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.
Alleles ; Animals ; Fetal Development ; Genes, Tumor Suppressor ; Genome ; Genomic Imprinting ; Humans ; Mice ; YY1 Transcription Factor

OBJECTIVETo investigate the expression of Yin Yang 1 (YY1) protein in human insulinoma and explore its clinical significance.

METHODSNineteen pancreatic neuroendocrine tumor tissue were collected from patients treated in Nanfang Hospital between 2000 and 2014. The protein expression of YY1 in benign and malignant insulinoma tissues were detected by immunohistochemistry.

RESULTSPositive expression for YY1 protein was detected in both benign and malignant tumor tissues, but the malignant tissues had a significantly greater intensity of YY1 expression than the benign tissues (P=0.042). The intensity of YY1 expression was positively correlated with the nature of the tumor, and the insulinomas with high expressions of YY1 had significantly greater malignant potentials (P=0.037).

CONCLUSIONThe high expression of YY1 protein is associated with the development of insulinima. YY1 may serve as a new tumor marker for detecting the malignant transformation of insulinoma.

Biomarkers, Tumor ; metabolism ; Cell Transformation, Neoplastic ; Humans ; Immunohistochemistry ; Insulinoma ; genetics ; metabolism ; Pancreatic Neoplasms ; genetics ; metabolism ; YY1 Transcription Factor ; genetics ; metabolism

This study was aimed to explore the effects of Notch ligand DLL4 on the protein expression of the transcription factor YY1 and proto-oncogene c-Myc, as well as K562 cell proliferation. The experiment was divided into 3 groups: normal control, negative control (pBudCE4.1-transfected) and experimental (pBudCE4.1-DLL4-transfected) groups. At 48 hours after transfection, the expression level of DLL4, YY1 and c-Myc proteins in K562 cells of each group were detected by Western blot and indirect immunocytochemical method; the CCK-8 method was used to detect proliferation of K562 cells; at 48 hours after transfection, cell cycle distribution and apoptosis of K562 cells were detected by flow cytometry. The results showed that the protein expression of DLL4, YY1 and c-Myc in K562 cells of every group were found. The protein expression levels of DLL4, YY1 and c-Myc in the experimental group cells were significantly higher than that in control groups (p < 0.05). The cell number in G(0)/G(1) phase increased in the experimental group and was higher than that in the control groups (p < 0.001), and the number of apoptotic cells were also increased (p < 0.001). It is concluded that DLL4 gene was successfully transfected into K562 cells, which increased the protein expression levels of transcription factor YY1 and proto-oncogene c-Myc, leading to the cell proliferation slower in experiment group, inducing the cell cycle arrested in G(0)/G(1) phase and increasing apoptosis.
Cell Cycle ; Cell Proliferation ; Humans ; Intercellular Signaling Peptides and Proteins ; genetics ; K562 Cells ; Proto-Oncogene Proteins c-myc ; metabolism ; Transfection ; YY1 Transcription Factor ; metabolism

OBJECTIVETo explore the expression of hsa-mir-186 in colorectal cancer and study its role in regulating the biological behaviors of human colorectal cancer SW620 cells in vitro.

METHODSThe expression of hsa-miR-186 in colon cancer tissue and the adjacent tissues as well as 5 colon carcinoma cells were analyzed using real-time quantitative RT-PCR. The precursor sequence of miR-186 gene was amplified from the genomic DNA by PCR and cloned into the lentiviral vector PLVTHM labeled with GFP. The colorectal cancer cell line SW620 was transfected with PLVTHM-miR186 vector and the lentivirus-infected cells were sorted with flow cytometry. Cell counting kit-8 (CCK-8) assay was used to detect the proliferation of the cells. The migration and invasion of SW620 cells were investigated using Transwell assay and scratch test. Western blotting was used to detect the expression of YY1 protein in SW620 cell lines.

RESULTSThe relative expression of miR-186 in the cancer tissues was 0.0024∓0.0027, significantly lower than that in the adjacent tissues (0.066∓0.068, P=0.008); the relative expression level of hsa-miR-186 in SW620 and LoVo cells with a high metastatic potential was 0.118∓0.138 and 0.157∓0.001, respectively, significantly lower than that in HT-29 cells with a low metastatic potential (1.000∓0.00, P<0.05). The recombinant lentiviral vector PLVTHM-miR186, verified by enzyme digestion, sequencing and qPCR, caused significant inhibition of cell proliferation, migration and invasion and suppressed the expression of YY1 protein in SW620 cells.

CONCLUSIONAs a tumor suppressor gene, Hsa-miR-186 is down-regulated in colon carcinoma tissues and in highly metastatic SW620 and LoVo cells. Has-miR-186 can inhibit the cell proliferation, migration and invasion of colon carcinoma cells in vitro possibly by suppressing YY1 expression.

Adult ; Aged ; Aged, 80 and over ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Colonic Neoplasms ; genetics ; pathology ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Genetic Vectors ; Humans ; Lentivirus ; genetics ; MicroRNAs ; Middle Aged ; Transfection ; YY1 Transcription Factor ; metabolism

The BCCIP (BRCA2- and CDKN1A-interacting protein) is an important cofactor for BRCA2 in tumor suppression. Although the low expression of BCCIP is observed in multiple clinically diagnosed primary tumor tissues such as ovarian cancer, renal cell carcinoma and colorectal carcinoma, the mechanism of how BCCIP is regulated in cells is still unclear. The human INO80/YY1 chromatin remodeling complex composed of 15 subunits catalyzes ATP-dependent sliding of nucleosomes along DNA. Here, we first report that BCCIP is a novel target gene of the INO80/YY1 complex by presenting a series of experimental evidence. Gene expression studies combined with siRNA knockdown data locked candidate genes including BCCIP of the INO80/YY1 complex. Silencing or over-expressing the subunits of the INO80/YY1 complex regulates the expression level of BCCIP both in mRNA and proteins in cells. Also, the functions of INO80/YY1 complex in regulating the transactivation of BCCIP were confirmed by luciferase reporter assays. Chromatin immunoprecipitation (ChIP) experiments clarify the enrichment of INO80 and YY1 at +0.17 kb downstream of the BCCIP transcriptional start site. However, this enrichment is significantly inhibited by either knocking down INO80 or YY1, suggesting the existence of both INO80 and YY1 is required for recruiting the INO80/YY1 complex to BCCIP promoter region. Our findings strongly indicate that BCCIP is a potential target gene of the INO80/YY1 complex.
Calcium-Binding Proteins ; genetics ; metabolism ; Cell Cycle Proteins ; genetics ; metabolism ; Chromatin Assembly and Disassembly ; physiology ; DNA Helicases ; genetics ; metabolism ; HeLa Cells ; Humans ; Multiprotein Complexes ; genetics ; metabolism ; Nuclear Proteins ; genetics ; metabolism ; Promoter Regions, Genetic ; physiology ; Transcription, Genetic ; physiology ; YY1 Transcription Factor ; genetics ; metabolism