OBJECTIVETo study the effect of down-regulation of histone deacetylase 2 (HDAC2) expression on cell proliferation and cell cycle in cervical carcinoma cell lines HeLa.

METHODSHDAC2 siRNA and control siRNA were transfected to HeLa cells. CCK-8 and flow cytometry were used to analyze the changes of cell proliferation and cell cycle, respectively. Western blot was employed to detect the changes of cell proliferation and cell cycle-related proteins.

RESULTSHDAC2 siRNA significantly down-regulated the expression of HDAC2 protein in HeLa cells, resulting in marked inhibition of cell proliferation. In addition, the percentage of cells in G(0)/G(1) phase in HDAC2 siRNA group (63.3% ± 2.0%) was significantly higher than that in untreated group (29.3% ± 1.7%) or control siRNA group (29.4% ± 1.7%), F = 354.181, P = 0.000. Furthermore, Western blot demonstrated that down-regulation of HDAC2 expression decreased the expression of cyclin D1, cyclin E and CDK2 proteins but increased the expression of p21 protein.

CONCLUSIONSDown-regulation of HDAC2 expression mediates proliferation inhibition and cell cycle arrest. It is associated with decrease in cyclin D1, cyclin E and CDK2 protein expression and increase in p21 protein expression.

Cell Cycle ; Cell Proliferation ; Cyclin D1 ; metabolism ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase 2 ; metabolism ; Down-Regulation ; HeLa Cells ; Histone Deacetylase 2 ; genetics ; metabolism ; Humans ; Oncogene Proteins ; metabolism ; Proto-Oncogene Proteins p21(ras) ; metabolism ; RNA, Small Interfering ; genetics ; Transfection

OBJECTIVETo study the roles of DNA dependent protein kinase (DNA-PK)in silica-induced cell cycle changes and expressions of CyclinE and CDK2 in human embryo lung fibroblasts (HELF).

METHODSThe expressions of Ku80 and DNA-PKcs proteins were inhibited by siRNA plasmids, respectively. Flow cytometry was used to detect the distributions of cell cycle and western blot assay was used to determine the expression levels of CyclinE and CDK2 after cells were exposed to 200 microg/ml silica for 0, 3, 6, 12, 24 h.

RESULTSThe proportion of G1 phases in negative control cells decreased from 83.53% +/- 2.24% to 69.11% +/- 3.12% after exposure to silica; the proportion of G1 phases in H-Ku80 and H-PKcs cells exposed to silica decreased from 85.16% +/- 3.73% to 59.92% +/- 3.31% and from 75.06% +/- 2.23% to 58.32% +/- 1.35%, respectively (P < 0.05). The exposure to silica resulted in the increasing protein expression levels of CyclinE and CDK2 in negative control cells, and the expression levels of CyclinE were obviously suppressed in H-Ku80 and H-PKcs as compared with control cells. However, the expression level of CDK2 protein did not change significantly.

CONCLUSIONDNA-PK might play a role in silica-induced alternations of cell cycle and regulate silica-induced overexpression of CyclinE in human embryo lung fibroblasts.

Cell Cycle ; drug effects ; Cells, Cultured ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase 2 ; metabolism ; DNA-Activated Protein Kinase ; genetics ; metabolism ; Fibroblasts ; cytology ; drug effects ; metabolism ; Humans ; Lung ; cytology ; Nuclear Proteins ; genetics ; metabolism ; Oncogene Proteins ; metabolism ; Silicon Dioxide ; pharmacology

OBJECTIVETo clarify the role of these cyclins in human gastric cancer.

METHODS38 gastric cancer patients, 29 first degree relatives of gastric cancer patients, as well as 18 healthy subjects were included. The mRNA expression of cyclins D1, D2, D3 and E in gastric biopsies was evaluated by RT-PCR analysis using specific primers. Histomorphological features such as intestinal metaplasia, atrophy, H. pylori infection and severity of gastritis were determined by the updated Sydney System.

