Relative efficacy of micronutrient powders versus iron-folic acid tablets in controlling anemia in women in the second trimester of pregnancy.

BACKGROUND: Iron deficiency is a major cause of anemia and the most prevalent nutrient deficiency among pregnant women in developing countries. The use of iron and folic acid supplements to treat and prevent iron-deficiency anemia has limited effectiveness, mainly due to poor adherence. Home fortification with a micronutrient powder for pregnant women may be an effective and acceptable alternative to traditional drug models. OBJECTIVE: To determine whether home fortification with micronutrient powders is at least as efficacious as iron and folic acid tablets for improving hemoglobin concentration in pregnant women. METHODS: A cluster-randomized noninferiority trial was conducted in the rural subdistrict of Kaliganj in central Bangladesh. Pregnant women (gestational age 14-22 weeks, n=478), were recruited from 42 community-based Antenatal Care Centres. Each centre was randomly allocated to receive either a micronutrient powder (containing iron,folic acid, vitamin C, and zinc) or iron and folic acid tablets. Changes in hemoglobin from baseline were compared across groups using a linear mixed-effects regression model. RESULTS: At enrolment, the overall prevalence of anemia was 45% (n = 213/478). After the intervention period, the mean hemoglobin concentrations among women receiving the micronutrient powder were not inferior to those among women receiving tablets (109.5 ± 12.9 vs. 112.0 ± 11.2 g/L; 95% CI, -0.757 to 5.716). Adherence to the micronutrient powder was lower than adherence to tablets (57.5 ± 22.5% vs. 76.0 ± 13.7%; 95% CI, -22.39 to -12.94); however, in both groups, increased adherence was positively correlated with hemoglobin concentration. CONCLUSIONS: The micronutrient powder was at least as efficacious as the iron and folic acid tablets in controlling moderate to severe anemia during pregnancy.

Daily use of Sprinkles micronutrient powder for 2 months reduces anemia among children 6 to 36 months of age in the Kyrgyz Republic: a cluster-randomized trial.

BACKGROUND: Iron-deficiency anemia is widespread among young children in the Kyrgyz Republic, and there is an urgent need to identify an effective intervention to address this significant public health problem. OBJECTIVE: To test the effectiveness of a 2-month intervention with daily home fortification of complementary food using micronutrient powder (Sprinkles) in reducing anemia among children 6 to 36 months of age in the Kyrgyz Republic. METHODS: In this cluster-randomized, community-based effectiveness trial conducted in three regions of the Kyrgyz Republic, 24 clusters of children aged 6 to 36 months were randomly assigned to two groups. The intervention group (12 clusters, n = 1,103) received 60 sachets of micronutrient powder (12.5 mg elemental iron), which were taken as one sachet daily for 2 months. The control group (12 clusters, n = 1,090) did not receive micronutrient powder until after the study period. Blood hemoglobin concentration was assessed at the start and end of the intervention. RESULTS: From baseline to follow-up, the mean hemoglobin concentration in the intervention group increased by 7 g/L, whereas it decreased by 2 g/L in the control group (p < .001). The prevalence of anemia (hemoglobin < 110 g/L) in the intervention group decreased from 72% at baseline to 52% at follow-up, whereas it increased from 72% to 75% in the control group (p < .001). Compliance with the intervention was high, with children consuming on average 45 of the 60 sachets given. CONCLUSIONS: A course of 60 Sprinkles micronutrient powder sachets taken daily for 2 months is effective in improving hemoglobin levels and reducing the prevalence of anemia among young children in the Kyrgyz Republic.

Unexpectedly high early prevalence of anaemia in 6-month-old breast-fed infants in rural Bangladesh.

