Abstract CT177: SQ3370 in advanced solid tumors: Interim phase 1 results

Background: SQ3370, a novel therapy, utilizes Shasqi’s proprietary Click Activated Protodrugs Against Cancer (CAPAC) platform where mutually-reactive click chemistry groups release Doxorubicin (Dox) at the tumor site while minimizing systemic exposure. In animals, SQ3370 enhanced T-cell infiltration, survival, and showed activity in both injected and non-injected lesions. Minimal to no toxicity, including no cardiotoxicity was seen in up to 9-fold dose increases in animals. Conventional Dox can induce cardiomyopathy with incidences of 6-20% for cumulative doses of 500 mg/m2 in humans. Here we report interim results of the Phase 1 trial (SQ3370-001; NCT04106492).

Methods: SQ3370 has 2 components: 1) Intratumoral injection of a protodrug-activating biopolymer (SQL70); 2) then 5 consecutive daily IV infusions of an attenuated protodrug of Dox (SQP33). Key criteria for enrollment include locally advanced to metastatic solid tumors, ≤300 mg/m2 prior exposure to DOX, ECOG status 0 or 1, and no limit to the number of prior systemic therapies. Primary objectives include safety and determining Phase 2 dose. Dose escalation was assessed in 2 stages: 1) accelerated titration; 2) 3+3 design. Dose-limiting toxicity (DLT) was evaluated in cycle 1.

Results: As of 26NOV2021 data cut, 17 patients (pts) in 8 dose escalation cohorts have been enrolled. MTD has not been reached. Median age was 59 years (26-79), 53% were females, and were ECOG 1 (59%). Prior procedures included surgery (82%) and radiation (47%). At study entry, 82% of pts had metastases with a median number of metastatic sites being 2 (1-5). Solid tumors were sarcoma (65%), and cancers of the skin, breast, and gynecologic organs were 12% for each, respectively. Sixteen of 17 (94%) pts received prior chemotherapy with 47% receiving prior Dox. Median number of prior systemic therapies was 2 (1-7). Intratumoral injection sites include soft tissue and chest wall. Of the 17 pts, 65% received >500 mg/m2, 53% (>1000), and 29% (>2000) cumulative Dox given as SQP33. Median duration of treatment was 3 cycles (1-10). No DLTs were observed. Most frequent AEs, regardless of causality, included nausea (n = 9), fatigue (n = 6) and anemia (n = 5). No signs of cardiomyopathy were seen in pts with an echo performed within 1 mo. of study start. Although >50% of pts received >1000 mg/m2, ejection fraction (LVEF) remained normal. No AEs that led to discontinuation or death were related to SQ3370. All pts were evaluable for response. At a median follow-up of 10 wks (4-30), 65% of pts had SD as best response. Median duration of SD was 80 days (37-186) with 64% sustaining SD for ≥60 days, corresponding to an overall disease control rate of 65%. The remainder of pts had PD as best response. Over 35% of pts remain on drug.

Conclusions: SQ3370 was well tolerated. No DLTs and normal LVEF were seen with pts receiving >1000 mg/m2 Dox cumulative doses. Dose escalation is ongoing. Preliminary evidence of disease control was observed in this heavily pre-treated, high cancer burden, solid tumor pt population.

Citation Format: Sant P. Chawla, Kathleen Batty, Vivek Bhadri, Nam Bui, Alexander D. Guminski, Jose M. Mejia Oneto, Sangeetha Srinivasan, James F. Strauss, Vivek Subbiah, Mia C. Weiss, Rosalind Wilson, Nathan A. Yee, Michael Zacharian, Vineet Kwatra. SQ3370 in advanced solid tumors: Interim phase 1 results [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT177.

Surufatinib in U.S. patients with soft tissue sarcoma

11557

Background: Surufatinib is an inhibitor of VEGFR1, 2, & 3, FGFR1, and CSF-1R. A manageable safety profile, and statistically significant improvement in progression-free survival (PFS) in patients (pts) treated with surufatinib have previously been demonstrated in pts with advanced NETs of extrapancreatic (epNET) and pancreatic (pNET) origin in 2 phase 3 randomized trials conducted in China (SANET-ep; NCT02588170 & SANET-p; NCT02589821). Similar safety and efficacy were demonstrated in this phase 1 study (NCT02549937) in pts with NETs. Here we report the results of surufatinib in pts with soft tissue sarcoma. Methods: This study is a phase 1, dose escalation (ESC)/expansion (EXP) study to evaluate the safety and efficacy of surufatinib in the US and Europe (EXP only). ESC previously reported the recommended phase 2 dose as 300mg once daily. Enrollment into advanced, adult, soft tissue sarcoma EXP cohorts is ongoing. The primary endpoint is PFS rate at 4 months (mo). Soft tissue sarcoma histological subtypes include: angiosarcoma (AS), epithelioid sarcoma (ES), leiomyosarcoma (LMS), pigmented villonodular synovitis (PVNS), synovial sarcoma (SS) and undifferentiated pleomorphic sarcoma (UPS). Results: 32 adults with soft tissue sarcoma were enrolled (2 each AS and ES; 10 LMS; 1 PVNS; 9 SS; 8 UPS). The median age across all subtypes was 56.5 years (range 26-77), and the majority of pts were female (68.8%). 59.3% of pts received ≥ 3 prior lines of therapy (Tx) (median lines of Tx: 3 [range 1-6]). As of 15 Nov 2021, 1 pt (PVNS) remained on Tx. The PFS rate at 4 mo was 17.5%. The median PFS was 2.56 mo (95% CI; 0.92-2.92). The median duration on treatment (mDoT) for all pts was 11.2 weeks (wks) (0.4-39.0). The mDoT for LMS pts was 11.6 wks (3.1-36.0), mDoT for SS pts was 11.9 wks (0.4-27.9), and mDoT for UPS pts was 8.2 wks (2.7-27.9). Of 29 pts with ≥ 1 post baseline assessment, 6 pts (20.7%) achieved stable disease of ≥ 8.0 wks from start of Tx. No pts achieved a partial or complete response. The safety profile of surufatinib remains consistent with previously completed trials. All pts (n = 32) reported ≥ 1 adverse event (AE), and 21 pts (65.6%) reported AEs ≥ grade 3. The most common AEs of any grade were fatigue (53.1%), hypertension (43.8%), diarrhea (40.6%), anemia (25.0%), blood bilirubin increase (25.0%), headache (21.9%), and proteinuria (21.9%). The most commonly reported AEs ≥ grade 3 in > 1 pt were hypertension (21.9%), fatigue (12.5%), and anemia (9.4%). AEs leading to Tx discontinuation occurred in 9.4% of pts. Conclusions: Surufatinib demonstrated minimal antitumor activity as a single agent in heavily pretreated pts across various types of soft tissue sarcoma. The safety profile in pts with soft tissue sarcoma remains consistent with previously reported and ongoing studies with surufatinib. Clinical trials are ongoing with surufatinib globally, with active recruitment in PD-L1 combination studies. Clinical trial information: NCT02549937.

Dose escalation of a phase 1b/2 study of modakafusp alfa, an immune-targeting attenuated cytokine, in patients (pts) with metastatic solid tumors

2503

Background: Modakafusp alfa (TAK-573) is a first-in-class immune-targeting attenuated cytokine designed to deliver attenuated interferon alpha-2b (IFNα2b) moieties to CD38-expressing cells. It consists of two attenuated IFNα2b molecules genetically fused to the Fc portion of a humanized, anti-CD38, IgG4 monoclonal antibody. Specificity for CD38 and reduced IFN receptor binding affinity of the attenuated IFNα2b molecules significantly reduces the potential for off-target binding and toxicity. Modakafusp alfa has demonstrated immune cell activation and antitumor activities in preclinical mouse models, including tumor models that do not express CD38, and has shown strong clinical responses and immune activation in pts with refractory/relapsed multiple myeloma. The dose-escalation phase of this phase 1b/2 study (NCT04157517) investigated safety, pharmacokinetics, immunogenicity, pharmacodynamics (PD), and preliminary efficacy of modakafusp alfa in metastatic solid tumors. Methods: Adult pts with advanced/metastatic solid tumors received modakafusp alfa IV on day 1 of a 21-day cycle (Q3W). Dose escalation started at 0.1 mg/kg and proceeded based on cycle 1 safety data via a Bayesian model with overdose control principles. Results: Twenty-one pts were dosed in the escalation phase at 0.1 (n = 3), 0.2 (n = 3), 0.4 (n = 3), 0.75 (n = 3), 1.0 (n = 3), and 1.5 mg/kg (n = 6) Q3W; median age 63 y (range 42–80); male 57.1%; GI malignancies 71.4%; median prior lines of therapy 3 (range 2–7). Two pts had dose-limiting toxicities in cycle 1 at 1.5 mg/kg; 1 pt with baseline bone infiltration had grade 4 thrombocytopenia and 1 pt had grade 3 confusion. As of Nov 2021, across all doses, pts received a median of 2 treatment cycles (range 1–11). Modakafusp alfa treatment-related adverse events (TRAEs) reported in 81% of pts included infusion-related reactions (52.4%), chills (47.6%), and nausea (33.3%). Grade ≥3 TRAEs reported in 42.9% of pts included neutropenia (14.3%) and hypertension (9.5%). There was a greater than dose proportional exposure increase in the dose range 0.1–1.5 mg/kg, with no exposure accumulation after Q3W dosing. Incidence rate of post-treatment anti-drug antibody (ADA) was 100%. PD data suggested saturation of peak IFN pathway modulation at ≥0.2 mg/kg in the peripheral blood with duration of modulation increasing with dose. Among the 14 response-evaluable pts, 7 had best response of stable disease, including 1 with cutaneous melanoma who had 21% target lesion reduction. Conclusions: Modakafusp alfa had a manageable safety profile in the dose range 0.1–1.5 mg/kg in pts with solid tumors. Proof of mechanism was validated. The recommended phase 2 dose was determined as 1.0 mg/kg Q3W based on assessment of holistic data and will be tested in combination with a checkpoint inhibitor in selected tumor types. Characterization of ADA and its impact is ongoing. Clinical trial information: NCT04157517.

