Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Sharon E. Johnatty is active.

Publication


Featured researches published by Sharon E. Johnatty.


JAMA | 2012

Association between BRCA1 and BRCA2 mutations and survival in women with invasive epithelial ovarian cancer

Kelly L. Bolton; Georgia Chenevix-Trench; Cindy Goh; Siegal Sadetzki; Susan J. Ramus; Beth Y. Karlan; Diether Lambrechts; Evelyn Despierre; Daniel Barrowdale; Lesley McGuffog; Sue Healey; Douglas F. Easton; Olga M. Sinilnikova; Javier Benitez; María J. García; Susan L. Neuhausen; Mitchell H. Gail; Patricia Hartge; Susan Peock; Debra Frost; D. Gareth Evans; Rosalind Eeles; Andrew K. Godwin; Mary B. Daly; Ava Kwong; Edmond S K Ma; Conxi Lázaro; Ignacio Blanco; Marco Montagna; Emma D'Andrea

CONTEXT Approximately 10% of women with invasive epithelial ovarian cancer (EOC) carry deleterious germline mutations in BRCA1 or BRCA2. A recent article suggested that BRCA2-related EOC was associated with an improved prognosis, but the effect of BRCA1 remains unclear. OBJECTIVE To characterize the survival of BRCA carriers with EOC compared with noncarriers and to determine whether BRCA1 and BRCA2 carriers show similar survival patterns. DESIGN, SETTING, AND PARTICIPANTS A pooled analysis of 26 observational studies on the survival of women with ovarian cancer, which included data from 1213 EOC cases with pathogenic germline mutations in BRCA1 (n = 909) or BRCA2 (n = 304) and from 2666 noncarriers recruited and followed up at variable times between 1987 and 2010 (the median year of diagnosis was 1998). MAIN OUTCOME MEASURE Five-year overall mortality. RESULTS The 5-year overall survival was 36% (95% CI, 34%-38%) for noncarriers, 44% (95% CI, 40%-48%) for BRCA1 carriers, and 52% (95% CI, 46%-58%) for BRCA2 carriers. After adjusting for study and year of diagnosis, BRCA1 and BRCA2 mutation carriers showed a more favorable survival than noncarriers (for BRCA1: hazard ratio [HR], 0.78; 95% CI, 0.68-0.89; P < .001; and for BRCA2: HR, 0.61; 95% CI, 0.50-0.76; P < .001). These survival differences remained after additional adjustment for stage, grade, histology, and age at diagnosis (for BRCA1: HR, 0.73; 95% CI, 0.64-0.84; P < .001; and for BRCA2: HR, 0.49; 95% CI, 0.39-0.61; P < .001). The BRCA1 HR estimate was significantly different from the HR estimated in the adjusted model (P for heterogeneity = .003). CONCLUSION Among patients with invasive EOC, having a germline mutation in BRCA1 or BRCA2 was associated with improved 5-year overall survival. BRCA2 carriers had the best prognosis.


Lancet Oncology | 2013

Hormone-receptor expression and ovarian cancer survival: an Ovarian Tumor Tissue Analysis consortium study

Weiva Sieh; Martin Köbel; Teri A. Longacre; David Bowtell; Anna deFazio; Marc T. Goodman; Estrid Høgdall; Suha Deen; Nicolas Wentzensen; Kirsten B. Moysich; James D. Brenton; Blaise Clarke; Usha Menon; C. Blake Gilks; Andre Kim; Jason Madore; Sian Fereday; Joshy George; Laura Galletta; Galina Lurie; Lynne R. Wilkens; Michael E. Carney; Pamela J. Thompson; Rayna K. Matsuno; Susanne K. Kjaer; Allan Jensen; Claus Høgdall; Kimberly R. Kalli; Brooke L. Fridley; Gary L. Keeney

