Objective To clarify whether Helicobacter pylori (H. pylori) can promote metastasis of gastric cancer cells via the high-expression of induced B cell specific Moloney murine leukemia virus integration site 1 (Bmi-1). Methods The gastric cancer tissue specimens from 82 patients were collected for this study. The protein and gene expression level of Bmi-1 in gastric adenocarcinoma tissue were detected by immunohistochemistry and real time quantitative PCR, respectively. And meanwhile the correlation between Bmi-1 levels and pathological features, and prognosis of gastric cancer were analyzed retrospectively. Then, the GES-1 cells were transfected with pLPCX-Bmi-1 plasmid and infected with H. pylori respectively. After the Bmi-1 overexpression in GES-1 cells, the invasion ability of the GES-1 cells was detected by Transwell assay, and the cell cycle and apoptosis were detected by flow cytometry. Results The mRNA and protein of Bmi-1 expression in gastric cancer tissues were higher than tumor-adjacent tissue, and the high expression of Bmi-1 was positively correlated with tumor invasion, TNM stage, tumor differentiation, lymph node metastasis and H. pylori infection. When expression of Bmi-1 was up-regulated as a result of H.pylori infection or pLPCX-Bmi-1 transfection, the GES-1 cells had higher invasiveness and lower apoptosis rate with the above treatment respectively. Conclusion H. pylori infection can inhibit the apoptosis of gastric cancer cells and promote their invasion via up-regulating expression of Bmi-1.
Humans ; Cell Line, Tumor ; Helicobacter Infections/genetics* ; Helicobacter pylori ; Lymphatic Metastasis ; Retrospective Studies ; Stomach Neoplasms/pathology* ; Polycomb Repressive Complex 1/genetics*

OBJECTIVE: To investigate the expression of PCGF1 in rectal adenocarcinoma (READ) and the effect of PCGF1 silencing on proliferation READ cells in vitro. METHODS: The UALCAN and ENCORI online databases were used to analyze the expression level of PCGF1 in READ tissues and normal tissues and its association with the clinicopathological parameters and survival outcomes of patients with READ. The expression levels of PCGF1 were detected in two READ cell lines and a normal rectal epithelial cell line (HcoEpiC cells) using qPCR and Western blotting. Lentiviral vectors were used to construct PCGF1-overexpressing and PCGF1-silenced cell lines, and the proliferative activity of the cells was assessed using CCK-8 assay. The effect of PCGF1 silencing on tumor proliferation in vivo was also evaluated by observing tumorigenicity of the cells in nude mice. RESULTS: PCGF1 was highly expressed in READ tissue (P < 0.001), and its expression levels was correlated with READ stage, differentiation and lymph node metastasis (P < 0.001). A high PCGF1 expression level was associated with a poor survival outcome of READ patients (P < 0.05). In SW837 and SW1463 cells, PCGF1 silencing significantly lowered the proliferative activity of the cells both in vitro (P < 0.05) and in nude mice (P < 0.01). CONCLUSION PCGF1 is highly expressed in READ tissue and may potentially serve as a prognostic biomarker as well as a therapeutic target for READ.
Adenocarcinoma/genetics* ; Animals ; Biomarkers ; Cell Line, Tumor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Mice ; Mice, Nude ; Polycomb Repressive Complex 1 ; Sincalide

OBJECTIVE: To explore the molecular mechanism by which miR-218 targeting Bmi-1 inhibits the proliferation of acute promyelocytic leukemia (APL) cells. METHODS: APL cell line HL-60 was transfected by miR-218 and RNA-negative control sequences, respectively. The expression of miR-218 in cells was detected by real-time fluorescence quantitative PCR. The effect of transfected miR-218 on the proliferation of APL cells was detected by MTT assay. Cell apoptosis was detected by flow cytometry. The regulation effect of miR-218 on Bmi-1 expression was determined by Western blot. The correlation of miR-218 expressions with Bmi-1 was analyzed by Spearman test. The targeted relationship between miR-218 and Bmi-1 was verified by luciferase assay. RESULTS: MTT assay showed that the proliferation of HL-60 cells in vitro was inhibited by high expression miR-218 significantly. Flow cytometry showed that the G1 and G2 phase cells increased while the S phase cells decreased after transfected by miR-218. Western blot showed that the level of Bmi-1 protein in HL-60 cells decreased significantly after transfection of miR-218 (P＜0.05). Spearman correlation analysis showed that the mRNA level of miR-218 negatively correlated with the protein content of Bmi-1 (r=-0.326, P＜0.01). Luciferase assay indicated that Bmi-1 could targeted on miR-218 directly. CONCLUSION miR-218 can inhibit the proliferation, metastasis and invasion of APL cells, which can be related with the down-regulated of Bmi-1.
Apoptosis ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; HL-60 Cells ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; MicroRNAs ; genetics ; Polycomb Repressive Complex 1 ; genetics

