with low PCB exposure (<or=5 ppb).

CONCLUSIONS

Our study does not support an association between PBB exposure and endometriosis. Findings for serum PCB level are consistent with an emerging body of literature suggesting an association between PCB exposure and endometriosis.

Expression of 17beta-hydroxysteroid dehydrogenase type 2 in pelvic endometriosis

Lack of expression or a deficiency of 17beta-hydroxysteroid dehydrogenase type 2 (17beta-HSD2), a key enzyme in estradiol inactivation, could be involved in the pathophysiology of endometriosis. The aim of the present study was to evaluate expression of the gene (17beta-Hsd2) encoding 17beta-HSD2 in eutopic and ectopic endometrial tissues of women with endometriosis. Thirty-four infertile women were divided into a control group, without any clinical or laparoscopic evidence of endometriosis (n = 19), and a group with pelvic endometriosis (n = 15). Diagnosis was confirmed by histological examination of the endometriotic lesions. 17beta-Hsd2 mRNA expression was detected by reverse transcription-polymerase chain reaction in the control group (54% of the samples), in the eutopic endometrium of patients with endometriosis (83% of the specimens analyzed) and in all endometriotic lesions. The semi-quantitative analysis of 17beta-Hsd2 mRNA showed a significantly higher gene expression in the endometriotic implants compared with the intrauterine endometrium of the control group (p < 0.05). 17beta-HSD2 protein was localized to the glandular epithelium of both eutopic endometrium and endometriotic implants. The present results refute the hypothesis of lower or absent 17beta-HSD2 expression in pelvic endometriosis; therefore further studies are needed to assess other potential mechanisms leading to increased estrogenic activity within endometriotic implants.

Uterine stem cells: what is the evidence?

The mucosal lining (endometrium) of the human uterus undergoes cyclical processes of regeneration, differentiation and shedding as part of the menstrual cycle. Endometrial regeneration also follows parturition, almost complete resection and in post-menopausal women taking estrogen replacement therapy. In non-menstruating species, there are cycles of endometrial growth and apoptosis rather than physical shedding. The concept that endometrial stem/progenitor cells are responsible for the remarkable regenerative capacity of endometrium was proposed many years ago. However, attempts to isolate, characterize and locate endometrial stem cells have only been undertaken in the last few years as experimental approaches to identify adult stem/progenitor cells in other tissues have been developed. Adult stem cells are defined by their functional properties rather than by marker expression. Evidence for the existence of adult stem/progenitor cells in human and mouse endometrium is now emerging because functional stem cell assays are being applied to uterine cells and tissues. These fundamental studies on endometrial stem/progenitor cells will provide new insights into the pathophysiology of various gynaecological disorders associated with abnormal endometrial proliferation, including endometrial cancer, endometrial hyperplasia, endometriosis and adenomyosis.

Health-related quality of life burden of women with endometriosis: a literature review

PURPOSE

The purpose of this study was to conduct a comprehensive and systematic literature review of the health-related quality of life (HRQL) burden of endometriosis in adults and adolescents.

METHODS

We conducted a systematic search and review of studies published between January 1999 and January 2006 using MEDLINE and relevant online resources. Search terms used included endometriosis, quality of life, burden of illness, psychology, and adolescent. We assessed: (1) the HRQL impact of endometriosis and related key symptoms; (2) the impact of specific pharmacologic and surgical treatments of endometriosis on HRQL; and (3) the presence and impact of endometriosis in adolescents.

RESULTS

Twenty relevant studies were identified and reviewed. Generic instruments most commonly used to assess HRQL in patients with endometriosis included the SF-36 and the SF-12. The EQ-5D was used to measure utilities. The Endometriosis Health Profile-30 (EHP-30) and its subset, the EHP-5, have been recently developed for use in endometriosis studies. Endometriosis was associated with significant impairments in pain, psychological functioning, and social functioning. Pharmacological and surgical treatments for endometriosis improved patients physical functioning, psychological functioning, vitality, pain level, and general health. Few studies used disease specific instruments to characterize the HRQL burden of endometriosis, addressed the HRQL impact of endometriosis-related infertility, and examined endometriosis in adolescents. Instruments specifically validated to measure HRQL in adolescents were not identified.

CONCLUSIONS

Endometriosis impairs HRQL, especially in the domains of pain, psychological and social functioning. Therapies have been shown to alleviate symptoms and improve HRQL. Further research is warranted to evaluate the impact of endometriosis on HRQL in adolescents and the impact of infertility due to endometriosis on HRQL.

β-Hydroxyisovalerylshikonin induces apoptosis and G0/G1 cell-cycle arrest of endometriotic stromal cells: a preliminary in vitro study

BACKGROUND

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. Beta-hydroxyisovalerylshikonin (beta-HIVS) is an ATP non-competitive inhibitor of protein-tyrosine kinases and is considered an apoptosis-inducing agent. The aim of this study is to evaluate the effects of beta-HIVS on the proliferation, cell cycle and apoptosis of endometriotic stromal cells.