BACKGROUND Few biomarkers of ovarian cancer prognosis have been established, partly because subtype-specific associations might be obscured in studies combining all histopathological subtypes. We examined whether tumour expression of the progesterone receptor (PR) and oestrogen receptor (ER) was associated with subtype-specific survival. METHODS 12 studies participating in the Ovarian Tumor Tissue Analysis consortium contributed tissue microarray sections and clinical data to our study. Participants included in our analysis had been diagnosed with invasive serous, mucinous, endometrioid, or clear-cell carcinomas of the ovary. For a patient to be eligible, tissue microarrays, clinical follow-up data, age at diagnosis, and tumour grade and stage had to be available. Clinical data were obtained from medical records, cancer registries, death certificates, pathology reports, and review of histological slides. PR and ER statuses were assessed by central immunohistochemistry analysis done by masked pathologists. PR and ER staining was defined as negative (<1% tumour cell nuclei), weak (1 to <50%), or strong (≥50%). Associations with disease-specific survival were assessed. FINDINGS 2933 women with invasive epithelial ovarian cancer were included: 1742 with high-grade serous carcinoma, 110 with low-grade serous carcinoma, 207 with mucinous carcinoma, 484 with endometrioid carcinoma, and 390 with clear-cell carcinoma. PR expression was associated with improved disease-specific survival in endometrioid carcinoma (log-rank p<0·0001) and high-grade serous carcinoma (log-rank p=0·0006), and ER expression was associated with improved disease-specific survival in endometrioid carcinoma (log-rank p<0·0001). We recorded no significant associations for mucinous, clear-cell, or low-grade serous carcinoma. Positive hormone-receptor expression (weak or strong staining for PR or ER, or both) was associated with significantly improved disease-specific survival in endometrioid carcinoma compared with negative hormone-receptor expression, independent of study site, age, stage, and grade (hazard ratio 0·33, 95% CI 0·21-0·51; p<0·0001). Strong PR expression was independently associated with improved disease-specific survival in high-grade serous carcinoma (0·71, 0·55-0·91; p=0·0080), but weak PR expression was not (1·02, 0·89-1·18; p=0·74). INTERPRETATION PR and ER are prognostic biomarkers for endometrioid and high-grade serous ovarian cancers. Clinical trials, stratified by subtype and biomarker status, are needed to establish whether hormone-receptor status predicts response to endocrine treatment, and whether it could guide personalised treatment for ovarian cancer. FUNDING Carraresi Foundation and others.


Clinical Cancer Research | 2008

ABCB1 (MDR 1) Polymorphisms and Progression-Free Survival among Women with Ovarian Cancer following Paclitaxel/Carboplatin Chemotherapy

Sharon E. Johnatty; Jonathan Beesley; James Paul; Sian Fereday; Amanda B. Spurdle; Penelope M. Webb; Karen Byth; Sharon Marsh; Howard L. McLeod; Paul Harnett; Robert Brown; Anna deFazio; Georgia Chenevix-Trench

Purpose: The human ABCB1 gene encodes P-glycoprotein, which transports a broad range of anticancer drugs, including paclitaxel. Although the functional consequences of ABCB1 polymorphisms have been the subject of numerous studies, few have assessed the association with clinical outcome. Experimental Design: We assessed the association between the 2677G>T/A, 3435C>T, and 1236C>T ABCB1 polymorphisms and progression-free and overall survival in 309 patients from the Australian Ovarian Cancer Study treated with paclitaxel/carboplatin and subsequently tested significant observations in an independent validation set. Results: Women who carried the minor T/A alleles at the 2677G>T/A polymorphism were significantly less likely to relapse following treatment compared with homozygote GG carriers (PLog-rank = 0.001) in the Australian Ovarian Cancer Study cohort. Subgroup analyses showed that this effect was limited to cases with residual disease ≤1 cm (PLog-rank = 0.0004), not for those with residual disease >1 cm (PLog-rank = 0.3). This effect was not confirmed in an independent validation set of carboplatin/paclitaxel-treated patients (n = 278) using a higher residual disease cut point (≤2 cm). However, analysis of the unrestricted data set expanded to include docetaxel-treated patients (n = 914) did support an effect of the 2677T/A allele in patients with no macroscopic residual disease (hazard ratio, 0.70; 95% confidence interval, 0.46-1.04; Pone-sided = 0.039). Conclusion: Our findings indicate that there is an effect of the 2677G>T/A polymorphism on progression-free survival in ovarian cancer patients who are treated with a taxane/carboplatin, which is dependent on the extent of residual disease, with a better prognosis for patients with the 2677T/A allele and minimal residual disease.


International Journal of Cancer | 2008

Consortium analysis of 7 candidate SNPs for ovarian cancer.

