Search

Small-molecule inhibitors of the mono (ADP) ribosyl transferase PARP7 are being evaluated asmonotherapy for tumors overexpressing PARP7 and in combination with immune checkpoint blockade. We previously showed that sensitivity to the PARP7 inhibitor (PARP7i) RBN-2397 could be enhanced by cotreatment with agonists of the aryl hydrocarbon receptor (AHRa) in cell lines that show strong intrinsic sensitivity to RBN-2397. In this study, we demonstrated that a range of tumor cell lines that are relatively insensitive to PARP7i or AHRa as individual agents are unexpectedly profoundly sensitive to their combination. Our data show that this synergistic response is dependent on the AHR/AHR nuclear translocator and is associated with increased levels of nuclear AHR and increased transcription of AHR target genes. In some hormone receptor-positive cell lines, we find that combination treatment is associated with proteasomal turnover of the steroid hormone receptors, androgen receptor and estrogen receptor. Both wild-type and hormone-resistant mutant forms of these receptors are degraded upon treatment with AHRa and PARP7i in breast and prostate cancer models. These results suggest that combining PARP7i with AHRa may extend the utility of these drugs to a wider range of tumors, including those that are refractory to hormone therapy., (©2024 American Association for Cancer Research.)

Despite the abundance of somatic structural variations (SVs) in cancer, the underlying molecular mechanisms of their formation remain unclear. In the present study, we used 6,193 whole-genome sequenced tumors to study the contributions of transcription and DNA replication collisions to genome instability. After deconvoluting robust SV signatures in three independent pan-cancer cohorts, we detected transcription-dependent, replicated-strand bias, the expected footprint of transcription-replication collision (TRC), in large tandem duplications (TDs). Large TDs are abundant in female-enriched, upper gastrointestinal tract and prostate cancers. They are associated with poor patient survival and mutations in TP53, CDK12 and SPOP. Upon inactivating CDK12, cells display significantly more TRCs, R-loops and large TDs. Inhibition of WEE1, CHK1 and ATR selectively inhibits the growth of cells deficient in CDK12. Our data suggest that large TDs in cancer form as a result of TRCs and their presence can be used as a biomarker for prognosis and treatment., Competing Interests: Competing interests: A.A. reports personal fees from Tango Therapeutics, Azkarra Therapeutics, Ovibio, Kytarro, CytomX, Cambridge Science Corporation, Genentech, Gladiator, Circle, Bluestar, Earli, Ambagon, Trial Library, Phoenix Molecular Designs, GSK, Prolynx; grants from SPARC and AstraZeneca outside the submitted work. In addition, he holds patents on the use of PARP inhibitors held jointly with AstraZeneca from which he has benefited financially (and may do so in the future). F.Y.F. reports personal fees from Bluestar Genomics, Astellas, Foundation Medicine, Exact Sciences, Tempus, POINT Biopharma, Janssen, Bayer, Myovant, Roivant, SerImmune, Bristol Myers Squibb and Novartis, and personal fees from POINT Biopharma outside the submitted work and other support from Artera. J.C. reports consulting fees from Exai Bio outside the submitted work. The other authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

SARS-CoV-2 continues to pose a threat to public health. Current therapeutics remain limited to direct acting antivirals that lack distinct mechanisms of action and are already showing signs of viral resistance. The virus encodes an ADP-ribosylhydrolase macrodomain (Mac1) that plays an important role in the coronaviral lifecycle by suppressing host innate immune responses. Genetic inactivation of Mac1 abrogates viral replication in vivo by potentiating host innate immune responses. However, it is unknown whether this can be achieved by pharmacologic inhibition and can therefore be exploited therapeutically. Here we report a potent and selective lead small molecule, AVI-4206, that is effective in an in vivo model of SARS-CoV-2 infection. Cellular models indicate that AVI-4206 has high target engagement and can weakly inhibit viral replication in a gamma interferon- and Mac1 catalytic activity-dependent manner; a stronger antiviral effect for AVI-4206 is observed in human airway organoids. In an animal model of severe SARS-CoV-2 infection, AVI-4206 reduces viral replication, potentiates innate immune responses, and leads to a survival benefit. Our results provide pharmacological proof of concept that Mac1 is a valid therapeutic target via a novel immune-restoring mechanism that could potentially synergize with existing therapies targeting distinct, essential aspects of the coronaviral life cycle. This approach could be more widely used to target other viral macrodomains to develop antiviral therapeutics beyond COVID-19., Competing Interests: A.R.R, P.J., R.L.G., T.T., M.R., J.S.F., G.J.C., B.K.S., R.J.N, A.A., M.D., P.C.O., Y.D.P., N.K., M.O., T.Y.T., R.S., F.Z.B., and M.M. are listed as inventors on a patent application describing small molecule macrodomain inhibitors, which includes compounds described herein. T.Y.T and M.O. are listed as inventors on a patent application filed by the Gladstone Institutes that covers the use of pGLUE to generate SARS-CoV-2 infectious clones and replicons. The Krogan laboratory has received research support from Vir Biotechnology, F. Hoffmann-La Roche and Rezo Therapeutics. N.J.K. has financially compensated consulting agreements with Maze Therapeutics and Interline Therapeutics. He is on the Board of Directors and is President of Rezo Therapeutics and is a shareholder in Tenaya Therapeutics, Maze Therapeutics, Rezo Therapeutics, GEn1E Lifesciences and Interline Therapeutics. B.K.S is co-founder of BlueDolphin LLC, Epiodyne Inc, and Deep Apple Therapeutics, Inc., and serves on the SRB of Genentech, the SAB of Schrodinger LLC, and the SAB of Vilya Therapeutics. M.O. is a cofounder of Directbio and board member of InVisishield. A.R.R. is a co-founder of TheRas, Elgia Therapeutics, and Tatara Therapeutics, and receives sponsored research support from Merck, Sharp and Dohme. A.A. is a co-founder of Tango Therapeutics, Azkarra Therapeutics and Kytarro; a member of the board of Cytomx, Ovibio Corporation, Cambridge Science Corporation; a member of the scientific advisory board of Genentech, GLAdiator, Circle, Bluestar/Clearnote Health, Earli, Ambagon, Phoenix Molecular Designs, Yingli/280Bio, Trial Library, ORIC and HAP10; a consultant for ProLynx, Next RNA and Novartis; receives research support from SPARC; and holds patents on the use of PARP inhibitors held jointly with AstraZeneca from which he has benefited financially (and may do so in the future). J.S.F. is a consultant to, shareholder of, and receives sponsored research support from Relay Therapeutics.