A phase 2, multiarm study of anti-CD47 antibody, magrolimab, in combination with docetaxel in patients with locally advanced or metastatic solid tumors

TPS584

Background: Patients with solid tumors who progress on standard chemotherapy and/or immune checkpoint inhibitors have limited efficacy with existing standard-of-care chemotherapy options (objective response rates [ORRs] ̃10%). These patients have a significant unmet medical need. Novel agents that can safely enhance treatment efficacy are urgently needed. Magrolimab is a first-in-class monoclonal antibody that blocks the macrophage inhibitory immune checkpoint CD47, a “do not eat me” signal overexpressed on tumor cells. Preclinical studies provide compelling evidence that magrolimab triggers phagocytosis and eliminates cancer cells from human solid tumors and hematologic malignancies. Magrolimab has demonstrated clinical activity in both hematologic and solid tumor malignancies. Chemotherapeutic agents, including taxanes, enhance prophagocytic signals on tumor cells, leading to synergistic antitumor activity when combined with magrolimab. This study (NCT04827576) is evaluating the safety, tolerability, and efficacy of magrolimab with docetaxel in relapsed/refractory (R/R) metastatic urothelial cancer (mUC), non-small-cell lung cancer (mNSCLC), and small-cell lung cancer (mSCLC). Methods: This Phase 2, open-label, multi-arm study (NCT04827576) consists of a safety run-in cohort and a Phase 2 cohort. Eligible patients are ≥18 years old with chemotherapy- and/or immunotherapy-refractory mUC, mNSCLC, or mSCLC. Magrolimab is administered intravenously (IV) with an initial 1-mg/kg priming dose to mitigate on-target anemia, followed by a 30-mg/kg dose during cycle 1 (cycles are 21 days) in the safety run-in to identify any dose-limiting toxicities (DLTs) and determine a recommended Phase 2 dose (RP2D). De-escalation may occur for DLTs per protocol. In Phase 2, following the priming dose on day 1, the highest acceptable dose of magrolimab will be administered on days 8 and 15 of cycle 1; days 1, 8, and 15 of cycle 2; and day 1 for cycles 3 and beyond. Docetaxel 75 mg/m2 is administered IV on day 1 of each cycle for all study participants. Patients may continue treatment until unacceptable toxicity, progressive disease by RECIST 1.1, or patient/investigator choice to discontinue. The primary endpoints are incidence of adverse events (safety and Phase 2 cohorts) and ORR (Phase 2). Secondary endpoints (Phase 2) are progression-free survival, duration of response, and overall survival. Exploratory endpoints are to evaluate the pharmacodynamic, mechanism of action, and/or therapeutic response of biomarkers in blood and tumor biopsy samples and to explore biomarkers that may predict response to therapy. Enrollment began in August 2021. Planned enrollment is approximately 116 patients, and as of October 1, 2021 recruitment is ongoing. Clinical trial information: NCT04827576.

Abstract CT110: Intratumoral injection of SYNB1891, a synthetic biotic designed to activate the innate immune system, demonstrates target engagement in humans including intratumoral STING activation

Introduction: SYNB1891 is a live, modified strain of the probiotic E. coli Nissle engineered to produce cyclic dinucleotides under hypoxia leading to stimulator of interferon genes (STING)-activation in phagocytic antigen-presenting cells in tumors and activating complementary innate immune pathways.

Methods: This first-in-human study (NCT04167137) is enrolling patients with refractory advanced solid tumors or lymphoma to receive an intratumoral (IT) injection of SYNB1891 on Days 1, 8 and 15 of the first 21-day cycle and then on Day 1 of each subsequent cycle. Dose escalation is planned across 7 cohorts (1x106 - 1x109 live cells) with Arm 1 consisting of escalating doses of SYNB1891 as monotherapy, and Arm 2 in combination with atezolizumab. The primary objective is to determine the single-agent maximum tolerated dose as monotherapy and the recommended Phase 2 dose in combination with atezolizumab. Other objectives include SYNB1891 kinetics in blood and the injected tumor, STING-target engagement as assessed by IT gene expression and serum cytokines, and tumor responses.

Results: This interim analysis includes the first 11 patients across 4 cohorts dosed at 1x106, 3x106, 1x107, or 3x107 live cells, with a total of 59 doses administered. The mean (range) age was 56 (25-70); 9 patients were female. There were no dose-limiting toxicities, SYNB1891-related infections or discontinuations due to adverse events. There was one SYNB1891-related serious adverse event in a patient who experienced a grade 2 cytokine release syndrome that resolved within one day, and one patient experienced a grade 2 injection site reaction of erythema which resolved. SYNB1891 was not detected in the blood at 6 or 24 hours after the first dose or intratumorally 7 days following the first dose. Treatment with SYNB1891 demonstrated activation of the STING pathway and target engagement as assessed by upregulation of interferon-stimulated genes (ISG15, IFIT1, IFIt2), chemokines/cytokines (CXCL9, CXCL10, TNFRS18, TNFSF10) and T-cell response genes (GZMA, CD4, PD-L2) in core biopsies obtained pre-dose and 7 days following the third weekly dose. In addition, there was a dose-response increase in serum cytokines at dose levels of 1x107 and 3x107 live cells (IL-6, TNFα, IFNγ, IL-1Ra) at 6 hours post-dose. Durable, stable disease was observed in two patients refractory to prior PD-1/L1 antibodies with vulvar melanoma (1x106 live cells) and small cell lung cancer (1x107 live cells).

Conclusions: Repeat IT injection of SYNB1891 as monotherapy is safe and well-tolerated up to at least 3x107 cells and shows evidence of STING pathway target engagement. These data support the continued dose escalation of SYNB1891 as monotherapy, and initiation of Arm 2 in combination with atezolizumab.

Citation Format: Filip Janku, Jason J. Luke, Aoife Brennan, Richard Riese, Mary Varterasian, Michael B. Armstrong, Karen L. Kuhn, Anna Sokolovska, James F. Strauss. Intratumoral injection of SYNB1891, a synthetic biotic designed to activate the innate immune system, demonstrates target engagement in humans including intratumoral STING activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT110.

A phase II trial combining tumor-targeting TP53 gene therapy with gemcitabine/nab-paclitaxel as a second-line treatment for metastatic pancreatic cancer

4139

Background: Nearly all stage IV pancreatic adenocarcinoma (PAC) patients progress after first-line treatment, and second-line options are limited. SGT-53 is an investigational product for tumor-targeted TP53 gene therapy that has completed phase Ia/Ib trials [Senser et al (2013), Mol Ther 21:1096; Pirollo et al (2016) Mol Ther 24:1697]. Methods: Here we provide an interim analysis of a Phase II trial (SGT53-02-1; NCT02340117) combining SGT-53 with gemcitabine/nab-paclitaxel (GEM/ABX). Eligible were first-line patients or those who had progressed after FOLFIRINOX (FFX) and/or gemcitabine-based therapy (second-line). In a 7-week treatment cycle, SGT-53 (3.6 mg DNA) was given once or twice weekly with GEM/ABX (1000 mg/m2/wk and 125 mg/m2/wk, respectively, for 3 of 4 weeks). Progression-free survival (PFS) and objective response rate (ORR) are primary endpoints.Overall survival (OS) and PFS are estimated by Kaplan-Meier analysis. Results: Of all evaluable patients (n=20), best response in 7 patients was determined to be partial response (PR) and 13 had stable disease (SD); none had progressive disease. In the second-line patients (n=11) there were 5 PR and 6 SD after 9 had failed FFX treatment, 3 had failed gemcitabine-based treatment and 1 had failed both. For patients with elevated CA19-9, SGT-53 + GEM/ABX resulted in marked reductions in the tumor marker. Published data for patients with PAC after therapy failure [Mita et al (2019) J Clin Med 8: 761; Portal et al (2015) Br J Cancer 113:989; Wang-Gillam et al (2016) Lancet 387:545] are shown for comparison. Notably, mPFS in our second-line patients was 7.4 months versus 3.1 months for the approved second-line therapy [Wang-Gillam et al (2016)]. This improvement in PFS exceeds the benchmark proposed to predict a clinically meaningful Phase III trial [Rahib et al (2016) Lancet Oncol 2:1209]. Conclusions: Our data suggest a clinically meaningful benefit of adding SGT-53 to GEM/ABX particularly for second-line PAC patients, most of whom had failed prior FFX treatment. Clinical trial information: NCT02340117. [Table: see text]

A phase 1 dose-escalation study of intravenously (IV) administered TAK-676, a novel STING agonist, alone and in combination with pembrolizumab in patients (pts) with advanced or metastatic solid tumors

TPS2670

Background: Immuno-oncology therapies, including immune checkpoint inhibitors (CPIs), are revolutionizing cancer treatment. However, primary and secondary resistance to CPIs remains a significant challenge. CPI resistance has been associated with reduced interferon (IFN) signaling, altered antigen presentation, and an immunosuppressive tumor phenotype. Stimulating innate immune cells to develop a proinflammatory tumor environment that activates IFN signaling and downstream adaptive antitumor immune mechanisms is predicted to overcome such resistance. Stimulator of Interferon Genes (STING) is a key mediator of type 1 IFN-dependent innate immune modulation. Most STING agonists evaluated clinically have required intratumoral administration, which has significant logistical challenges and excludes many pts whose tumors are not accessible for injection. TAK-676 is a novel STING agonist under clinical investigation as an IV administered systemic therapy in pts with solid tumors. Methods: The primary objective of this study is to determine the safety and tolerability of TAK-676 alone and in combination with pembrolizumab. Secondary objectives are to: determine the pharmacologically active dose and recommended phase 2 dose; characterize TAK-676 pharmacokinetics; assess preliminary antitumor activity; and assess STING agonism gene signature induction. An exploratory objective is to assess immune cell activation and clinical response. The study comprises a single-pt safety lead-in with single-agent (SA) TAK-676 0.1 mg IV, followed by dose escalation using Bayesian Logistic Regression Model design. Dose escalation will start in the combination arm when ≥2 dose levels in the SA arm have been evaluated and considered safe. In both arms, pts will receive TAK-676 on days 1, 8, and 15 in 21-day cycles for up to 1 year. In the combination arm, pts will also receive pembrolizumab 200 mg IV on day 1 of each cycle. Adult pts with histologically confirmed advanced or metastatic solid tumors who have no standard therapeutic options or are intolerant to them, with an Eastern Cooperative Oncology Group (ECOG) performance status 0–1, and ≥1 Response Evaluation Criteria in Solid Tumors (RECIST) v.1.1- evaluable lesion are eligible; pts with tumors that have relapsed, are refractory or naïve to anti-programmed death 1 (PD-1) or anti-programmed death ligand 1 (PD-L1) therapy are eligible for the combination arm. Planned enrollment is ̃76 pts; recruitment is ongoing. Clinical trial information: NCT04420884.