Susan J. Ramus; Robert A. Vierkant; Sharon E. Johnatty; Malcolm C. Pike; David Van Den Berg; Anna H. Wu; Celeste Leigh Pearce; Usha Menon; Aleksandra Gentry-Maharaj; Simon A. Gayther; Richard A. DiCioccio; Valerie McGuire; Alice S. Whittemore; Honglin Song; Douglas F. Easton; Paul Pharoah; Montserrat Garcia-Closas; Stephen J. Chanock; Jolanta Lissowska; Louise A. Brinton; Kathryn L. Terry; Daniel W. Cramer; Shelley S. Tworoger; Susan E. Hankinson; Andrew Berchuck; Patricia G. Moorman; Joellen M. Schildkraut; Julie M. Cunningham; Mark Liebow; Susanne K. Kjaer

The Ovarian Cancer Association Consortium selected 7 candidate single nucleotide polymorphisms (SNPs), for which there is evidence from previous studies of an association with variation in ovarian cancer or breast cancer risks. The SNPs selected for analysis were F31I (rs2273535) in AURKA, N372H (rs144848) in BRCA2, rs2854344 in intron 17 of RB1, rs2811712 5′ flanking CDKN2A, rs523349 in the 3′ UTR of SRD5A2, D302H (rs1045485) in CASP8 and L10P (rs1982073) in TGFB1. Fourteen studies genotyped 4,624 invasive epithelial ovarian cancer cases and 8,113 controls of white non‐Hispanic origin. A marginally significant association was found for RB1 when all studies were included [ordinal odds ratio (OR) 0.88 (95% confidence interval (CI) 0.79–1.00) p = 0.041 and dominant OR 0.87 (95% CI 0.76–0.98) p = 0.025]; when the studies that originally suggested an association were excluded, the result was suggestive although no longer statistically significant (ordinal OR 0.92, 95% CI 0.79–1.06). This SNP has also been shown to have an association with decreased risk in breast cancer. There was a suggestion of an association for AURKA, when one study that caused significant study heterogeneity was excluded [ordinal OR 1.10 (95% CI 1.01–1.20) p = 0.027; dominant OR 1.12 (95% CI 1.01–1.24) p = 0.03]. The other 5 SNPs in BRCA2, CDKN2A, SRD5A2, CASP8 and TGFB1 showed no association with ovarian cancer risk; given the large sample size, these results can also be considered to be informative. These null results for SNPs identified from relatively large initial studies shows the importance of replicating associations by a consortium approach.


PLOS Genetics | 2010

Evaluation of candidate stromal epithelial cross-talk genes identifies association between risk of serous ovarian cancer and TERT, a cancer susceptibility "Hot-Spot"

Sharon E. Johnatty; Jonathan Beesley; Xiaoqing Chen; Stuart Macgregor; David L. Duffy; Amanda B. Spurdle; Anna deFazio; Natalie Gava; Penelope M. Webb; Australian Cancer Study; Mary Anne Rossing; Jennifer A. Doherty; Mt Goodman; Galina Lurie; Pamela J. Thompson; Lynne R. Wilkens; Roberta B. Ness; Kirsten B. Moysich; Jenny Chang-Claude; Shan Wang-Gohrke; Daniel W. Cramer; Kathryn L. Terry; Susan E. Hankinson; Shelley S. Tworoger; Montserrat Garcia-Closas; Hannah P. Yang; Jolanta Lissowska; Stephen J. Chanock; Paul Pharoah; Honglin Song

