mRNA expression of insulin-like growth factor-I (IGF-I) is suppressed and those of IGF-II and IGF-binding protein-1 are constantly expressed in the endometrium during use of an intrauterine levonorgestrel system

The Influence of Biologically Active Substances Secreted by the Adipose Tissue on Endometrial Cancer

Endometrial cancer is one of the most frequently diagnosed gynecological neoplasms in developed countries and its incidence is rising. Usually, it is diagnosed in the early stages of the disease and has a good prognosis; however, in later stages, the rate of recurrence reaches up to 60%. The discrepancy in relapse rates is due to the heterogeneity of the group related to the presence of prognostic factors affecting survival parameters. Increased body weight, diabetes, metabolic disturbances and estrogen imbalance are important factors for the pathogenesis of endometrial cancer. Even though prognostic factors such as histopathological grade, clinical stage, histological type and the presence of estrogen and progesterone receptors are well known in endometrial cancer, the search for novel prognostic biomarkers continues. Adipose tissue is an endocrine organ involved in metabolism, immune response and the production of biologically active substances participating in cell growth and differentiation, angiogenesis, apoptosis and carcinogenesis. In this manuscript, we review the impact of factors secreted by the adipose tissue involved in the regulation of glucose and lipid metabolism (leptin, adiponectin, omentin, vaspin, galectins) and factors responsible for homeostasis maintenance, inflammatory processes, angiogenesis and oxidative stress (IL-1β, 6, 8, TNFα, Vascular endothelial growth factor (VEGF), Fibroblast growth factors (FGFs)) in the diagnosis and prognosis of endometrial cancer.

Effects of progestin-only contraceptives on the endometrium

INTRODUCTION

The contraceptive activity of synthetic progestins is mediated through three basic mechanisms: (a) An anti-gonadotrophic action leading to the inhibition of ovulation; (b) Changes in cervical mucus characteristics that inhibit sperm penetration and (c) desynchronization of the endometrial picture necessary for implantation.

AREAS COVERED

Mechanisms involved in the progestin-induced endometrium desynchronization are individually reviewed for each of the routes of administration and, whenever possible, by individual members of the various families of synthetic progestin derivatives.

EXPERT OPINION

For contraceptive purposes, progestins are today administered through several routes: orally, as injections, subdermally and via the vagina or the uterine cavity. Given this variety of modalities, their effects may differ, depending on the route of administration, concentration reached at the level of the endometrium and the duration of use. These are characterized by inactivation of the endometrium. Progestin-only contraception provides a safe and effective control of fertility regulation, although, they are associated with the problem of endometrial break through bleeding that may lead to discontinuation. Unfortunately, in spite of a major research effort over two decades, there is not, as yet, an established long-term intervention available to manage bleeding irregularities, making mandatory a deeper understanding of the mechanisms involved is required.

Morphologic Changes in the Endometrium Associated With the Use of the Mirena Coil: A Retrospective Study of 106 Cases

This study outlines the histologic changes seen in 106 endometrial specimens after use of the Mirena coil (levonorgestrel) and compares these changes with previous studies. The variables assessed include nature of the endometrial glands, metaplastic glandular changes, nuclear atypia, hobnail change, and endometrial hyperplasia. Stromal changes include pseudodecidualization, mucinous change, ulceration, and infiltration by granulocytes, neutrophils, and plasma cells, and stromal hyaline nodules, a feature not described previously. Additional changes include superficial micropapillary change, infarcted decidua, dystrophic calcification, hemosiderophages, polypoid indentations, cervical microglandular hyperplasia and endocervical pseudodecidualization. These variables are compared with a similar previous study. Significant differences in the incidence of glandular metaplasia, dystrophic calcification, plasma cell infiltrates, hemosiderophages, and presence of nuclear atypia are noted. With increased use of the Mirena coil, histopathologists need to be aware of the characteristic and constant endometrial changes due to progestogenic and mechanical effects, despite a wide variation in the duration of usage.