OBJECTIVE: To determine the prevalence of anaemia and maternal and infant factors associated with Hb values in infants at 6 months of age in rural Bangladesh. DESIGN: Infants (born to mothers supplemented with Fe-folic acid from mid-pregnancy) were visited at birth and 6 months of age. Mothers' anthropometric status, and infants' birth weight, gestational age at birth, weight and Hb concentration at 6 months were measured. Household socio-economic and demographic data, infant feeding practices and health status were collected using a pre-tested structured questionnaire. SETTING: Rural Bangladesh. SUBJECTS: Four hundred and two infants. RESULTS: For the total cohort (n 402), the range of anaemia prevalence values was from 30.6 % using a cut-off value of Hb < 95 g/l to 71.9 % using a value of Hb < 110 g/l. Birth weight and month of birth were the only factors positively associated with infant Hb in a linear regression model (P = 0.008 and 0.011, respectively). CONCLUSIONS: There was an unexpectedly high prevalence of anaemia in infants at 6 months of age, before the assumed period of vulnerability. Hb at this age tended to be higher in those with higher birth weight. We also found a season effect on Hb, as it tended to be higher as the study progressed. The high prevalence of anaemia at such an early age needs to be addressed to minimize the disease's long-term consequences.

Improved adherence and anaemia cure rates with flexible administration of micronutrient Sprinkles: a new public health approach to anaemia control.

BACKGROUND/OBJECTIVES: Despite repeated public commitments and availability of various forms of iron supplements, rates of anaemia in developing countries remain high. A major reason for this lack of success has been poor adherence. The objective of this study was to compare the effectiveness of daily and flexible administration of micronutrient Sprinkles on adherence, acceptability and haematological status among young children in rural Bangladesh. SUBJECTS/METHODS: A sample of 362 children (haemoglobin (Hb)>or=70 g l(-1)) aged 6-24 months were cluster-randomized to receive 60 sachets of Sprinkles either (i) daily over 2 months; (ii) flexibly over 3 months; or (iii) flexibly over 4 months. With a flexible regimen, mothers/caregivers decided how frequently to use Sprinkles without exceeding one sachet per day. Adherence was assessed monthly by counting the number of sachets used and acceptability was evaluated through focus group discussions. Haemoglobin was measured at baseline, at the end of each intervention period and 6 months post-intervention. RESULTS: Mean percent adherence was significantly higher in the flexible-4-month group (98%) compared to the flexible-3-month (93%) and daily-2-month (88%) groups (P<0.01). Most mothers found flexible administration to be more acceptable than daily due to perceived benefits of use. Hb at the end of intervention was significantly higher in the flexible-4-month group compared to the daily group (P=0.03). Anaemia prevalence decreased by 65% in the flexible-4-month group compared to 54% in the flexible-3-month and 51% in the daily-2-month groups. Percent of cured children who maintained a non-anaemic status 6 months post-intervention was significantly higher in the flexible-4-month (82%) and flexible-3-month (80%) groups than the daily-2-month (53%) group (P<0.05). CONCLUSIONS: The adherence, acceptability and haematological response to flexible administration over 4 months were found preferable to daily.

A multiple-micronutrient-fortified beverage affects hemoglobin, iron, and vitamin A status and growth in adolescent girls in rural Bangladesh.

Adolescent girls have high nutrient needs and are susceptible to micronutrient deficiencies. The objective of this study was to test the effect of a multiple-micronutrient-fortified beverage on hemoglobin (Hb) concentrations, micronutrient status, and growth among adolescent girls in rural Bangladesh. A total of 1125 girls (Hb > or = 70 g/L) enrolled in a randomized, double-blind, placebo-controlled trial and were allocated to either a fortified or nonfortified beverage of similar taste and appearance. The beverage was provided at schools 6 d/wk for 12 mo. Concentrations of Hb and serum ferritin (sFt), retinol, zinc, and C-reactive protein were measured in venous blood samples at baseline, 6 mo, and 12 mo. In addition, weight, height, and mid-upper arm circumference (MUAC) measurements were taken. The fortified beverage increased the Hb and sFt and retinol concentrations at 6 mo (P < 0.01). Adolescent girls in the nonfortified beverage group were more likely to suffer from anemia (Hb <120 g/L), iron deficiency (sFt <12 microg/L), and low serum retinol concentrations (serum retinol <0.70 micromol/L) (OR = 2.04, 5.38, and 5.47, respectively; P < 0.01). The fortified beverage group had greater increases in weight, MUAC, and BMI over 6 mo (P < 0.01). Consuming the beverage for an additional 6 mo did not further improve the Hb concentration, but the sFt level continued to increase (P = 0.01). The use of multiple-micronutrient-fortified beverage can contribute to the reduction of anemia and improvement of micronutrient status and growth in adolescent girls in rural Bangladesh.