Purpose: Urologic chronic pelvic pain syndrome (UCPPS), which encompasses interstitial cystitis/bladder pain syndrome in women and men and chronic prostatitis/chronic pelvic pain syndrome in men, is a common, often disabling urological disorder that is neither well understood nor satisfactorily treated with medical treatments. The past 25 years have seen the development and validation of a number of behavioral pain treatments, of which cognitive behavioral therapy (CBT) is arguably the most effective. CBT combines strategies of behavior therapy, which teaches patients more effective ways of behaving, and cognitive therapy, which focuses on correcting faulty thinking patterns. As a skills-based treatment, CBT emphasizes "unlearning" maladaptive behaviors and thoughts, and replacing them with more adaptive ones that support symptom self-management., Materials and Methods: This review describes the rationale, technical procedures, and empirical basis of CBT., Results: While evidence supports CBT for treatment-refractory chronic pain disorders, there is limited understanding of why or how CBT might work, for whom it is most beneficial, or the specific UCPPS symptoms (eg, pain, urinary symptoms) it effectively targets. This is the focus of EPPIC (Easing Pelvic Pain Interventions Clinical Research Program), a landmark NIH trial examining the efficacy of low-intensity, home-based CBT for UCPPS relative to a nonspecific comparator featuring self-care recommendations of AUA guidelines., Conclusions: Systematic efforts to increase both the efficiency of CBT and the way it is delivered (eg, home-based treatments) are critical to scaling up CBT, optimizing its therapeutic potential, and reducing the public health burden of UCPPS.

Despite the abundance of somatic structural variations (SVs) in cancer, the underlying molecular mechanisms of their formation remain unclear. Here, we use 6,193 whole-genome sequenced tumors to study the contributions of transcription and DNA replication collisions to genome instability. After deconvoluting robust SV signatures in three independent pan-cancer cohorts, we detect transcription-dependent replicated-strand bias, the expected footprint of transcription-replication collision (TRC), in large tandem duplications (TDs). Large TDs are abundant in female-enriched, upper gastrointestinal tract and prostate cancers. They are associated with poor patient survival and mutations in TP53 , CDK12 , and SPOP . Upon inactivating CDK12, cells display significantly more TRCs, R-loops, and large TDs. Inhibition of G2/M checkpoint proteins, such as WEE1, CHK1, and ATR, selectively inhibits the growth of cells deficient in CDK12. Our data suggest that large TDs in cancer form due to TRCs, and their presence can be used as a biomarker for prognosis and treatment.

