ABSTRACT
OBJECTIVE@#To explore the role of small nuclear noncoding RNA 7SK in embryonic stem cell (ESCs) proliferation and the value of 7SK as a target for early diagnosis and treatment for primordial dwarfism (PD).@*METHODS@#ESC line R1 was transfected with the CRISPR/Cas9 system, and sequencing of the PCR product and glycerol gradient analysis were performed to identify novel 7SK deletion mutations. A lentivirus system was used to knock down cyclin-dependent kinase 9 (CDK9) in clones with 7SK deletion mutations, and the effect of CDK9 knockdown on the protein level of cell division cycle 6 (CDC6) was analyzed with Western blotting.@*RESULTS@#We identified a novel deletion mutation of 7SK at 128-179 nt in the ESCs, which resulted in deficiency of cell proliferation. 7SK truncation at 128-179 nt significantly reduced the protein expressions of La-related protein 7 (LARP7) and CDC6.@*CONCLUSIONS@#7SK truncation at 128-179 nt can significantly impair proliferation of ESCs by downregulating CDC6. 7SK is a key regulator of proliferation and mediates the growth of ESCs through a mechanism dependent on CDK9 activity, suggesting the value of 7SK truncation at 128-179 nt as a potential target for early diagnosis and treatment of PD.
Subject(s)
Humans , Cell Cycle Proteins , Cell Proliferation , Embryonic Stem Cells/metabolism , HeLa Cells , Nuclear Proteins , Positive Transcriptional Elongation Factor B/metabolism , RNA, Long Noncoding/genetics , RNA-Binding Proteins , Ribonucleoproteins , Transcription FactorsABSTRACT
Several comparative studies on anti-implantation and estrogenicities of noret histerone oxime(NETO)and norethisterone(NET) or ethynyl estradiol (EE2)were carried out in order to clarify their relationships. It was observed that NETO was showed much stronger potency than NET, which the anti-implantation, uterotrophic and vaginal cornifi-cation effect were 25, 26, and 21 times, respectively. The ratio of anti-implantation to vaginal cornification of NETO was 14-fold stronger than that of EE2. These results suggest that the increased antiimplantative activity of NETO is related to its stronger estrogenic activity, but other mechanisms contribute to the anti-implantation besides estragenicity.