RESULTSSignificant mRNA overexpression was found for cyclins D2, D3 and E compared with healthy normal specimen, but cyclin D1 expression was not different between tumor and normal tissues. In addition, cyclin D2 and D3 overexpression was significantly more frequent in first degree relatives than in healthy controls (P < 0.05). Among the various pathological findings, the overexpression of cyclins D2 and E was associated with intestinal metaplasia, and the overexpression of cyclin D3 was associated with intestinal metaplasia as well as atrophy. The overexpression of cyclins D2 and D3 was significantly correlated with H. pylori infection. No correlation was observed between the overexpression of cyclin D1 and any pathological variables.

CONCLUSIONThe overexpression of cyclins D2, D3 and E is a frequent event in patients with gastric cancer and their first degree relatives and may be an early event in gastric carcinogenesis.

Adult ; Aged ; Aged, 80 and over ; Cyclin D1 ; genetics ; Cyclin D2 ; Cyclin D3 ; Cyclin E ; genetics ; Cyclins ; genetics ; Family Health ; Gastritis ; genetics ; Gene Expression Regulation, Neoplastic ; Helicobacter Infections ; genetics ; microbiology ; Helicobacter pylori ; growth & development ; Humans ; Middle Aged ; RNA, Messenger ; genetics ; metabolism ; Stomach ; metabolism ; microbiology ; pathology ; Stomach Neoplasms ; genetics ; pathology

OBJECTIVETo investigate the expression of cyclin E mRNA, p21(WAF1) mRNA and p27(KIP1) protein in human ameloblastoma (AB), and to explore the clinical and biological characteristics of AB.

METHODSThe expression of cyclin E mRNA, p21(WAF1) mRNA and p27(KIP1) protein in 54 cases of human AB were detected by in situ hybridization or immunohistochemistry (SP method).

RESULTSThe positive expression rate of cyclin E mRNA in the cytoplasm or cell nucleus of AB was 66.7% (36/54). The expression of cyclin E mRNA increased with AB recurrence and malignant transformation, and the difference of expression among primary AB, recurrent AB, and malignant AB, was statistically significant. The positive expression ratio of cyclin E mRNA in OKC was 50.0% (8/16). The p21(WAF1) mRNA expression in the cytoplasm or cell nucleus of AB decreased, and the positive ratio was 22.6% (12/54) in AB, 37.5% (6/16) in OKC, respectively. The p27(KIP1) protein expression in the cell nucleus of AB was positive in a small number of cases, and the positive rate was 16.7% (9/54) in AB, 6.3% (1/16) in OKC, respectively.

CONCLUSIONSThe genesis and invasion of AB is associated with the cell proliferation and differentiation, and regulated by the higher expression of cyclin E and the lower expression of p21(WAF1) and p27(KIP1).

Adolescent ; Adult ; Aged ; Ameloblastoma ; metabolism ; pathology ; Child ; Cyclin E ; genetics ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; Female ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Jaw Neoplasms ; metabolism ; pathology ; Middle Aged ; Oncogene Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Young Adult

OBJECTIVETo evaluate the value of FOXP1 and Cyclin E gene in primary central nervous system lymphoma(PCNSL) of immunocompetent patients on prognostic significance.

METHODSClinical data of 71 patients with newly diagnosed PCNSL from 2002 to 2007 was analyzed retrospectively. Immunohistochemistry method (HRP-EnVision(TM)) was performed to observe the expression of FOXP1 and Cyclin E gene in tumor tissue samples. The survival was analyzed by Kaplan-Meier survival curve, survival factors analysis by the Log-rank test and COX proportional hazards regression model.

RESULTSFOXP1 positive was observed in 35 of 51 patients (68.63%) and Cyclin E staining was present in 29 of 50 cases (58.00%). FOXP1(+) patients had a shorter overall survival (OS) than FOXP1(-) ones. 2-year OS rate in FOXP1(+) and FOXP1(-) patients were 23.33% and 73.56%, respectively(P = 0.0015). Cyclin E(+) patients had a shorter overall survival(OS) than cyclinE(-) ones. 2-year OS rate in Cyclin E(+) and Cyclin E(-) patients were 17.56% and 69.76%, respectively (P = 0.0017). Multivariate analysis showed that Cyclin E expression was an independent prognostic factor for shorter OS (P = 0.048). FOXP1 expression might be an important prognostic factor for shorter OS (P = 0.065).

CONCLUSIONCyclin E expression is an independent prognostic factor and FOXP1 expression is a possible prognostic factor for poor clinical outcome in patients with PCNSL.

Aged ; Aged, 80 and over ; Central Nervous System Neoplasms ; genetics ; metabolism ; Cyclin E ; genetics ; metabolism ; Female ; Forkhead Transcription Factors ; genetics ; metabolism ; Humans ; Lymphoma, Non-Hodgkin ; genetics ; metabolism ; Male ; Middle Aged ; Prognosis ; Repressor Proteins ; genetics ; metabolism ; Retrospective Studies ; Survival Rate

OBJECTIVE: To investigate the role of histone deacetylase 7 (HDAC7) in the occurrence and development of hepatocellular carcinoma. METHODS: HepG2 cells and human microvascular endothelial cells (HMEC-1) were divided into 3 groups after transfection pSUPER-HDAC7 retroviral interference plasmid: a pSUPER(HDAC7RNAi+) group, a pSUPER(HDAC7RNAi-) group, and a pSUPER group as the control group. The expression of HDAC7, p21, cyclin E, matrix metalloproteinases 10 (MMP10), and hypoxiainducible factor-1alpha (HIF-1alpha) were detected by Western blot. The expression of HDAC7 in cell lines was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, the nude mice modle, and vascular endothelial cells 2-dimensional tubulogenesis in vitro and in vivo. RESULTS: Compared with the control group and the pSUPER(HDAC7RNAi-) group, the expression of HDAC7 was downregulated, the rate of cell growth inhibition and apoptosis in the pSUPER(HDAC7RNAi+) group increased more significantly; the expression of p21 and HIF-1alpha was increased significantly, while the expression of cyclin E and MMP10 in the pSUPER(HDAC7RNAi+) group was downregulated (P<0.05). CONCLUSION The expression of HDAC7 protein plays an important role in the apoptosis and vascular tubulogenesis of hepatocellular carcinoma by the upregulation of p21 and HIF-1alpha and the downregulation of cyclin E and MMP10.
Animals ; Apoptosis ; genetics ; Cells, Cultured ; Cyclin E ; genetics ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; metabolism ; Endothelial Cells ; cytology ; metabolism ; Hep G2 Cells ; Histone Deacetylases ; genetics ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Matrix Metalloproteinase 10 ; genetics ; metabolism ; Mice ; Mice, Nude ; Neovascularization, Pathologic ; genetics ; RNA Interference ; Transfection

To identify the integration sites in the host genome for the hepatitis B virus (HBV)-encoded X protein (HBx) in hepatocellular carcinoma (HCC) biopsies that are positive for hepatitis B surface antigen (HBsAg). HCC biopsies were obtained from six patients that were HBV carriers, as demonstrated by the presence of HBsAg in their serum and sero-negativity for antibody to HBsAg. DNA was extracted from the tissue, fractionated, and circularized. Primers were designed according to the HBx sequence and used to amplify the circularized DNA templates by inverse polymerase chain reaction (IPCR). The amplified DNA fragments were checked by electrophoresis, cloned into the PMD18-T expression vector, and sequenced. Sequence alignment was performed by the Blast algorithms. Seven electrophoresis bands yielded 22 sequencing results, which represented a total of three HBx integration sites in the host genome: 19q12, 2q32.2, 22q12. The 19q12 integration site encompasses the CCNE1 gene, which encodes a G1/S-specific cyclin-E1. HBx-related integration sites exist in HBsAg-positive HCC biopsies. The CCNE1 gene may play a role in the development of HBx-related HCC.
Carcinoma, Hepatocellular ; blood ; genetics ; Cyclin E ; genetics ; DNA Primers ; DNA, Viral ; genetics ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B virus ; genetics ; physiology ; Humans ; Liver Neoplasms ; blood ; genetics ; Oncogene Proteins ; genetics ; Trans-Activators ; genetics ; Virus Integration