Effect of daily versus once-weekly home fortification with micronutrient Sprinkles on hemoglobin and iron status among young children in rural Bangladesh.

BACKGROUND: The effectiveness of commonly suggested public health interventions to control childhood iron-deficiency anemia has been low. OBJECTIVE: To determine whether iron provided in Sprinkles daily or in a higher dose once weekly affected hemoglobin, serum ferritin levels, and serum transferrin receptor levels, and to determine whether there were differences in the effects of the two regimens. METHODS: In this cluster-randomized, community-based trial conducted in rural areas of Bangladesh, 136 children aged 12 to 24 months with mild to moderate anemia (hemoglobin 70-109 g/L) were randomly allocated to receive Sprinkles daily (12.5 mg of elemental iron, n = 79) or once weekly (30 mg of elemental iron, n = 73) for 8 weeks. Hemoglobin, serum ferritin, and serum transferrin receptor were assessed at the start and end of the intervention. RESULTS: In both groups, there were significant increases in hemoglobin and serum ferritin and a significant decrease in serum transferrin receptor (p < .01). There were no significant differences between the groups in the increases in hemoglobin (16.1 +/- 13.2 g/L for the group receiving Sprinkles daily and 12.3 +/- 13.3 g/L for the group receiving Sprinkles once weekly) and serum ferritin (10.6 and 5.7 microg/L, respectively). The decrease in serum transferrin receptor also did not significantly differ between the groups (median, -2.5 and -1.8 mg/L, respectively). The prevalence rates of iron-deficiency anemia, depleted iron stores, and tissue iron deficiency decreased significantly within each group (p < .01), with no significant differences between the groups. CONCLUSIONS: Home fortification of complementary foods with Sprinkles given either daily or once weekly improved iron-deficiency anemia and iron status among young children.

Sex-steroid regulation of vascular endothelial growth factor in breast cancer.

Angiogenesis is a key event, which occurs in both normal and pathological expansion of tissues and provides the nourishment necessary for growth. The role of angiogenic growth factors in breast pathology is rapidly gaining recognition since scientists and clinicians realized that these factors could function as molecular targets event 550 209822 for controlling tumor expansion. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. Although significant advances have been made in understanding the sex-steroid-dependent regulation of this key factor, the role of VEGF in controlling breast tumors is not well understood. In this review, I discuss recent studies describing the role of the female sex steroids estrogens and progestins in the regulation of VEGF in breast cancer cells. Furthermore, I present a summary of recent studies from other biological systems (mainly focused on tumor biology) directed towards providing us with a better understanding of the regulation of classical VEGF and VEGF receptors. I propose that by extending such studies we will gain deeper insights into how we might combat the progression of breast cancer by controlling hormone-dependent angiogenesis within tumor tissue. I believe that information gained from such studies will permit us to target angiogenic growth factors and their initiated signal transduction pathways in a more precise and selective manner, and thereby to control the formation of new blood vessels that fuel the rapid growth of breast tumors. Finally, it is my hope that the concepts discussed here will help elucidate molecular targets in the hormone-dependent angiogenesis pathway that will ultimately allow us to overcome anti-hormone resistance and to provide insights into how we might pursue the concept of chemoprevention by considering 'angioprevention' as the end point.

Controlling iron deficiency anemia through the use of home-fortified complementary foods.

Iron deficiency anemia (IDA) is more common in South Asian countries including India, Bangladesh and Pakistan than anywhere else in the world. During infancy and early childhood, IDA is associated with impaired psycho-motor development and cognitive function that may be irreversible. As a consequence, there is a growing awareness that IDA is one of many factors impeding socio-economic prosperity of developing nations. The combination of unacceptably high prevalence rates and inadequate preventative programs highlights the need for new effective sustainable strategies to control IDA. The burden of iron deficiency can be reduced by taking a more holistic approach that would include promotion of healthy weaning practices and use of appropriate complementary foods, together with improving the nutritional value of such foods. There is an increasing body of peer-reviewed literature to support the contention that "micronutrient Sprinkles" is an effective strategy to improve the nutritional value of home-prepared complementary foods and thus to reduce the burden of iron deficiency among children. By combining data from recently conducted randomised control trials, Sprinkles were shown to be as efficacious as iron drops for treating childhood anemia. The iron in Sprinkles is well absorbed, and Sprinkles are easy to use and well accepted by young children and their caregivers. Integrated into existing public health programs, Sprinkles has the potential to improve the effectiveness of such programs.