We hypothesized that variants in genes expressed as a consequence of interactions between ovarian cancer cells and the host micro-environment could contribute to cancer susceptibility. We therefore used a two-stage approach to evaluate common single nucleotide polymorphisms (SNPs) in 173 genes involved in stromal epithelial interactions in the Ovarian Cancer Association Consortium (OCAC). In the discovery stage, cases with epithelial ovarian cancer (n = 675) and controls (n = 1,162) were genotyped at 1,536 SNPs using an Illumina GoldenGate assay. Based on Positive Predictive Value estimates, three SNPs—PODXL rs1013368, ITGA6 rs13027811, and MMP3 rs522616—were selected for replication using TaqMan genotyping in up to 3,059 serous invasive cases and 8,905 controls from 16 OCAC case-control studies. An additional 18 SNPs with P per-allele<0.05 in the discovery stage were selected for replication in a subset of five OCAC studies (n = 1,233 serous invasive cases; n = 3,364 controls). The discovery stage associations in PODXL, ITGA6, and MMP3 were attenuated in the larger replication set (adj. P per-allele≥0.5). However genotypes at TERT rs7726159 were associated with ovarian cancer risk in the smaller, five-study replication study (P per-allele = 0.03). Combined analysis of the discovery and replication sets for this TERT SNP showed an increased risk of serous ovarian cancer among non-Hispanic whites [adj. ORper-allele 1.14 (1.04–1.24) p = 0.003]. Our study adds to the growing evidence that, like the 8q24 locus, the telomerase reverse transcriptase locus at 5p15.33, is a general cancer susceptibility locus.


PLOS ONE | 2011

Functional Polymorphisms in the TERT Promoter Are Associated with Risk of Serous Epithelial Ovarian and Breast Cancers

Jonathan Beesley; Hilda A. Pickett; Sharon E. Johnatty; Alison M. Dunning; Xiaoqing Chen; Jun Li; Kyriaki Michailidou; Yi Lu; David N. Rider; Rachel T. Palmieri; Michael D. Stutz; Diether Lambrechts; Evelyn Despierre; Sandrina Lambrechts; Ignace Vergote; Jenny Chang-Claude; Stefan Nickels; Alina Vrieling; Dieter Flesch-Janys; Shan Wang-Gohrke; Ursula Eilber; Natalia Bogdanova; Natalia Antonenkova; Ingo B. Runnebaum; Thilo Dörk; Marc T. Goodman; Galina Lurie; Lynne R. Wilkens; Rayna K. Matsuno; Lambertus A. Kiemeney

Genetic variation at the TERT-CLPTM1L locus at 5p15.33 is associated with susceptibility to several cancers, including epithelial ovarian cancer (EOC). We have carried out fine-mapping of this region in EOC which implicates an association with a single nucleotide polymorphism (SNP) within the TERT promoter. We demonstrate that the minor alleles at rs2736109, and at an additional TERT promoter SNP, rs2736108, are associated with decreased breast cancer risk, and that the combination of both SNPs substantially reduces TERT promoter activity.


Cancer Epidemiology, Biomarkers & Prevention | 2011

Assessment of Hepatocyte Growth Factor in Ovarian Cancer Mortality

Ellen L. Goode; Georgia Chenevix-Trench; Lynn C. Hartmann; Brooke L. Fridley; Kimberly R. Kalli; Robert A. Vierkant; Melissa C. Larson; Kristin L. White; Gary L. Keeney; Trynda N. Oberg; Julie M. Cunningham; Jonathan Beesley; Sharon E. Johnatty; Xiaoqing Chen; Katelyn E. Goodman; Sebastian M. Armasu; David N. Rider; Hugues Sicotte; Michele Schmidt; Elaine A. Elliott; Estrid Høgdall; Susanne K. Kjaer; Peter A. Fasching; Arif B. Ekici; Diether Lambrechts; Evelyn Despierre; Claus Høgdall; Lene Lundvall; Beth Y. Karlan; Jenny Gross