Effect of single post-ovulatory administration of levonorgestrel on gene expression profile during the receptive period of the human endometrium

The hypothesis that levonorgestrel (LNG) used as an emergency contraceptive interferes with endometrial receptivity remains unproven. We compared the endometrial gene expression profile during the receptive period after administering a single dose of LNG 1.5 mg or placebo on day 1 of the luteal phase. An endometrial biopsy was done on day LH+7 or LH+8 and samples were taken from seven volunteers, each one contributing with one cycle treated with placebo and another with LNG. The expression of 20 383 genes was determined using cDNA microarrays. Real-time RT-PCR was used 1) to confirm the differences found in DNA microarray analysis and 2) to determine the effect of LNG on transcript levels of C3, C4BPα, COX2, MAOA, S100A4, and SERPINB9, known to be upregulated during receptivity, and on cPLA2α, JAK1, JNK1, CTSL1, and GSTP1, known to respond to mifepristone. Additional endometrial biopsies were done during the pre-receptive (LH+3) and receptive (LH+7) period and samples were taken from eight untreated volunteers in order to determine the changes associated with acquisition of receptivity of 14 genes. Mean levels of PAEP, TGM2, CLU, IGF2, and IL6ST mRNAs increased after administering LNG while those of HGD, SAT1, EVA1, LOC90133, ANXA1, SLC25A29, CYB5A, CRIP1, and SLC39A14 decreased. Except for the level of ANXA1 transcript, all changes remained within the range observed in untreated controls, and none of the transcripts responding to mifepristone changed in response to LNG. Post-ovulatory administration of LNG caused minimal changes in gene expression profiling during the receptive period. Neither the magnitude nor the nature or direction of the changes endorses the hypothesis that LNG interferes with endometrial receptivity.

Cytokines and Growth Factors in Implantation

Implantation failure is the most important rate limiting factor in the success of assisted reproductive techniques like In vitro fertilization–embryo transfer (IVF-ET). Cytokines are multifunctional signaling molecules having an implicit role in the human implantation process. This review focuses on the redundant roles of cytokines during the various stages of implantation. It also indicates that levels of cytokines in biological fluids like serum and follicular fluid obtained during oocyte retrieval might act as determinants of implantation potential of the blastocyst. Thus a holistic, metabolomic approach of analyzing biological fluids may provide a simpler approach to study the hitherto enigmatic process rather than the proteomic and genomic approach.

Clinical profile of contraceptive progestins

The term progestogen has been widely utilized to indicate the general class of agents that includes both progesterone and its synthetic analogs, whereas the term progestin refers only to synthetic progestational steroids. The development of progestins has been influenced in a major way by the search for orally active hormonal contraceptives, since it is likely that hormonal contraceptives will continue to utilize a progestin, the only possible alternative being represented by the utilization of antiprogestins. Synthetic progestogens in clinical use today belong to three main chemical families: progesterone derivatives (progesterone, retro-progesterone, 19-norprogesterone and 17alpha-hydroxyprogesterone); gonane and 19-nortestosterone derivatives (norethisterone, levonorgestrel, desogestrel, gestodene, norgestimate); a spironolactone derivative. Biological potency of progestogens varies depending on the end-point measured, usually ovulation inhibition and endometrial transformation; with both these tests, the most active compounds are all gonane derivatives, with a potency over a 100 times that of the natural hormone. When administered in adequate doses, a progestin inhibits fertility by inhibiting ovulation. This action is mainly exerted at the hypothalamic level where, physiologically, progesterone decreases the number of LH pulses. When progestogens are delivered directly to the uterine cavity, their action seems to be purely local. It has been amply proven that--even when administered in doses that do not constantly inhibit ovulation--a progestin can still remain effective as a contraceptive by acting at the level of the cervical mucus and, at least in part, of the endometrium. Progestogens utilized today differ largely in their pharmacokinetics. In general, after intake, these compounds are rapidly absorbed and distributed so that peak serum concentrations are reached between 1 and 4 h. Third-generation progestins (desogestrel, gestodene, norgestimate) have common characteristics: a higher affinity for progesterone receptors than their predecessors, a lower affinity for androgen receptors, a higher selectivity of action, a higher central inhibitory activity, a higher potency at the level of the endometrium, and an overall metabolic neutrality, in terms of effects on lipid and carbohydrate metabolism. In general, progestins can induce two types of adverse effects: changes in lipid metabolism and bleeding irregularities. Whereas the newer compounds seem to have overcome the first of these adverse effects, the second remains untouched: to this day, proper cycle control can only be achieved with combined hormonal contraceptives.

