The role of metformin and statins in the incidence of epithelial ovarian cancer in type 2 diabetes: a cohort and nested case-control study.

OBJECTIVE: To obtain evidence of the effects of metformin and statins on the incidence of ovarian cancer in women with type 2 diabetes (T2D). DESIGN: A retrospective cohort study and nested case-control study. SETTING: The data were obtained from a diabetes database (FinDM) combining information from several nationwide registers. POPULATION: A cohort of 137 643 women over 40 years old and diagnosed with T2D during 1996-2011 in Finland. METHODS: In full cohort analysis Poisson regression was used to estimate the hazard ratios (HR) in relation to ever use of metformin, insulin other oral anti-diabetic medication or statins. In the nested case-control analysis 20 controls were matched to each case of ovarian cancer. Conditional logistic regression was used to estimate HRs in relation to medication use and cumulative use of different medications. The estimates were adjusted for age and duration of T2D. MAIN OUTCOME MEASURE: Incidence of ovarian cancer. RESULTS: In all, 303 women were diagnosed with ovarian cancer during the follow up. Compared with other forms of oral anti-diabetic medication, metformin (HR 1.02, 95% CI: 0.72-1.45) was not found to be associated with the incidence of ovarian cancer. Neither was there evidence for statins to affect the incidence (HR 0.99, 95% CI: 0.78-1.25). In nested case-control analysis the results were essentially similar. CONCLUSIONS: No evidence of an association between the use of metformin or statins and the incidence of ovarian cancer in women with T2D was found. TWEETABLE ABSTRACT: No evidence found for metformin or statins reducing the incidence of ovarian cancer.

Cause-specific mortality in endometrioid endometrial cancer patients with type 2 diabetes using metformin or other types of antidiabetic medication.

AIM: To obtain further evidence of the association between metformin or other types of antidiabetic medication (ADM) and mortality from endometrial cancer (EC) and other causes of death in patients with endometrioid EC and type 2 diabetes (T2D). MATERIALS AND METHODS: A retrospective cohort of women with existing T2D and diagnosed with endometrioid EC from 1998 to 2011, obtained from a nationwide diabetes database (FinDM), were included in the study. Cumulative mortality from EC and that from other causes was described by using the Aalen-Johansen estimator. Cause-specific mortality rates were analyzed by using Cox models, and adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) were estimated in relation to the use of different forms of ADM during the three-year period preceding EC diagnosis. RESULTS: From the FinDM cohort we identified 1215 women diagnosed with endometrioid EC, of whom 19% were metformin users, 12% were users of other types of oral antidiabetic medication, 25% used other types of oral antidiabetic medication plus metformin, 26% used insulin and 14% had no antidiabetic medication. Mortality from EC was not found to be different in women using metformin (HR 0.89, 95% Cl 0.52-1.54) but mortality from other causes was lower (HR 0.52, 95% Cl 0.31-0.88) compared with women using other types of oral ADM. CONCLUSIONS: Our findings are inconclusive as to the possible effect of metformin on the prognosis of endometrioid EC in women with T2D. However, use of metformin may reduce mortality from other causes.

Absence of the DNA repair enzyme human 8-oxoguanine glycosylase is associated with an aggressive breast cancer phenotype.

BACKGROUND: 8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) is the most abundant marker of DNA damage and it reflects oxidative stress. Human 8-oxoguanine glycosylase (hOGG1) is a DNA-repair enzyme that participates in 8-oxodG removal. METHODS: hOGG1 protein expression was immunohistochemically studied in 96 patients with local or locally advanced breast cancer and in 20 lesions of non-malignant breast disease. 8-OxodG levels had been previously determined in all patients. RESULTS: hOGG1 was overexpressed in invasive vs non-invasive lesions (P=0.006). 8-OxodG and hOGG1 had a significant inverse association (P=0.046). Lack of hOGG1 expression was associated with the most poor prognostic factors of breast cancer. In addition, all triple-negative breast carcinomas (TNBCs) were hOGG1 negative (P=0.027 vs non-TNBCs). Patients with a lack of both hOGG1- and 8-oxodG immunostaining showed extremely poor breast cancer-specific survival compared with those with either 8-oxodG- or hOGG1-positive tumours (P<0.000005). CONCLUSION: The current results imply that absence of hOGG1 expression is associated with features of aggressive breast cancer. Tumours lacking both 8-oxodG and hOGG1 seem to indicate especially poor prognosis.

