ABSTRACT
Objective:To investigate the effects of circ_000543 derived from hypoxic exosomes on proliferation and invasion of breast cancer (BC) cells.Methods:Bioinformatic website was used to predict the abnormal expression of circ_000543 in BC tissue and the transcription factor that might regulate circ_000543. Double luciferase report experiment and ChIP assay were used to confirm the regulation relationship between YY1 and circ_000543. Exosomes were separated from normal BC cells and BC cells under hypoxic condition, and qRT-PCR was adopted to detect the expression of circ_000543 in exosomes. The expression of circ_000543 and YY1 in exosomes was intervened and the exosomes were cocultured with BC cells under normoxia. CCK8 and Transwell assay was used to detect the proliferation and invasive ability individually.Results:qRT-PCR experiment found that, compared with MCF-10A cells (1±0.11) and exosomes isolated from normoxic cells (1±0.10), circ_000543 expression was up-regulated in BC cells (1.59±0.13) and exosomes derived from cells under hypoxic condition (1.63±0.12) ( t=6.001, P=0.004; t=6.986, P=0.002). Exosomes derived from cells under hypoxic condition promoted proliferation and invasion of BC cells under normoxia. Inhibition of circ_000543 partially offset the effects of exosomes. YY1 induced the expression of circ_000543 in BC cells as a transcription factor. The expression of circ_000543 was inhibited when YY1 expression was down-regulated; at the same time, down-regulation of YY1 inhibited the effects of exosomes on proliferation and invasion of BC cells. Conclusion:The transcription factor YY1 promoted proliferation and invasion of BC cells by inducing hypoxic breast cancer-derived exosomal circ_000543.
ABSTRACT
BACKGROUND:YY1 is mainly expressed in the undifferentiated epidermic cells in mouse basal lamina, and the expression level is gradual y down-regulated as the differentiation towards suprabasal lamina. The differential expression indicates that, YY1 is one of the regulators in the process of epidermic cells differentiation. OBJECTIVE:To observe the effects of YY1 over-expression on the differentiation of HaCaT cells infected with lentivirus. METHODS:Lentivirus-YY1 was transferred into the HaCaT cells by using Lipofectamine 2000. After selection of the puromycin, monoclonal celllines were established, and the control group were lentivirus-infected HaCaT cells and uninfected HaCaT cells. The expression of YY1 was detected by using western blot analysis. cells in Lentivirus-YY1-HaCaT group and HaCaT-YY1 group were further divided into two subgroups according to the calcium concentration in culture medium, cells were either cultured in low-calcium medium (0.12 mmol/L) for 48 hours, or cultured in low-calcium medium (0.12 mmol/L) for 24 hours and in high-calcium medium (0.35 mmol/L) for additional 24 hours. Keratin K1, K10, K14, and involucrin, filaggrin and loricrin after over-expression of YY1 were detected with western blot analysis. RESULTS AND CONCLUSION:The HaCaT cells were successful y infected with lentivirus-YY1, and we obtained over-expression of YY1 protein in monoclonal celllines under high-calcium concentrations, the over-expressed YY1 could decrease the expression of K1, involucrin and loricrin, thereby preventing the process of epidermal keratinocytes and maintaining the cells in an undifferentiated state. Lentivirus can efficiently infect human immortalized epidermal cellHaCaT, and YY1 may the important factor of inhibiting the differentiation of basal epidermal cells and maintaining the undifferentiated proliferation status.
ABSTRACT
A subset of mammalian genes differ functionally between two alleles due to genomic imprinting, and seven such genes (Peg3, Usp29, APeg3, Zfp264, Zim1, Zim2, Zim3) are localized within the 500-kb genomic interval of the human and mouse genomes, constituting the Peg3 imprinted domain. This Peg3 domain shares several features with the other imprinted domains, including an evolutionarily conserved domain structure, along with transcriptional co-regulation through shared cis regulatory elements, as well as functional roles in controlling fetal growth rates and maternal-caring behaviors. The Peg3 domain also displays some unique features, including YY1-mediated regulation of transcription and imprinting; conversion and adaptation of several protein-coding members as ncRNA genes during evolution; and its close connection to human cancers through the potential tumor suppressor functions of Peg3 and Usp29. In this review, we summarize and discuss these features of the Peg3 domain.
Subject(s)
Animals , Humans , Mice , Alleles , Fetal Development , Genes, Tumor Suppressor , Genome , Genomic Imprinting , YY1 Transcription FactorABSTRACT
Yin-Yang1 (YY1),as a ubiquitous nuclear transcription factor with double transcriptional activity in eukaryotic cells,regulates many genes transcription and plays an important role in the cellule biological processes.Overexpression of YY1 is found in several tumor types recently,and may play a role in tumor development and progression by regulating oncogenes,tumor suppressor genes,angiogenesis related factors,as well as apoptosis.YY1 may become a new kind of tumor markers,is conducive to estimate the prognosis of patients with tumor and gain important breakthrough in cancer targeted therapy.