ARTISTRY-1: Nemvaleukin alfa monotherapy and in combination with pembrolizumab in patients (pts) with advanced solid tumors

2513

Background: Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel, engineered cytokine that selectively binds the intermediate-affinity interleukin-2 (IL-2) receptor complex to preferentially activate CD8+ T cells and natural killer cells with minimal expansion of regulatory T cells, designed to leverage antitumor effects of the IL-2 pathwaywhile mitigating potential toxicity that would limit use. Methods: ARTISTRY-1 (NCT02799095) is a phase 1/2 study. Parts A (dose escalation 0.1-10 µg/kg) and B (6 µg/kg [recommended phase 2 dose]) are monotherapy; pts receive intravenous nemvaleukin for 5 days every 14 or 21 days. In Part C, pts receive nemvaleukin (3 or 6 µg/kg) every 21 days in combination with pembrolizumab (200 mg on day 1). We present safety and antitumor activity (RECIST v1.1, iRECIST) data as of 12/02/2020. Results: In Part A, 39 pts received nemvaleukin. No dose-limiting toxicities were observed; maximum tolerated dose was not reached. Part B enrolled immune checkpoint inhibitor–pretreated pts into melanoma or renal cell carcinoma (RCC) cohorts. 18 pts with melanoma enrolled; 10 were evaluable, 2 (both with metastatic mucosal melanoma) achieved a partial response (PR; 1 unconfirmed). 24 pts with RCC enrolled; 1 of 16 evaluable pts achieved a PR (awaiting confirmation). 12 pts in each cohort continue on study. In Parts A and B, treatment-related adverse events in ≥40% included chills (74.4% and 52.4%, respectively) and pyrexia (74.4% and 47.6%, respectively). In Part C (83 evaluable pts), 12 objective responses (OR) were observed; an additional 5 pts had stable disease (SD) >6 months (1 pt with breast cancer, 2 with ovarian cancer, and 2 with non-small-cell lung cancer). Nemvaleukin did not demonstrate any additive toxicity to that already established with pembrolizumab alone. OR data are summarized in the table. Conclusions: Nemvaleukin was generally well tolerated and demonstrated antitumor activity as monotherapy and in combination with pembrolizumab. Pharmacodynamic studies to identify biomarkers are ongoing. Future research of monotherapy and combination therapy with nemvaleukin is warranted. Clinical trial information: NCT02799095. [Table: see text]

Impact of Diabetes and Insulin Use on Prognosis in Patients With Resected Pancreatic Cancer: An Ancillary Analysis of NRG Oncology RTOG 9704

PURPOSE

Diabetes mellitus (DM) has been proposed to be tumorigenic; however, prior studies of the association between DM and survival are conflicting. The goal of this ancillary analysis of RTOG 9704, a randomized controlled trial of adjuvant chemotherapy in pancreatic cancer, was to determine the prognostic effects of DM and insulin use on survival.

METHODS AND MATERIALS

Eligible patients from RTOG 9704 with available data on DM and insulin use were included. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method, and variable levels were compared using log-rank test. Cox proportional hazards models were created to assess the associations among DM, insulin use, and body mass index phenotypes on outcomes.

RESULTS

Of 538 patients enrolled from 1998 to 2002, 238 patients were eligible with analyzable DM and insulin use data. Overall 34% of patients had DM and 66% did not. Of patients with DM, 64% had insulin-dependent DM, and 36% had non-insulin-dependent DM. On univariable analysis, neither DM nor insulin dependence were associated with OS or DFS (P > .05 for all). On multivariable analysis, neither DM, insulin use, nor body mass index were independently associated with OS or DFS. Nonwhite race (hazard ratio [HR], 2.18; 95% confidence interval [CI], 1.35-3.50; P = .0014), nodal involvement (HR, 1.74; 95% CI, 1.24-2.45; P = .0015), and carbohydrate antigen 19-9 (CA19-9) ≥90 U/mL (HR, 3.61; 95% CI, 2.32-5.63; P < .001) were associated with decreased OS. Nonwhite race (HR, 1.67; 95% CI, 1.05-2.63; P = .029) and CA19-9 ≥90 U/mL (HR, 2.86; 95% CI, 1.85-4.40; P < .001) were associated with decreased DFS.

CONCLUSIONS

DM and insulin use were not associated with OS or DFS in patients with pancreatic cancer in this study. Race, nodal involvement, and increased CA19-9 were significant predictors of outcomes. These data might apply to the more modern use of neoadjuvant therapies for potentially resectable pancreatic cancer.

Impact of FTO genotypes on BMI and weight in polycystic ovary syndrome: a systematic review and meta-analysis

AIMS/HYPOTHESIS

FTO gene single nucleotide polymorphisms (SNPs) have been shown to be associated with obesity-related traits and type 2 diabetes. Several small studies have suggested a greater than expected effect of the FTO rs9939609 SNP on weight in polycystic ovary syndrome (PCOS). We therefore aimed to examine the impact of FTO genotype on BMI and weight in PCOS.

METHODS

A systematic search of medical databases (PubMed, EMBASE and Cochrane CENTRAL) was conducted up to the end of April 2011. Seven studies describing eight distinct PCOS cohorts were retrieved; seven were genotyped for SNP rs9939609 and one for SNP rs1421085. The per allele effect on BMI and body weight increase was calculated and subjected to meta-analysis.

RESULTS

A total of 2,548 women with PCOS were included in the study; 762 were TT homozygotes, 1,253 had an AT/CT genotype, and 533 were AA/CC homozygotes. Each additional copy of the effect allele (A/C) increased the BMI by a mean of 0.19 z score units (95% CI 0.13, 0.24; p = 2.26 × 10(-11)) and body weight by a mean of 0.20 z score units (95% CI 0.14, 0.26; p = 1.02 × 10(-10)). This translated into an approximately 3.3 kg/m(2) increase in BMI and an approximately 9.6 kg gain in body weight between TT and AA/CC homozygotes. The association between FTO genotypes and BMI was stronger in the cohorts with PCOS than in the general female populations from large genome-wide association studies. Deviation from an additive genetic model was observed in heavier populations.

CONCLUSIONS/INTERPRETATION

The effect of FTO SNPs on obesity-related traits in PCOS seems to be more than two times greater than the effect found in large population-based studies. This suggests an interaction between FTO and the metabolic context or polygenic background of PCOS.

Germ cell-specific disruption of the Meig1 gene causes impaired spermiogenesis in mice

Meiosis expressed gene 1 (Meig1) was originally identified in a search for mammalian genes potentially involved in meiosis. Seven mouse Meig1 transcripts with the same coding region, but different 5'-UTRs, have been identified. These transcripts have different tissue distributions, two are only present in the testis. In the testis, Meig1 is present in germ cells and Sertoli cells. A Meig1 conditional knockout model has been generated. When Meig1 was inactivated globally by crossing with Cmv-Cre transgenic mice, the Meig1-deficient males were sterile due to severe spermiogenic defects, and had no obvious defects in meiosis. To further study its role in individual cell types in the testis, the Meig1(flox) mice were crossed with Hsp2a-Cre, Prm-Cre, and Amh-Cre mice, in which the Cre recombinase is driven by the heat shock protein 2 (Hsp2a) gene promoter (expressed in spermatocytes), the protamine 1 gene promoter (expressed in post-meiotic spermatids) and the anti-Mullerian hormone (Amh) gene promoter (expressed in Sertoli cells) respectively. Both Meig1 mRNA and protein were undetectable in testis of the Hsp2a-Cre; Meig1(flox/flox) mice and all the mutant adult males tested were sterile. This phenotype mirrors that of the Cmv-Cre; Meig1(flox/flox) mice. Even though the total testicular Meig1 mRNA and protein expression levels were dramatically reduced in testis of the Prm-Cre; Meig1(flox/flox) males, all the mice tested were fertile, and there was no significant difference in sperm count and sperm motility compared with age-matched Meig1(flox/flox) male mice. Disruption of Meig1 in the Sertoli cells did not affect the MEIG1 protein expression. Amh-Cre; Meig1(flox/flox) males were fertile, and produced the same amount of spermatozoa as age-matched Meig1(flox/flox) mice. The testicular histology was also normal. Our results indicate that MEIG1 regulates spermiogenesis through effects in germ cells alone, and that the Meig1 gene must be active during a discrete period in spermatogenesis after which it is dispensable.

Connective tissue and related disorders and preterm birth: clues to genes contributing to prematurity

To identify candidate genes contributing to preterm birth, we examined the existing literature on the association between known disorders of connective tissue synthesis and metabolism and related diseases and prematurity. Our hypothesis was that abnormal matrix metabolism contributes to prematurity by increasing risk of preterm premature rupture of membranes (PPROM) and cervical incompetence. Based on this review, we identified gene mutations inherited by the fetus that could predispose to preterm birth as a result of PPROM. The responsible genes include COL5A1, COL5A2, COL3A1, COL1A1, COL1A2, TNXB, PLOD1, ADAMTS2, CRTAP, LEPRE1 and ZMPSTE24. Marfan syndrome, caused by FBN1 mutations, and polymorphisms in the COL1A1 and TGFB1 genes have been associated with cervical incompetence. We speculate that an analysis of sequence variation at the loci noted above will reveal polymorphisms that may contribute to susceptibility to PPROM and cervical incompetence in the general population.

Fine mapping of genetic susceptibility to polycystic ovary syndrome on chromosome 19p13.2 and tests for regulatory activity

CONTEXT

Little is known about genes that contribute to polycystic ovary syndrome (PCOS). We previously found linkage and association of PCOS with the dinucleotide marker D19S884 in two independent sets of families; allele 8 of D19S884 confers increased risk.

OBJECTIVE/DESIGN

The objectives of the study were: 1) use the transmission/disequilibrium test (TDT) to assess linkage and association between PCOS and D19S884 (and nearby markers) in a third set of families; and 2) test D19S884 and surrounding DNA sequence for in vitro regulatory activity in lymphoblastoid cell lines (LCLs) and granulosa cells.

SETTING/SUBJECTS

We studied 98 new families with a PCOS proband, father, mother, and other available offspring. We analyzed data from these families separately and in combination with data obtained previously.

INTERVENTIONS

Interventions were venipuncture.

MAIN OUTCOME MEASURES

Measures were transmission frequencies and in vitro functional studies.

RESULTS

The first result we found was that in the 98 new families, the TDT was significant for allele 8 of D19S884 (P = 0.043). In the total collection of 465 families, the TDT evidence is very strong (nominal P < 7 x 10(-5)). Results for all other genetic markers near D19S884 were nonsignificant after correction for multiple testing. The second result was that an approximately 800-bp fragment containing various alleles of D19S884 showed modest but reproducible promoter activity in LCLs. However, no allelic differences were detected. No activity of this fragment was detected in granulosa cells.

CONCLUSIONS

This is the second independent confirmation of linkage and association of D19S884 with PCOS. We found in addition that some sequence in the region of D19S884 confers in vitro promoter activity in LCLs.

Candidate gene region for polycystic ovary syndrome on chromosome 19p13.2

CONTEXT

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that is believed to have a genetic basis. However, no specific susceptibility gene or region has been conclusively identified.

OBJECTIVE

The objective of this study was to duplicate a previous study that localized a PCOS susceptibility region to chromosome 19p13.2 and to narrow the susceptibility region.

DESIGN

This study was designed to test for genetic linkage and association between PCOS and short tandem repeat polymorphisms in 367 families, by analysis of linkage and family-based association.

SETTING

The study was conducted at academic medical centers.

PATIENTS OR OTHER PARTICIPANTS

We studied 367 families of predominantly European origin with at least one PCOS patient. Families included 107 affected sibling (sister) pairs (ASPs) in 83 families, and 390 trios with both parents and an affected daughter. The data set comprises two independent groups. Set 1 consists of 44 ASPs and 163 trios. Set 2 consists of 63 ASPs and 227 trios.

INTERVENTION(S)

The intervention was the drawing of blood for DNA extraction.

MAIN OUTCOME MEASURE

We employed measures of evidence for linkage and association between PCOS and 19 STRs.

RESULTS

Linkage with PCOS was observed over a broad region of chromosome 19p13.2. The strongest evidence for association was observed with D19S884 (chi2 = 11.85; nominal P < 0.0006; permutation P = 0.034) and duplicated our earlier findings.

CONCLUSIONS

The present analysis suggests that a PCOS susceptibility locus maps very close to D19S884. Additional studies that systematically characterize DNA sequence variation in the immediate area of D19S884 are required to identify the PCOS susceptibility variant.

A serum proteomics approach to the diagnosis of ectopic pregnancy

An ectopic pregnancy (EP) occurs when implantation of the embryo occurs outside of the uterus. If left untreated, the developing fetus will continue to grow, leading to life-threatening consequences for the mother. A major difficulty with the diagnosis of ectopic pregnancy is that methods of detection are limited, and some, such as ultrasound, are not very reliable in the earliest days of gestation. Currently, no effective serum test exists to distinguish an ectopic pregnancy from a normal intrauterine pregnancy. The incidence of ectopic pregnancy is increasing and has doubled in the last 20 years. It is now the second most common cause of maternal death in the first trimester of pregnancy. To address this issue, we initiated a project to identify serum markers of ectopic pregnancy. The subjects for these studies presented at the Hospital of the University of Pennsylvania. We obtained over 140 serum samples from women with suspected ectopic pregnancy: women presenting with pain and/or bleeding in the first trimester of pregnancy. The approximate racial breakdown of the subjects is as follows: African American, 36%; Caucasian, 3%; Asian, 2%; Hispanic, 1%; unknown, 58%. Serum samples from 139 women (62 with ectopic pregnancy and 77 with a normal intrauterine pregnancy) were applied to WCX2 (weak ion exchange) protein chip surfaces and analyzed for serum markers using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Several proteins in the 7500-18,000 Da mass range were identified that may discriminate an ectopic pregnancy from an intrauterine pregnancy. The most promising markers were analyzed using classification and regression tree analysis (CART) with and without clinical variables (serum hCG value, length of amenorrhea). Two different algorithms were developed that classify the patients on the basis of sensitivity (number of EPs who screen positive/# of EPs) or specificity (# of healthy patients who screen negative/# of healthy). Our current approach is to refine these two "rule sets" to segregate patients into three groups: those who need immediate intervention for a probable ectopic pregnancy, those who appear to have a normal pregnancy, and those who need further monitoring for diagnosis.

In-vitro secretion of proinflammatory cytokines by human amniochorion carrying hyper-responsive gene polymorphisms of tumour necrosis factor-alpha and interleukin-1beta

The identification of polymorphisms in genes encoding proinflammatory cytokines that affect transcription or the secretion rate has opened new ways to understand the variation in responses to infection during pregnancy. In this study, human amniochorion carrying hyper-responsive alleles of tumour necrosis factor-alpha (TNF-alpha: TNF*2 at -308) and interleukin-1beta (IL-1beta: IL-1*2 at +3953) were stimulated in vitro with bacterial lipopolysaccharide (LPS) and compared with tissues carrying the common alleles (TNF*1 and IL-1*1). Fetal membranes carrying the TNF*1 allele displayed an identical dose-response pattern to tissues carrying a TNF*2 allele, except at the highest dose of LPS tested (50 ng/ml) there was a significantly greater production of TNF-alpha in the presence of a TNF*2 allele. Membranes carrying the IL-1*2 polymorphism secreted IL-1beta in a dose-response curve that was different from IL-1* tissues when challenged with 5, 10 and 50 ng/ml LPS. These observations support the hypothesis that reproductive tissues carrying hyper-responsive proinflammatory cytokine genes may over-respond to intrauterine infection secreting higher amounts of cytokines, which in turn, may lead to adverse pregnancy outcomes.

The biochemical basis for increased testosterone production in theca cells propagated from patients with polycystic ovary syndrome

Ovarian theca cells propagated from patients with polycystic ovary syndrome (PCOS) convert steroid precursors into T more efficiently than normal theca cells. To identify the basis for increased T production by PCOS theca cells, we examined type I-V 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) isoform expression in long-term cultures of theca and granulosa cells isolated from normal and PCOS ovaries. RT-PCR analysis demonstrated that theca cells express type V 17 beta HSD a member of the aldo-keto reductase (AKR) superfamily (17 beta HSDV, AKR1C3), whereas expression of type I, II, and IV 17 beta HSD, which are members of the short-chain dehydrogenase/reductase superfamily, was limited to granulosa cells. Type III 17 beta HSD, the testicular isoform, was not detected in either granulosa or theca cells. Northern and real-time PCR analyses demonstrated that 17 beta HSDV transcripts were not significantly increased in PCOS theca cells compared with normal theca cells. RT-PCR analysis revealed that theca cells also express another AKR, 20 alpha HSD (AKR1C1). Both basal and forskolin-stimulated 20 alpha HSD mRNA levels were increased in PCOS theca cells compared with normal theca cells. However, 17 beta HSD enzyme activity per theca cell was not significantly increased in PCOS, suggesting that neither AKR1C3 nor AKR1C1 contributes to the formation of T in this condition. In contrast, 17 alpha-hydroxylase/C17,20 lyase and 3 beta HSD enzyme activities were elevated in PCOS theca cells, driving increased production of T precursors. These findings indicate that 1) increased T production in PCOS theca cells does not result from dysregulation of "androgenic" 17 beta HSD activity or altered expression of AKRs that may express 17 beta HSD activity; and 2) increased synthesis of T precursors is the primary factor driving enhanced T secretion in PCOS.

Amniotic fluid matrix metalloproteinase-8 indicates intra-amniotic infection

OBJECTIVE

This study was undertaken to determine whether matrix metalloproteinase-8, which is produced by neutrophils, is a useful marker for the detection of intra-amniotic infection.

STUDY DESIGN

We performed a case-control study using enzyme-linked immunosorbent assays to detect matrix metalloproteinase-8 in 77 amniotic fluid specimens that were obtained by amniocentesis from women with preterm contractions or preterm labor and intact fetal membranes (n = 66) and from women with preterm premature rupture of membranes (n = 11).

RESULTS

Thirty women had culture-proven intra-amniotic infection (cases), 21 of whom had intact membranes. After constructing receiver operating characteristic curves to establish the optimal threshold concentration of matrix metalloproteinase-8 for a positive test result, we detected matrix metalloproteinase-8 in 27 of 30 women with intra-amniotic infection; only 10 of 47 control specimens contained matrix metalloproteinase-8 (P <.001; odds ratio, 33.3; 95% CI, 8.4, 132.7). Matrix metalloproteinase-8 was present in 20 of 21 women with intact membranes and intra-amniotic infection and in only 10 of 45 control subjects (P <.001; odds ratio, 70.0; 95% CI, 8.3, 587.6). Among women with intact membranes, the sensitivity of the assay was 0.95 and the specificity was 0.78.

CONCLUSION

Our results indicate that matrix metalloproteinase-8 is highly correlated with intra-amniotic infection and that enzyme-linked immunosorbent assay for matrix metalloproteinase-8 may be a clinically useful test for the diagnosis of intra-amniotic infection in women with preterm contractions and preterm labor.

Steroidogenic acute regulatory protein: an update on its regulation and mechanism of action

Steroidogenic acute regulatory (StAR) protein controls the rate-limiting step in steroidogenesis: the transport of cholesterol from the outer to the inner mitochondrial membrane. Early studies indicated that rate of transcription of the StAR gene is a primary determinant of steroidogenesis. The transcription factors that govern basal and cAMP-dependent StAR expression are reviewed, as are new findings regarding chromatin modifications associated with activation of the StAR promoter. Molecular genetic studies of congenital lipoid adrenal hyperplasia, a rare disease caused by mutations in the StAR gene, and structure-function studies defined two major domains within the StAR protein, the N-terminal mitochondrial targeting sequence and the C-terminal StAR-related lipid transfer (START) domain, which promotes the translocation of cholesterol between the two mitochondrial membranes. Several models of StAR's mechanism of action have been proposed based on a combination of structure/function studies or on the crystal structure of a related START domain. The models-intermembrane shuttle hypothesis, and cholesterol desorption hypothesis-are discussed with respect to the known biochemical and biophysical events associated with steroidogenesis and the structure of StAR.