8-Hydroxydeoxyguanosine: a new potential independent prognostic factor in breast cancer.

BACKGROUND: 8-Hydroxydeoxyguanosine (8-oxodG) is the commonly used marker of oxidative stress-derived DNA damage. 8-OxodG formation is regulated by local antioxidant capacity and DNA repair enzyme activity. Earlier studies have reported contradictory data on the function of 8-oxodG as a prognostic factor in different cancer types. METHODS: We assessed pre-operative serum 8-oxodG levels with an enzyme-linked immunosorbent assay in a well-defined series of 173 breast cancer patients. 8-OxodG expression in the nuclei of cancer cells from 150 of these patients was examined by immunohistochemistry. RESULTS: The serum 8-oxodG levels and immunohistochemical 8-oxodG expression were in concordance with each other (P<0.05). Negative 8-oxodG immunostaining was an independent prognostic factor for poor breast cancer-specific survival according to the multivariate analysis (P<0.01). This observation was even more remarkable when ductal carcinomas only (n=140) were considered (P<0.001). A low serum 8-oxodG level was associated statistically significantly with lymphatic vessel invasion and a positive lymph node status. CONCLUSIONS: Low serum 8-oxodG levels and a low immunohistochemical 8-oxodG expression were associated with an aggressive breast cancer phenotype. In addition, negative 8-oxodG immunostaining was a powerful prognostic factor for breast cancer-specific death in breast carcinoma patients.

Prognostic significance of extracellular matrix metalloproteinase inducer and matrix metalloproteinase 2 in epithelial ovarian cancer.

AIMS: We investigated the prognostic significance of extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase 2 (MMP-2) in epithelial ovarian cancer as well as their relation to hyaluronan (HA) expression. METHODS: The expression of EMMPRIN and MMP-2 was analyzed immunohistochemically in 295 primary epithelial ovarian cancer patients and 67 metastases. RESULTS: A low membranous EMMPRIN expression was detected more often in serous tumors than in other types (p < 0.0005) and it was associated with tumors of advanced stage (p = 0.012) or with a large primary residual (p = 0.011). A low expression of MMP-2 in cancer cells was associated with a high histologic grade (grade 3) of the tumor (p = 0.005) and endometrioid type of tumors (p < 0.0005). Stromal MMP-2 expression was significantly associated with strong stromal HA expression (p = 0.002, r = 0.187). In univariate analysis, 10-year disease-related (DRS) and recurrence-free survivals were significantly better when MMP-2 expression in cancer cells was high (p = 0.0057 and p = 0.0467, respectively). DRS was also better when membranous EMMPRIN expression was high (p = 0.013). In multivariate analysis, strong MMP-2 in cancer cells (RR = 1.48, CI = 1.07-2.04, p = 0.017) indicated favorable DRS. CONCLUSION: Our results show that EMMPRIN and MMP-2 in cancer cells are significant indicators of a favorable prognosis of epithelial ovarian cancer.

Amino-terminal propeptide of type III procollagen: a new prognosis indicator in human ovarian cancer.