Anaemia and iron deficiency during pregnancy in rural Bangladesh.

OBJECTIVE: To study the prevalence of anaemia and its association with measures of iron deficiency (ID) among a group of pregnant women. DESIGN: Cross-sectional survey. SETTING: Pregnant women identified through house-to-house visits and participating in community-based antenatal care activities in a rural location of Mymensingh, Bangladesh. SUBJECTS: The estimates are based on 214 reportedly healthy pregnant women in their second trimester. Information on socio-economic status and reproductive history were obtained through home visits and venous blood samples were collected at antenatal care centres. Haemoglobin concentration (Hb) was measured by HemoCue, serum ferritin (sFt) by radioimmunoassay and serum transferrin receptor (sTfR) by enzyme-linked immunosorbent assay methods. ID was defined as presence of either low sFt (<12 microg l(-1)) or high sTfR (>8.5 mg l(-1)). RESULTS: The prevalence of anaemia (Hb <110 g l(-1)) was 50%, but severe anaemia (Hb <70 g l(-1)) was absent. Low sFt was observed in 42%, high sTfR in 25%, either low sFt or high TfR in 54% and both low sFt and high TfR in 13% of the pregnant women. Two out of three anaemic women had an indication of ID, which was present in 80% of women with moderate (Hb 70-99 g l(-1)) and 50% with mild (Hb 100-109 g l(-1)) anaemia. Four out of 10 non-anaemic women (Hb >/=110 g l(-1)) also had ID, but the prevalence was significantly lower than that observed in anaemic women (P=0.001). CONCLUSIONS: Despite the high prevalence of anaemia, severe cases were absent. The prevalence of ID increased at lower Hb. However, an increased prevalence was also found among women in the highest category of Hb.

Efficacy and trial effectiveness of weekly and daily iron supplementation among pregnant women in rural Bangladesh: disentangling the issues.

BACKGROUND: According to our current understanding, iron absorption with weekly iron supplements is not higher than that with daily supplements (ie, there is no mucosal block). However, community-based trials have repeatedly shown that a weekly regimen is as effective as a daily one. Furthermore, when differences in absorption are found, they are commonly smaller than would be expected on the basis of differences in the amount of iron provided. The possibility of differential compliance between the regimens needs to be evaluated to explain these findings. OBJECTIVE: Taking compliance into account, we compared the efficacy and trial effectiveness of weekly and daily iron supplementation during pregnancy. DESIGN: In Bangladesh, 50 antenatal centers were randomly assigned to prescribe either 2 doses of 60 mg Fe once weekly or 1 dose of 60 mg Fe/d. Compliance was monitored by using a pill bottle equipped with an electronic counting device. Hemoglobin concentrations were measured at baseline and after 4, 8, and 12 wk of supplementation. RESULTS: There was no differential effect per iron tablet between weekly and daily regimens. A 12-wk daily regimen (68% compliance) produced a small but significantly greater hemoglobin response than did the weekly regimen (104% compliance). The first 20 tablets consumed produced most of the effect; after 40 tablets, there was no further response. CONCLUSIONS: There was no evidence of a mucosal block in the daily regimen. Over 12 wk, 50% of the amount of iron in a daily regimen was sufficient for maximum hemoglobin effect. The weekly regimen provided a large part of this amount, explaining the limited difference in effect. It appears that the current international recommendation for iron supplementation in pregnancy is higher than necessary.

Do side-effects reduce compliance to iron supplementation? A study of daily- and weekly-dose regimens in pregnancy.