Expression of steroidogenic acute regulatory protein in the human corpus luteum throughout the luteal phase

The expression of the steroidogenic acute regulatory protein (StAR) in the human corpus luteum (CL) was examined throughout the luteal phase. The primary 1.6-kb StAR transcript was in greater abundance in early (3.1-fold) and mid (2.2-fold) luteal phase CL compared with late luteal phase CL. The larger StAR transcript (4.4 kb) was found in early and midluteal phase CL, but was not detected in late luteal phase specimens. Mature StAR protein (30 kDa) was present in lower amounts within late CL compared with early and midluteal phase CL. The StAR preprotein (37 kDa) was also detected in greater abundance in early and midluteal CL. Immunohistochemistry revealed that StAR staining was most prominent in thecal-lutein cells throughout the luteal phase. The intensity of the signal for StAR exhibited significant changes throughout the luteal phase, being most intense during the midluteal phase and least during the late luteal phase. Plasma progesterone concentrations were highly correlated (r = 0.73 and r = 0.79) with luteal expression of the preprotein and mature StAR isoforms, respectively, throughout the luteal phase. To examine the LH dependency of StAR expression, the GnRH antagonist, Cetrorelix, was administered during the midluteal phase. Cetrorelix caused a decline in serum LH levels within 2 h, which, in turn, caused a pronounced decline in plasma progesterone within 6 h. The StAR 4.4-kb transcript was not detectable, and the 1.6-kb transcript was reduced by approximately 50% within 24 h of Cetrorelix treatment. The mature 30-kDa StAR protein level declined approximately 30% after Cetrorelix treatment. We conclude that 1) StAR mRNA and protein are highly expressed in early and midluteal phase CL; 2) StAR protein is present in both thecal-lutein and granulosa-lutein cells throughout the luteal phase; 3) StAR protein levels in the CL are highly correlated with plasma progesterone levels; 4) declining StAR mRNA and protein levels are characteristic of late luteal phase CL; and 5) suppression of LH levels during the midluteal phase results in a marked decline in plasma progesterone and a diminished abundance of StAR transcripts in the CL without a corresponding significant decline in StAR protein. Collectively, these data are consistent with the idea that StAR gene expression is a key determinant of luteal progesterone during the normal menstrual cycle. However, the pharmacologically induced withdrawal in the midluteal phase of LH support diminishes luteal progesterone output by mechanisms others than reduced StAR protein levels.

Steroidogenic acute regulatory protein binds cholesterol and modulates mitochondrial membrane sterol domain dynamics

The steroidogenic acute regulatory protein (StAR) mediates the rate-limiting step of steroidogenesis, delivery of cholesterol to the inner mitochondrial membrane. However, the mechanism whereby cholesterol translocation is accomplished has not been resolved. Recombinant StAR proteins lacking the first N-terminal 62 amino acids comprising the mitochondrial-targeting sequence were used to determine if StAR binds cholesterol and alters mitochondrial membrane cholesterol domains to enhance sterol transfer. First, a fluorescent NBD-cholesterol binding assay revealed 2 sterol binding sites (K(d) values near 32 nm), whereas the inactive A218V N-62 StAR mutant had only a single binding site with 8-fold lower affinity. Second, NBD-cholesterol spectral shifts and fluorescence resonance energy transfer from StAR Trp residues to NBD-cholesterol showed (i) close molecular interaction between these molecules (R(2/3) = 33 A) and (ii) sensitized NBD-cholesterol emission from only one of the two sterol binding sites. Third, circular dichroism showed that cholesterol binding induced a change in StAR secondary structure. Fourth, a fluorescent sterol transfer assay that did not require separation of donor and acceptor mitochondrial membranes demonstrated that StAR enhanced mitochondrial sterol transfer as much as 100-fold and induced/increased the formation of rapidly transferable cholesterol domains in isolated mitochondrial membranes. StAR was 67-fold more effective in transferring cholesterol from mitochondria of steroidogenic MA-10 cells than from human fibroblast mitochondria. In contrast, sterol carrier protein-2 (SCP-2) was only 2.2-fold more effective in mediating sterol transfer from steroidogenic cell mitochondria. Taken together these data showed that StAR is a cholesterol-binding protein, preferentially enhances sterol transfer from steroidogenic cell mitochondria, and interacts with mitochondrial membranes to alter their sterol domain structure and dynamics.

Quantitative analysis of the hormone-induced hyperacetylation of histone H3 associated with the steroidogenic acute regulatory protein gene promoter

Transcriptional regulation of steroidogenic acute regulatory protein (StAR) determines adrenal and gonadal cell steroidogenesis. Chromatin immunoprecipitation assays were combined with quantitative real-time polymerase chain reaction to assess histone acetylation associated with the StAR promoter. MA-10 cells treated with 8-bromo-cAMP had increased acetylated histone H3 associated with the proximal (but not distal) StAR promoter, nascent StAR transcripts, and progesterone production within 15 min, whereas StAR mRNA increased at 30 min. At 360 min, steroidogenesis remained elevated, but mRNA, nascent RNA, and StAR promoter-associated H3 acetylation all declined. StAR promoter-associated H4 acetylation was unchanged by 8-bromo-cAMP treatment of MA-10 cells. In vivo analysis of macaque and human granulosa cells showed that luteinization was associated with increased StAR promoter-associated H3 acetylation. We conclude that acetylation of H3 (but not H4) associated with the proximal promoter is associated with StAR gene transcription, that chromatin modification occurs in discrete regions of the promoter, that the initial steroidogenic response to 8-bromo-cAMP occurs prior to increased StAR mRNA accumulation, and that MA-10 cell StAR gene transcription and promoter-associated H3 acetylation are biphasic during a 6-h treatment period. The union of the chromatin immunoprecipitation assay with quantitative real-time polymerase chain reaction described and validated here should enhance the analysis of gene expression.

The ERK signaling cascade inhibits gonadotropin-stimulated steroidogenesis

The response of granulosa cells to luteinizing hormone (LH) and follicle-stimulating hormone (FSH) is mediated mainly by cAMP/protein kinase A (PKA) signaling. Notably, the activity of the extracellular signal-regulated kinase (ERK) signaling cascade is elevated in response to these stimuli as well. We studied the involvement of the ERK cascade in LH- and FSH-induced steroidogenesis in two granulosa-derived cell lines, rLHR-4 and rFSHR-17, respectively. We found that stimulation of these cells with the appropriate gonadotropin induced ERK activation as well as progesterone production downstream of PKA. Inhibition of ERK activity enhanced gonadotropin-stimulated progesterone production, which was correlated with increased expression of the steroidogenic acute regulatory protein (StAR), a key regulator of progesterone synthesis. Therefore, it is likely that gonadotropin-stimulated progesterone formation is regulated by a pathway that includes PKA and StAR, and this process is down-regulated by ERK, due to attenuation of StAR expression. Our results suggest that activation of PKA signaling by gonadotropins not only induces steroidogenesis but also activates down-regulation machinery involving the ERK cascade. The activation of ERK by gonadotropins as well as by other agents may be a key mechanism for the modulation of gonadotropin-induced steroidogenesis.

The extra domain A of fibronectin activates Toll-like receptor 4

Cellular fibronectin, which contains an alternatively spliced exon encoding type III repeat extra domain A (EDA), is produced in response to tissue injury. Fragments of fibronectin have been implicated in physiological and pathological processes, especially tissue remodeling associated with inflammation. Because EDA-containing fibronectin fragments produce cellular responses similar to those provoked by bacterial lipopolysaccharide (LPS), we examined the ability of recombinant EDA to activate Toll-like receptor 4 (TLR4), the signaling receptor stimulated by LPS. We found that recombinant EDA, but not other recombinant fibronectin domains, activates human TLR4 expressed in a cell type (HEK 293 cells) that normally lacks this Toll-like receptor. EDA stimulation of TLR4 was dependent upon co-expression of MD-2, a TLR4 accessory protein. Unlike LPS, the activity of EDA was heat-sensitive and persisted in the presence of the LPS-binding antibiotic polymyxin B and a potent LPS antagonist, E5564, which completely suppressed LPS activation of TLR4. These observations provided a mechanism by which EDA-containing fibronectin fragments promote expression of genes involved in the inflammatory response.

The steroidogenic acute regulatory protein (StAR): a window into the complexities of intracellular cholesterol trafficking

Stimulation of steroid-producing cells of the gonads and adrenals with tropic hormone results in a marked increase in steroid hormone synthesis within minutes. The rate-limiting step in this acute steroidogenic response is the transport of cholesterol from the outer to the inner mitochondrial membrane, where the first committed step in steroid synthesis is performed by the side-chain cleavage enzyme system. This process of cholesterol translocation is blocked by inhibitors of protein synthesis, suggesting that the effect of trophic hormones, acting through the intermediacy of cAMP, most likely involves the de novo synthesis of a protein that is rapidly inactivated. The recently identified steroidogenic acute regulatory (StAR) protein appears to be the most likely candidate for the "labile" protein, based on the following observations: 1) Expression of StAR in COS-1 cells engineered to contain the cholesterol side-chain cleavage system substantially augments pregnenolone formation; 2) StAR protein is expressed almost exclusively in steroid-producing cells, except the trophoblast of the human placenta, and its presence is correlated with steroid hormone production; 3) StAR mRNA increases in response to cAMP; 4) StAR is a target for serine phosphorylation mediated by protein kinase A, a process that is essential for maximizing StAR activity; and 5) lack of functional StAR causes the autosomal recessive disease, congenital lipoid adrenal hyperplasia, characterized by markedly impaired gonadal and adrenal steroid hormone synthesis. Studies on the mechanism of action of StAR revealed that import into mitochondria is not essential to its steroidogenesis-enhancing activity and more likely represents a means of rapidly inactivating StAR. Truncation mutations and site-directed mutations established that the C-terminus of the StAR protein contains the functionally important domains. The demonstration of steroidogenic activity of recombinant StAR protein on isolated mitochondria from bovine corpus luteum using protein that lacks the mitochondrial targeting sequence confirmed that StAR import is not essential for its steroidogenic activity and suggested that StAR acts directly on the outer mitochondrial membrane in the absence of intermediary cytosolic factors. Evidence that StAR functions as a cholesterol transfer protein raises the possibility that StAR acts directly on lipids of the outer mitochondrial membrane, probably stimulating cholesterol desorption from the sterol-rich outer membrane and its movement to the relatively sterol-poor inner membrane.