Despite unprecedented efforts, our therapeutic arsenal against SARS-CoV-2 remains limited. The conserved macrodomain 1 (Mac1) in NSP3 is an enzyme exhibiting ADP-ribosylhydrolase activity and a possible drug target. To determine the role of Mac1 catalytic activity in viral replication, we generated recombinant viruses and replicons encoding a catalytically inactive NSP3 Mac1 domain by mutating a critical asparagine in the active site. While substitution to alanine (N40A) reduced catalytic activity by ~10-fold, mutations to aspartic acid (N40D) reduced activity by ~100-fold relative to wild-type. Importantly, the N40A mutation rendered Mac1 unstable in vitro and lowered expression levels in bacterial and mammalian cells. When incorporated into SARS-CoV-2 molecular clones, the N40D mutant only modestly affected viral fitness in immortalized cell lines, but reduced viral replication in human airway organoids by 10-fold. In mice, the N40D mutant replicated at >1000-fold lower levels compared to the wild-type virus while inducing a robust interferon response; all animals infected with the mutant virus survived infection. Our data validate the critical role of SARS-CoV-2 NSP3 Mac1 catalytic activity in viral replication and as a promising therapeutic target to develop antivirals., Competing Interests: T.Y.T. and M.O. are inventors on a patent application filed by the Gladstone Institutes that covers the use of pGLUE to generate SARS-CoV-2 infectious clones and replicons. A.A. is a co-founder of Tango Therapeutics, Azkarra Therapeutics, Ovibio Corporation and Kytarro, a member of the board of Cytomx and Cambridge Science Corporation, a member of the scientific advisory board of Genentech, GLAdiator, Circle, Bluestar, Earli, Ambagon, Phoenix Molecular Designs and Trial Library, a consultant for SPARC, ProLynx, GSK and Novartis, receives grant or research support from SPARC and AstraZeneca, and holds patents on the use of PARP inhibitors held jointly with AstraZeneca from which he has benefited financially (and may do so in the future). The Krogan Laboratory has received research support from Vir Biotechnology, F. Hoffmann-La Roche, and Rezo Therapeutics. N.J.K has financially compensated consulting agreements with Maze Therapeutics, Interline Therapeutics, Rezo Therapeutics, and GEn1E Lifesciences, Inc.. N.J.K is on the Board of Directors of Rezo Therapeutics and is a shareholder in Tenaya Therapeutics, Maze Therapeutics, Rezo Therapeutics, and Interline Therapeutics. All other authors declare no competing interests., (Copyright: © 2023 Taha et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Despite unprecedented efforts, our therapeutic arsenal against SARS-CoV-2 remains limited. The conserved macrodomain 1 (Mac1) in NSP3 is an enzyme exhibiting ADP-ribosylhydrolase activity and a possible drug target. To determine the therapeutic potential of Mac1 inhibition, we generated recombinant viruses and replicons encoding a catalytically inactive NSP3 Mac1 domain by mutating a critical asparagine in the active site. While substitution to alanine (N40A) reduced catalytic activity by ~10-fold, mutations to aspartic acid (N40D) reduced activity by ~100-fold relative to wildtype. Importantly, the N40A mutation rendered Mac1 unstable in vitro and lowered expression levels in bacterial and mammalian cells. When incorporated into SARS-CoV-2 molecular clones, the N40D mutant only modestly affected viral fitness in immortalized cell lines, but reduced viral replication in human airway organoids by 10-fold. In mice, N40D replicated at >1000-fold lower levels compared to the wildtype virus while inducing a robust interferon response; all animals infected with the mutant virus survived infection and showed no signs of lung pathology. Our data validate the SARS-CoV-2 NSP3 Mac1 domain as a critical viral pathogenesis factor and a promising target to develop antivirals., Competing Interests: COMPETING INTERESTS The authors declare the following competing interests: T.Y.T. and M.O. are inventors on a patent application filed by the Gladstone Institutes that covers the use of pGLUE to generate SARS-CoV-2 infectious clones and replicons. All other authors declare no competing interests. A.A. is a co-founder of Tango Therapeutics, Azkarra Therapeutics, Ovibio Corporation and Kytarro, a member of the board of Cytomx and Cambridge Science Corporation, a member of the scientific advisory board of Genentech, GLAdiator, Circle, Bluestar, Earli, Ambagon, Phoenix Molecular Designs and Trial Library, a consultant for SPARC, ProLynx, GSK and Novartis, receives grant or research support from SPARC and AstraZeneca, and holds patents on the use of PARP inhibitors held jointly with AstraZeneca from which he has benefited financially (and may do so in the future).

Over one million cases of gastric cancer are diagnosed each year globally, and the metastatic disease continues to have a poor prognosis. A significant proportion of gastric tumors have defects in the DNA damage response pathway, creating therapeutic opportunities through synthetic lethal approaches. Several small-molecule inhibitors of ATR, a key regulator of the DNA damage response, are now in clinical development as targeted agents for gastric cancer. Here, we performed a large-scale CRISPR interference screen to discover genetic determinants of response and resistance to ATR inhibitors (ATRi) in gastric cancer cells. Among the top hits identified as mediators of ATRi response were UPF2 and other components of the nonsense-mediated decay (NMD) pathway. Loss of UPF2 caused ATRi resistance across multiple gastric cancer cell lines. Global proteomic, phosphoproteomic, and transcriptional profiling experiments revealed that cell-cycle progression and DNA damage responses were altered in UPF2-mutant cells. Further studies demonstrated that UPF2-depleted cells failed to accumulate in G1 following treatment with ATRi. UPF2 loss also reduced transcription-replication collisions, which has previously been associated with ATRi response, thereby suggesting a possible mechanism of resistance. Our results uncover a novel role for NMD factors in modulating response to ATRi in gastric cancer, highlighting a previously unknown mechanism of resistance that may inform the clinical use of these drugs., Significance: Loss of NMD proteins promotes resistance to ATR inhibitors in gastric cancer cells, which may provide a combination of therapeutic targets and biomarkers to improve the clinical utility of these drugs., (©2022 American Association for Cancer Research.)

Inhibitors directed toward PARP1 and PARP2 are approved agents for the treatment of BRCA1 and BRCA2-related cancers. Other members of the PARP family have also been implicated in cancer and are being assessed as therapeutic targets in cancer and other diseases. Recently, an inhibitor of PARP7 (RBN-2397) has reached early-stage human clinical trials. Here, we performed a genome-wide CRISPR screen for genes that modify the response of cells to RBN-2397. We identify the polycyclic aromatic hydrocarbon receptor AHR and multiple components of the cohesin complex as determinants of resistance to this agent. Activators and inhibitors of AHR modulate the cellular response to PARP7 inhibition, suggesting potential combination therapy approaches., (©2022 American Association for Cancer Research.)