Human placental IGF-I and IGF-II expression: correlating maternal and infant anthropometric variables and micronutrients at birth in the Pakistani population

AIM

To correlate infant birth weight with maternal and infant biometric data, including the expression of placental IGF-I and IGF-II at birth, and levels of serum zinc and ferritin.

METHODS

The data consisted of observations from 89 women from Karachi, Pakistan. Placental and cord blood samples were taken immediately following delivery and were subsequently divided into two groups, small and large for gestational age (SGA and LGA).

RESULTS

The mean birth weight was 2.79 kg; the prevalence of SGA being 13.4% (< or =10th percentile); the prevalence of LGA being 23.6% (> or =90th percentile). Placental IGF-I and IGF-II mRNA expression was greater in the LGA group (p < 0.05). Furthermore, a significant correlation was noted between infant birth weight and maternal anthropometric parameters (p < 0.01). Cord zinc levels were also significantly higher in the LGA group (p < 0.05).

CONCLUSION

Maternal anthropometry, along with placental IGF-I and IGF-II mRNA levels, correlated significantly with infant birth weight suggesting the importance of these growth factors for birth weight outcomes. The higher zinc levels in the LGA group also suggest the importance of this micronutrient in foetal growth. Our results suggest that growth problems have a multifactorial aetiology arising from within the infant rather than due to maternal constraint alone.

Contraceptive and Therapeutic Effects of the Levonorgestrel Intrauterine System: An Overview

The levonorgestrel intrauterine system (LNG IUS), a steroid-releasing intrauterine system, is a T-shaped device that releases levonorgestrel directly into the uterine cavity at an initial rate of 20 mug per day. The contraceptive and therapeutic benefits of the LNG IUS stem primarily from its local effects. The local hormone delivery causes high levonorgestrel levels in the endometrial tissue but low levels in the systemic circulation. This leads to strong endometrial suppression and, in many cases, a dramatic reduction in menstrual blood loss. The high contraceptive efficacy is well documented through extensive international clinical research. This review article provides an overview of the LNG IUS and addresses the following topics: mechanisms of action, contraceptive efficacy, changes in bleeding patterns, principal safety issues, potential noncontraceptive benefits, and implications for women's reproductive health.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to explain that the levonorgestrel intrauterine system (LNG IUS) has contraceptive and therapeutic benefits, identify the main site of action as the endometrium, and to recall that the safety of the system has been validated over time.

Levonorgestrel intrauterine system (LNG-IUS) with conjugated oral equine estrogen: a successful regimen for HRT in perimenopausal women

BACKGROUND

This study was designed to assess the long-term efficacy (5 years) of the levonorgestrel-releasing intrauterine system (LNG-IUS) in protecting the endometrium from hyperplasia during estrogen replacement therapy in perimenopausal women.

METHODS

Prospective, open, outpatient clinical trial in London and Oxford. Eighty-two women received oral conjugated equine estrogen 1.25 mg daily and LNG-IUS releasing 20 mug levonorgestrel per 24 h. Endometrial biopsy and histological assessment were performed annually. Endometrial thickness was measured by vaginal ultrasonography.

RESULTS

Non-proliferative endometrium was present at the end of cycles 12, 24, 36, 48 and 60 in 98.6, 98.6, 95.5, 96.8 and 95.2% of the participants respectively. No endometrial hyperplasias were confirmed throughout a period of 60 cycles. The proportion of amenorrhoeic women increased from 54.4% at 12 cycles to 92.7% at the end of the study. The continuation rate per 100 women at 60 cycles was 79.84 (95% CI 71.0-88.6).

CONCLUSIONS

The LNG-IUS with estrogen supplementation in perimenopausal women suppresses endometrial proliferation resulting in amenorrhoea and relieves vasomotor symptoms. The treatment regimen is well tolerated and provides an alternative strategy for perimenopausal women with the likelihood of increasing compliance.