OBJECTIVETo detect the expression of histone deacetylase 6 (HDAC6) in laryngeal squamous cell carcinoma, and to analyze the effects of downregulation of HDAC6 expression on cell cycle, proliferation and migration of laryngeal squamous cell carcinoma cell line Hep-2 cells, and to explore their possible molecular mechanisms.

METHODSImmunohistochemistry was used to detect the expression of HDAC6 protein in 55 cases of laryngeal squamous cell carcinoma and 20 cases of normal laryngeal mucosa. HDAC6 siRNA and control siRNA were transfected into Hep-2 cells via lipofectamine 2000, and the interfering effect was analyzed using Western blotting. The effects of downregulation of HDAC6 expression on cell cycle, proliferation and migration were determined by cell counting kit-8 (CCK-8), flow cytometry and Boyden chamber, respectively. Finally, Western blotting was used to detect the expressions of cell cycle, proliferation and migration related proteins.

RESULTSThere was a high level expression of HDAC6 protein in laryngeal squamous cell carcinoma, and its expression was not related to age and sex of the patients (P > 0.05), but closely associated with the degree of histological differentiation, TNM staging and lymph node metastasis (P < 0.05). HDAC6 siRNA effectively down-regulated the expression of HDAC6 protein in laryngeal squamous cell carcinoma cell line Hep-2 cells, and downregulation of its expression obviously inhibited cell proliferation, arrested cell cycle at G(0)/G(1) phase and decreased cell migration ability in Hep-2 cells. Additionally, the downregulation of HDAC6 protein expression markedly decreased the expressions of cyclin D1, cyclin E, cdk2 and MMP-9 proteins, but increased the expressions of p21 and E-cadherin proteins.

CONCLUSIONSHDAC6 may play a pivotal role in the carcinogenesis and development of laryngeal squamous cell carcinoma. The downregulation of HDAC6 expression-mediated cell proliferation inhibition, cell cycle arrest and decreased cell migration ability may be closely associated with the decrease of cyclin D1, cyclin E, cdk2 and MMP-9 proteins and increase of p21 and E-cadherin proteins.

Adult ; Aged ; Cadherins ; metabolism ; Carcinoma, Squamous Cell ; genetics ; metabolism ; pathology ; Cell Cycle ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Cyclin D1 ; metabolism ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase 2 ; metabolism ; Down-Regulation ; Female ; Histone Deacetylase 6 ; Histone Deacetylases ; genetics ; metabolism ; Humans ; Laryngeal Neoplasms ; genetics ; metabolism ; pathology ; Lymphatic Metastasis ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; Neoplasm Staging ; Oncogene Proteins ; metabolism ; Proto-Oncogene Proteins p21(ras) ; metabolism ; RNA, Small Interfering ; genetics ; Transfection