Background: There is growing evidence for personalizing colorectal cancer screening based on risk factors. We compared the cost-effectiveness of personalized colorectal cancer screening based on polygenic risk and family history to uniform screening., Methods: Using the MISCAN-Colon model, we simulated a cohort of 100 million 40-year-olds, offering them uniform or personalized screening. Individuals were categorized based on polygenic risk and family history of colorectal cancer. We varied screening strategies by start age, interval and test and estimated costs, and quality-adjusted life years (QALY). In our analysis, we (i) assessed the cost-effectiveness of uniform screening; (ii) developed personalized screening scenarios based on optimal screening strategies by risk group; and (iii) compared the cost-effectiveness of both., Results: At a willingness-to-pay threshold of $50,000/QALY, the optimal uniform screening scenario was annual fecal immunochemical testing (FIT) from ages 50 to 74 years, whereas for personalized screening the optimal screening scenario consisted of annual and biennial FIT screening except for those at highest risk who were offered 5-yearly colonoscopy from age 50 years. Although these scenarios gained the same number of QALYs (17,887), personalized screening was not cost-effective, costing an additional $428,953 due to costs associated with determining risk (assumed to be $240 per person). Personalized screening was cost-effective when these costs were less than ∼$48., Conclusions: Uniform colorectal cancer screening currently appears more cost-effective than personalized screening based on polygenic risk and family history. However, cost-effectiveness is highly dependent on the cost of determining risk., Impact: Personalized screening could become increasingly viable as costs for determining risk decrease., (©2019 American Association for Cancer Research.)

Background: Our previous work has shown peroxiredoxin-1 (PRDX1), one of major antioxidant enzymes, to be a biomarker in human breast cancer. Hereby, we further investigate the role of PRDX1, compared to its close homolog PRDX2, in mammary malignant cells., Methods: CRISPR/Cas9- or RNAi-based methods were used for genetic targeting PRDX1/2. Cell growth was assessed by crystal violet, EdU incorporation or colony formation assays. In vivo growth was assessed by a xenotransplantation model. Adenanthin was used to inhibit the thioredoxin-dependent antioxidant defense system. The prooxidant agents used were hydrogen peroxide, glucose oxidase and sodium L-ascorbate. A PY1 probe or HyPer-3 biosensor were used to detect hydrogen peroxide content in samples., Results: PRDX1 downregulation significantly impaired the growth rate of MCF-7 and ZR-75-1 breast cancer cells. Likewise, xenotransplanted PRDX1-deficient MCF-7 cells presented a retarded tumour growth. Furthermore, genetic targeting of PRDX1 or adenanthin, but not PRDX2, potently sensitised all six cancer cell lines studied, but not the non-cancerous cells, to glucose oxidase and ascorbate., Conclusions: Our study pinpoints the dominant role for PRDX1 in management of exogeneous oxidative stress by breast cancer cells and substantiates further exploration of PRDX1 as a target in this disease, especially when combined with prooxidant agents.

Objective: Guidelines for thyroid function evaluation recommend testing TSH first, then assessing fT4 only if TSH is out of the reference range (two-step), but many clinicians initially request both TSH and fT4 (one-step). Given limitations of previous studies, we aimed to compare the two-step with the one-step approach in an unselected community-dwelling study population, and develop a prediction score based on clinical parameters that could identify at-risk patients for thyroid dysfunction., Design: Cross-sectional analysis of the population-based Busselton Health Study., Methods: We compared the two-step with the one-step approach, focusing on cases that would be missed by the two-step approach, i.e. those with normal TSH, but out-of-range fT4. We used likelihood ratio tests to identify demographic and clinical parameters associated with thyroid dysfunction and developed a clinical prediction score by using a beta-coefficient based scoring method., Results: Following the two-step approach, 93.0% of all 4471 participants had normal TSH and would not need further testing. The two-step approach would have missed 3.8% of all participants (169 of 4471) with a normal TSH, but a fT4 outside the reference range. In 85% (144 of 169) of these cases, fT4 fell within 2 pmol/l of fT4 reference range limits, consistent with healthy outliers. The clinical prediction score that performed best excluded only 22.5% of participants from TSH testing., Conclusion: The two-step approach may avoid measuring fT4 in as many as 93% of individuals with a very small risk of missing thyroid dysfunction. Our findings do not support the simultaneous initial measurement of both TSH and fT4.

Background: The TSH-T4 relationship was thought to be inverse log-linear, but recent cross-sectional studies of selected populations report a complex, nonlinear relationship. The TSH-T4 relationship has not been evaluated in an unselected, community-based cohort, and there are limited data regarding clinical factors which affect it., Objective: To analyse the TSH-free T4 relationship in a community-based cohort., Design, Participants and Methods: In a cross-sectional, retrospective study, we analysed serum TSH and free T4 concentrations from 4427 participants (55% female) in the 1994 Busselton Health Study who were not taking thyroxine. Simple linear, segmented-linear and nonlinear regression models of log 10 TSH on free T4 were compared for goodness of fit., Results: All 5 log TSH-free T4 models tested (separate lines, segmented conterminal line, quartic, error function, double-sigmoid curve) fitted significantly better than a simple linear model (each P < 0·01 by Vuong test). Ranking by Akaike information criterion indicated that the segmented conterminal line and double-sigmoid models provided best fit, followed by the error function, quartic and separate lines models. From multiple regression analysis, age tertile, current smoking and TPOAb status each significantly influenced the TSH-free T4 relationship, whereas BMI category and diabetes did not. A sex difference in the TSH-free T4 relationship was apparent only in the lower part of the free T4 reference range., Conclusion: In a community-based setting, the relationship between log TSH and free T4 is complex, nonlinear and influenced by age, smoking and TPOAb status., (© 2016 John Wiley & Sons Ltd.)