OBJECTIVE: To study whether the Bmi-1 gene can be a biomarker for analysis of clinical risk stratification and prognosis of ALL patients. METHODS: The expression level of Bmi-1 gene in bone marrow samples from 127 cases of newly diagnosed ALL was detected by qRT-PCR, at the same time the expression level of Bmi-1 protein in bone marrow samples from above-mentioned cases was detected by Western blot. The collected samples were divided into 3 groups: high, intermediate and low risk according to clinical risk stratfication, the relationship between Bmi-1 expression and risk grade of ALL patients was analyzed; at the same time the collected samples were divided into 2 groups: prednisone good response (PGR) and prednisone poor respouse (PPR) according to the sensitivity of prednison test, and the sensitivily to prednisone in 2 groups was compared; moreover, the collected samples were divided into 2 groups: high level and low level according to median of Bmi-1 level, and the relation of Bmi-1 level with prognosis of patients was analyzed by using the Kaplan-Meier method. RESULTS: The expression level of Bmi-1 in low risk group was lowest, while that in high risk group was highest, however that in intermediat risk group was between the low and high risk groups, statistical analysis showed significant difference (P＜0.05). The expression level of Bmi-1 in PPR group was significantly higher than that in PGR group (P＜0.001). The Kaplan-Meier analysis showed that the RFS rate in Bmi-1 high expression group was significantly lower than that in Bmi-1 low expression group (73.0% vs 90.6%) (P＜0.001). CONCLUSION The Bmi-1 can be used as a molecular marker for the analysis of chinical risk and prognosis of pediatric ALL.
Biomarkers ; Child ; Humans ; Kaplan-Meier Estimate ; Polycomb Repressive Complex 1 ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Prednisone ; Prognosis

OBJECTIVE: To investigate the effect of Bmi-1 gene silence on the proliferation ability of K562 cells in vitro and in vivo, and to explore the relation of molecular mechanism between proliferation ability of K562 cells in vitro and in vivo with PTEN/pAKT signaling pathway. METHODS: The Bmi-1 small interference RNA (siRNA) sequences were transfected into K562 cells for decreasing Bmi-1 expression. The effect of Bmi-1 siRNA on the proliferation of K562 cells in vitro and in vivo was detected by MTT method and colony-forming test, the effect of Bmi-1 siRNA on the tumorogenicity of K562 cells was observed by subcutaneous inoculation of K562 cells, LY294002 and Bpv treated K562 cells in nude mice, the expression of Bmi-1, PTEN and pAKT proteins were detected by Western blot. RESULTS: The Bmi-1 siRNA could inhibit the proliferation activity, colony-forming and tumor-forming abilities of K562 cells. After the silence of Bmi-1 gene, the PTEN expression in Bmi-1 gene-silenced group was significantly enhanced. While the pAKT expression in Bmi-1 gene-silenced group was significantly reduced; after the K562 cells were treated with LY294002 (an inhibitor of pAKT), the pAKT expression colony-forming and tumor forming abilities were reduced in comparison with untreated K562 cells; after the K562-S1 cells were treated with Bpv (an inhibitor of PTEN), the PTEN expression decreased, while the pAKT expression, colony forming and tumor-forming abilities were restored. CONCLUSION The Bmi-1 gene possibly involves in regulation of K562 proliferation in vivo and in vitro, the effect of PTEN/pAKT signaling pathway maybe one of molecular mechanisms mediating this regulation.
Animals ; Apoptosis ; Cell Proliferation ; Humans ; K562 Cells ; Leukemia ; Mice ; Mice, Nude ; PTEN Phosphohydrolase ; Polycomb Repressive Complex 1 ; Proto-Oncogene Proteins c-akt ; RNA, Small Interfering ; Signal Transduction