Phenotype and genotype in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common disorder in premenopausal women and is characterized by hyperandrogenic chronic anovulation. The cause is unknown. PCOS is associated with significant insulin resistance as well as with defects in insulin secretion. These abnormalities place these women at substantial risk for developing type 2 diabetes mellitus. A defect in insulin-mediated receptor autophosphorylation has been found in a substantial proportion of PCOS women. Both PCOS and the insulin resistance that accompanies it appear to have major genetic components. Family studies of PCOS have supported this, although they suffer from incomplete phenotyping of probands and first-degree relatives. The phenotype in males and nonreproductive age females is uncertain. Despite the shortcomings of the family studies of PCOS, they have consistently indicated familial clustering and suggested that the mode of inheritance is dominant. Our initial studies of 50 families of PCOS probands indicate that 24% of sisters are affected with PCOS. There also appears to be an intermediate phenotype of sisters with regular menstrual cycles who are hyperandrogenic per se (22% of sisters). Additionally, there appears to be a major familial defect, with 50% of first-degree relatives having glucose intolerance (impaired glucose tolerance by oral glucose tolerance test or type 2 diabetes mellitus). These findings suggest that hyperandrogenism in females and glucose intolerance may be genetic traits in PCOS kindreds. Systematic phenotyping will allow assignment of affected status for eventual linkage analysis.

The proteasome inhibitor MG132 promotes accumulation of the steroidogenic acute regulatory protein (StAR) and steroidogenesis

StAR, a protein synthesized in the cytoplasm and subsequently imported into mitochondria, regulates the rate-determining step in steroidogenesis, the transport of cholesterol from the outer to the inner mitochondrial membrane. The active form of StAR is the 37 kDa pre-protein, which has a short half-life. To determine whether proteasomes participate in the turnover of StAR, we incubated primary cultures of preovulatory rat granulosa cells and immortalized human granulosa cells in the presence of MG132, a specific inhibitor to proteasome catalysis. This treatment caused accumulation of StAR in unstimulated cells. Moreover, incubation of the cells with MG132 in the presence of forskolin (FK), luteinizing hormone/chorionic gonadotropin or follicular stimulating hormone augmented the accumulation of both the 37 kDa cytoplasmic protein and the 30 kDa mature mitochondrial protein, compared to cells incubated with FK or the gonadotropic hormones alone. Concomitantly, progesterone production was enhanced. In contrast no elevation in the 37 kDa StAR intracellular levels or progesterone production was observed following incubation of the cells with the cysteine protease inhibitor E-64. The increase of the 37 kDa StAR protein was evident after 15 min and 30 min of incubation with MG132 (143% and 187% of control values, respectively) with no significant elevation of the 30 kDa protein. Accumulation of the intermediate mitochondrial 32 kDa protein was evident after 1-2 h and the accumulation of the 30 kDa protein was evident only after 4 h of incubation with MG132. In contrast, no elevation in adrenodoxin, a component of the cytochrome P450scc enzyme system, was found. These data suggest that StAR protein is either directly or indirectly degraded by the proteasome which may explain, in part, its short half-life. Moreover, it seems that the cytosolic 37 kDa protein, which is responsible for the steroidogenic activity of StAR, is the primary proteasomal substrate and that the inhibition of its degradation by MG132 causes the up-regulation of progesterone production.

Sterol-modulated glycolipid sorting occurs in niemann-pick C1 late endosomes

The Niemann-Pick C1 (NPC1) protein and endocytosed low density lipoprotein (LDL)-derived cholesterol were shown to enrich separate subsets of vesicles containing lysosomal associated membrane protein 2. Localization of Rab7 in the NPC1-containing vesicles and enrichment of lysosomal hydrolases in the cholesterol-containing vesicles confirmed that these organelles were late endosomes and lysosomes, respectively. Lysobisphosphatidic acid, a lipid marker of the late endosomal pathway, was found in the cholesterol-enriched lysosomes. Recruitment of NPC1 to Rab7 compartments was stimulated by cellular uptake of cholesterol. The NPC1 compartment was shown to be enriched in glycolipids, and internalization of GalNAcbeta1-4[NeuAcalpha2-3]Galbeta1-4Glcbeta1-1'-ceramide (G(M2)) into endocytic vesicles depends on the presence of NPC1 protein. The glycolipid profiles of the NPC1 compartment could be modulated by LDL uptake and accumulation of lysosomal cholesterol. Expression in cells of biologically active NPC1 protein fused to green fluorescent protein revealed rapidly moving and flexible tubular extensions emanating from the NPC1-containing vesicles. We conclude that the NPC1 compartment is a dynamic, sterol-modulated sorting organelle involved in the trafficking of plasma membrane-derived glycolipids as well as plasma membrane and endocytosed LDL cholesterol.

Conditional response of the human steroidogenic acute regulatory protein gene promoter to sterol regulatory element binding protein-1a

The steroidogenic acute regulatory protein (StAR) gene controls the rate-limiting step in the biogenesis of steroid hormones, delivery of cholesterol to the cholesterol side-chain cleavage enzyme on the inner mitochondrial membrane. We determined whether the human StAR promoter is responsive to sterol regulatory element-binding proteins (SREBPs). Expression of SREBP-1a stimulated StAR promoter activity in the context of COS-1 cells and human granulosa-lutein cells. In contrast, expression of SREBP-2 produced only a modest stimulation of StAR promoter activity. One of the SREBP-1a response elements in the StAR promoter was mapped in deletion constructs and by site-directed mutagenesis between nucleotides -81 to -70 from the transcription start site. This motif bound recombinant SREBPs in electrophoretic mobility shift assays, but with lesser affinity than a low density lipoprotein receptor SREBP-binding site. An additional binding site for the transcriptional modulator, yin yang 1 (YY1), was observed within the SREBP-binding site (nucleotides -73 to -70). Mutation of the YY1-binding site increased the responsiveness of the StAR promoter to exogenous SREBP-1a, but did not alter the affinity for SREBP-1a binding in electrophoretic mobility gel shift assays. Manipulations that altered endogenous mature SREBP-1a levels (e.g. culture in lipoprotein-deficient medium and addition of 27-hydroxycholesterol) did not affect StAR promoter function, but influenced low density lipoprotein receptor promoter activity. We conclude that 1) the human StAR promoter is conditionally responsive to SREBP-1a such that promoter activity is up-regulated in the presence of high levels of SREBP-1a, but is unaffected when mature SREBP levels are suppressed; and 2) the human StAR promoter is selectively responsive to SREBP-1a.

Steroidogenic acute regulatory protein (StAR) and the intramitochondrial translocation of cholesterol

The steroidogenic acute regulatory (StAR) protein regulates the rate limiting step in steroidogenesis, the transport of cholesterol from the outer to the inner mitochondrial membrane. Insight into the structure and function of StAR was attained through molecular genetic studies of congenital lipoid adrenal hyperplasia, a rare disease caused by mutations in the StAR gene. Subsequent functional analysis defined two major domains within the StAR protein, the N-terminal mitochondrial targeting sequence and the C-terminus, which promotes the translocation of cholesterol between the two mitochondrial membranes. Two models of StAR's mechanism of action, (1) stimulation of cholesterol desorption from the outer mitochondrial membrane and (2) an intermembrane shuttle hypothesis, are discussed with respect to the known biochemical and biophysical events associated with the process of steroidogenesis and the structure of StAR. StAR gene expression is regulated primarily at the transcriptional level, and the roles of transcription factors that govern basal and cAMP-dependent StAR expression including SF-1, C/EBP beta, Sp1 and GATA-4 are reviewed.

Allelic variants of the follistatin gene in polycystic ovary syndrome

In an earlier study of 37 candidate genes for polycystic ovary syndrome (PCOS), the strongest evidence for genetic linkage was found with the region of the follistatin gene. We have now carried out studies to detect variation in the follistatin gene and assess its relevance to PCOS. By sequencing the gene in 85 members of 19 families of PCOS patients, we found sequence variants at 17 sites. Of these, 16 sites have variants that are too rare to make a major contribution to susceptibility; the only common variant is a single base pair change in the last exon at a site that is not translated. In our sample of 249 families, the evidence for linkage between PCOS and this variant is weak. We also examined the expression of the follistatin gene; messenger RNA levels in cultured fibroblasts from PCOS and control women did not differ appreciably. We conclude that contributions to the etiology of PCOS from the follistatin gene, if any, are likely to be small.

Implementing a new model of integrated women's health in academic health centers: lessons learned from the National Centers of Excellence in Women's Health

The National Centers of Excellence in Women's Health Program (CoE) represents a new model for women's health in academic health centers that unites women's health research, teaching, clinical care, public education and outreach, and career advancement for women in the health sciences. Lessons learned from the first 3 years of implementation indicate that this type of model requires a transformation from the traditionally fragmented set of activities in academic health centers to an integrated system united around the goal of advancing women's health. The transformation requires institutional commitment, dedicated players, and an ability to build on existing resources and bring added value to the institution. Challenges and strategies to link women's health activities and increase collaboration are also discussed.