Benefit-Risk Assessment of the Levonorgestrel Intrauterine System in Contraception

The levonorgestrel-releasing intrauterine system (IUS) is a long-acting, fully reversible method of contraception. It is one of the most effective forms of contraception available, and combines the advantages of both hormonal and intrauterine contraception. The levonorgestrel-releasing IUS also gives the users many non-contraceptive benefits: the amount of menstrual bleeding and the number of days of menstrual bleeding are reduced, which makes it suitable for the treatment of menorrhagia (heavy menstrual blood loss). Dysmenorrhoea (painful menstruation) and premenstrual symptoms are also relieved. In addition, the levonorgestrel-releasing IUS provides protection for the endometrium during hormone replacement therapy. The local release of levonorgestrel into the uterine cavity results in a strong uniform suppression of the endometrial epithelium as the epithelium becomes insensitive to estradiol released from the ovaries. This accounts for the reduction in menstrual blood loss. All possible patterns of bleeding are seen among users of the levonorgestrel-releasing IUS; however, most of the women who experience total amenorrhoea continue to ovulate. The first months of use are often characterised by irregular, scanty bleeding, which in most cases resolves spontaneously. The menstrual pattern and fertility return to normal soon after the levonorgestrel-releasing IUS is removed. The contraceptive efficacy is high with 5-year failure rates of 0.5-1.1 per 100 users. The absolute number of ectopic pregnancies is low, as is the rate per 1000 users. The levonorgestrel-releasing IUS is equally effective in all age groups and the bodyweight of the user is not associated with failure of the method. In Western cultures continuance rates among users of the levonorgestrel-releasing IUS are comparable with those of other long-term methods of contraception. Premature removal of the device is most often associated with heavy menstrual bleeding and pain, as with other long-term methods of contraception, and is most common in the youngest age group. When adequately counselled about the benign nature of oligo- or amenorrhoea, most women are very willing to accept life without menstruation. The risk of premature removal can be markedly diminished with good pre-insertion counselling, which also markedly increases user satisfaction. User satisfaction is strongly associated with the information given at the time of the levonorgestrel-releasing IUS insertion. Thus, the benefits of the levonorgestrel-releasing IUS make it a very suitable method of contraception for most women.

Use of a levonorgestrel-releasing intrauterine system to treat bleeding related to uterine leiomyomas

OBJECTIVE

This study was designed to evaluate the potential usefulness of the levonorgestrel-releasing intrauterine system (LNG IUS) in treating women with uterine leiomyomas.

DESIGN

Prospective before-and-after study.

SETTING

Family planning unit in an academic research institute.

PATIENT(S)

Sixty-seven women with uterine leiomyomas who chose the LNG IUS as their method of contraception.

INTERVENTION(S)

Clinical and ultrasound examinations were performed prior to and 3, 6, and 12 months after the LNG IUS insertion.

MAIN OUTCOME MEASURE(S)

Menstrual blood loss assessed with pictorial blood loss assessment charts, ferritin and hemoglobin concentrations, and uterine and leiomyoma volume.

RESULT(S)

Use of the LNG IUS was associated with a marked reduction in menstrual blood loss. After 12 months of use, the mean pictorial blood loss assessment chart score declined from 97 to 16 (P<.001). Hemoglobin and ferritin levels increased significantly over 1 year of use. Eighteen of 19 women (95%) who were anemic at the beginning of the study were no longer anemic at 12 months, as judged by hemoglobin levels. No pregnancies occurred during the study.

CONCLUSION(S)

The LNG IUS was associated with a profound reduction in menstrual blood loss. For women with leiomyomas of this size, the LNG IUS provides effective medical treatment of bleeding.

Comparative Biology of the IGF System in Endometrium, Decidua, and Placenta, and Clinical Implications for Foetal Growth and Implantation Disorders

The insulin like growth factors and their binding proteins appear to play a central role during implantation and establishment of pregnancy in all species studied. Although there are similarities among species in the cell types that express IGFs and IGFBPs and their regulation during implantation and pregnancy, there are also significant differences. Understanding of the role of the IGF system in placental function in the human is of immense clinical importance, because serious complications of pregnancy such as intrauterine growth restriction and pre-eclampsia are thought to be associated with alterations in IGF system during early pregnancy and later in gestation. Research in laboratory and domestic animals, including transgenic and gene targeting studies in mice, has significantly improved our understanding of the role of IGF system in placental and foetal development. This paper reviews the diversity in the expression and regulation of IGF system in the decidua and placenta at the foetal-maternal interface in the human and different animal species, which may benefit in directing future studies in understanding of various complications of human pregnancy.

