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Báo cáo khoa hoc:" Human haematopoietic stem cells express Oct4 pseudogenes and lack the ability to initiate Oct4 promoter-driven gene expression"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Human haematopoietic stem cells express Oct4 pseudogenes and lack the ability to initiate Oct4 promoter-driven gene expression | Redshaw and Strain Journal of Negative Results in BioMedicine 2010 9 2 http www.jnrbm.eom content 9 1 2 r M 1 JOURNAL OF NEGATIVE RESULTS IN BIOMEDICINE RESEARCH Open Access Human haematopoietic stem cells express Oct4 pseudogenes and lack the ability to initiate Oct4 promoter-driven gene expression Zoe Redshaw1 Alastair J Strain2 Abstract The transcription factor Oct4 is well defined as a key regulator of embryonic stem ES cell pluripotency. In recent years the role of Oct4 has purportedly extended to the self renewal and maintenance of multipotency in adult stem cell ASC populations. This profile has arisen mainly from reports utilising reverse transcription-polymerase chain reaction RT-PCR based methodologies and has since come under scrutiny following the discovery that many developmental genes have multiple pseudogenes associated with them. Six known pseudogenes exist for Oct4 all of which exhibit very high sequence homology three 97 and for this reason the generation of artefacts may have contributed to false identification of Oct4 in somatic cell populations. While ASC lack a molecular blueprint of transcription factors proposed to be involved with stemness as described for ES cells it is not unreasonable to assume that similar gene patterns may exist. The focus of this work was to corroborate reports that Oct4 is involved in the regulation of ASC self-renewal and differentiation using a combination of methodologies to rule out pseudogene interference. Haematopoietic stem cells HSC derived from human umbilical cord blood UCB and various differentiated cell lines underwent RT-PCR product sequencing and transfection studies using an Oct4 promoter-driven reporter. In summary only the positive control expressed Oct4 with all other cell types expressing a variety of Oct4 pseudogenes. Somatic cells were incapable of utilising an exogenous Oct4 promoter construct leading to the conclusion that Oct4 does not appear involved in the multipotency of human HSC from UCB.