OBJECTIVE: Analysis of the correlation between telomerase and expression of its related proteins may provide insight into the molecular mechanism of nasopharyngeal carcinogenesis. Here, we investigate the effect of short hairpin RNA (shRNA) specific for human telomerase reverse transcriptase (hTERT) mRNA on the expression of proliferating cell nuclear antigen (PCNA) and Caspase-3 in nasopharyngeal carcinoma (CNE) cells. METHOD: shRNA expression vectors targeting the mRNA of hTERT were constructed. Cells were treated with the constructed expression vectors and telomerase activity was measured by telomeric repeat amplification ELISA (TRAP-ELISA). Cell viability was examined using the MTT assay. Cell apoptosis was detected by TUNEL method. The expression of PCNA and Caspase-3 proteins, was determined by Western blotting. RESULT: shRNA specific for hTERT mRNA significantly inhibited telomerase activity, suppressed cell viability and induced apoptosis in CNE cells. In addition, the expression of PCNA was inhibited, while the expression of Caspase-3 was up-regulated. CONCLUSION Our results suggest that shRNA directed against hTERT inhibits cell viability by regulating telomerase activity and its related protein expression in NPC cells. Therefore, RNA-interfering technology may be a promising strategy for the treatment of nasopharyngeal cancer.
Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Survival ; Humans ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; Proliferating Cell Nuclear Antigen ; metabolism ; RNA, Small Interfering ; Telomerase ; genetics ; Transfection

To explore the effects of the physiological range of hydrostatic pressure on human bladder smooth muscle cells (HBSMCs) cultured in vitro, we used a hydrostatic compression device designed in our laboratory into the experiments, which were grouped by varied hydrostatic pressure gradients. Cellular morphology was observed with HE staining; cytoskeleton F-actin, cell cycle, both proliferating cell nuclear antigen (PCNA) and matrix metalloproteinase 7 (MMP-7) were detected respectively with immunofluorescence, flow cytometry and RT-PCR. We found that the proliferation, cytoskeleton and cycle distribution of HBSMCs were not obviously different among the groups of different hydrostatic pressure; however, the mRNA expression of MMP-7 exhibited a trend of first increasing and then declining as the pressure gradually rises. Thus the physiological range of hydrostatic pressure may not have significant influence on proliferation, morphology, skeleton, and cell cycle of HBSMCs, but it may have great effect on the expression of MMP-7.
Cells, Cultured ; Humans ; Hydrostatic Pressure ; Matrix Metalloproteinase 7 ; genetics ; metabolism ; Myocytes, Smooth Muscle ; cytology ; physiology ; Proliferating Cell Nuclear Antigen ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Urinary Bladder ; cytology

Aneuploidy ; Biomarkers, Tumor ; metabolism ; DNA, Neoplasm ; genetics ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; Lymphatic Metastasis ; Nucleolus Organizer Region ; metabolism ; Proliferating Cell Nuclear Antigen ; metabolism ; S Phase

To investigate the role of progesterone receptor (PR) expression in malignant melanoma (MM), PR and proliferative cell nuclear antigen (PCNA) expression were immunohistochemistrically evaluated in a series of 35 specimens of MM, and the correlation between the immunohistochemistrical findings and clinicopathological data was also analyzed. PR expression was detected in 25.7% (9/35) of the patients with MM. No PR expression was observed in nevi. PR expression was inversely correlated with PCNA expression (r=-0.353, P=0.026). PR expression was slightly increased in females, subjects aged under 55 y, those with ulceration, non-acral subtype and diagnosis delay longer than 1 y, but the difference was not statistically significant. Selective expression of progesterone receptor in malignant melanoma might be correlated with inhibited tumor growth.
Gene Expression Regulation, Neoplastic ; Immunohistochemistry ; Melanoma/*metabolism ; Models, Biological ; Prognosis ; Proliferating Cell Nuclear Antigen/*metabolism ; Receptors, Progesterone/*biosynthesis ; Receptors, Progesterone/genetics ; Skin/metabolism ; Skin Neoplasms/metabolism

OBJECTIVETo study the effects of Box-3 region of the leukemia inhibitory factor receptor (LIFR) alpha-chain cytoplasmic domain on the proliferation and differentiation of HL-60 cells.