To investigate the clinical usefulness of the amino-terminal propeptide of type III procollagen (PIIINP) as an indicator of ovarian cancer behavior, 30 patients with advanced epithelial malignancy were monitored with serial serum PIIINP and CA-125 determinations before and during treatment. Initially, PIIINP and CA-125 concentrations were each separately increased in 87% of the cases and, simultaneously, in 77% of the cases. In monitoring treatment responses, PIIINP and CA-125 were identical in 17 patients (57%), both being good predictors of the clinical behavior of the disease in 16 cases and poor predictors in one case. In 13 patients (43%) they were complementary to each other. In three cases PIIINP alone and in one case CA-125 alone were clinically useful prognosis indicators. During the period of complete clinical response to cytotoxic chemotherapy of 16 patients, the CA-125 concentrations decreased to normal before the clinical disappearance of the tumor in eight cases. PIIINP did so in only two cases, thus correlating more precisely with the presence of malignancy. In second-look laparotomies, PIIINP concentrations correlated with the presence of occult cancer better than those of CA-125. In predicting recurrent malignancy in patients with transient complete response, PIIINP and CA-125 were clinically equal. According to the present data, PIIINP concentrations often give information not obtainable by CA-125, thus being useful in monitoring the clinical behavior of ovarian cancer.

Progressive ovarian carcinoma induces synthesis of type I and type III procollagens in the tumor tissue and peritoneal cavity.

Increased serum concentrations of aminoterminal propeptide of type III procollagen occur in advanced ovarian cancer. To study their origin, we compared the expressions of type I and type III procollagens in ovarian tumor tissue and the peritoneal cavity with immunoassays for the propeptide domains of these procollagens. Samples of tumor cyst fluid, peritoneal ascitic fluid, tumor vein blood, and peripheral blood were obtained at operation from 50 women with malignant ovarian neoplasms and 61 women with benign neoplasms. The ascitic fluid concentrations of both type I and type III procollagen antigens were significantly higher in the malignant tumors than in the benign ones, but this difference was evident only for type I procollagen in the tumor cysts. The aminoterminal propeptide of type III procollagen concentration in the peripheral blood was higher in the patients with malignant tumors, whereas the concentrations were similar in the tumor veins. The enhanced type I procollagen synthesis in the malignant tumors did not affect the corresponding antigen in the blood. The findings suggest that progressive ovarian carcinoma invariably induces a fibroproliferative response, characterized by active expression of type I and type III procollagens. The increased circulating aminoterminal propeptide of type III procollagen is derived from the peritoneal cavity rather than from the tumor tissue via the ovarian vein.

Evidence for a relative excess of lysyl hydroxylase in chick embryo tendon and cartilage compared with bone and skin.

Various chick embryo tissues were incubated in vitro with a range of Zn2+ concentrations, and inhibition of the hydroxylations of collagen proline and lysine residues was studied in the intact tissues. At an constant inhibition level of proline hydroxylation, lysine hydroxylation proved to be inhibited more in the skin and bone than in the tendon and cartilage. The ratios of lysyl hydroxylase to prolyl hydroxylase activity were also distinctly lower in the former than in the latter. The variations observed in the reduction of lysine hydroxylation by Zn2+ thus correlate well with the differences seen in the enzyme activity ratios. No differences are found in the Ki values for Zn2+ between purified prolyl and lysyl hydroxylases or between the same enzymes from different tissues, and consequently the differences in lysine hydroxylation inhibition between the various tissues cannot be explained by differences in the kinetic constants. Recent studies also suggest that the existence of tissue-specific lysyl hydroxylase isoenzymes is improbable. The data thus suggest that there is a relative excess of lysyl hydroxylase activity in tissues such as tendon and cartilage, in which the lysine hydroxylation was less sensitive to Zn2+ inhibition, compared with skin and bone, where lysine hydroxylation was inhibited to a greater extent. These data are in a good agreement with the findings concerning variation in the reduction in lysine hydroxylation in different tissues with age or in the Ehlers-Danlos Syndrome Type VI.

Studies on the lysyl hydroxylase reaction. I. Initial velocity kinetics and related aspects.

