Georgios Giamas

Dr. Georgios Giamas

University of Sussex, Brighton, Brighton and Hove, UK
orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 September 2009 in Proceedings of the National Academy of Sciences
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Journal Article
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Leandro CastellanoLeandro Castellano
Leandro Castellano
Georgios GiamasGeorgios Giamas
Georgios Giamas
JJJimmy Jacob
Jimmy Jacob
RCR. Charles Coombes
R. Charles Coombes
WLWalter Lucchesi
Walter Lucchesi
JSJustin Stebbing
Justin Stebbing
Following estrogenic activation, the estrogen receptor-α (ERα) directly regulates the transcription of target genes via DNA binding. MicroRNAs (miRNAs) modulated by ERα have the potential to fine tune these regulatory systems and also provide an alternate mechanism that could impact on estrogen-dependent developmental and pathological systems. Through a microarray approach, we identify the subset of microRNAs (miRNAs) modulated by ERα, which include upregulation of miRNAs derived from the processing of the paralogous primary transcripts (pri-) mir-17–92 and mir-106a-363. Characterization of the mir-17–92 locus confirms that the ERα target protein c-MYC binds its promoter in an estrogen-dependent manner. We observe that levels of pri-mir-17–92 increase earlier than the mature miRNAs derived from it, implicating precursor cleavage modulation after transcription. Pri-mir-17–92 is immediately cleaved by DROSHA to pre-miR-18a, indicating that its regulation occurs during the formation of the mature molecule from the precursor. The clinical implications of this novel regulatory system were confirmed by demonstrating that pre-miR-18a was significantly upregulated in ERα-positive compared to ERα-negative breast cancers. Mechanistically, miRNAs derived from these paralogous pri-miRNAs (miR-18a, miR-19b, and miR-20b) target and downregulate ERα, while a subset of pri-miRNA-derived miRNAs inhibit protein translation of the ERα transcriptional p160 coactivator, AIB1. Therefore, different subsets of miRNAs identified act as part of a negative autoregulatory feedback loop. We propose that ERα, c-MYC, and miRNA transcriptional programs invoke a sophisticated network of interactions able to provide the wide range of coordinated cellular responses to estrogen.

1 October 2018 in Advances in Methods and Practices in Psychological Science
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Journal Article
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HMHannah Moshontz
Hannah Moshontz
LCLorne Campbell
Lorne Campbell
CECharles R. Ebersole
Charles R. Ebersole
HIHans Ijzerman
Hans Ijzerman
HUHeather L. Urry
Heather L. Urry
CCChristopher R. Chartier
Christopher R. Chartier
Concerns about the veracity of psychological research have been growing. Many findings in psychological science are based on studies with insufficient statistical power and nonrepresentative samples, or may otherwise be limited to specific, ungeneralizable settings or populations. Crowdsourced research, a type of large-scale collaboration in which one or more research projects are conducted across multiple lab sites, offers a pragmatic solution to these and other current methodological challenges. The Psychological Science Accelerator (PSA) is a distributed network of laboratories designed to enable and support crowdsourced research projects. These projects can focus on novel research questions or replicate prior research in large, diverse samples. The PSA’s mission is to accelerate the accumulation of reliable and generalizable evidence in psychological science. Here, we describe the background, structure, principles, procedures, benefits, and challenges of the PSA. In contrast to other crowdsourced research networks, the PSA is ongoing (as opposed to time limited), efficient (in that structures and principles are reused for different projects), decentralized, diverse (in both subjects and researchers), and inclusive (of proposals, contributions, and other relevant input from anyone inside or outside the network). The PSA and other approaches to crowdsourced psychological science will advance understanding of mental processes and behaviors by enabling rigorous research and systematic examination of its generalizability.

31 May 2008 in Advances in Health Sciences Education
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CHCraig Hassed
Craig Hassed
SLSteven de Lisle
Steven de Lisle
GSGavin Sullivan
Gavin Sullivan
CPCiaran Pier
Ciaran Pier

21 September 2018 in Glia
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Journal Article
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MBMayra Brandao
Mayra Brandao
TSThomas Simon
Thomas Simon
GCGiles Critchley
Giles Critchley
Georgios GiamasGeorgios Giamas
Georgios Giamas

24 May 2019 in Frontiers in Endocrinology
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Journal Article
Open access
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ARAradhana Rani
Aradhana Rani
JSJustin Stebbing
Justin Stebbing
Georgios GiamasGeorgios Giamas
Georgios Giamas
JMJohn Murphy
John Murphy
The importance and role of the estrogen receptor (ER) pathway has been well-documented in both breast cancer (BC) development and progression. The treatment of choice in women with metastatic breast cancer (MBC) is classically divided into a variety of endocrine therapies, 3 of the most common being: selective estrogen receptor modulators (SERM), aromatase inhibitors (AI) and selective estrogen receptor down-regulators (SERD). In a proportion of patients, resistance develops to endocrine therapy due to a sophisticated and at times redundant interference, at the molecular level between the ER and growth factor. The progression to endocrine resistance is considered to be a gradual, step-wise process. Several mechanisms have been proposed but thus far none of them can be defined as the complete explanation behind the phenomenon of endocrine resistance. Although multiple cellular, molecular and immune mechanisms have been and are being extensively studied, their individual roles are often poorly understood. In this review, we summarize current progress in our understanding of ER biology and the molecular mechanisms that predispose and determine endocrine resistance in breast cancer patients.

4 March 2016 in Science
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Journal Article
Closed access
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CAChristopher J. Anderson
Christopher J. Anderson
ŠBŠtěpán Bahník
Štěpán Bahník
MBMichael Barnett-Cowan
Michael Barnett-Cowan
FBFrank A. Bosco
Frank A. Bosco
JCJesse Chandler
Jesse Chandler
KZKellylynn Zuni
Kellylynn Zuni
Gilbert et al . conclude that evidence from the Open Science Collaboration’s Reproducibility Project: Psychology indicates high reproducibility, given the study methodology. Their very optimistic assessment is limited by statistical misconceptions and by causal inferences from selectively interpreted, correlational data. Using the Reproducibility Project: Psychology data, both optimistic and pessimistic conclusions about reproducibility are possible, and neither are yet warranted.