Deregulation of G1 cyclins has been reported in several human and rodent tumors including colon cancer. To investigate the expression pattern of G1 cyclins in 1,2- dimethyl-hydrazine dihydrochloride (DMH)-induced rat colon carcinogenesis, we studied the expression of cyclin D1 and cyclin E by quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry (IHC). The mRNA level of cyclin D1 was increased 1.2-fold in adenocarcinomas but not significantly in adenomas, when compared with normal rat colonic mucosa (p<0.05). The cyclin E mRNA level was increased 2.7-fold in adenomas and 3.3-fold in adenocarcinomas (p<0.05). The PCNA mRNA level was also increased 1.9-fold in adenomas and 1.8-fold in adenocarcinomas (p<0.05). Immunohistochemical staining revealed exclusive nuclear staining of the neoplastic cells for cyclin D1, cyclin E and PCNA. Cyclin D1 expression was detected in 56.3% of the adenomas and in 61.5% of the adenocarcinomas examined, whereas cyclin E expression was detected in 87.5% of the adenomas and in 92.3% of the adenocarcinomas. Overall, cyclin D1, cyclin E and PCNA expression was significantly increased at both the mRNA and protein levels in normal colonic mucosa, adenomas and adenocarcinomas, but there was no significant difference in the degree of expression of these genes in adenomas and adenocarcinomas. Our results indicate that the overexpression of cyclin D1 and cyclin E may play an important role during the multistage process of rat colon carcinogenesis, at a relatively early stage, and may disturb cell-cycle control in benign adenomas, and thereafter, participate in tumor progression.
1,2-Dimethylhydrazine/toxicity ; Adenocarcinoma/*chemically induced/metabolism ; Adenoma/*chemically induced/metabolism ; Animals ; Carcinogens/toxicity ; Cell Cycle/drug effects/physiology ; Colon/metabolism ; Colonic Neoplasms/*chemically induced/metabolism ; Cyclin D1/*biosynthesis/genetics ; Cyclin E/*biosynthesis/genetics ; Gene Expression Regulation, Neoplastic ; Immunohistochemistry ; Male ; Proliferating Cell Nuclear Antigen/biosynthesis/genetics ; RNA, Messenger/metabolism ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo detect the gene expression profile in gastric cancer cell cycle and explain the mechanism of gastric cancer cell proliferation by a genomic study.

METHODSGastric cancer cells MKN45 were synchronized at G2/M and G1/S point by nocodazole-thymidine and double thymidine methods. The synchronizing degree of cells was monitored by flow cytometry. The gene expression profiles at G2/M point, M/G1 transition, G1 early phase, G1 late phase, G1/S point, S early phase, S late phase, G2 early phase and G2 late phase in MKN45 cell cycling were examined using cDNA microarray chips. Hierarchy analysis was conducted with a professional software package and the up-regulated genes at G1 late and G2 phase were analyzed according to gene database. Furthermore, the mRNA level of cyclin E, cyclin B, plk1 and STK15 in above mentioned nine points were measured by quatitative PCR.

RESULTS2001 genes were detected to be available at all 9 points via software processing, out of which 959 appeared up-regulated or down-regulated. 379 genes showed to be up-regulated at late G1 (147) or G2 phases (232), 40 at S and M phases (also up-regulated at G1 late and G2 phases). The 147 up-regulated genes at G1 late phase are involved in DNA metabolism, transcription and translation, protein transportation, ubiquitination and signal transduction, etc. The 232 up-regulated genes in G2 phase are involved in RNA synthesis and processing, intracellular protein transportation, cytoskeleton synthesis, signal transduction, apoptosis and anti-apoptosis, transcription regulation, ubiquitination, mitosis regulation and oncogene expression, etc. The mRNA level of 4 genes detected by quantitative PCR during cell cycle was in agreement with that detected by microarray.

CONCLUSIONDuring MKN45 cell cycling, the preparation for DNA synthesis and chromosome separation are conducted in G1 and G2, which are implicated in multiple genes, may be the main impetus of driving MKN45 cell cycle. Some of these genes may be related to tumor over-proliferation. The cDNA microarray technique has characteristic features such as reliability and can provide a great deal for future research on cell cycle related genes in gastric cancer.

Aurora Kinase A ; Aurora Kinases ; Cell Cycle ; genetics ; Cell Cycle Proteins ; genetics ; Cell Line, Tumor ; Cyclin B ; genetics ; Cyclin E ; genetics ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Humans ; Oligonucleotide Array Sequence Analysis ; methods ; Polymerase Chain Reaction ; methods ; Protein-Serine-Threonine Kinases ; genetics ; Proto-Oncogene Proteins ; genetics ; RNA, Messenger ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; pathology