METHODSExpression vector of gp190CT3 was constructed and expressed in HL-60 cells. The expression level of gp190CT3 was assayed by immunocytochemistry. The growth of wild type and gp190CT3 transfected HL-60 cells were examined under microscope. The PCNA levels were assayed by Western blot, and the levels of CD15 by flow cytometry.

RESULTSThe gp190CT3 transfected HL-60 cells were enlarged in size and their proliferation was slower than that of wild type. The expression level of PCNA was down-regulated while the level of CD15 up-regulated in transfected HL-60 cells as compared with that of the wild type cells.

CONCLUSIONThe Box-3 region of the leukemia inhibitory factor receptor alpha-chain cytoplasmic domain (gp190CT3) participates the LIFR signal transduction in inhibiting the growth and inducing the differentiation of HL-60 cells.

Binding Sites ; genetics ; Blotting, Western ; Cell Differentiation ; genetics ; physiology ; Cell Proliferation ; Genetic Vectors ; genetics ; HL-60 Cells ; Humans ; Immunohistochemistry ; Lewis X Antigen ; metabolism ; Proliferating Cell Nuclear Antigen ; metabolism ; Receptors, OSM-LIF ; genetics ; metabolism ; Transfection

OBJECTIVETo study relation of the expression of hTERT mRNA and cyclin A, p53 protein, proliferation cell nuclear antigen (PCNA) in ameloblastoma (AB) and to investigate clinical biological characteristics of AB.

METHODSThe hTERT mRNA was detected by in situ hybridization, cyclin A, p53 protein and PCNA by SP method. Normal oral mucosa and odontogenic keratocyst (OKC) are comparition.

RESULTSThe positive ratio of hTERT mRNA was 1/7 cases in normal oral mucosa. The expression of cyclin A, p53 and PCNA in normal oral mucosa were similar, and the positive cells distributed in stratum basale. In OKC, the positive cells distributed in stratum basale and super-strrtum basale. And the positive ratio of hTERT, cyclin A, p53, PCNA in OKC was 14/16 cases, 4/32 cases, 11/25 cases, 5/9 cases, respectively. In AB, the positive ratio of hTERT mRNA, cyclin A, p53 protein and PCNA was 94.4% (51/54), 66.7% (40/60), 85.7% (42/49) and 78.1% (25/32), respectively. A strong correlation was found between hTERT mRNA with cyclin A, p53 protein and PCNA (r(s) = 0.914, 0.848, 0.804, P < 0.05).

CONCLUSIONSThe expression of hTETR mRNA, cyclin A, p53 and PCNA is different in different tissues and lesions, and correlates with cell differentiation and clinical biology behaviour. Telomerase activity is related to cumulation of p53 protein, related to cell proliferation and differentiation, regulated by cyclin A, and higher in S phase.

Ameloblastoma ; metabolism ; pathology ; Cyclin A ; biosynthesis ; Humans ; Jaw Neoplasms ; metabolism ; pathology ; Proliferating Cell Nuclear Antigen ; biosynthesis ; RNA, Messenger ; biosynthesis ; Telomerase ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis

A common DNA polymerase can replicate DNA which functions normally. However, if DNA suffers damage, the genome can not be replicated by a common DNA polymerase because DNA lesions will block the replication apparatus. Another kind of DNA polymerases in organism, Y-family DNA polymerases which is also called translesion synthesis (TLS) polymerases, can deal with this problem. Their main functions are bypassing the lesions in DNA, replicating the genome and saving the dying cells. This thesis presents a historical review of the literature pertinent to the structure, functions and roles of Y-family DNA polymerases.
DNA Damage ; DNA Repair ; DNA Replication ; DNA-Directed DNA Polymerase ; classification ; metabolism ; physiology ; Humans ; Mutagenesis ; Mutagens ; Proliferating Cell Nuclear Antigen ; genetics