METHODS

We investigated the effects of beta-HIVS on 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 beta-HIVS on the cell cycle of ECSC was determined by flow cytometry. The expression of apoptosis-related molecules was examined in ECSC using western blot analysis.

RESULTS

Beta-HIVS significantly inhibited the proliferation and DNA synthesis of ECSC and induced apoptosis and G0/G1 phase cell-cycle arrest of these cells. Down-regulation of the B-cell lymphoma/leukaemia-2 (Bcl-2) expression with the activation of caspase-3, caspase-8 and caspase-9 was observed in ECSC after beta-HIVS treatment.

CONCLUSIONS

These results suggest that beta-HIVS induces apoptosis of ECSC by suppressing anti-apoptotic proteins. Although our present findings are preliminary, beta-HIVS could potentially be a therapeutic agent for the treatment of endometriosis.

Endometriosis as a model for inflammation–hormone interactions in ovarian and breast cancers

Chronic inflammation has been implicated in a variety of cancers. In this review, we consider associations between endometriosis and cancers both local (ovarian) and distant (breast). We review the epidemiological data linking endometriosis to ovarian and breast cancers. We then consider evidence for a role for sex steroid hormones and for inflammation in the aetiology of each of these cancers. Finally, we consider that endometriosis may promote alterations in sex steroid hormones and inflammatory mediators. A possible explanation for the association between endometriosis and these reproductive cancers may then be local and systemic enhancement of aberrant inflammatory and hormonal mediators. If this hypothesis is true, endometriosis may need to be considered as a risk factor for ovarian and breast cancers, triggering increasingly intensive surveillance. Moreover, treatments for endometriosis may require consideration of the impact on long-term cancer risk.

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.

Evaluation of clinical parameters and estrogen receptor alpha gene polymorphisms for patients with endometriosis

Endometriosis is a chronic inflammatory disease, which is especially found in women with subfertility problems with an incidence of up to 30%. The disease is considered an estrogen-dependent disorder, where DNA polymorphisms of the estrogen receptor α (ERα) in connection with endometriosis are controversially discussed. From a German population of women, clinical data associated with the disease, including the American Fertility Society (AFS) I–IV classification, and non-clinical parameters were evaluated statistically in endometriosis patients (n= 98) and in control women (n= 98) without endometriosis. Using a multivariate statistical analysis, significant associations of endometriosis with dysmenorrhea (P< 0.001) and allergies against medicaments (P= 0.042) were found. A positive trend between first grade family history of endometriosis and allergies against medicaments was also observed, suggesting a genetic relationship. From both collectives, DNA from peripheral blood was analyzed for the frequency of the ERα DNA polymorphisms Xba1 (A/G) and PvuII (T/C) in intron 1 and the ERα exonic DNA polymorphism (G229A) with an amino acid exchange (Gly77Ser) in the transactivation domain. DNA samples from endometriosis lesions and control tissues from the same collectives were also analyzed for the exonic G229A polymorphism. Only homozygote wild-type alleles for the polymorphism G229A were found, making it a rare polymorphism in mid-European individuals. Allele types for the PvuII and Xba1 polymorphisms were analyzed with the observed statistically significant clinical parameters and showed no significant association with endometriosis; however a trend with AFS IV was noted, which could contribute to lesion severity. In conclusion, the analyzed polymorphisms in the ERα do not have a functional role concerning specific clinical parameters associated with endometriosis.

Changes in the T-helper cytokine profile and in lymphocyte activation at the systemic and local levels in women with endometriosis

OBJECTIVE

To estimate regulatory cytokine synthesis and lymphocyte activation in the peripheral blood and endometrial tissue of patients with endometriosis.

DESIGN

Controlled clinical study.

SETTING

Medical center.

PATIENT(S)

Fifteen women with laparoscopically diagnosed endometriosis; 20 gynecologically healthy women with previously documented fertility (control group).

INTERVENTION(S)

Peripheral venous blood sampling; laparoscopic collection of ectopic and matched eutopic endometrium.

MAIN OUTCOME MEASURE(S)

Messenger RNA (mRNA) for interleukin (IL)-2, IL-4, and IL-10 expression in peripheral and endometrium lymphocytes was assessed by real-time reverse transcriptase polymerase chain reaction; intracellular synthesis of these cytokines and lymphocyte phenotype profile were established by flow cytometry.

RESULT(S)

Both mRNA expression and intracellular synthesis of IL-4 and IL-10 were sharply increased in peripheral lymphocytes. The same changes were observed for IL-4 in ectopic endometrium of women with endometriosis. Simultaneously, elevation of the amount of pan-B cells, CD20+CD5+ B-1 cells, and activated HLA-DR+CD20+ B lymphocytes was observed in endometriosis lesions. Only an enhanced amount of B lymphocytes was seen in eutopic endometrium.

CONCLUSION(S)

Endometriosis development is accompanied by the activation of a T-helper type 2 immune response at the systemic and local levels. Our results support the hypothesis regarding the autoimmune nature of endometriosis and can explain the high level of autoantibody production in patients with endometriosis.