Because of advances in targeted therapies, the clinical evaluation of cutaneous melanoma is increasingly based on a combination of traditional histopathology and molecular pathology. Therefore, it is necessary to expand our knowledge of the molecular events that accompany the development and progression of melanoma to optimize clinical management. The central objective of this study was to increase our knowledge of the mutational events that complement melanoma progression. High-throughput genotyping was adapted to query 159 known single nucleotide mutations in 33 cancer-related genes across two melanoma cohorts from Ireland (n=94) and Belgium (n=60). Results were correlated with various clinicopathological characteristics. A total of 23 mutations in 12 genes were identified, that is--BRAF, NRAS, MET, PHLPP2, PIK3R1, IDH1, KIT, STK11, CTNNB1, JAK2, ALK, and GNAS. Unexpectedly, we discovered significant differences in BRAF, MET, and PIK3R1 mutations between the cohorts. That is, cases from Ireland showed significantly lower (P<0.001) BRAF(V600E) mutation rates (19%) compared with the mutation frequency observed in Belgian patients (43%). Moreover, MET mutations were detected in 12% of Irish cases, whereas none of the Belgian patients harbored these mutations, and Irish patients significantly more often (P=0.027) had PIK3R1-mutant (33%) melanoma versus 17% of Belgian cases. The low incidence of BRAF(V600E)(-) mutant melanoma among Irish patients was confirmed in five independent Irish cohorts, and in total, only 165 of 689 (24%) Irish cases carried mutant BRAF(V600E). Together, our data show that melanoma-driving mutations vary by demographic area, which has important implications for the clinical management of this disease.

Introduction: Peroxiredoxin-1 (PRDX1) is a multifunctional protein, acting as a hydrogen peroxide (H2O2) scavenger, molecular chaperone and immune modulator. Although differential PRDX1 expression has been described in many tumors, the potential role of PRDX1 in breast cancer remains highly ambiguous. Using a comprehensive antibody-based proteomics approach, we interrogated PRDX1 protein as a putative biomarker in estrogen receptor (ER)-positive breast cancer., Methods: An anti-PRDX1 antibody was validated in breast cancer cell lines using immunoblotting, immunohistochemistry and reverse phase protein array (RPPA) technology. PRDX1 protein expression was evaluated in two independent breast cancer cohorts, represented on a screening RPPA (n = 712) and a validation tissue microarray (n = 498). In vitro assays were performed exploring the functional contribution of PRDX1, with oxidative stress conditions mimicked via treatment with H2O2, peroxynitrite, or adenanthin, a PRDX1/2 inhibitor., Results: In ER-positive cases, high PRDX1 protein expression is a biomarker of improved prognosis across both cohorts. In the validation cohort, high PRDX1 expression was an independent predictor of improved relapse-free survival (hazard ratio (HR) = 0.62, 95% confidence interval (CI) = 0.40 to 0.96, P = 0.032), breast cancer-specific survival (HR = 0.44, 95% CI = 0.24 to 0.79, P = 0.006) and overall survival (HR = 0.61, 95% CI = 0.44 to 0.85, P = 0.004). RPPA screening of cancer signaling proteins showed that ERα protein was upregulated in PRDX1 high tumors. Exogenous H2O2 treatment decreased ERα protein levels in ER-positive cells. PRDX1 knockdown further sensitized cells to H2O2- and peroxynitrite-mediated effects, whilst PRDX1 overexpression protected against this response. Inhibition of PRDX1/2 antioxidant activity with adenanthin dramatically reduced ERα levels in breast cancer cells., Conclusions: PRDX1 is shown to be an independent predictor of improved outcomes in ER-positive breast cancer. Through its antioxidant function, PRDX1 may prevent oxidative stress-mediated ERα loss, thereby potentially contributing to maintenance of an ER-positive phenotype in mammary tumors. These results for the first time imply a close connection between biological activity of PRDX1 and regulation of estrogen-mediated signaling in breast cancer.

Context: In cross-sectional studies, serum TSH concentrations increase with age. This has not been examined longitudinally, and it is uncertain whether the TSH increase reflects healthy aging or occult thyroid failure., Methods: We measured serum TSH, free T(4), thyroid peroxidase, and thyroglobulin antibodies in 1100 participants in the 1981 and 1994 Busselton Health Surveys and derived a reference group of 908 individuals without thyroid disease or thyroid antibodies. We examined changes in thyroid function longitudinally and, in 781 participants, explored associations with the CAPZB polymorphism rs10917469., Results: At 13 yr follow-up, mean serum TSH increased from 1.49 to 1.81 mU/liter, a change in mean TSH (ΔTSH) of 0.32 mU/liter [95% confidence interval (CI) 0.27, 0.38, P < 0.001], whereas mean free T(4) concentration was unchanged (16.6 vs. 16.6 pmol/liter, P = 0.7). The TSH increase was most marked in the elderly, such that gender-adjusted ΔTSH increased by 0.08 mU/liter (95% CI 0.04, 0.11) for each decade of baseline age. People with higher baseline TSH values had proportionally smaller increases in TSH, with each additional 1.0 mU/liter of baseline TSH associated with a 0.13 mU/liter decrease (age and gender adjusted) in ΔTSH (95% CI 0.09, 0.16). The ΔTSH did not differ significantly by CAPZB genotype., Conclusions: Aging is associated with increased serum TSH concentrations, with no change in free T(4) concentrations. The largest TSH increase is in people with the lowest TSH at baseline. This suggests that the TSH increase arises from age-related alteration in the TSH set point or reduced TSH bioactivity rather than occult thyroid disease.

