N-terminal truncated forms of insulin-like growth factor binding protein-3 in the peritoneal fluid of women without laparoscopic evidence of endometriosis. Le groupe d'investigation en gynécologie

MicroRNA-210-3p Regulates Endometriotic Lesion Development by Targeting IGFBP3 in Baboons and Women with Endometriosis

MicroRNAs (miRs) play an important role in the pathophysiology of endometriosis; however, the role of miR-210 in endometriosis remains unclear. This study explores the role of miR-210 and its targets, IGFBP3 and COL8A1, in ectopic lesion growth and development. Matched eutopic (EuE) and ectopic (EcE) endometrial samples were obtained for analysis from baboons and women with endometriosis. Immortalized human ectopic endometriotic epithelial cells (12Z cells) were utilized for functional assays. Endometriosis was experimentally induced in female baboons (n = 5). Human matched endometrial and endometriotic tissues were obtained from women (n = 9, 18-45 years old) with regular menstrual cycles. Quantitative reverse transcript polymerase chain reaction (RT-qPCR) analysis was performed for in vivo characterization of miR-210, IGFBP3, and COL8A1. In situ hybridization and immunohistochemical analysis were performed for cell-specific localization. Immortalized endometriotic epithelial cell lines (12Z) were utilized for in vitro functional assays. MiR-210 expression was decreased in EcE, while IGFBP3 and COL8A1 expression was increased in EcE. MiR-210 was expressed in the glandular epithelium of EuE but attenuated in those of EcE. IGFBP3 and COL8A1 were expressed in the glandular epithelium of EuE and were increased compared to EcE. MiR-210 overexpression in 12Z cells suppressed IGFBP3 expression and attenuated cell proliferation and migration. MiR-210 repression and subsequent unopposed IGFBP3 expression may contribute to endometriotic lesion development by increasing cell proliferation and migration.

Chronic Niche Inflammation in Endometriosis-Associated Infertility: Current Understanding and Future Therapeutic Strategies

Endometriosis is an estrogen-dependent inflammatory disease that affects up to 10% of women of reproductive age and accounts for up to 50% of female infertility cases. It has been highly associated with poorer outcomes of assisted reproductive technology (ART), including decreased oocyte retrieval, lower implantation, and pregnancy rates. A better understanding of the pathogenesis of endometriosis-associated infertility is crucial for improving infertility treatment outcomes. Current theories regarding how endometriosis reduces fertility include anatomical distortion, ovulatory dysfunction, and niche inflammation-associated peritoneal or implantation defects. This review will survey the latest evidence on the role of inflammatory niche in the peritoneal cavity, ovaries, and uterus of endometriosis patients. Nonhormone treatment strategies that target these inflammation processes are also included. Furthermore, mesenchymal stem cell-based therapies are highlighted for potential endometriosis treatment because of their immunomodulatory effects and tropism toward inflamed lesion foci. Potential applications of stem cell therapy in treatment of endometriosis-associated infertility in particular for safety and efficacy are discussed.

A prospective study of insulin-like growth factor 1, its binding protein 3, and risk of endometriosis

Several retrospective case-control studies suggested that insulin-like growth factor 1 (IGF-1) or insulin-like growth factor binding protein 3 (IGFBP-3) was associated with endometriosis. However, results are inconsistent and no prospective study exists. We prospectively evaluated associations between plasma levels of IGF-1 and IGFBP-3 and laparoscopically confirmed endometriosis in a case-control study nested within the Nurses' Health Study II. Between blood collections in 1996-1999 and 2007, we ascertained 310 premenopausal women with incident endometriosis and 615 matched controls. We estimated incidence rate ratios and 95% confidence intervals using multivariable conditional logistic regression. We observed no statistically significant associations between endometriosis and IGF-1 (incidence rate ratio (IRR) = 0.88, 95% confidence interval (CI): 0.61, 1.27; Ptrend = 0.48), IGFBP-3 (IRR = 1.12, 95% CI: 0.80, 1.57; Ptrend = 0.51), and the IGF-1:IGFBP-3 molar ratio (IRR = 0.94, 95% CI: 0.66, 1.34; Ptrend = 0.64), comparing the top with the bottom tertile. IGF-1, IGFBP-3, and the molar ratio appeared to be positively associated with endometriosis risk among women aged <40 years at blood draw (IGF-1: IRR = 1.60, 95% CI: 0.86, 2.98; IGFBP-3: IRR = 1.85, 95% CI: 1.08, 3.16; IGF-1:IGFBP-3: IRR = 1.57, 95% CI: 0.85, 2.88) but not among women aged ≥40 years at blood draw (all Pheterogeneity ≤ 0.05). Overall, these data suggest that, if IGF-1 or IGFBP-3 plays a role in the etiology of endometriosis, it is minimal and perhaps only among younger women.