The kinetics of the lysyl hydroxylase (peptidyllysine, 2-oxoglutarate:oxygen 5-oxidoreductase, EC 1.14.11.4) reaction were studied using enzyme from chick embryos by varying the concentration of one substrate in the presence of different fixed concentrations of the second substrate, while the concentrations of the other substrates were held constant. Intersecting lines were obtained in double-reciprocal plots for all possible pairs involving Fe2+, alpha-ketoglutarate, O2 and the peptide substrate, whereas parallel lines were obtained for pairs comprising ascorbate and each of the other substrates. The pair composed of Fe2+ and alpha-ketoglutarate gave an asymmetrical initial veolcity pattern, indicating binding of these two reactants in this order, that of Fe2+ being at thermodynamic equilibrium. The initial velocity patterns are identical with those reported for prolyl 4-hydroxylase, and the apparent Km and Kd values calculated from these data are also very similar. The largest difference was fo-nd in Km and Kd for alpha-ketoglutarate, which were about 4 times the corresponding values for prolyl 4-hydroxylase. Ascorbate was found to be a quite specific requirement for lysyl hydroxylase, but the enzyme catalyzed its reaction for a short time at a high rate in the complete absence of this vitamin, suggesting that the reaction with ascorbate does not occur during each catalytic cycle. Lysyl hydroxylase catalyzed an uncoupled decarboxylation of alpha-ketoglutarate in the absence of the peptide substrate, the rate being about 4% of that observed in the presence of a saturating concentration of the peptide substrate. This uncoupled decarboxylation required the same cosubstrates as the complete reaction.

Studies on the lysyl hydroxylase reaction. II. Inhibition kinetics and the reaction mechanism.

Product inhibition of lysyl hydroxylase (peptidyllysine, 2-oxoglutarate:oxygen 5-oxidoreductase, EC 1.14.11.4) was studied with succinate, CO2, dehydroascorbate and hydroxylysine-rich polypeptide chains. The product inhibition patterns and addition data are consistent with a reaction mechanism involving an ordered binding of Fe2+, alpha-ketoglutarate, O2 and the peptide substrate to the enzyme in this order, and an ordered release of the hydroxylated peptide, CO2, succinate and Fe2+, in which Fe2+ need not leave the enzyme during each catalytic cycle and in which the order of release of the hydroxylated peptide and CO2 is uncertain. Ascorbate probably reacts by a substitution mechanism, either after the release of the hydroxylated peptide, CO2 and succinate or after the release of all products, including Fe2+, and dehydroascorbate is released before the binding of Fe2+. It is suggested that the ascorbate reaction is required to reduce either the enzyme-iron complex or the free enzyme, which may be oxidized by a side-reaction during some catalytic cycles, but not the majority. The mechanisms of the prolyl 4-hydroxylase and lysyl hydroxylase reactions are suggested to be identical. Zn2+, several citric acid cycle intermediates, nitroblue tetrazolium and homogentisic acid inhibited lysyl hydroxylase competitively with regard to Fe2+, alpha-ketoglutarate, O2 and ascorbate respectively, and epinephrine non-competitively with regard to all cosubstrates. Apparent Ki values are given for the product and other inhibitors.

Differences between proline and lysine hydroxylations in their inhibition by zinc or by ascorbate deficiency during collagen synthesis in various cell types.

The addition of Zn2+ inhibited lysine hydroxylation markedly less effectively than it did proline hydroxylation in chick embryo tendon cells, 3T6 fibroblasts and lysyl hydroxylase-deficient Ehlers-Danlos Syndrome Type VI fibroblasts. With low Zn2+ concentrations, a similar difference was also seen in chick embryo cartilage cells, whereas with high concentrations both hydroxylations were affected to the same extent in this cell type. Ascorbate deficiency likewise had a much less effect on lysine than proline hydroxylation when studied with 3T6 fibroblasts. As these two effectors involve quite different mechanisms, it is suggested that relative insensitivity to inhibition may be a property of lysine hydroxylation seen in many cell types with a number of agents. Studies on the mechanism of the difference in the inhibition indicates that the phenomenon is probably not due to differences in the kinetic constants of Zn2+ and ascorbate for the two enzymes. Neither is it probably to any major extent due to delayed procollagen triple helix formation nor a difference in the location of the two hydroxylases within the cisternae of the rough endoplasmic reticulum. The difference similarly cannot be explained solely by an excess of lysyl hydroxylase in the cell. It may thus be due either to some other intracellular property or to the combined effect of several factors.