A trypsin-sensitive protein is required for utilization of exogenous cholesterol for pregnenolone synthesis by placental mitochondria

The utilization of cholesterol for steroid hormone synthesis by human placental mitochondria is poorly understood. The human placenta does not express the steroidogenic acute regulator protein, which is critical for cholesterol delivery to the cholesterol side chain cleavage system in adrenal and gonadal mitochondria. We explored the mechanism underlying cholesterol transport in human placental mitochondria by measuring its transformation into pregnenolone. Mitochondria of syncytiotrophoblast from human term placenta were isolated by centrifugation through a sucrose gradient. The synthesis of pregnenolone in the presence of exogenous cholesterol was increased two-fold in syncytiotrophoblast mitochondria. Treatment of mitochondria with trypsin prevented the increase in the synthesis of pregnenolone in the presence of exogenous cholesterol. However, when 22-OH cholesterol, a substrate that readily crosses membranes, was added, the trypsin-treated mitochondria synthesized increased amounts of pregnenolone. The trypsin-treated mitochondria were intact, since oxygen consumption, succinate dehydrogenase and the adenine nucleotide translocase activities were not significantly different from in untreated mitochondria. However, activity of NADH cytochrome c oxidoreductase, an outer mitochondrial membrane enzyme, was reduced in the trypsin-treated mitochondria, reflecting the selective degradation of proteins. In addition, SDS-PAGE analysis revealed the loss of a prominent 34 kDa band which proved to be a novel porin-like protein that binds to cholesterol. These results support our previous assumption that human placental mitochondria employ a novel protein(s)-mediated the mechanism to take up cholesterol for steroidogenesis.

Determinants of NPC1 expression and action: key promoter regions, posttranscriptional control, and the importance of a "cysteine-rich" loop

Mutations in the NPC1 gene cause Niemann-Pick type C disease, which is characterized by the accumulation of free cholesterol and other lipids in lysosomes. The NPC1 glycoprotein is located in a late endosomal compartment that transiently interacts with lysosomes. To identify factors regulating NPC1 expression and action, we analyzed the function of the human NPC1 promoter in human-derived ovarian, hepatic, and neuronal cells. A fragment containing the first 208 base pairs upstream from the major transcription initiation site was sufficient to drive near maximal NPC1 promoter activity. Deletion analysis revealed that sequences between base pairs -111 and -37 play an important role in controlling NPC1 transcription. Treatment of proliferating granulosa cells with 30 microM progesterone, which induces a reversible phenocopy of the cholesterol trafficking defect of Niemann-Pick type C disease, increased NPC1 mRNA levels threefold. The protein synthesis inhibitor, cycloheximide, also increased NPC1 mRNA levels, augmenting the progesterone-induced increase in NPC1 mRNA abundance. Progesterone treatment was shown to increase the mRNA half-life, but did not affect NPC1 promoter activity. Cysteine residues in a "cysteine-rich" loop predicted to reside in the intralumenal compartment of vesicles containing NPC1 were mutated, resulting in proteins that were incapable of correcting the cholesterol trafficking defect in CT60 cells, a Chinese hamster cell line in which the endogenous NPC1 gene is inactivated. Converting isoleucine 1061, also predicted to lie within the cysteine-rich loop, to a threonine residue inactivated the protein as well. The I1061T mutation is one of the most common mutations in Niemann-Pick type C disease. All of the cysteine-rich loop mutants were localized to cholesterol-engorged lysosomes in a pattern mimicking the distribution of NPC1 in progesterone-treated cells. A recombinant protein representing the cysteine-rich loop was shown to bind to a zinc-NTA agarose column. We conclude: (1) that cis elements residing in the first 111 base pairs upstream from the transcription start site are critical for transcription of the NPC1 gene; (2) that NPC1 expression is subject to posttranscriptional regulation in response to treatments that disrupt NPC1 function; and (3) that an intralumenal cysteine-rich loop with zinc-binding activity is critical to NPC1's ability to unload lysosomal cargo.

Providing progesterone for pregnancy: control of cholesterol flux to the side-chain cleavage system

Progesterone, which is required to support human gestation, is derived initially from the corpus luteum and subsequently from the placenta. The rate-limiting step in progesterone synthesis is the delivery of cholesterol to the mitochondrial cholesterol side-chain cleavage system. The steroidogenic acute regulatory protein (StAR) mediates this process in the corpus luteum, whereas in the placenta, which does not express StAR, a StAR homologue, MLN64, may accomplish this function. StAR expression is regulated in the ovary at the transcriptional level by a cAMP-activated signal transduction system and StAR activity is also increased acutely by protein kinase A-mediated phosphorylation. These long-term (transcriptional) and short-term (post-translational, that is, phosphorylation) mechanisms govern luteal steroidogenic activity. The StAR protein has two key functional domains. The StAR C-terminal domain increases cholesterol movement to cytochrome P450scc by promoting sterol desorption from the sterol-rich outer mitochondrial membrane, driving it to the relatively sterol-poor inner membrane. The N-terminal domain mitochondrial targeting sequence directs the StAR protein to the mitochondria.

Endocrine and paracrine-autocrine regulation of the human corpus luteum during the mid-luteal phase

Human corpora lutea undergo an extremely rapid period of growth, development and regression during the course of non-fertile cycles. The tissue consists of steroidogenic (parenchymal) and non-steroidogenic (stromal) cells. In women and other primates, steroid hormone production by corpora lutea depends on the presence of pituitary-derived LH. Nevertheless, there is also intra-luteal regulation of steroid synthesis. Steroidogenic luteal cells and non-steroidogenic cells interact via endocrine and paracrine pathways, and by contact-dependent pathways (gap junctions). Thus, hormones and locally produced factors including steroids, growth factors, cytokines, reactive oxygen species and nitric oxide may modulate luteal lifespan. The factors regulating regression and rescue of the corpus luteum are not understood completely. This review describes the expression of two representative intragonadal peptides that may influence luteal regression (interleukin 1 beta) and luteal rescue (steroidogenic acute regulatory protein).

Differential activity of the cytochrome P450 17alpha-hydroxylase and steroidogenic acute regulatory protein gene promoters in normal and polycystic ovary syndrome theca cells

17alpha-Hydroxylase (CYP17) expression in propagated theca cells isolated from the ovaries of women with polycystic ovary syndrome (PCOS) is persistently elevated, compared with theca cells isolated from normal ovaries. To investigate the mechanism for increased CYP17 messenger RNA accumulation in PCOS theca cells, we examined CYP17 and steroidogenic acute regulatory protein (StAR) promoter activities in normal and PCOS theca cells. Conditions were established to transiently transfect human theca cells with reporter gene constructs containing 5' truncations of the human CYP17 and StAR promoters. Cotransfection of a steroidogenic factor-1 expression plasmid was found to be required for detection of basal and forskolin-stimulated CYP17 promoter activity but not for StAR promoter activity. However, cotransfection with a steroidogenic factor-1 expression plasmid augmented both basal and forskolin-stimulated StAR promoter activity. CYP17 reporter activity was compared in theca cells isolated from normal and PCOS patients. Basal and forskolin-stimulated CYP17 promoter activity was 4-fold greater in PCOS cells than in theca cells isolated from normal ovaries. In contrast, StAR promoter activity, and the activity of a reporter construct containing three copies of a cAMP response element (3xCRE), were similar in normal and PCOS theca cells. The results of these studies document: 1) that basal and cAMP-dependent CYP17 gene transcription is increased in PCOS theca cells; 2) that there is differential regulation of promoters of genes required for steroidogenesis in PCOS theca cells; and 3) that passaged normal and PCOS theca cells provide a model system for studying tissue-specific regulation of genes encoding steroidogenic enzymes and identifying the molecular mechanisms involved in increased androgen production in PCOS.

Lipopolysaccharide induces expression of genes encoding pro-inflammatory cytokines and the elastin-degrading enzyme, cathepsin S, in human cervical smooth-muscle cells

OBJECTIVE

Vaginal and amniotic infection with gram-negative bacteria is associated with preterm birth. We previously reported that human cervical smooth-muscle cells (CSMC) respond to pro-inflammatory cytokines by expressing enzymes that degrade the extracellular matrix. Our objective was to characterize the effects of lipopolysaccharide (LPS) from Escherichia coli (E coli), Bacteroides fragilis, (B frag)and Fusobacterium nucleatum (F nuc)on the expression of pro-inflammatory cytokines and the elastin-degrading enzyme, cathepsin S, in human CSMC.

METHODS

Human CSMC were exposed to LPS and the expression of mRNAs encoding pro-inflammatory cytokines and cathepsin S, and selected matrix metalloproteinases (MMPs) was analyzed by Northern blotting. The effect of cytokine-neutralizing antibodies on LPS-induced cathepsin S mRNA expression also was determined.

RESULTS

E coli LPS increased expression of cathepsin S 12.5-fold after 12 hours; MMP-1 and MMP-3 mRNAs also were increased 2.9- and 3.5-fold, respectively. Tumor necrosis factor (TNF)-alpha, interleukin (IL-1)alpha, and IL-1beta mRNAs were markedly up-regulated after 3 hours of LPS treatment. B frag and F nuc LPS also induced TNF-alpha and cathepsin S mRNAs. E coli LPS caused a sevenfold increase in TNF-alpha secretion after 5 to 8 hours. Antihuman TNF-alpha monoclonal antibody, but not a monoclonal antibody to the low-density lipoprotein receptor, reduced the LPS-induced increase in cathepsin S mRNA by 27%, whereas neutralizing antibodies against IL-1alpha and IL-1beta did not suppress the response. Human CSMC were shown to express the toll-like receptor (TLR-2) and TLR-4 genes, which mediate the action of LPS. TLR-2 mRNA was up-regulated by TNF-alpha.

CONCLUSION

CSMC respond to LPS with increased expression of pro-inflammatory cytokines and cathepsin S. Increases in cathepsin S mRNA result only in part from the rapid induction of TNF-alpha gene expression. TNF-alpha may also augment the CSMC response to LPS by increasing expression of the LPS signaling receptor, TLR-2, which probably directly mediates LPS action. These observations provide a mechanism by which gram-negative bacteria can precipitate cervical changes associated with preterm birth.

Sperm antigen 6 is the murine homologue of the Chlamydomonas reinhardtii central apparatus protein encoded by the PF16 locus

A cDNA encoding sperm antigen 6 (Spag6), the murine homologue of the Chlamydomonas reinhardtii PF16 protein-a component of the flagella central apparatus-was isolated from a mouse testis cDNA library. The cDNA sequence predicted a 55.3-kDa polypeptide containing 8 contiguous armadillo repeats with 65% amino acid sequence identity and 81% similarity to the Chlamydomonas PF1 protein. An antipeptide antibody generated against a C-terminal sequence recognized a 55-kDa protein in sperm extracts and localized Spag6 to the principal piece of permeabilized mouse sperm tails. When expressed in COS-1 cells, Spag6 colocalized with microtubules. The Spag6 gene was found to be highly expressed in testis and was mapped using the T31 radiation hybrid panel to mouse chromosome 16. Mutations in the Chlamydomonas PF16 gene cause flagellar paralysis. The presence of a highly conserved mammalian PF16 homologue (Spag6) raises the possibility that Spag6 plays an important role in sperm flagellar function.