BACKGROUND AND OBJECTIVES: Human amniotic fluid-derived mesenchymal stem cells (AF-MSCs) may be a valuable source for cardiovascular tissue engineering and cell therapy. The aim of this study is to verify angiotensin II and transforming growth factor-beta 1 (TGF-β1) as potential cardiomyogenic differentiation inducers of AF-MSCs. METHODS AND RESULTS: AF-MSCs were obtained from amniocentesis samples from second-trimester pregnant women, isolated and characterized by the expression of cell surface markers (CD44, CD90, CD105 positive; CD34 negative) and pluripotency genes (OCT4, SOX2, NANOG, REX1). Cardiomyogenic differentiation was induced using different concentrations of angiotensin II and TGF-β1. Successful initiation of differentiation was confirmed by alterations in cell morphology, upregulation of cardiac genes-markers NKX2-5, TBX5, GATA4, MYH6, TNNT2, DES and main cardiac ion channels genes (sodium, calcium, potassium) as determined by RT-qPCR. Western blot and immunofluorescence analysis revealed the increased expression of Connexin43, the main component of gap junctions, and Nkx2.5, the early cardiac transcription factor. Induced AF-MSCs switched their phenotype towards more energetic and started utilizing oxidative phosphorylation more than glycolysis for energy production as assessed using Agilent Seahorse XF analyzer. The immune analysis of chromatin-modifying enzymes DNMT1, HDAC1/2 and Polycomb repressive complex 1 and 2 (PRC1/2) proteins BMI1, EZH2 and SUZ12 as well as of modified histones H3 and H4 indicated global chromatin remodeling during the induced differentiation. CONCLUSIONS: Angiotensin II and TGF-β1 are efficient cardiomyogenic inducers of human AF-MSCs; they initiate alterations at the gene and protein expression, metabolic and epigenetic levels in stem cells leading towards cardiomyocyte-like phenotype formation.
Amniocentesis ; Amniotic Fluid ; Angiotensin II ; Angiotensins ; Blotting, Western ; Calcium ; Cell Differentiation ; Cell- and Tissue-Based Therapy ; Chromatin ; Chromatin Assembly and Disassembly ; Connexin 43 ; Epigenomics ; Female ; Fluorescent Antibody Technique ; Gap Junctions ; Glycolysis ; Histones ; Humans ; Ion Channels ; Mesenchymal Stromal Cells ; Muscle Cells ; Oxidative Phosphorylation ; Phenotype ; Polycomb Repressive Complex 1 ; Pregnant Women ; Smegmamorpha ; Stem Cells ; Tissue Engineering ; Transcription Factors ; Up-Regulation

B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1), a core member of polycomb repressive complex 1 (PRC1), has been intensely investigated in the field of cancer epigenetics for decades. Widely known as a critical regulator in cellular physiology, BMI1 is essential in self-renewal and differentiation in different lineages of stem cells. BMI1 also plays a significant role in cancer etiology for its involvement in pathological progress such as epithelial-mesenchymal transition (EMT) and cancer stem cell maintenance, propagation, and differentiation. Importantly, overexpression of BMI1 is predictive for drug resistance, tumor recurrence, and eventual therapy failure of various cancer subtypes, which renders the pharmacological targeting at BMI1 as a novel and promising therapeutic approach. The study on prostate cancer, a prevalent hormone-related cancer among men, has promoted enormous research advancements in cancer genetics and epigenetics. This review summarizes the role of BMI1 as an oncogenic and epigenetic regulator in tumor initiation, progression, and relapse of prostate cancer.
Animals ; Gene Expression Regulation, Neoplastic ; Humans ; Lymphoma, B-Cell/genetics* ; Male ; Mice ; Moloney murine leukemia virus/genetics* ; Mutagenesis, Insertional/genetics* ; Polycomb Repressive Complex 1/genetics* ; Prostatic Neoplasms/genetics*

CRISPR-Cas Systems ; Embryo, Mammalian ; Gene Editing ; methods ; HEK293 Cells ; Humans ; Polycomb Repressive Complex 1 ; genetics ; Zygote

OBJECTIVETo explore the role of Bmi-1 gene in the proliferation of squamous carcinoma cells and whether the silencing Bmi-1 can inhibit the growth of squamous cell carcinomas cells.

METHODSThe expressions of Bmi-1 in primary cultured Fibroblasts, karatinocyte cell line Hacat,squamous carcinoma cell line A431, and ECA109 were detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. Recombinant plasmid inserted with Bmi-1 gene short hairpin RNA (shRNA) expression vector PGPU6/GFP/Neo-shBmi-1 was constructed and transfected into ECA109 cells with control set. After transfection for 48 and 72 hours,the mRNA and protein levels of Bmi-1 were examined with RT-PCR and Western blot analysis, respectively. The proliferation of the ECA109 cells was evaluated by MTT method and flow cytometry.