Affinity chromatography of lysyl hydroxylase on concanavalin A-agarose.

Lysyl hydroxylase (peptidyllysine, 2-oxoglutarate: oxygen 5-oxidoreductase, EC 1.14.11.4) has a high affinity for columns of concanavalin A-agarose, which was markedly reduced in the presence of alpha-methyl-D-mannoside, suggesting that the enzyme is a glycoprotein. Once bound, the enzyme could not be eluted with the glycoside alone, whereas an effective elution was achieved by a combination of alpha-methyl-D-mannoside and ethylene glycol. The data thus suggest that hydrophobic interaction stabilized the complex of the enzyme with the column. This information was applied to obtain a lysyl hydroxylase purification of about 3000-fold with a recovery of more than 10% from extract of chick embryos by relatively simple steps.

Markers of type I and type III collagen synthesis in serum as indicators of tissue growth during pregnancy.

The concentrations of the carboxy-terminal propeptide of type I procollagen (PICP) and the amino-terminal propeptide of type III procollagen (PIIINP) in serum were followed prospectively as indicators of synthesis of the respective collagens in 266 healthy primiparas during the second and third trimesters of pregnancy. The PIIINP concentration increased 2-fold during the third trimester; the median value was 10.0 micrograms/L at gestational week 40, with a range from 4.6-32.7 micrograms/L (reference interval for nonpregnant women, 1.7-4.2 micrograms/L). A significant increase also took place in the PICP concentration. The frequency distributions of the two parameters were near normal at week 26. They started to broaden out at week 32 and were wide at week 38. In severe preeclampsia, PIIINP tended to increase more than in normal pregnancies of the same duration. The increase in PIIINP correlated significantly with maternal weight gain and the birth weight of the infant, but not with other parameters related to pregnancy or delivery. At gestational week 38, there was a significant correlation between the circulating concentrations of insulin-like growth factor-I and PIIINP or PICP, but not between human placental lactogen and PICP, and only a weak association between human placental lactogen and PIIINP. This suggests that insulin-like growth factor-I is involved in the regulation of type I and type III collagen synthesis during pregnancy.

Ovarian cancer cell invasion is inhibited by paclitaxel.

Overproduction of matrix metalloproteinases (MMPs) and alterations in adhesive and migratory behavior are common characteristics of metastatic cancer cells. Ovarian cancer is a highly invasive type of malignancy. The effect of the antineoplastic drug paclitaxel on human ovarian cancer cell (Ovcar-3) invasion was studied using an in vitro invasion assay with reconstituted basement membrane. The effect of treatment with paclitaxel was also determined separately on certain invasion-associated events, such as the secretion of 72 kDa type IV collagenase (gelatinase A/MMP-2), the expression of the tissue inhibitor of metalloproteinase-2 (TIMP-2), cell attachment and migration. Ovcar-3 cell attachment, migration and in vitro invasion were significantly decreased after paclitaxel treatment (P = 0.02, P < 0.01 and P = 0.001, respectively) whereas no alteration in the secretion of latent MMP-2 was noted. However, the intracellular localization of the immunoreactive protein for MMP-2 was altered in response to paclitaxel treatment. Interestingly, paclitaxel increased the appearance of TIMP-2 protein in culture medium (P = 0.002) but did not change the expression of mRNA for TIMP-2 in Ovcar-3 cells. These data show that paclitaxel is an effective suppressor of Ovcar-3 cell invasion. It inhibits attachment and migratory activities of the cells but also causes a release of TIMP-2 protein into the tissue culture medium.

Type-I and type-iii procollagen metabolites and ca 125 in epithelial ovarian-cancer.

The clinical courses of 24 patients with advanced epithelial ovarian cancer were monitored with serial serum CA125, PIIINP and PICP determinations before, during and after treatment. Initial serum CA125, PIIINP and PICP concentrations were pathologic in 93%, 80% and 11% of the cases, respectively. Eight patients responded to therapy with complete remission and 16 patients died of the malignancy. Initial serum PIIINP concentration, but not that of CA125 or PICP, was significantly lower in responders than in nonresponders. The pathologic serum CA125 and PIIINP levels of the responders decreased to normal within two months, whereas in patients with a poor prognosis they remained elevated. Serum CA 125 and PIIINP responded to progression with an increase and to remission with a decrease. The changes in the serum PICP concentration took place predominantly within the reference interval. In seven patients with progressive malignancy, it increased to a pathologic level during the final stage of the disease. Our results indicate that extensive ovarian malignancy strongly affects the metabolism of type I and type III collagens. The PIIINP assay is clinically useful. PIIINP and PICP determinations also have potential to increase our understanding of the mechanisms of invasion and spread of malignant tumours.

Loss of heterozygosity at chromosomes 3, 6, 8, 11, 16, and 17 in ovarian cancer: correlation to clinicopathological variables.

Tumor specimens from 78 epithelial ovarian cancer patients were examined for loss of heterozygosity (LOH) at 11 microsatellite markers at chromosomes 3p14.2, 6q27, 8p12, 11p15.5, 11q23.1-q24, 16q24.3, and 17p13.1, to evaluate the involvement, possible clustering, and prognostic significance of these lesions in the progression of the disease. The LOH analysis was performed on polymerase chain reaction (PCR)-amplified DNA from sections of paraffin-embedded tumor and normal tissue pairs. In addition to primary tumors, specimens of metastatic tissues were studied from 19 patients. In the combined results from primary and metastatic tumors, LOH frequencies varied between 31% (6q27) and 69% (17p13.1). Only LOH at chromosomal regions 3p14.2 (D3S1300), 11p15.5 (D11S1318), 11q23.3-q24 (D11S1340 and D11S912), 16q24.3 (D16S476 and D16S3028), and 17p13.1 (D17S938) was associated with an adverse disease course. Our results indicate that LOH at 17p13.1 occurs independently from the other chromosomal sites studied, and is an early event in ovarian tumorigenesis. The LOH at 16q24.3, 11q23.3/q24, and 11p15.5 seems to occur later. The LOH at 11p15.5 and 11q23.3 was associated with reduced cancer-specific survival time; therefore, the studied markers could be located close to genes with influence on patient survival. Of the studied chromosomal regions, the most important tumor suppressor genes involved in the evolution of ovarian cancer appear to be located on chromosomes 11, 16, and 17. The genetic heterogeneity observed in primary and metastatic specimens demonstrates that there are multiple pathways involved in the progression of ovarian cancer.

Type IV collagenolytic activity in human preovulatory follicular fluid.

During normal ovulation, the two basement membrane layers of the ovarian follicle are degraded locally. The main component of basement membranes is type IV collagen, which is specifically cleaved by type IV collagenase. According to our results, type IV collagenolytic activity is present within follicular fluid and increases toward ovulation, decreasing rapidly as the follicles rupture. These results suggest that importance of type IV collagenolytic activity in the ovulatory process.

Extracellular matrix interactions in early human embryos: implications for normal implantation events.

OBJECTIVE: To study the role of the extracellular matrix (ECM) proteins in supporting the development and implantation competence of human embryos. DESIGN: Expression of an implantation site adhesive glycoprotein, oncofetal fibronectin, and basement membrane collagen-degrading matrix metalloproteinase-2 and -9 were studied in cultured human embryos. The ability of exogenously added laminin and fibronectin to enhance hatching and matrix metalloproteinase-2 expression was quantitated also. PATIENTS: Fifty-four women with tubal factor infertility enrolled in the IVF program at the University Hospital of Oulu agreed to participate by providing 20 residual oocytes and 227 residual early embryos for this study. MAIN OUTCOME MEASURES: The presence of oncofetal fibronectin immunoreactive protein was assayed by immunocytochemical staining with two specific monoclonal antibodies, FDC-6 and X18A4. These antibodies bind to specific and distinct epitopes within tumor and trophoblast-derived oncofetal fibronectin. Changes in embryo matrix metalloproteinase-2 production were measured by zymography and confirmed by immunocytochemical staining. RESULTS: Intracellular oncofetal fibronectin was identified within blastomeres of early stage embryos. The immunoreactivity of oncofetal fibronectin in the zona pellucida was associated with fragmentation and dissolution of the zona. Exogenously added laminin or adult-type fibronectin significantly increased the hatching rate of the cultured embryos. Embryos cultured with added adult-type fibronectin or trophoblast-derived oncofetal fibronectin stimulated the matrix metalloproteinase-2 production (72-kd type IV collagenase) by 2.25 +/- 0.16-fold when compared with control embryos (mean +/- SD). CONCLUSIONS: Embryonic production of specific ECM proteins, such as oncofetal fibronectin, appears to be important for the morphological and biochemical development of human preimplantation embryos. Moreover, ECM proteins promote acquisition of the adhesive and degradative properties required by human embryos for successful implantation.

Regulation of 72-kd type IV collagenase-matrix metalloproteinase-2 by estradiol and gonadotropin-releasing hormone agonist in human granulosa-lutein cells.

OBJECTIVE: To examine the hormonal regulation of 72-kd type IV collagenase-gelatinase-matrix metalloproteinase-2 in human granulosa-lutein cells. DESIGN: The effect of E2 and GnRH agonist (GnRH-a) on matrix metalloproteinase-2 amount was examined on a long-term granulosa-lutein cell cultures. PATIENTS: The preovulatory follicles from women participating in our IVF program were aspirated through the vaginal wall. Follicular fluids were centrifuged and the granulosa cells were separated and pooled for culturing. MAIN OUTCOME MEASURES: Matrix metalloproteinase-2 enzyme activity was assayed with type IV collagen degradation assay and zymography. The matrix metalloproteinase-2 immunoreactive protein was studied by using specific antibodies. RESULTS: Matrix metalloproteinase-2 was the predominant form of gelatinase in cultured granulosa-lutein cells. The enzyme activity as well as the immunoreactive protein increased in the culture medium of the granulosa-lutein cells in the presence of E2. The effect of E2 was abolished by GnRH-a. CONCLUSIONS: Estradiol regulates the matrix metalloproteinase-2 enzyme amount in granulosa-lutein cells; the effect may be antagonized by GnRH-a.

Hypoprolactinemia and ovarian function.

Thirty-two patients with ovarian hyperstimulation were randomized to receive bromocriptine or placebo from cycle day 5 onward. Bromocriptine decreased serum and follicular fluid prolactin (PRL), accelerated ovarian follicle growth, increased serum and follicular fluid estradiol, lowered luteal phase progesterone, and shortened the luteal phase length of the cycle. The maximal luteal phase estradiol and progesterone concentrations correlated with each other in the placebo group, but not in the bromocriptine group. These findings indicate that hypoprolactinemia interferes with ovarian function. The unchanged concentrations of gonadotropic hormones and pattern of luteinizing hormone pulsation during bromocriptine suggest direct ovarian effects of hypoprolactinemia. Because PRL suppression enhanced follicular responses and inhibited corpus luteum formation and function, the follicular and corpus luteum actions of PRL may be different.