Immunology of endometriosis

Endometriosis is a benign gynecologic disorder characterized by the ectopic growth of misplaced endometrial cells. A unifying hypothesis to explain endometriosis has not been elucidated as yet but numerous investigations have implicated disturbances in the immune response as fundamental to its etiology and pathogenesis. Clearly, the immune system is involved in endometriosis. It is not clear, however, whether and to what extent this involvement is a primary response leading to the initiation, promotion, and progression of the disease or a secondary response to the ectopic endometrial growth in an attempt to restore homeostasis. Thus, although numerous studies have shown alterations in cell-mediated and humoral immunity in subjects with endometriosis, the importance of these changes remains obscure. This review considers the past two decades of investigation of immune function changes in women with endometriosis with the expectation that this information will ultimately provide the basis for developing new approaches to patient management.

Different concentrations of interleukins in the peritoneal fluid of women with endometriosis: relationships with lymphocyte subsets

The present study explored the possible relationships between immune cell subsets and interleukin (IL)-12 or IL-13 levels in the peritoneal fluid of patients with and without endometriosis. Peritoneal fluid samples were obtained from 80 women while they were undergoing laparoscopy for pain, infertility, tubal ligation or re-anastomosis. The American Fertility Society scoring system was used to determine the extension of endometriosis. The peritoneal fluid mononuclear cells were analyzed for immunophenotyping using cytometry, whereas peritoneal fluid concentrations of interleukins were measured using two ultrasensitive commercially available enzyme-linked imnunosorbent assay kits. Significantly higher peritoneal fluid IL-12 levels were found in women with moderate or severe endometriosis (stages III and IV) than in healthy controls (p < 0.01). Conversely, subjects with endometriosis showed remarkably lower peritoneal fluid IL-13 concentrations than controls, independent of the severity of the disease (p < 0.05). Considering immune system effectors, patients with endometriosis presented a significantly higher peritoneal fluid CD8+/CD4+ ratio when compared with healthy controls. Moreover, the number of peritoneal fluid CD8+ and CD4+ activated T cells was significantly lower in the former than in the latter group, independent of the endometriosis stage. Connections were observed between peritoneal fluid interleukins and peritoneal fluid T cells: both patients with endometriosis and controls presented an inverse correlation between peritoneal fluid activated T cells and IL-13 levels, and a direct correlation between peritoneal fluid T cells and IL-12 concentrations. These data seem to suggest that a reciprocal modulation exists between peritoneal fluid cytokines and T lymphocyte subsets in patients with endometriosis.

Role of immunoreactions and mast cells in pathogenesis of human endometriosis -morphologic study and gene expression analysis-

STUDY OBJECTIVES

To investigate the pathophysiology of human endometriosis, we examined by morphological and molecular biological methods.

METHODS

Samples of ovarian endometriosis and normal ovarian tissues were obtained laparoscopically after informed consent. A morphological study by toluidine blue staining, immunohistochemistry of c-kit and electron microscopy demonstrated the localization of mast cells in the stromal lesions of endometriosis. Oligonucleotide microarrays were used for gene expression analysis.

RESULTS

Infiltration of numerous mast cells and development of fibrosis was observed throughout the stromal lesions. Gene expression analysis by oligonucleotide microarrays indicated inflammatory immunoreactions in the lesions. Expressions of the FCER1G and PGDS, which are considered to be mast cell-specific genes, were upregulated in the ovarian endometriotic lesions as compared to the normal ovarian tissues. Furthermore, expressions of genes associated with immunological inflammation, such as IL-8, GRO1, GRO2, CXCR4, MCP1, and those related to tissue remodeling (MMP, COL4A2, and COL5A2) were also higher in endometriotic lesions than in the normal ovarian tissue.

CONCLUSIONS

Thus it is likely that mast cells and their related inflammatory immunoreactions via chemokines play important roles in producing fibrosis and adhesions in endometriotic lesions.

Endometriosis and ovarian cancer: thoughts on shared pathophysiology

BACKGROUND

Endometriosis appears to predispose to ovarian cancer. How this may occur has been little discussed.

STUDY DESIGN

This article reviews the English language literature for in vitro, animal, clinical, and epidemiologic studies linking the two conditions.

RESULTS

Pathology case series consistently report endometrioid and clear cell types of ovarian cancer arising from endometriotic foci. Epidemiologic studies have been consistent with this association. There are also marked similarities between the proposed etiology of ovarian cancer and the observed pathophysiology of endometriosis. Specifically, both are characterized by immune alterations. Both conditions are promoted by estrogen excess and by progesterone deficit. Finally, steroid hormones interacting with the immune system may stimulate both endometriosis and ovarian cancer. I propose that the biology common to endometriosis and ovarian cancer represents not just a parallelism, but instead a causal pathway: aberrant immune function, fed by and feeding on estrogens, unbalanced by progesterone, may create a positive feed-forward loop that enhances the growth and invasiveness of endometriosis and promotes its malignant transformation.

CONCLUSIONS

The same pathophysiology may orchestrate the progression of endometriosis and its transformation to endometroid and clear cell ovarian neoplasias. This notion of a unifying biology suggests a directed approach to future research and identifies possible chemoprevention strategies for women with endometriosis.