Adenomyosis--a result of disordered stromal differentiation

Adenomyosis is a fairly frequent disorder in adult women characterized by the haphazard location of endometrial glands and stroma deep within the myometrium of the uterus. This study compared the effects on uterine development of the selective estrogen receptor modulators, tamoxifen, toremifene, and raloxifene with estradiol when given orally to female mice on days 2 to 5 after birth. Uterine adenomyosis was found in all (14 of 14) mice dosed with tamoxifen and most mice (12 of 14) treated with toremifene, but in none of the vehicle-dosed controls, in only one animal treated with raloxifene at 42 and 90 days after dosing and in none of the mice treated with estradiol at 42 days. At 6 days, the uterus in the groups that developed a high incidence of adenomyosis showed histological evidence of disturbed differentiation of the myometrium. Gene-expression XY-scatterplots using Clontech mouse 1.2 Atlas mouse cDNA expression arrays analyzing total uterine RNA showed nerve growth factor-alpha, preadipocyte factor-1, and insulin-like growth factor-2 were key genes differentially modified by tamoxifen or toremifene treatment, relative to the controls. As these genes may play an important role in regulating differentiation and development of the myometrium, these data suggest that adenomyosis may be caused primarily by defects in the formation of the myometrium.

Induction of endometrial plasminogen activator-inhibitor 1: a possible mechanism contributing to the effect of intrauterine levonorgestrel in the treatment of menorrhagia

OBJECTIVE

To elucidate molecular mechanisms accounting for excessive menstrual blood loss, and to present the therapeutic effect of an intrauterine levonorgestrel system (LNG-IUS) in menorrhagia.

DESIGN

A multicenter study comparing hysterectomy with the LNG-IUS in treating menorrhagia.

SETTING

A university hospital.

PATIENT(S)

Women with (n = 27) and without (n = 14) menorrhagia, and women with uterine fibroids but undetermined menstrual blood loss (n = 35).

INTERVENTION(S)

An LNG-IUS was inserted into the uterine cavity in 11 women with menorrhagia and six women experiencing normal menstrual blood loss.

MAIN OUTCOME MEASURE(S)

Expression of the messenger ribonucleic acid (mRNA) of tissue-type plasminogen activator (t-PA) and that of a specific PA inhibitor type 1 (PAI-1) in endometrial tissue samples, as evaluated with the use of Northern blot analysis.

RESULT(S)

t-PA mRNA was expressed in the endometrium throughout the menstrual cycle, with no statistically significant difference between a proliferative (n = 30) and a secretory endometrium (n = 40), or between women experiencing normal menstrual blood loss (n = 14) and those with menorrhagia (n = 27). The levels of t-PA mRNA in menstrual phase samples (n = 6) were significantly higher than those in proliferative or secretory endometrium. PAI-1 mRNA was detected in the endometrium during menstruation only. Both t-PA mRNA and PAI-1 mRNA were expressed in all endometrial samples (n = 17) obtained 6 months after an LNG-IUS was inserted, regardless of the menstrual cycle phase. The relative levels of both types of mRNA were significantly higher in LNG endometrium than in proliferative or secretory endometrium, but levels did not differ from those in menstrual-phase endometrium.

CONCLUSION(S)

The mean (+/-SD) levels of t-PA mRNA and PAI-1 mRNA in the endometrium of women with and without menorrhagia did not differ, suggesting that the PA system is not the major determinant of menstrual blood loss. However, continuous induction of PAI-1 may contribute to the therapeutic effect of LNG-IUS in treating menorrhagia.