To explore a novel strategy for antisense gene therapy of cancer, the coding sequence of human proliferating cell nuclear antigen (PCNA) cDNA was reversely inserted into the eukaryotic vector pLXSN by molecular cloning techniques and transferred into bladder cancer EJ cells with liposome. The PCNA expression in transferred cells was dynamically detected by immunofluorescence and RT-PCR techniques. Changes of proliferation activities of cancer cells were assayed by MTT colorimetric and cloning formation methods. In the experiment, the antisense eukaryotic vector was successfully constructed and named as pLAPSN. After transfection with it for 1-7 days, PCNA protein and mRNA levels in cancer cells were blocked by 16.74%-84.21% (P < 0.05) and 23.27%-86.15% (P < 0.05) respectively. The proliferation activities of transferred cells were inhibited by 27.91%-62.07% (P < 0.01), with cloning formation abilities being decreased by 50.81% (P < 0.01). It was concluded that the in vitro proliferation activities of cancer cells could be effectively inhibited by blocking PCNA expression with antisense technique, which could serve as an ideal strategy for gene therapy of bladder cancer.
Cell Division ; Cell Line, Tumor ; Cloning, Molecular ; DNA, Complementary ; DNA, Neoplasm ; metabolism ; Eukaryotic Cells ; metabolism ; Gene Expression ; Genetic Vectors ; Humans ; Proliferating Cell Nuclear Antigen ; biosynthesis ; genetics ; RNA, Antisense ; genetics ; Transfection ; Urinary Bladder Neoplasms ; genetics ; metabolism

OBJECTIVETo construct a plasmid vector expressing the short hairpin RNA (shRNA) targeting proliferation cell nuclear antigen (PCNA), and to investigate its effect in vitro on the expression of PCNA, proliferation and apoptosis of human osteosarcoma cells.

METHODSA plasmid vector expressing the short hairpin RNA targeting at PCNA was constructed and transfected into human osteosarcoma cell line MG-63 by dosper liposomal method. PCNA mRNA and protein expressions were examined using RT-PCR and immunohistochemical staining, respectively. Inhibition of the cell proliferation was studied by MTT method and colony forming assay. DNA synthesis was analyzed by (3)H-TdR incorporation and the cell cycle was determined by flow cytometry. The apoptotic cells were stained with acridine orange.

RESULTSExpression of PCNA mRNA after the transfection was markedly inhibited by 80.51% with a PI value of 25.68% of that of the control group. PCNA shRNA inhibited MG-63 cell growth detected by using MTT method, with an inhibition rate of 61.78% at 48 h. DNA synthesis rate also decreased in the (3)H-TdR incorporation test. Flow cytometry analysis showed an increase of the percentage of G(0)/G(1) phase cells, along with a decrease of cell population in the S phase. The apoptosis rate of cells transfected with the plasmid vector was 16.54%.

CONCLUSIONSPCNA shRNA significantly suppresses the expression of PCNA at both mRNA and protein levels, corresponding to an inhibition of the proliferation of MG-63 cell and an increase of the cellular apoptosis.

Apoptosis ; Bone Neoplasms ; metabolism ; pathology ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; Humans ; Osteosarcoma ; metabolism ; pathology ; Plasmids ; Proliferating Cell Nuclear Antigen ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; RNA, Small Interfering ; biosynthesis ; genetics ; Transfection

OBJECTIVE: To investigate the effect of high mobility group box-1 protein (HMGB1) on the proliferative activity of human hepatoma cell line HepG2 and its potential regulating mechanism. METHODS: The cultured HepG2 cells were treated with recombinant HMGB1 (0, 10, 50, and 100 ng/mL, respectively) for 24 h. Cell proliferation was observed by MTT analysis. Western blot and reverse transcriptase-polymerase chain reaction were used to detect the expression of proliferating cell nuclear antigen (PCNA) and cyclin D1 protein and mRNA, respectively. RESULTS: Compared with the control group, HMGB1 at 10, 50, and 100 ng/mL obviously increased HepG2 cells proliferation, cyclin D1 and PCNA protein and mRNA expression after the treatment for 24 h, respectively (P<0.05). Anti-HMGB1 significantly inhibited the proliferation and cyclin D1 and PCNA mRNA and protein expression of HMGB1 on HepG2 cells (P<0.05). CONCLUSION Proliferation of HMGB1 on HepG2 cells may be associated with increasing cyclin D1 and PCNA expression. Anti-HMGB1 may have a therapeutic effect on hepatocellular carcinoma.
Cell Proliferation ; drug effects ; Cyclin D1 ; genetics ; metabolism ; HMGB1 Protein ; pharmacology ; Hep G2 Cells ; Humans ; Proliferating Cell Nuclear Antigen ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Recombinant Proteins ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction