1.7SK truncation at 128-179 nt suppresses embryonic stem cell proliferation
Rui CHEN ; Yurong ZHANG ; Peng CHEN ; Yixin PANG ; Hongbao LI ; Ziwei CHEN ; Xiaoyong ZHANG ; Hongyi ZHANG ; Wujun LI
Journal of Southern Medical University 2021;41(8):1125-1130
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.
Cell Cycle Proteins
;
Cell Proliferation
;
Embryonic Stem Cells/metabolism*
;
HeLa Cells
;
Humans
;
Nuclear Proteins
;
Positive Transcriptional Elongation Factor B/metabolism*
;
RNA, Long Noncoding/genetics*
;
RNA-Binding Proteins
;
Ribonucleoproteins
;
Transcription Factors
2.Transient expression in microplasmodia of Physarum polycephalum.
Shide LIU ; Caixia CHENG ; Ziyang LIN ; Jianhua ZHANG ; Minghua LI ; Zhuolong ZHOU ; Shengli TIAN ; Miao XING
Chinese Journal of Biotechnology 2009;25(6):854-862
The plasmodium of Physarum polycephalum is a suitable eukaryotic cell for cell cycle investigation, but there is no compatible transient expression system for the plasmodium. Using the promoter and terminator of ardC actin of Physarum polycephalum substituted the CMV IE and SV40 polyA of plasmid pDsRedl-N1, using cassette PardC-MCS-DsRed1-TardC substituted the cassette PardC-hph-TardC of plasmid pTB38, we constructed plasmids pXM1 and pXM2 for transient expression of red fluorescent protein (RFP) in Physarum polycephalum respectively. After reconstituting the transcription elongation factor homologous gene (pelf1) of Physarum polycephalum into the pXM2, we generated a plasmid pXM2-pelf1. After the plasmid pXM1, pXM2 and pXM2-pelf1 were electroporated into the plasmodium of Physarum polycephalum, we observed optimum RFP and PELF1-RFP expression under fluoroscope and confocal microscope between 24-48 h after electroporation, and found that ELF1-RFP expression was accumulated in nucleus of microplasmodium, the optimum electroporation parameters were 40 V/cm electric field, 1 ampere current, and 70 micros electric shock time. The results suggest that this expression system is qualified for transient expression of specific protein in plasmodium of Physarum polycephalum.
Actins
;
genetics
;
metabolism
;
Electroporation
;
Luminescent Proteins
;
biosynthesis
;
genetics
;
Physarum polycephalum
;
genetics
;
metabolism
;
Plasmids
;
genetics
;
metabolism
;
Transcriptional Elongation Factors
;
genetics
3.AFF4 regulates osteogenic differentiation of human dental follicle cells.
Qingyue XIAO ; Yuning ZHANG ; Xingying QI ; Yaqian CHEN ; Rui SHENG ; Ruoshi XU ; Quan YUAN ; Chenchen ZHOU
International Journal of Oral Science 2020;12(1):20-20
As a member of the AFF (AF4/FMR2) family, AFF4 is a transcription elongation factor that is a component of the super elongation complex. AFF4 serves as a scaffolding protein that connects transcription factors and promotes gene transcription through elongation and chromatin remodelling. Here, we investigated the effect of AFF4 on human dental follicle cells (DFCs) in osteogenic differentiation. In this study, we found that small interfering RNA-mediated depletion of AFF4 resulted in decreased alkaline phosphatase (ALP) activity and impaired mineralization. In addition, the expression of osteogenic-related genes (DLX5, SP7, RUNX2 and BGLAP) was significantly downregulated. In contrast, lentivirus-mediated overexpression of AFF4 significantly enhanced the osteogenic potential of human DFCs. Mechanistically, we found that both the mRNA and protein levels of ALKBH1, a critical regulator of epigenetics, changed in accordance with AFF4 expression levels. Overexpression of ALKBH1 in AFF4-depleted DFCs partially rescued the impairment of osteogenic differentiation. Our data indicated that AFF4 promoted the osteogenic differentiation of DFCs by upregulating the transcription of ALKBH1.
Biomarkers
;
metabolism
;
Cell Differentiation
;
Cells, Cultured
;
Dental Sac
;
drug effects
;
metabolism
;
Gene Expression Regulation
;
Humans
;
Osteogenesis
;
genetics
;
Repressor Proteins
;
Transcription Factors
;
genetics
;
metabolism
;
Transcriptional Elongation Factors
;
metabolism
4.AF4/FMR2 and IL-10 gene single nucleotide polymorphisms are correlated with disease susceptibility and immune infiltration in ankylosing spondylitis.
Jie MU ; Yongshen XU ; Hui ZHU
Journal of Southern Medical University 2023;43(5):741-748
OBJECTIVE:
To explore the correlation of polymorphisms of AF4/FMR2 family genes and IL-10 gene with genetic susceptibility to ankylosing spondylitis (AS) and identify the high-risk factors of AS.
METHODS:
This case-control study was conducted among 207 AS patients and 321 healthy individuals. The tag single nucleotide polymorphisms (SNPs) rs340630, rs241084, rs10865035, rs1698105, and rs1800896 of the AF4/FMR2 family gene and IL-10 gene of the AS patients were genotyped, and the distribution frequencies of the genotypes and alleles were analyzed to explore the relationship between different genetic models and AS and the gene-gene and gene-environment interactions.
RESULTS:
Gender ratio, smoking history, drinking history, hypertension, erythrocyte sedimentation rate and C-reactive protein differed significantly between the case group and the control group (P < 0.05). The dominant model and recessive model of AFF1 rs340630, the recessive model of AFF3 rs10865035, and the recessive model of IL-10 rs1800896 were significantly different between the two groups (P=0.031, 0.010, 0.031, and 0.019, respectively). Gene-environment interaction analysis suggested that the interaction model incorporating AFF1 rs340630, AFF2 rs241084, AFF3 rs10865035, AFF4 rs1698105, IL-10 rs1800896, smoking history and drinking history was the best model. The genes related with AF4/FMR2 and IL-10 were enriched in the biological processes of AF4 super extension complex, interleukin family signal transduction, cytokine stimulation and apoptosis. The expression levels of AF4/FMR2 and IL-10 were positively correlated with immune infiltration (r > 0).
CONCLUSION
The SNPs of AF4/FMR2 and IL-10 genes are associated with the susceptibility to AS, and the interactions of AF4/FMR2 and IL-10 genes with the environmental factors contributes causes AS through immune infiltration.
Humans
;
Case-Control Studies
;
Genetic Predisposition to Disease
;
Interleukin-10/genetics*
;
Polymorphism, Single Nucleotide
;
Spondylitis, Ankylosing/genetics*
;
Transcriptional Elongation Factors/genetics*
;
Nuclear Proteins/genetics*
6.Protein Phosphatase 2C of Toxoplasma Gondii Interacts with Human SSRP1 and Negatively Regulates Cell Apoptosis.
Xue Juan GAO ; Jun Xia FENG ; Sen ZHU ; Xiao Hui LIU ; Isabelle TARDIEUX ; Lang Xia LIU
Biomedical and Environmental Sciences 2014;27(11):883-893
<b>OBJECTIVEb>The protozoan Toxoplasma gondii expresses large amounts of a 37 kDa Type 2C serine-threonine phosphatase, the so-called TgPP2C which has been suggested to contribute to parasite growth regulation. Ectopic expression in mammalian cells also indicated that the enzyme could regulate growth and survival. In this study, we aimed to investigate the interaction of TgPP2C with human SSRP1 (structure-specific recognition protein 1) and the effects of TgPP2C on cell viability.
<b>METHODSb>The yeast two hybrid system, His-tag pull-down and co-immunoprecipitation assays were used to confirm the interaction of TgPP2C with SSRP1 and determine the binding domain on SSRP1. The evaluation of cell apoptosis was performed using cleaved caspase-3 antibody and Annexin-V/PI kit combined with flow cytometry.
<b>RESULTSb>We identified human SSRP1 as an interacting partner of TgPP2C. The C-terminal region of SSRP1 including the amino acids 471 to 538 was specifically mapped as the region responsible for interaction with TgPP2C. The overexpression of TgPP2C down-regulated cell apoptosis and negatively regulated apoptosis induced by DRB, casein kinase II (CKII) inhibitor, through enhanced interaction with SSRP1.
<b>CONCLUSIONb>TgPP2C may be a parasitic factor capable of promoting cell survival through interaction with the host protein SSRP1, thereby creating a favorable environment for parasite growth.
Apoptosis ; Blotting, Western ; DNA-Binding Proteins ; genetics ; metabolism ; Flow Cytometry ; HeLa Cells ; High Mobility Group Proteins ; genetics ; metabolism ; Humans ; Immunoprecipitation ; Phosphoprotein Phosphatases ; genetics ; metabolism ; Protein Phosphatase 2C ; Toxoplasma ; enzymology ; Transcriptional Elongation Factors ; genetics ; metabolism ; Two-Hybrid System Techniques
7.Effect of downregulation of Tiam1 by siRNA on esophageal squamous cell carcinoma EC9706 cells.
Huaimin LIU ; Lifeng JIANG ; Xiaoli LIU ;
Chinese Journal of Oncology 2014;36(4):250-256
<b>OBJECTIVEb>To explore the effect of downregulation of Tiam1 by siRNA on the esophageal squamous cell carcinoma (ESCC) EC9706 cells, and provide theoretical basis for gene therapy of ESCC using Tiam1 as a molecular target.
<b>METHODSb>Tiam1 siRNA was transfected into EC9706 cells, and expression changes of Tiam1 mRNA and protein after transfection were detected by quantitative real-time PCR and Western blotting. Cell proliferation was analyzed using CCK-8 kit. Cell cycle and apoptosis of the EC9706 cells were assessed by flow cytometry. Cell cycle-related proteins and cell apoptosis-associated proteins were analyzed by Western blotting.
<b>RESULTSb>Compared with the untreated group and control siRNA group, the relative expression levels of Tiam1 mRNA (1.00 and 0.11 ± 0.02) were not significantly different (P > 0.05). The relative expression levels of Tiam1 mRNA in the Tiam1 siRNA group at 24, 48 and 72 h after transfection were 0.30 ± 0.04, 0.09 ± 0.01 and 0.09 ± 0.006, respectively, significantly lower than that of the untreated group (P < 0.05 for all). The expression level of Tiam1 protein at 24 h after Tiam1 siRNA transfection in the EC9706 cells was 0.11 ± 0.02, significantly lower than that in the un-treated group (0.44 ± 0.05) and control siRNA group (0.44 ± 0.04, P < 0.05 for all). The percentages of G0/G1 cells in the Tiam1 siRNA group, untreated group and control siRNA group were (54.48 ± 2.14)%, (40.69 ± 1.85)% and (41.78 ± 1.31)%, respectively (P < 0.01). The percentages of S phase cells in the Tiam1 siRNA group, untreated group and control siRNA group were (27.18 ± 1.65)%, (32.32 ± 1.15)% and (30.35 ± 1.09)%, respectively (P < 0.01). The expression levels of cyclin D1 protein in the untreated group, control siRNA group and Tiam1 siRNA group were 0.43 ± 0.02, 0.41 ± 0.01 and 0.11 ± 0.02, respectively (P < 0.05). The expression levels of p27 protein in the untreated group, control siRNA group and Tiam1 siRNA group were 0.10 ± 0.01, 0.09 ± 0.02 and 0.20 ± 0.02, respectively (P < 0.05). The ratios of early apoptotic cells in the untreated group, control siRNA group and Tiam1 siRNA group were (10 ± 0.9)%, (10 ± 0.5)% and (27 ± 0.7)%, respectively (P < 0.01). The expression levels of Mcl-1 protein in EC9706 cells of untreated group, control siRNA group and Tiam1 siRNA group were 0.47 ± 0.12, 0.48 ± 0.13 and 0.16 ± 0.02, respectively (P < 0.05). The expression levels of Bcl-2 protein in EC9706 cells of the untreated group, control siRNA group and Tiam1 siRNA group were 0.49 ± 0.08, 0.50 ± 0.05 and 0.04 ± 0.03, respectively (P < 0.05). The caspase-3 activities in the untreated group, control siRNA group and Tiam1 siRNA group were 2.3 ± 0.09, 2.3 ± 0.10 and 16.0 ± 1.50, respectively; and that of caspase-9 were 2.3 ± 0.08, 2.3 ± 0.11 and 14.5 ± 0.9, respectively (P < 0.05 for all).
<b>CONCLUSIONSb>Tiam1 siRNA can significantly inhibit the proliferation of esophageal cancer EC9706 cells, induce cell cycle arrest and cell apoptosis. These effects are related to the regulation of the expressions of cell cycle-related genes (cyclin D1 and p27) and cell apoptosis-related genes (Mcl-1, Bcl-1, caspase-3 and caspase-9) by Tiam1 siRNA.
Apoptosis ; Carcinoma, Squamous Cell ; genetics ; metabolism ; pathology ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Cycle Checkpoints ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Down-Regulation ; Esophageal Neoplasms ; genetics ; metabolism ; pathology ; Guanine Nucleotide Exchange Factors ; genetics ; metabolism ; Humans ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; T-Lymphoma Invasion and Metastasis-inducing Protein 1 ; Transfection
8.Mechanism of HL-60 cells apoptosis induced by proteasome inhibitor MG132.
Yong-Ming ZHOU ; Mei-Xia YU ; Yu-Zhen QIU ; Xiao-Lei XING ; Chun-Hong YAO ; Ru-Jun BAI
Journal of Experimental Hematology 2013;21(4):911-915
The purpose of this study was to elucidate the apoptosis, apoptotic pathway of HL-60 cells induced by proteasome inhibitor MG132 and its effect on allogeneic mixed lymphocyte reaction. Apoptosis of HL-60 cells was detected by flow cytometry, the expression of P21, P27 and P53 proteins in HL-60 cells treated with MG132 was assayed by Western blot. The HL-60 cells were treated with 1 µmol/L MG132 for 48 h, and irradiated by 75 Gy of (60)Co γ-ray, but their antigenicity was preserved. The effect of irradiated HL-60 cells treated with MG132 on proliferation of peripheral blood mononuclear cells (PBMNC) was measured by CCK-8 method. The results showed that the apoptotic rate of MG132-treated HL-60 cells increased in dose-and time-dependent manner. No significant changes in MG132-induced apoptosis were observed after inhibiting caspase-8 and caspase-9 pathway. The expression of P21 and P27 protein increased after treatment of HL-60 cells with MG132. CCK-8 test showed that HL-60 cells induced with low-dose of MG132 displayed the enhancing effect on proliferation of PBMNC. It is concluded that high dose of MG132 can induce the apoptosis of HL-60 cells, and has direct killing effect on HL-60 cells, but this inducing apoptotic effect on HL-60 cells can not be realized through caspase-8 and caspase-9 pathway. The P21 and P27 protein may be involved in MG132 induced HL-60 cell apoptosis. Low dose of MG132 promotes the proliferation of PBMNC in healthy individuals and enhance the immunity of organism.
Apoptosis
;
drug effects
;
Caspase 8
;
metabolism
;
Caspase 9
;
metabolism
;
Cyclin-Dependent Kinase Inhibitor p21
;
metabolism
;
Cyclin-Dependent Kinase Inhibitor p27
;
metabolism
;
HL-60 Cells
;
Humans
;
Leupeptins
;
pharmacology
;
Proteasome Inhibitors
;
pharmacology
9.Inhibitions of SphK1 inhibitor SKI II on cell cycle progression and cell invasion of hepatoma HepG2 cells.
Cai-Xia ZHANG ; Hong LIU ; Yu-Yan GONG ; Hong-Wei HE ; Rong-Guang SHAO
Acta Pharmaceutica Sinica 2014;49(2):204-208
Sphingosine kinase 1 (SphK1) plays critical roles in cell biological functions. Here we investigated the effects of SphK1 inhibitor SKI II on hepatoma HepG2 cell cycle progression and invasion. Cell survival was determined by SRB assay, cell cycle progression was assayed by flow cytometry, the ability of cell invasion was measured by Matrigel-Transwell assay and protein expression was detected by Western blotting. The results showed that SKI II markedly inhibited HepG2 cell survival in a dose-dependent manner, induced G1 phase arrest in HepG2 cell and inhibited cell invasion. SKI II markedly decreased the expressions of G1-phase-related proteins CDK2, CDK4 and Cdc2 and the levels of cell invasion-associated proteins MMP2 and MMP9. The results showed that SKI II inhibited cell cycle progression and cell invasion, implying SphK1 as a potential target for hepatoma treatment.
CDC2 Protein Kinase
;
Cell Movement
;
drug effects
;
Cell Survival
;
drug effects
;
Cyclin-Dependent Kinase 2
;
metabolism
;
Cyclin-Dependent Kinase 4
;
metabolism
;
Cyclin-Dependent Kinases
;
metabolism
;
G1 Phase
;
drug effects
;
Hep G2 Cells
;
Humans
;
Matrix Metalloproteinase 2
;
metabolism
;
Matrix Metalloproteinase 9
;
metabolism
;
Phosphotransferases (Alcohol Group Acceptor)
;
antagonists & inhibitors
;
Thiazoles
;
pharmacology
10.Study of loss of heterozygosity at 9p21 and P16 expression in gastrointestinal stromal tumors.
Yun ZHANG ; Hui CAO ; Ming WANG ; Dan-ping SHEN ; Xing-zhi NI ; Zhi-yong WU ; Yan-ying SHEN ; Yan-yan SONG
Chinese Journal of Gastrointestinal Surgery 2010;13(10):762-765
<b>OBJECTIVEb>To evaluate the impact of loss of heterozygosity (LOH) at chromosome 9p21 and P16(INK4A)(CDKN2A) expression on the prognosis of gastrointestinal stromal tumor (GIST).
<b>METHODSb>A total of 51 cases with GISTs were characterized by immunohistochemistry and evaluated for LOH at 9p21 by microsatellite analysis in 4 markers(D9S1751, D9S1846, D9S942 and D9S1748). Associations of LOH at 9p21 and P16(INK4A) expression encoded by CDKN2A with clinicopathological parameters and prognosis in GISTs were analyzed.
<b>RESULTSb>The frequency of 9p21 LOH was 37.0% (10/27) at D9S1751, 37.5%(12/32) at D9S1846, 42.1%(16/38) at D9S942 and 24.2%(8/33) at D9S1748. The overall frequency of LOH at 9p21 was 63.3%(31/49). In 21 samples of 51 GISTs(41.2%), P16 expression was not detected. Loss of P16 expression was 60%(12/20) in high risk group and 23.5%(4/17) in very low and low risk groups(P<0.05). The 5-year overall survival rate of p16-negative patients was 70.8%, while in P16-positive patients it was 92.0%(P<0.05).
<b>CONCLUSIONSb>LOH at 9p21 is a frequent event in GIST. Loss of CDKN2A gene at 9p21 may contribute to the progression and malignant transformation of GIST. P16 expression in GIST is associated with prognosis.
Adult ; Aged ; Aged, 80 and over ; Chromosomes, Human, Pair 9 ; genetics ; Cyclin-Dependent Kinase Inhibitor p16 ; metabolism ; Female ; Gastrointestinal Stromal Tumors ; genetics ; metabolism ; pathology ; Genes, p16 ; Humans ; Loss of Heterozygosity ; Male ; Microsatellite Repeats ; Middle Aged