Side-effects of iron supplementation lead to poor compliance. A weekly-dose schedule of iron supplementation rather than a daily-dose regimen has been suggested to produce fewer side-effects, thereby achieving a higher compliance. This study compared side-effects of iron supplementation and their impact on compliance among pregnant women in Bangladesh. These women were assigned to receive either weekly doses of 2 x 60 mg iron (one tablet each Friday morning and evening) or a daily dose of 1 x 60 mg iron. Fifty antenatal care centres were randomly assigned to prescribe either a weekly- or a daily-supplementation regimen (86 women in each group). Side-effects were assessed by recall after one month of supplementation and used for predicting compliance in the second and third months of supplementation. Compliance was monitored using a pill bottle equipped with an electronic counting device that recorded date and time whenever the pill bottle was opened. Of five gastrointestinal side-effects (heartburn, nausea, vomiting, diarrhoea, or constipation) assessed, vomiting occurred more frequently in the weekly group (21%) than in the daily group (11%, p<0.05). Compliance (ratio between observed and recommended tablet intake) was significantly higher in the weekly-supplementation regimen (93%) than in the daily-supplementation regimen (61%, p<0.05). Overall, gastrointestinal side-effects were not significantly associated with compliance. However, the presence of nausea and/or vomiting reduced compliance in both the regimens-but only among women from the lower socioeconomic group. In conclusion, weekly supplementation of iron in pregnancy had a higher compliance compared to daily supplementation of iron despite a higher frequency of side-effects. The findings support the view that gastrointestinal side-effects generally have a limited influence on compliance, at least in the dose ranges studied. Efforts to further reduce side-effects of iron supplementation may not be a successful strategy for improving compliance and effectiveness of antenatal iron supplementation.

Pharmacological and endogenous progestins induce vascular endothelial growth factor expression in human breast cancer cells.

Tumor expansion is dependent on angiogenesis, which is regulated by peptide growth factors of which vascular endothelial growth factor (VEGF) is one of the most selective and potent. VEGF expression is regulated by steroid hormones in a number of systems, including T47-D human breast cancer cells in which VEGF protein levels are elevated by progestins. In the present study, we investigated the effect of progestins on VEGF mRNA levels in human breast cancer cells. For these experiments, T47-D cells were exposed to progestins, RNA was prepared for measurement of VEGF transcript levels by Northern blot analysis and VEGF protein in the cell culture media was measured by enzyme-linked immunosorbent assay. Basal expression of VEGF mRNA is low in these cells, and is rapidly induced following exposure to progestins, reaching a maximum induction of 2- to 5-fold between 3 and 6 hr after hormone addition. This induction was inhibited by the antiprogestin RU-486 indicating that it is progesterone receptor (PR) dependent. Transcripts for VEGF165 and VEGF121 were the two major spliced forms of VEGF mRNA that were detected by reverse transcription-polymerase chain reaction in basal and progestin-stimulated T47-D cells. Maximum induction of VEGF mRNA was achieved with 10(-8) M progesterone, and induction was hormone specific, as estrogens, glucocorticoids, and androgens were without effect. Actinomycin D completely abolished the induction of VEGF transcript levels by progestins, suggesting that this response involves de novo mRNA synthesis, but puromycin did not inhibit induction, suggesting that this effect does not require protein synthesis. This report demonstrates that progestins stimulate VEGF mRNA levels and raises the possibility that anti-progestins may be useful to inhibit proliferation and metastasis in some human breast cancers by blocking VEGF production.

Estradiol rapidly inhibits soluble guanylyl cyclase expression in rat uterus.

Previous reports that investigated the regulation of the NO/soluble guanylyl cyclase (sGC)/cGMP pathway by estrogenic compounds have focused primarily on the levels of NO, NO-producing enzymes, and cGMP in various tissues. In this study, we demonstrate that 17beta-estradiol (E2) regulates the alpha(1) and beta(1) subunits of the NO receptor, sGC, at the mRNA and protein levels in rat uterus. Using real-time quantitative PCR, we found that within 1 h of in vivo E2 administration to rats, sGC mRNA levels begin to diminish. After 3 h, there is a maximal diminution of sGC mRNA expression (sGC alpha(1) 10% and sGC beta(1) 33% of untreated). This effect was blocked by the estrogen receptor antagonist, ICI 182,780, indicating that estrogen receptor is required. The effect of E2 also was observed in vitro with incubations of uterine tissue, indicating that the response does not depend on the secondary release of other hormones or factors from other tissues. Puromycin did not block the effect, suggesting the effects occur because of preexisting factors in uterine tissues and do not require new protein synthesis. Using immunoblot analysis, we found that sGC protein levels also were reduced by E2 over a similar time course as the sGC mRNA. We conclude that sGC plays a vital role in the NO/sGC/cGMP regulatory pathway during conditions of elevated estrogen levels in the rat uterus as a result of the reduction of sGC expression.

Regulation of vascular endothelial growth factor expression by estrogens and progestins.

Estrogens increase the expression of vascular endothelial growth factor (VEGF) mRNA in the rodent uterus. This regulatory effect is rapid, beginning within 1 hr after hormone treatment, dose dependent, and blocked by the pure antiestrogen ICI 182,780. The induction of the transcript is blocked by inhibitors of RNA but not of protein synthesis, and we have recently identified estrogen response elements in the VEGF gene. Collectively, these findings indicate that estrogens regulate uterine VEGF expression at the transcriptional level via the classical nuclear estrogen receptor pathway. Estrogen induction of VEGF occurs in the stromal layer of the rodent uterus, and estradiol induces expression of VEGF transcript levels in cultured human uterine stromal cells. Progestins also induce VEGF expression in the rodent uterus, although the effect is less marked and slower in onset than estrogenic effects. The effect of progestins is blocked by the antiprogestin mifepristone (RU-486), suggesting that it is also mediated by a classical nuclear receptor pathway. In addition, progestins regulate expression of VEGF mRNA and protein in cultured human T47-D breast cancer cells. The development of uterine leiomyomas is associated with exposure to ovarian sex steroids, abnormal uterine bleeding is commonly seen in patients with leiomyomas, and fibroids require an increased vascular supply for their growth. These observations suggest that VEGF and other angiogenic factors may represent potential targets for the treatment and prevention of uterine fibroids.

Expression of estrogen receptor coactivators in the rat uterus.

Nuclear receptor coactivators associate in a ligand-dependent manner with estrogen receptors (ER) and other nuclear receptors, and they enhance ligand-dependent transcriptional activation. This study examined basal coactivator expression in rat uterus to investigate if expression of these genes is regulated by estradiol-17 beta or tamoxifen. Ovariectomized mature and immature rats were injected with estradiol-17 beta, tamoxifen, or vehicle (i.e., sesame oil) alone. Uteri were collected and analyzed for changes in coactivator mRNA expression using Northern blot and in situ hybridization analyses. Constitutive uterine mRNA expression of switch protein for antagonist (SPA), SRC-1, GRIP1, RAC3, RIP140, and p300 mRNAs was observed in control uteri, and treatment with ER ligands did not alter coactivator mRNA levels. The data suggest that expression of these coactivator genes is not sensitive to estradiol or tamoxifen in the rat uterus. No cell type-specific pattern of expression was apparent in uterine sections from mature and immature rats; however, silver grains were more abundant in luminal and glandular epithelial cells compared with the stroma and myometrium, indicating that coactivator mRNA levels vary among the uterine compartments. Thus, to our knowledge, we show for the first time that there is constitutive expression of several uterine nuclear receptor coactivators in a physiological setting that remains insensitive to estrogenic regulation. Furthermore, we speculate that higher constitutive levels of coactivator expression in glandular and luminal epithelial cells may be associated with increased hormonal responsiveness by these uterine compartments.

Identification of functional estrogen response elements in the gene coding for the potent angiogenic factor vascular endothelial growth factor.

Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis and a prognostic factor for many tumors including those of endocrine-responsive tissues such as the breast and uterus. We and others have previously shown that VEGF is regulated by estradiol and tamoxifen in the uterus and by estradiol in human breast cancer cells, and pharmacological evidence has suggested that this regulation was mediated by transcriptional activation of the estrogen receptor (ER). This prompted us to investigate whether the VEGF gene contains sequences that bind the ER and confer hormonal inducibility to reporter constructs in the presence of the two ER subtypes. These studies identified two sequences homologous to the consensus estrogen response element, GGTCAnnnTGACC, which bind both ER-alpha and ER-beta. One of these elements is located in the 5'-untranslated region of the VEGF gene (GGGCAaagTGACT), and the other is located in the 3'-untranslated region (GAGCAcccTGCCC). Competition with excess unlabeled oligonucleotides indicates that these two elements bind both ERs specifically, mutations in either half-site of the two elements abolish receptor binding, and ER-alpha- and ER-beta-specific antibodies interact with complexes formed with the corresponding receptor subtypes. In cells containing either ER-alpha or ER-beta, the 3'-element behaves as a traditional enhancer that confers hormone inducibility to reporter constructs in an orientation-independent manner, and transcriptional activity is blocked by the pure antiestrogen ICI 182,780. The pattern of transcriptional activity of the element located in the 5'-flanking region is more complex. In the orientation found in the endogenous gene, this element is nonresponsive to ER-beta but confers estrogen-dependent inhibition of transcription with ER-alpha that is blunted by ICI 182,780. In the opposite orientation, the 5'-element confers hormone inducibility with either ER-alpha or -beta, and ICI 182,780 blocks activation by ER-alpha but not by ER-beta. These findings support the hypotheses that estrogens directly regulate VEGF transcription in target tissues and tumors, although such regulation appears likely to involve a complex interplay of cis- and trans-acting elements not previously observed for other hormone-responsive genes.

Induction of the angiogenic factor VEGF in the uterus by the antiprogestin onapristone.

Onapristone (also referred to as ZK 98,299) is an antiprogestin that shares a number of structural similarities to mifepristone (RU-486) and other drugs in this class. While investigating the actions of antiprogestins on steroid hormone induced gene expression of angiogenic factors such as vascular endothelial growth factor (VEGF), we noted that onapristone alone induces VEGF transcript levels in the immature, ovariectomized rat uterus. In addition, onapristone induces expression of c-fos mRNA, which is induced by estrogens but not progestins in this target tissue. This induction of VEGF and c-fos by onapristone is inhibited by the antiestrogen ICI 182,780, but not by the antiprogestin RU-486. Both transcripts are very rapidly induced by onapristone, with maximal mRNA levels observed 3-6 h after in vivo administration of the drug. This time course is similar to that for induction of these genes by estrogenic hormones. Dose-response studies show that both these genes are maximally induced by a 2.5 mg/kg dose of onapristone following intra peritoneal injection. These results indicate that onapristone rapidly upregulates several genes normally under estrogenic regulation in the immature rat uterus. Importantly, this is the first report of the induction of a major angiogenic factor by an antiprogestin. Since an increase in vascularity increases tumor expansion and metastasis, the induction of angiogenesis and its regulatory factors such VEGF may be an important end-point to consider in the development and use of antiprogestins for the treatment of neoplastic disease.

Regulation of VEGF in the reproductive tract by sex-steroid hormones.

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. In adults, angiogenesis is an infrequent event in the normal tissue except in the female reproductive tract where angiogenesis occurs frequently during the cyclical repair and regeneration of the endometrium as well as in the ovary. Little is known about angiogenesis in the male reproductive tract. The role of VEGF in controlling reproductive tract physiology and the role of hormones in regulating this key regulator of angiogenesis is not well understood. Since reproductive tract physiology is largely under sex-steroid regulation, we have reviewed some recent studies describing the role of sex-steroid hormones in regulating VEGF. We have also included studies on the role of sex-steroids in regulating VEGF and angiogenesis in endometrial, breast and prostate pathologies. We have provided an extensive review of the classical VEGF and VEGF receptors with examples drawn from numerous studies in the literature using diverse biological systems to encourage similar studies in the area of reproductive tract physiology. It is speculated that such studies will provide insights into understanding the role of VEGF in reproductive tract development, causes of infertility, and cancer. Such knowledge would allow us to target VEGF for improving human reproductive tract abnormalities, for enhancing implantation and fertility, and for designing drugs for treatment of endocrine dependent cancers.

Synthetic estrogen 17alpha-ethinyl estradiol induces pattern of uterine gene expression similar to endogenous estrogen 17beta-estradiol.

17alpha-Ethinyl estradiol is one of most widely prescribed estrogens. We compared the effects of this synthetic estrogen to those of the endogenous ovarian hormone 17beta-estradiol on the expression of four estrogen-inducible genes in the rat uterus. The genes examined include c-fos, c-jun, vascular endothelial growth factor, and creatine kinase B, which are all known to be primary responses to estrogen administration. Both estrogens induced the four target genes with similar time courses and produced the same pattern of cell-specific expression of c-fos and vascular endothelial growth factor in the uterine epithelium and stroma, respectively. Dose-response studies established that the potency and efficacy of both estrogens in the uterus were the same for all four hormone-regulated genes. These studies suggest that 17alpha-ethinyl and 17beta-estradiol produce similar if not identical patterns of gene expression in the uterus.