Objective: Hypothyroidism and hyperthyroidism are each associated with anaemia, but relationships between thyroid function and erythrocyte indices in euthyroid subjects have not been examined. The aim of this study was to examine these relationships in a community-based cohort., Design, Subjects and Measurements: Linear regression models with free T4, free T3 and TSH as predictors of erythrocyte indices and serum iron parameters were fitted to data from a cohort of 1179 participants in the 1994 Busselton health study and a subset of 1011 euthyroid participants. All models were adjusted for age, age(2), sex and an age-sex interaction., Results: In the full cohort and euthyroid subset, there were significant, positive linear relationships between free T4 and each of haemoglobin, haematocrit and erythrocyte count (P < 0·01 for each), such that in euthyroid participants, each 1·0 pM increase in free T4 was associated with an increase in haemoglobin of 0·39 g/l. There were significant relationships between free T3 and each of haemoglobin, haematocrit and erythrocyte count (P < 0·001 for each), with the best model fits obtained using free T3(2), indicating curved relationships. TSH had a significant (P < 0·05) inverse relationship with serum iron and transferrin saturation in the full cohort and the euthyroid subset. Serum iron concentrations were lower in participants with subclinical hypothyroidism (n = 87) than euthyroid subjects [mean (SD) 15·9 (4·7) vs 18·4 (6·0) μM, P = 0·001]., Conclusion: In euthyroid subjects, small differences in thyroid function are associated with significant differences in erythrocyte indices., (© 2011 Blackwell Publishing Ltd.)

Objective: Overt or subclinical thyroid dysfunction is common within the community, yet the significance of subtle anomalies in thyroid function tests remains contentious. The aims of this study were to: (a) establish reference intervals for serum-free thyroxine (FT4), thyroid-stimulating hormone (TSH) and thyroid antibodies (antithyroperoxidase, TPOAb and antithyroglobulin, TgAb) in the Busselton community of south-western Western Australia; and (b) determine the prevalence of thyroid hormone anomalies in this community., Subjects and Design: In 1981, 2115 adults residing in Busselton participated in a cross-sectional health survey that involved blood collection and a questionnaire on lifestyle and general health history., Measurements: Serum samples were analysed for FT4, TSH, TPOAb and TgAb by immunochemiluminescent assays., Results: Based on standard statistical approaches and using guidelines recommended by the National Academy of Clinical Biochemistry (NACB), reference intervals were derived for each analyte: 9-23 pmol/l for FT4, 0.4-4.0 mIU/l (TSH), < 35 KIU/l (TPOAb) and < 55 KIU/l (TgAb). The prevalence of elevated thyroid antibodies was 12.4% among subjects without a history of thyroid disease and is more common in women than in men. Elevated thyroid antibody levels were observed at both extremes of TSH abnormality, but were more commonly increased when TSH levels were above 4.0 mIU/l (63% subjects) than for those with TSH levels 0.4-4.0 mIU/l (7.8% subjects)., Conclusions: This study establishes the prevalence of antibodies to thyroperoxidase and thyroglobulin in a community-based sample and reference intervals for free T4 and TSH. When the NACB decision limits are applied to older men or women, there is a markedly increased number with 'elevated' autoantibody levels compared to sex- and age-specific reference intervals.

The patent system has been seen as a critical factor driving innovation in clinical medicine, particularly in medical devices and diagnostic assays. The licence terms and business model proposed by Myriad Genetics Inc. for testing the hereditary breast cancer susceptibility genes BRCA1 and BRCA2 could stifle innovation (particularly if other companies adopt similar business models), and are likely to limit the ability to provide high quality public genetic testing services in Australia. Under the Myriad model, testing for the BRCA1 gene would be undertaken by an organisation removed from the integrated public healthcare system. Based on overseas experience, Australia can expect a 2-3-fold increase in the cost of this testing, which will provide only partial information on the hereditary breast cancer status of the patient. Commercial exploitation of gene patents needs to be regulated to balance the patent holders' right to profit from their inventions (necessary to drive further innovation) and the public policy objective of high quality, equitable healthcare.

This study investigated the transdermal uptake and subsequent tissue distribution of [(3)H]progesterone applied in a commercially available progesterone cream in a rat model. Concentrations of lipid- and water-soluble metabolites of [(3)H]progesterone were also measured in plasma, urine and selected tissues (uterus, liver, kidney, salivary gland) 3 h after its topical application. Female rats were ovariectomized and adrenalectomized to remove all endogenous progesterone, and 4 weeks later were anaesthetized and 150 mg Pro-Feme cream (containing progesterone 3.2% w/w and 200 microCi [(3)H]progesterone) was applied to the abdominal skin. Six arterial blood samples were then obtained from a carotid cannula over the following 3h, and urine and selected tissue samples were collected after the final blood sample. Plasma progesterone increased progressively until 90 min, then remained relatively stable. Plasma levels of [(3H)]progesterone were high by the 15-min sample and increased only slightly thereafter. Water-soluble metabolites were detectable in plasma at 15 min, whereas lipid-soluble metabolites became apparent only by 60 min then increased progressively to 180 min. The tissue:plasma concentration ratio for [(3)H]progesterone exceeded 1 in all tissues, most notably in uterus (8.4) and lung (9.6), whereas urinary [(3)H]progesterone levels were only half those in plasma. Concentrations of lipid- and water-soluble progesterone metabolites were most prevalent in liver and kidney, and both reached very high concentrations in urine. These results demonstrate that topically applied progesterone is rapidly absorbed transdermally and that its patterns of distribution and metabolism are comparable to those previously reported for intravascularly administered progesterone.