Evidence for the Possible Biological Significance of the igf-1 Gene Alternative Splicing in Prostate Cancer

Insulin-like growth factor-I (IGF-I) has been implicated in the pathogenesis of prostate cancer (PCa), since it plays a key role in cell proliferation, differentiation, and apoptosis. The IGF-I actions are mediated mainly via its binding to the type I IGF receptor (IGF-IR), however IGF-I signaling via insulin receptor (IR) and hybrid IGF-I/IR is also evident. Different IGF-I mRNA splice variants, namely IGF-IEa, IGF-IEb, and IGF-IEc, are expressed in human cells and tissues. These transcripts encode several IGF-I precursor proteins which contain the same bioactive product (mature IGF-I), however, they differ by the length of their signal peptides on the amino-terminal end and the structure of the extension peptides (E-peptides) on the carboxy-terminal end. There is an increasing interest in the possible different role of the IGF-I transcripts and their respective non-(mature)IGF-I products in the regulation of distinct biological activities. Moreover, there is strong evidence of a differential expression profile of the IGF-I splice variants in normal versus PCa tissues and PCa cells, implying that the expression pattern of the various IGF-I transcripts and their respective protein products may possess different functions in cancer biology. Herein, the evidence that the IGF-IEc transcript regulates PCa growth via Ec peptide specific and IGF-IR/IR-independent signaling is discussed.

Peripheral biomarkers of endometriosis: a systematic review

BACKGROUND

Endometriosis is estimated to affect 1 in 10 women during the reproductive years. There is often delay in making the diagnosis, mainly due to the non-specific nature of the associated symptoms and the need to verify the disease surgically. A biomarker that is simple to measure could help clinicians to diagnose (or at least exclude) endometriosis; it might also allow the effects of treatment to be monitored. If effective, such a marker or panel of markers could prevent unnecessary diagnostic procedures and/or recognize treatment failure at an early stage.

METHODS

We used QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria to perform a systematic review of the literature over the last 25 years to assess critically the clinical value of all proposed biomarkers for endometriosis in serum, plasma and urine.

RESULTS

We identified over 100 putative biomarkers in publications that met the selection criteria. We were unable to identify a single biomarker or panel of biomarkers that have unequivocally been shown to be clinically useful.

CONCLUSIONS

Peripheral biomarkers show promise as diagnostic aids, but further research is necessary before they can be recommended in routine clinical care. Panels of markers may allow increased sensitivity and specificity of any diagnostic test.

Concentrations of alpha-fetoprotein, insulin-like growth factor binding protein-3, c-erbB-2, and epidermal growth factor in serum of patients with endometriosis

OBJECTIVE

Endometriosis, although it is a benign disorder, shares many similarities with cancer. There is increasing levels of evidence suggesting that some circulating factors involved in gynecologic cancers, such as alpha-fetoprotein (AFP), insulin-like growth factor binding protein-3 (IGFBP-3), c-erbB-2 (HER-2/neu), and epidermal growth factor (EGF), could also play a role in endometriosis. Hence, the present study was aimed at evaluating whether the levels of these molecules are modulated in the serum of patients with endometriosis.

METHODS

Levels of AFP, IGFBP-3, c-erbB-2, and EGF were determined by enzyme-linked immunosorbent assay in serum from 36 subjects with surgically confirmed endometriosis and 36 controls with no surgical evidence of the disease. In addition, information such as demographic characteristics, personal habits, menstrual characteristics, and clinical profile was collected from each participating subject.

RESULTS

No significant difference was found between serum levels of AFP, IGFBP-3, c-erbB-2, and EGF in patients with endometriosis and controls, even when we adjusted for potential confounders and took into account the menstrual cycle. Moreover, no correlation was observed between the serum concentrations of these molecules and the stage of the disease. However, a correlation was detected between soluble levels of IGFBP-3 and presence of uterine leiomyoma.

CONCLUSION

Although AFP, IGFBP-3, c-erbB-2, and EGF are not altered in the circulation of patients with endometriosis, their involvement in the development of endometriotic lesions cannot be excluded.

Urokinase-Type Plasminogen Activator and Insulin-Like Growth Factor-Binding Protein 3 mRNA Expression in Endometriotic Lesions and Eutopic Endometrium

The peritoneal fluid of women with endometriosis contains an increased insulin-like growth factor 1 (IGF-1) bioavailability, which is produced by limited hydrolysis of urokinase-type plasminogen activator (uPA) on IGF-binding protein 3 (IGFBP-3). Recently, IGF-1 was shown to inhibit apoptosis of endometrial-like cells in vitro, suggesting that a microenvironment of increased IGF-1 bioavailability can optimize the survival of endometrial cells grown ectopically. Here the expression of mRNA of IGFBP-3 and uPA in tissue biopsies from eutopic endometrium and endometriotic lesions obtained at laparoscopy from women with endometriosis have been analyzed, and it is documented that both IGFBP-3 and uPA mRNA expression are increased from 3- to 10-fold in endometriotic lesions versus eutopic endometrium. Consequently, the necessary components (uPA and IGFBP-3 expression) of endocrine/autocrine/paracrine enhancement of local IGF bioavailability mediated by uPA hydrolysis of the IGFBP-3 were present in endometriotic lesions. These data possibly explain the origin of the increased content of uPA activity, IGF-1 bioavailability, and NH(2)-truncated forms of IGFBP-3 in the peritoneal fluid of women with endometriosis.

Insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and IGFBP-3 protease activity in the peritoneal fluid of patients with and without endometriosis

OBJECTIVE

To compare levels of insulin-like growth factor (IGF) components in the peritoneal fluid of patients with and without endometriosis.

DESIGN

Patients with endometriosis were compared with control patients.

SETTING

Seoul National University Hospital, Korea.

PATIENT(S)

Forty-three patients with endometriosis and 20 patients without endometriosis.

INTERVENTION(S)

Peritoneal fluid specimens were collected.

MAIN OUTCOME MEASURE(S)

Insulin-like growth factors, IGF binding protein (IGFBP) profiles and IGFBP-3 protease activity.

RESULT(S)

The IGF-I levels in peritoneal fluid were significantly higher in patients with endometriosis than in control patients, while the IGFBP-3 levels and the relative proportion of IGFBP-2 in peritoneal fluid were significantly lower in patients with endometriosis than in control patients. However, IGF-II levels, IGFBP-4 profiles, and IGFBP-3 protease activity did not differ significantly between the two groups. No correlation between these IGF components in peritoneal fluid and the stage of endometriosis was noted.

CONCLUSION(S)

The profiles of IGF components in peritoneal fluid of patients with pelvic endometriosis may play an important role in the growth of ectopic endometrium and endometriosis-induced infertility.

Immunohistochemical localization of insulin-like growth factor-binding protein-3 in eutopic and ectopic endometrial tissues

OBJECTIVE

To evaluate the expression of insulin-like growth factor-binding protein-3 (IGFBP-3) in the eutopic endometrium and in endometriotic lesions.

DESIGN

Retrospective immunohistochemical study.

PATIENT(S)

Twenty-five normal women and 39 women with endometriosis.

INTERVENTION(S)

Endometrial and endometriotic tissue biopsies obtained at laparoscopy.

MAIN OUTCOME MEASURE(S)

Expression of IGFBP-3 assessed by immunohistochemistry.

RESULT(S)

In the endometrium, positive immunostaining of IGFBP-3 was observed both in the stroma and the epithelial glands. The intensity of staining in the glands during the secretory phase was significantly higher in women with endometriosis compared with controls (P = .018). An increased expression of IGFBP-3 over controls was found in stages I and II of the disease (P = .018), whereas in stages III and IV, the difference between controls and women with endometriosis was not significant (P = .300). In endometriotic tissues, a much-marked immunostaining of IGFBP-3 was noted in 90% of the glands and 67% of the stroma without apparent differences related to cycle phase.

CONCLUSION(S)

These data show intense staining of IGFBP-3 in endometriosis lesions and increased expression of the protein in the endometrium of patients with endometriosis compared to controls. This marked expression of IGFBP-3 could be related to its previous finding in the peritoneal fluid and to its potential involvement in the pathophysiology of endometriosis.