RESULTSBmi-1 was highly expressed in A431 and ECA109 cells than in Fibroblast cells and Hacat cells. The mRNA and protein expressions of Bmi-1 were significantly silenced in ECA109 cells after recombinant expression vector PGPU6/GFP/Neo-shBmi-1 transfection (P<0.05). Compared with the control groups,the proliferation of ECA109 transfected with PGPU6/GFP/Neo-shBmi-1 was significantly inhibited (P<0.05), and cells in G1 phase increased while in S phase decreased (P<0.05).

CONCLUSIONSBmi-1 is involved in the proliferation of squamous carcinoma cells. After the silencing of Bmi-1 expression,the proliferation ECA109 cells is suppressed due to the altered cell cycle.

Blotting, Western ; Carcinoma, Squamous Cell ; Cell Cycle ; Cell Line ; Cell Proliferation ; Fibroblasts ; Flow Cytometry ; Humans ; Plasmids ; Polycomb Repressive Complex 1 ; RNA, Messenger ; RNA, Small Interfering ; Transfection

Bmi1 is a member of the polycomb group family of proteins, and it drives the carcinogenesis of various cancers and governs the self-renewal of multiple types of stem cells. However, its role in the initiation and progression of bladder cancer is not clearly known. The present study aimed to investigate the function of Bmi1 in the development of bladder cancer. Bmi1 expression was detected in human bladder cancer tissues and their adjacent normal tissues (n=10) by immunohistochemistry, qRT-PCR and Western blotting, respectively. Bmi1 small interference RNA (siRNA) was synthesized and transfected into human bladder carcinoma cells (EJ) by lipofectamine 2000. The Bmil expression at mRNA and protein levels was measured in EJ cells transfected with Bmil siRNA (0, 80, 160 nmol/L) by qRT-PCR and Western blotting, respectively. Cell viability and Ki67 expression (a marker of cell proliferation) were determined in Bmi1 siRNA-transfected cells by CCK-8 assay and qRT-PCR, respectively. Cell cycle of transfected cells was flow-cytometrically determined. Immunofluorescence and Western blotting were used to detect the expression levels of cell cycle-associated proteins cyclin D1 and cyclin E in the cells. Pro-apoptotic proteins Bax and caspase 3 and anti-apoptotic protein Bcl-2 were detected by Western blotting as well. Additionally, xenograft tumor models were established by inoculation of EJ cells (infected with Bmil shRNA/pLKO.1 lentivirus or not) into nude mice. The tumor volumes were measured every other day for 14 days. The results showed that the Bmil expression was significantly increased in bladder tumor tissues when compared with that in normal tissues (P<0.05). Perturbation of Bmi1 expression by using siRNA could significantly inhibit the proliferation of EJ cells (P<0.05). Bmi1 siRNA-transfected EJ cells were accumulated in G1 phase and the expression levels of cyclin D1 and cyclin E were down-regulated. Bax and caspase-3 expression levels were significantly increased and Bcl-2 levels decreased after Bmi1 knockdown. Tumor volume was conspicuously reduced in mice injected with EJ cells with Bmi1 knockdown. Our findings indicate that Bmi1 is a potential driver oncogene of bladder cancer and it may become a potential treatment target for human bladder cancer.
Animals ; Apoptosis ; genetics ; Carcinogenesis ; genetics ; metabolism ; pathology ; Carcinoma ; genetics ; metabolism ; pathology ; therapy ; Caspase 3 ; genetics ; metabolism ; Cell Line, Tumor ; Cyclin D1 ; antagonists & inhibitors ; genetics ; metabolism ; Cyclin E ; antagonists & inhibitors ; genetics ; metabolism ; G1 Phase Cell Cycle Checkpoints ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Injections, Intralesional ; Ki-67 Antigen ; genetics ; metabolism ; Mice ; Mice, Nude ; Polycomb Repressive Complex 1 ; antagonists & inhibitors ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; antagonists & inhibitors ; genetics ; metabolism ; RNA, Small Interfering ; administration & dosage ; genetics ; metabolism ; Signal Transduction ; Tumor Burden ; Urinary Bladder ; metabolism ; pathology ; Urinary Bladder Neoplasms ; genetics ; metabolism ; pathology ; therapy ; Xenograft Model Antitumor Assays ; bcl-2-Associated X Protein ; agonists ; genetics ; metabolism