Elevation of insulin-like growth factor-binding protein-1 mRNA expression following hormone replacement therapy

The purpose of this study was to investigate the possible regulatory roles of insulin-like growth factors (IGF) and IGF binding protein-1 (IGFBP-1) on postmenopausal endometrium in women undergoing hormone replacement therapy (HRT). Endometrial tissues and blood samples were collected from 25 postmenopausal women with abnormal uterine bleeding before and after HRT. As a control, blood and endometrial samples were also obtained at mid-luteal phase (days 18-23 of the menstrual cycle) from 10 women with benign uterine leiomyoma during surgical intervention. Expression of mRNA for IGF-I, IGF-II, type 1-IGF receptor, IGFBP-1, oestrogen receptor (ER) and progesterone receptor (PR) in the endometrium was explored by a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Serum concentrations of IGFBP-1, oestradiol, progesterone, follicle stimulating hormone (FSH) and sex hormone-binding globulin (SHBG) were also determined. In the endometrium obtained from postmenopausal women with abnormal uterine bleeding (before HRT), expression of IGFBP-1 was undetectable, whereas PR expression was abundant. HRT significantly up-regulated expression of IGFBP-1 but down-regulated PR. Moderate expression of IGF-I, IGF-II, type 1-IGF receptor and ER was identified in the postmenopausal endometrium before HRT. HRT significantly down-regulated IGF-I, up-regulated IGF-II, but had no effects on expression of type 1-IGF receptor and ER. In conclusion, up-regulation of IGFBP-1 collaboratively with down-regulation of IGF-I may account for the protective effect of progesterone in HRT on the endometrium.

Effect of the levonorgestrel-releasing intrauterine system on uterine myomas in a renal transplant patient

The levonorgestrel-releasing intrauterine system (LNG-IUS) has been used in the treatment of both idiopathic menorrhagia and adenomyosis. An electronic search of the on-line medical literature revealed no reports of its use for menorrhagia secondary to uterine myomas. Presented here is the successful treatment of uterine myomas with menorrhagia in a woman with a renal transplant. There was a significant reduction in menorrhagia, dysmenorrhea, and uterine and myoma size with the use of the LNG-IUS. We believe that this system provides an alternative to conventional hysterectomy and gonadotrophin-releasing hormonal analog medical treatment for uterine myomas, with a possibly inhibitory effect on myoma growth.

Regulation of endometrial angiogenesis

Bleeding problems are the most common reason for discontinuation of hormone replacement therapy. Human endometrium undergoes the unique process of benign angiogenesis under the control of ovarian steroids during reproductive life and it is presumed that similar processes occur when women take hormone replacement therapy. The key players in endometrial growth and angiogenesis are vascular endothelial growth factor, thymidine phosphorylase and adrenomedullin. Regulation of these angiogenic factors is described.

Insulin-like growth factors in endometrial function

Growth factors and related peptides are believed to mediate and modulate the actions of hormones at their target tissues through autocrine/paracrine mechanisms. Endometrial stromal cells produce insulin-like growth factors I and II (IGF-I and IGF-II) as well as the high-affinity IGF binding proteins (IGFBPs), whereas epithelial cells and, in a lesser amount, also stromal cells contain cell membrane receptors for IGFs. IGFs have proliferative, differentiative and metabolic effects. Estrogen stimulates IGF-I gene expression in the endometrium, and IGF-I is assumed to mediate estrogen action. IGF-II gene expression is associated with endometrial differentiation. All six high-affinity IGFBPs are expressed in human endometrium, the most abundant being IGFBP-1. This is secreted by predecidualized/decidualized endometrial stromal cells in late secretory phase endometrium and pregnancy decidua, i.e. under the action of progesterone. The primary negative regulator of IGFBP-1 expression is insulin, by inhibiting IGFBP-1 transcription. IGFBP-1 inhibits the receptor binding and biological actions of IGF-I in the endometrium and in cultured human trophoblastic cells. These findings support the view that the IGF system has autocrine and paracrine functions in the regulation of endometrial proliferation and differentiation. After implantation, decidual IGFBP-1 may regulate IGF actions at the embryo-endometrial interface, since trophoblast cells contain IGF receptors and express IGF-II, but do not express IGFBP-1. Clinical conditions that are known to increase the risk of endometrial cancer are all characterized by the absence of IGFBP-1. Thus, like unopposed estrogen, unopposed IGF-I action may also lead to uncontrolled endometrial proliferation and favor the development of endometrial cancer. The measurement of mRNAs encoding the IGF system might provide a novel tool to evaluate the endometrial response to endogenous and exogenous estrogens and progestins at the molecular level.