Background: Invasive ovarian cancer is a significant cause of gynecologic cancer mortality. Methods: We examined whether this mortality was associated with inherited variation in approximately 170 candidate genes/regions [993 single-nucleotide polymorphisms (SNPs)] in a multistage analysis based initially on 312 Mayo Clinic cases (172 deaths). Additional analyses used The Cancer Genome Atlas (TCGA; 127 cases, 62 deaths). For the most compelling gene, we immunostained Mayo Clinic tissue microarrays (TMA, 326 cases) and conducted consortium-based SNP replication analysis (2,560 cases, 1,046 deaths). Results: The strongest initial mortality association was in HGF (hepatocyte growth factor) at rs1800793 (HR = 1.7, 95% CI = 1.3–2.2, P = 2.0 × 10−5) and with overall variation in HGF (gene-level test, P = 3.7 × 10−4). Analysis of TCGA data revealed consistent associations [e.g., rs5745709 (r2 = 0.96 with rs1800793): TCGA HR = 2.4, CI = 1.4–4.1, P = 2.2 × 10−3; Mayo Clinic + TCGA HR = 1.6, CI = 1.3–1.9, P = 7.0 × 10−5] and suggested genotype correlation with reduced HGF mRNA levels (P = 0.01). In Mayo Clinic TMAs, protein levels of HGF, its receptor MET (C-MET), and phospho-MET were not associated with genotype and did not serve as an intermediate phenotype; however, phospho-MET was associated with reduced mortality (P = 0.01) likely due to higher expression in early-stage disease. In eight additional ovarian cancer case series, HGF rs5745709 was not associated with mortality (HR = 1.0, CI = 0.9–1.1, P = 0.87). Conclusions: We conclude that although HGF signaling is critical to migration, invasion, and apoptosis, it is unlikely that HGF genetic variation plays a major role in ovarian cancer mortality. Furthermore, any minor role is not related to genetically-determined expression. Impact: Our study shows the utility of multiple data types and multiple data sets in observational studies. Cancer Epidemiol Biomarkers Prev; 20(8); 1638–48. ©2011 AACR.


JAMA Oncology | 2017

Dose-Response Association of CD8+ Tumor-Infiltrating Lymphocytes and Survival Time in High-Grade Serous Ovarian Cancer.

Ellen L. Goode; Matthew S. Block; Kimberly R. Kalli; Robert A. Vierkant; Wenqian Chen; Zachary C. Fogarty; Aleksandra Gentry-Maharaj; Aleksandra Tołoczko; Alexander Hein; Aliecia L. Bouligny; Allan Jensen; Ana Osorio; Andreas D. Hartkopf; Andy Ryan; Anita Chudecka-Głaz; Anthony M. Magliocco; Arndt Hartmann; Audrey Y. Jung; Bo Gao; Brenda Y. Hernandez; Brooke L. Fridley; Bryan M. McCauley; Catherine J. Kennedy; Chen Wang; Chloe Karpinskyj; Christiani Bisinoto de Sousa; Daniel Guimarães Tiezzi; David L. Wachter; Esther Herpel; Florin Andrei Taran

Importance Cytotoxic CD8+ tumor-infiltrating lymphocytes (TILs) participate in immune control of epithelial ovarian cancer; however, little is known about prognostic patterns of CD8+ TILs by histotype and in relation to other clinical factors. Objective To define the prognostic role of CD8+ TILs in epithelial ovarian cancer. Design, Setting, and Participants This was a multicenter observational, prospective survival cohort study of the Ovarian Tumor Tissue Analysis Consortium. More than 5500 patients, including 3196 with high-grade serous ovarian carcinomas (HGSOCs), were followed prospectively for over 24 650 person-years. Exposures Following immunohistochemical analysis, CD8+ TILs were identified within the epithelial components of tumor islets. Patients were grouped based on the estimated number of CD8+ TILs per high-powered field: negative (none), low (1-2), moderate (3-19), and high (≥20). CD8+ TILs in a subset of patients were also assessed in a quantitative, uncategorized manner, and the functional form of associations with survival was assessed using penalized B-splines. Main Outcomes and Measures Overall survival time. Results The final sample included 5577 women; mean age at diagnosis was 58.4 years (median, 58.2 years). Among the 5 major invasive histotypes, HGSOCs showed the most infiltration. CD8+ TILs in HGSOCs were significantly associated with longer overall survival; median survival was 2.8 years for patients with no CD8+ TILs and 3.0 years, 3.8 years, and 5.1 years for patients with low, moderate, or high levels of CD8+ TILs, respectively (P value for trend = 4.2 × 10−16). A survival benefit was also observed among women with endometrioid and mucinous carcinomas, but not for those with the other histotypes. Among HGSOCs, CD8+ TILs were favorable regardless of extent of residual disease following cytoreduction, known standard treatment, and germline BRCA1 pathogenic mutation, but were not prognostic for BRCA2 mutation carriers. Evaluation of uncategorized CD8+ TIL counts showed a near-log-linear functional form. Conclusions and Relevance This study demonstrates the histotype-specific nature of immune infiltration and provides definitive evidence for a dose-response relationship between CD8+ TILs and HGSOC survival. That the extent of infiltration is prognostic, not merely its presence or absence, suggests that understanding factors that drive infiltration will be the key to unraveling outcome heterogeneity in this cancer.