NPC1-containing compartment of human granulosa-lutein cells: a role in the intracellular trafficking of cholesterol supporting steroidogenesis

Steroidogenic cells represent unique systems for the exploration of intracellular cholesterol trafficking. We employed cytochemical and biochemical methods to explore the expression, regulation, and function of the Niemann-Pick C1 protein (NPC1) in human granulosa-lutein cells. NPC1 was localized in a subset of lysosome-associated membrane glycoprotein 2 (LAMP-2)-positive vesicles. By analyzing the sensitivity of NPC1 N-linked oligosaccharide chains to glycosidases and neuraminidase, evidence was obtained for movement of nascent NPC1 from the endoplasmic reticulum through the medial and trans compartments of the Golgi apparatus prior to its appearance in cytoplasmic vesicles. NPC1 protein content and the morphology and cellular distribution of NPC1-containing vesicles were not affected by treatment of the granulosa-lutein cells with 8-Br-cAMP, which stimulates cholesterol metabolism into progesterone. In contrast, steroidogenic acute regulatory (StAR) protein levels were increased by 8-Br-cAMP. Incubation of granulosa-lutein cells with low-density lipoprotein (LDL) in the presence of the hydrophobic amine, U18666A, caused accumulation of free cholesterol in granules, identified by filipin staining, that contained LAMP-2 and NPC1. These granules also stained for neutral lipid with Nile red, reflecting accumulation of LDL-derived cholesterol esters. LDL-stimulated progesterone synthesis was completely blocked by U18666A, leaving steroid output at levels similar to those of cells incubated in the absence of LDL. The hydrophobic amine also blocked the LDL augmentation of 8-Br-cAMP-stimulated progesterone synthesis, reducing steroid production to levels seen in cells stimulated with 8-Br-cAMP in the absence of LDL. Steroidogenesis recovered after U18666A was removed from the culture medium. U18666A treatment caused a 2-fold or more increase in NPC1 protein and mRNA levels, suggesting that disruption of NPC1's function activates a compensatory mechanism resulting in increased NPC1 synthesis. We conclude that the NPC1 compartment plays an important role in the trafficking of LDL-derived substrate in steroidogenic cells; that NPC1 expression is up-regulated when NPC1 action is blocked; and that the NPC1 compartment can be functionally separated from other intracellular pathways contributing substrate for steroidogenesis.

Directed vascular expression of the thromboxane A2 receptor results in intrauterine growth retardation

Thromboxane (Tx) A2 is a platelet agonist, smooth muscle cell constrictor, and mitogen. Urinary Tx metabolite (Tx-M) excretion is increased in syndromes of platelet activation and early in both normal pregnancies and in pregnancy-induced hypertension. A further increment occurs in patients presenting with severe preeclampsia, in whom Tx-M correlates with other indices of disease severity. TxA2 exerts its effects through a membrane receptor (TP), of which two isoforms (alpha and beta; refs. 5,6) have been cloned. Overexpression of TP in the vasculature under the control of the pre-proendothelin-1 promoter results in a murine model of intrauterine growth retardation (IUGR), which is rescued by timed suppression of Tx synthesis with indomethacin. IUGR is commonly associated with maternal diabetes or cigarette smoking, both conditions associated with increased TxA2 biosynthesis.

Molecular phenotype of the human oocyte by PCR-SAGE

Consecutive application of PCR and serial analysis of gene expression (SAGE) was used to generate a catalog of approximately 50, 000 SAGEtags from nine human oocytes. Matches for known genes were identified using the National Institutes of Health SAGEtag database. This database links directly to the UniGene database, providing rapid discrimination between SAGEtags that match known genes and expressed sequence tags and those that currently have no match. Matches in the oocyte SAGE catalog were found for surface receptors, second-messenger systems, and cytoskeletal, apoptotic, and secreted proteins. Many of these proteins were not previously known to be expressed in mammalian oocytes. The relative abundances of transcripts for cytoskeletal proteins and proteins known to be in oocytes are consistent with their documented expression, suggesting an absence of representational distortion by the PCR step. The expression profile of the human oocyte may help identify factors that reprogram somatic cell nuclei to totipotency.

Searching for the polycystic ovary syndrome genes

PCOS is a common disorder of unknown etiology. Studies of first-degree relatives of women diagnosed with PCOS suggest familial clustering of the disease. A prospective study of first-degree female relatives of women with PCOS conducted by NCPIR found that 46% of ascertainable sisters of women with PCOS were hyperandrogenemic. NCPIR has conducted linkage and association studies using affected sibling-pair analysis and the transmission/disequilibrium test to explore candidate PCOS genes. These studies point a finger at a region 1 MB centromeric to the insulin receptor gene on chromosome 19.

Insulin and insulin-like growth factor-I and -II modulate human granulosa-lutein cell steroidogenesis: enhancement of steroidogenic acute regulatory protein (StAR) expression

Insulin and insulin-like growth factors (IGF)-I and -II stimulate granulosa cell steroidogenesis. Since steroidogenic acute regulatory protein (StAR) regulates the rate-limiting step in steroid hormone biosynthesis, the ability of insulin and IGF to modulate StAR protein and mRNA expression was examined in two human granulosa cell culture systems: (i) proliferating granulosa-lutein cells and (ii) luteinized-granulosa cells derived during in-vitro fertilization (IVF). In proliferating granulosa-lutein cells, IGF-I and IGF-II increased StAR protein approximately 4-5-fold, while insulin and 8-bromoadenosine 3',5'-cAMP (8-Br-cAMP) increased amounts of StAR protein 2.5- and 6-fold respectively. A combination of IGFs/insulin and 8-Br-cAMP increased StAR 7-9-fold. Luteinized granulosa cells also had increased StAR expression after treatment with IGF-I (2. 8-fold), IGF-II (3-fold), insulin (2.5-fold) and 8-Br-cAMP (4. 5-fold). Progesterone production generally followed a pattern similar to StAR protein in both cell systems. In proliferating granulosa-lutein cells, both IGF-I and insulin increased StAR mRNA (3-fold) and 8-Br-cAMP increased StAR mRNA 4-fold, whereas a combination of IGF-I and 8-Br-cAMP had an additive effect on StAR mRNA expression (7-fold). Transient transfection of proliferating granulosa-lutein cells with StAR promoter-luciferase reporter constructs demonstrated that IGF-I, IGF-II, and insulin had no effect on the StAR promoter activity, while 8-Br-cAMP stimulated StAR promoter function. The results indicate that: (i) IGFs and insulin stimulate StAR mRNA and protein expression in human granulosa-lutein cells; (ii) IGF-I and 8-Br-cAMP have an additive effect on StAR gene expression; and (iii) IGF-I increases StAR mRNA and protein by a mechanism that does not involve activation of the proximal StAR gene promoter.

cDNA cloning and characterization of a human sperm antigen (SPAG6) with homology to the product of the Chlamydomonas PF16 locus

Serum from an infertile male with high-titer anti-sperm antibodies was used to identify a novel human sperm antigen by screening of a testis expression library. The clone, initially designated Repro-SA-1 (HUGO-approved symbol SPAG6), was found to encode a sequence highly enriched in testis. The deduced amino acid sequence of the full-length cDNA revealed striking homology to the product of the Chlamydomonas reinhardtii PF16 locus, which encodes a protein localized to the central pair of the flagellar axoneme. The human gene encodes 1.8- and 2.8-kb mRNAs highly expressed in testis but not in prostate, ovary, spleen, thymus, small intestine, colon, peripheral blood leukocytes, heart, brain, placenta, liver, muscle, kidney, and pancreas. The gene was mapped to chromosome 10p11.2-p12. Antibodies raised against SPAG6 sequences localized the protein to the tails of permeabilized human sperm. Both the Chlamydomonas protein and SPAG6 contain eight contiguous armadillo repeats, which place them in a family of proteins known to mediate protein-protein interactions. The cloning of the human homologue of the Chlamydomonas PF16 locus provides a new avenue to explore the role of the axoneme central pair in human sperm function.

CCAAT/enhancer-binding proteins regulate expression of the human steroidogenic acute regulatory protein (StAR) gene

Two putative CCAAT/enhancer-binding protein (C/EBP) response elements were identified in the proximal promoter of the human steroidogenic acute regulatory protein (StAR) gene, which encodes a key protein-regulating steroid hormone synthesis. Expression of C/EBPalpha and -beta increased StAR promoter activity in COS-1 and HepG2 cells. Cotransfection of C/EBPalpha or -beta and steroidogenic factor 1, a transcription factor required for cAMP regulation of StAR expression, into COS-1 augmented 8-bromoadenosine 3':5'-cyclic monophosphate (8-Br-cAMP)-stimulated promoter activity. When the putative C/EBP response elements were mutated, individually or together, a pronounced decline in basal StAR promoter activity in human granulosa-lutein cells resulted, but the fold stimulation of promoter activity by 8-Br-cAMP was unaffected. Recombinant C/EBPalpha and -beta bound to the two identified sequences but not the mutated elements. Human granulosa-lutein cell nuclear extracts also bound these elements but not the mutated sequences. An antibody to C/EBPbeta, but not C/EBPalpha, supershifted the nuclear protein complex associated with the more distal element. The complex formed by nuclear extracts with the proximal element was not supershifted by either antibody. Western blot analysis revealed the presence of C/EBPalpha and C/EBPbeta in human granulosa-lutein cell nuclear extracts. C/EBPbeta levels were up-regulated 3-fold by 8-Br-cAMP treatment. Our studies demonstrate a role for C/EBPbeta as well as yet to be identified proteins, which can bind to C/EBP response elements, in the regulation of StAR gene expression and suggest a mechanism by which C/EBPbeta participates in the cAMP regulation of StAR gene transcription.