Are enrollment sites the key to optimizing participation in genetic studies?Helgesson, Gert
doi: 10.1186/gm257pmid: 21722348
In a time when the challenge of people being over-researched and experiencing research fatigue is increasingly discussed, low participation rates and potential sample biases are a growing concern in genetic research. In a recent study assessing factors relevant to successful recruitment of patients with myocardial infarction to a genetic study, enrollment site was identified as the most important factor associated with patient participation, whereas patient-level factors such as race, gender and education played a limited or no role. These results underline the importance of appropriate recruitment routines at enrollment sites in order to reach high levels of participation in genetic research.
microRNAs become macro players in somatic cell reprogrammingOnder, Tamer; Daley, George
doi: 10.1186/gm256pmid: 21699744
Embryonic stem cell specific microRNAs (miRNAs) have previously been shown to enhance the efficiency of transcription-factor-based reprogramming. However, whether reprogramming could be achieved entirely by miRNAs remained unclear. A recent report shows that the expression of the miR-302/367 cluster of miRNAs can directly reprogram somatic cells without the use of any transcription factors. This new method raises interesting questions about the mechanisms of reprogramming and is likely to facilitate the generation of induced pluripotent stem cells for potential future clinical use.
Epigenomics of human embryonic stem cells and induced pluripotent stem cells: insights into pluripotency and implications for diseaseRada-Iglesias, Alvaro; Wysocka, Joanna
doi: 10.1186/gm252pmid: 21658297
Human pluripotent cells such as human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) and their in vitro differentiation models hold great promise for regenerative medicine as they provide both a model for investigating mechanisms underlying human development and disease and a potential source of replacement cells in cellular transplantation approaches. The remarkable developmental plasticity of pluripotent cells is reflected in their unique chromatin marking and organization patterns, or epigenomes. Pluripotent cell epigenomes must organize genetic information in a way that is compatible with both the maintenance of self-renewal programs and the retention of multilineage differentiation potential. In this review, we give a brief overview of the recent technological advances in genomics that are allowing scientists to characterize and compare epigenomes of different cell types at an unprecedented scale and resolution. We then discuss how utilizing these technologies for studies of hESCs has demonstrated that certain chromatin features, including bivalent promoters, poised enhancers, and unique DNA modification patterns, are particularly pervasive in hESCs compared with differentiated cell types. We outline these unique characteristics and discuss the extent to which they are recapitulated in iPSCs. Finally, we envision broad applications of epigenomics in characterizing the quality and differentiation potential of individual pluripotent lines, and we discuss how epigenomic profiling of regulatory elements in hESCs, iPSCs and their derivatives can improve our understanding of complex human diseases and their underlying genetic variants.