Granulosa cells can exhibit the properties of stem cells and tumour cells. Contact with neighbouring cells does not inhibit their replication in vivo and they can divide in vitro while embedded in agar and thus without anchorage on a substratum. By culturing granulosa cells without anchorage, those cells that do not require anchorage, and thus exhibit at least one property of stem cells, divide. The effects of insulin-like growth factors (IGFs) and insulin-like growth factor binding protein 1 (IGFBP-1) on the replication of such cells was investigated by isolating granulosa cells from follicles (3-5 mm diameter) from cyclic cows and culturing them in soft agar-methylcellulose solution. Cell division was measured as [3H]thymidine incorporation into DNA, total DNA, or as the amount of the nuclear La antigen. This antigen is involved in RNA synthesis and is expressed ubiquitously; here it was used to estimate the number of cells indirectly. Both IGF-I (100 ng ml-1) and IGF-II (100 ng ml-1) and their respective analogues, as well as insulin, all at the same concentration, significantly increased DNA synthesis as determined by [3H]thymidine incorporation (n = 5). An increase in the number of cells in the presence of IGF-I was also confirmed by DNA measurement (P < 0.05, n = 5) and by western immunoblotting analyses of La antigen (n = 3). IGFBP-1 significantly inhibited cell division stimulated by IGF-I (P < 0.001) and IGF-II (P < 0.001), but not that stimulated by the analogue, LR3IGF-I, which has low affinity for IGFBPs. Other factors also known to affect IGF synthesis or effectiveness (FSH, oestradiol, growth hormone) did not appear to influence division of granulosa cells when cultured under anchorage-independent conditions, while dibutyryl cAMP significantly inhibited cell division (P < 0.01, n = 5). In conclusion, IGFs have a role to play in stimulating division of stem-cell-like granulosa cells during follicular development and IGFBP-1 can specifically inhibit the mitogenic effects of IGFs.

We measured growth hormone (GH) concentrations in first morning urine samples in 110 prepubertal children to determine whether asthma therapies affected GH secretion. The children with asthma were assigned to two groups depending on their asthma treatments: 1) 16 children with a history of asthma, currently not on any treatment, and 2) asthmatics taking inhaled corticosteroids (n = 37), short-term oral corticosteroids (n = 15), or long-term non-corticosteroidal therapies (n = 19). Results obtained from these children were compared with a control group of healthy prepubertal children (n = 23) without previous or current symptoms of asthma. Five consecutive urine samples were collected from each child, and GH concentrations (corrected for urine creatinine) were determined by an enzyme immunoassay. The mean (+/- SD) urine GH concentration determined in the control group (23 healthy prepubertal children) was 15.6 +/- 8.7 ng/L (1.88 +/- 1.29 ng GH/mmol creatinine). The mean (+/- SD) urine GH concentrations in overnight samples were similar in untreated asthmatics (14.1 +/- 6.1 ng/L) and in the treatment groups (14.1 +/- 7.7 ng/L, inhaled corticosteroids; 16.5 +/- 11.7 ng/L, oral corticosteroids; 15.9 +/- 9.8 ng/L, long-term non-corticosteroidal therapies). Irrespective of the manner of expression of urine GH (ng/L) or after correction for urine creatinine concentration (ng GH/mmol), no significant differences were found in the GH excretion among any of the groups. In this study, the intra-individual coefficient of variation for urine GH, expressed as ng/L, ranged between 11 and 87% (median, 32%). When the urine GH was expressed as ng GH/mmol creatinine, the coefficient of variation ranged between 12 and 92% (median, 35%), accounting for approximately 60% of the inter-individual coefficient of variation (mean CV, 56%) and 47% when the urine GH is expressed as ng GH/mmol creatinine. We were unable to determine any short-term differences in urine GH excretion between non-asthmatic children and asthmatics treated with inhaled corticosteroids, oral corticosteroids, or bronchodilators. Our results suggest that there is not an adverse effect of current corticosteroid therapies for childhood asthma on GH secretion.

An association is described between women with lupus anticoagulant and abnormal prenatal serum screening results. Three cases of positive second-trimester serum screening for Down syndrome, with karyotypically normal fetuses, in women demonstrated to have lupus anticoagulant are presented. Serum screening positivity was principally due to a disproportionately elevated maternal serum human chorionic gonadotrophin (hCG) level. In each case, early, severe intrauterine growth restriction was documented, with only one fetus surviving the neonatal period. As maternal lupus anticoagulant may have a profoundly adverse effect on the course of pregnancy, we suggest that an elevated hCG level on prenatal screening prompt consideration of maternal lupus anticoagulant testing if ultrasonography demonstrates an otherwise normal singleton gestation and the fetal karyotype is normal.

Serum concentrations of insulin-like growth factor binding protein-1 (IGFBP-1) were measured in men and in non-pregnant and pregnant women. Peak serum IGFBP-1 levels occurred mid-gestation followed by a slight decline towards term. Women with gestational diabetes had higher serum IGFBP-1 concentrations than apparently healthy women at comparable gestation. Following administration of an oral glucose load, serum IGFBP-1 concentrations were decreased within 2 h in men and in pregnant women while IGF-I levels remained constant. These results suggested that IGFBP-1 regulates IGF-I activity in pregnancy in a similar manner to that in the non-pregnant state.

We undertook a prospective longitudinal study of thyroid function in 60 normal pregnant women and measured serum concentrations of T4, triiodothyronine (T3), T-uptake, thyroxine binding globulin (TBG), free thyroxine index (FTI), free T4, albumin and thyrotropin (TSH). From these data we established reference ranges for each of these analytes for each trimester and examined the inter-relationships between laboratory measurements of thyroid function tests. We observed significant increases in serum concentrations of thyrotropin and decreases in free T4, assays commonly used as first line investigations of thyroid activity during pregnancy. However, the 95th centile intervals for both analytes remained within the reference range for nonpregnant women.

Ethylene dimethane sulphonate (DS) administered to adult male rats in a single dose of 75 mg/kg body weight results in a rapid destruction of Leydig cells which, in turn, is associated with a marked decline in levels of serum testosterone. For 24-72 h after treatment with EDS (post-EDS) the Leydig cells undergo degenerative changes consisting of chromatin condensation and cytoplasmic vacuolation, and testicular macrophages progressively remove Leydig cells from the intertubular tissue by phagocytosis. This results in the total absence of Leydig cells on Days 7-14 and the absence of any detectable specific 125I-hCG binding to testis homogenates. Associated with the low levels of serum testosterone, levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in serum rise, LH to levels found in castrate rats. Morphometric and 125I-hCG binding studies indicate that a new generation of Leydig cells develop from Day 21 and reach control levels by Day 49. Morphologic observations suggest that the Leydig cells arise by differentiation from a pool of connective tissue cells that includes fibroblasts, lymphatic endothelial cells and pericytes. The new Leydig cells, which appear around Day 21 post-EDS, have the features of fetal Leydig cells. The latter appear to transform into Leydig cells typical of normal adult rats between 35-49 days post-EDS. The differentiation of new Leydig cells is associated with a reestablishment of normal levels of testosterone 21 days post-EDS. Serum LH and FSH return to normal at 28 days and 49 days respectively.

A single dose of EDS was given to mature male rats and interstitial fluid (IF) was collected to determine the potency of mitogenic and steroidogenic activities therein. The potency of the factor stimulating testosterone secretion in vitro by Percoll-purified Leydig cells was significantly elevated 2 weeks after EDS, whilst the potency of mitogenic activities (stimulation of DNA synthesis by BALB/c 3T3 cells) was not elevated until 4 weeks after EDS treatment. This study suggests that two separate factors, one with mitogenic and the other steroidogenic activity, may be involved in the response of Leydig cells after EDS administration. The mitogenic factor may play a role in Leydig cell regeneration whereas the testosterone-stimulating factor may be involved in testicular testosterone homeostasis.

Administration of ethane dimethane sulphonate (EDS) (75 mg/kg) to unilaterally cryptorchid rats, results in a rapid decline in serum testosterone levels and a marked reduction in hCG binding to homogenates of scrotal and cryptorchid testes, consistent with the destruction of Leydig cells within the testes as shown by morphological and morphometric analysis. Between 3 and 7 days after EDS, serum LH and FSH levels rise, LH to levels found in castrate rats. hCG binding begins to recover in scrotal testes, reaching 32% of control values 28 days after EDS. However, the recovery of hCG binding to cryptorchid testes is more rapid, reaching 51% of control levels by 21 days which coincides with the re-establishment of serum testosterone to normal levels. Since a different rate of recovery is observed for hCG binding to scrotal and cryptorchid testes, and both testes are exposed to the same circulating levels of LH and FSH, the likely stimulus for recovery of hCG binding and regeneration of Leydig cells is intratesticular in origin. This supports the concept that local factors, released following damage to the seminiferous epithelium by cryptorchidism, play a role in the differentiation and growth of Leydig cells within the testis.

The effects of a single injection of ethane dimethane sulphonate (EDS) on aspects of seminiferous tubule function were assessed over a period of 49 days. Ethane dimethane sulphonate, which is known to cause destruction of Leydig cells, reduced the levels of testosterone in both serum and testicular interstitial fluid for 21 days, after which recovery occurred. The low testosterone levels were associated with elevated serum levels of LH and FSH. Daily sperm production was decreased from 14 to 42 days post-EDS but returned to control levels at 49 days. The production of seminiferous tubule fluid, measured after unilateral efferent duct ligation, decreased significantly at 7 and 14 days but then recovered. The testicular content of androgen binding protein (ABP) was decreased from 14 to 28 days but returned to normal thereafter. These results demonstrate significant effects on seminiferous tubule function, which may be due to the decrease in testosterone or be associated with a direct effect of EDS.

Adult male rats given a single intraperitoneal injection of the Leydig cell cytotoxin ethane dimethane sulphonate (EDS) show a significant decrease in testosterone from 7 to 14 days, and elevation of serum FSH and LH levels commencing 7 days after treatment, returning to normal at 28 days for LH and 49 days for FSH. A significant rise in serum inhibin levels was seen at day 14 after EDS treatment with levels returning to normal at day 49. In a second series of experiments, silastic implants of testosterone, either 2.5 cm or 22.5 cm in length, were introduced subcutaneously into adult male rats which were treated with EDS 10 days later. Both doses of testosterone suppressed basal LH levels but did not significantly change FSH levels. The rise in FSH and LH levels seen in normal rats after EDS treatment did not occur in either group of testosterone-implanted rats. However, serum inhibin levels rose significantly in both groups after EDS treatment, suggesting that the rise in serum inhibin levels was not due to stimulation arising from the increase in FSH levels after EDS treatment. The data suggest that the rise in serum inhibin levels after EDS treatment is linked to destruction of the Leydig cells through mechanisms that require further investigation.