Cancer Epidemiology, Biomarkers & Prevention | 2013

Analysis of Over 10,000 Cases Finds No Association between Previously Reported Candidate Polymorphisms and Ovarian Cancer Outcome

Kristin L. White; Robert A. Vierkant; Zachary C. Fogarty; Bridget Charbonneau; Matthew S. Block; Paul Pharoah; Georgia Chenevix-Trench; Mary Anne Rossing; Daniel W. Cramer; Celeste Leigh Pearce; Joellen M. Schildkraut; Usha Menon; Susanne K. Kjaer; Douglas A. Levine; Jacek Gronwald; Hoda Anton Culver; Alice S. Whittemore; Beth Y. Karlan; Diether Lambrechts; Nicolas Wentzensen; Jolanta Kupryjanczyk; Jenny Chang-Claude; Elisa V. Bandera; Estrid Høgdall; Florian Heitz; Stanley B. Kaye; Peter A. Fasching; Ian G. Campbell; Marc T. Goodman; Tanja Pejovic

Background: Ovarian cancer is a leading cause of cancer-related death among women. In an effort to understand contributors to disease outcome, we evaluated single-nucleotide polymorphisms (SNP) previously associated with ovarian cancer recurrence or survival, specifically in angiogenesis, inflammation, mitosis, and drug disposition genes. Methods: Twenty-seven SNPs in VHL, HGF, IL18, PRKACB, ABCB1, CYP2C8, ERCC2, and ERCC1 previously associated with ovarian cancer outcome were genotyped in 10,084 invasive cases from 28 studies from the Ovarian Cancer Association Consortium with over 37,000-observed person-years and 4,478 deaths. Cox proportional hazards models were used to examine the association between candidate SNPs and ovarian cancer recurrence or survival with and without adjustment for key covariates. Results: We observed no association between genotype and ovarian cancer recurrence or survival for any of the SNPs examined. Conclusions: These results refute prior associations between these SNPs and ovarian cancer outcome and underscore the importance of maximally powered genetic association studies. Impact: These variants should not be used in prognostic models. Alternate approaches to uncovering inherited prognostic factors, if they exist, are needed. Cancer Epidemiol Biomarkers Prev; 22(5); 987–. ©2013 AACR.


Breast Cancer Research and Treatment | 2011

No evidence for an association between the earwax-associated polymorphism in ABCC11 and breast cancer risk in Caucasian women

Jonathan Beesley; Sharon E. Johnatty; Xiaoqing Chen; Amanda B. Spurdle; Paolo Peterlongo; Monica Barile; Valeria Pensotti; Siranoush Manoukian; Paolo Radice; Georgia Chenevix-Trench

ABCC11 is an ATP-binding cassette transporter responsible for the transport of a diverse range of lipophilic compounds. A single nucleotide polymorphism (SNP) encoding an amino acid change has recently been shown to determine whether cerumen (earwax) is wet or dry. We hypothesised that this ABCC11 SNP may be associated with breast cancer risk because an association has been reported between wet earwax and increased risk of breast cancer. We therefore analysed the frequency of the functional SNP in 1342 cases and 2256 controls from two breast cancer studies of Caucasian women but found no evidence for an association with breast cancer risk.

Collaboration


Dive into the Sharon E. Johnatty's collaboration.

Top Co-Authors

Avatar

Jonathan Beesley

QIMR Berghofer Medical Research Institute

View shared research outputs
Top Co-Authors

Avatar

Georgia Chenevix-Trench

QIMR Berghofer Medical Research Institute

View shared research outputs
Top Co-Authors

Avatar

Xiaoqing Chen

QIMR Berghofer Medical Research Institute

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Yi Lu

QIMR Berghofer Medical Research Institute

View shared research outputs
Top Co-Authors

Avatar

Bo Gao

University of Sydney

View shared research outputs
Top Co-Authors

Avatar

Diether Lambrechts

Katholieke Universiteit Leuven

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Amanda B. Spurdle

QIMR Berghofer Medical Research Institute

View shared research outputs
Top Co-Authors

Avatar

Penelope M. Webb

QIMR Berghofer Medical Research Institute

View shared research outputs
Researchain Logo
Decentralizing Knowledge