This study was aimed to investigate the anti-proliferation effect of interferon-alpha (IFN-alpha) on leukemic U937 cells and its mechanism. The U937 cells were given with various concentrations of IFN-alpha (500, 1 000, 2,000, 3,000 and 4,000 U/L) and at different time (0, 12, 24, 36, 48 hours), the inhibitory ratio was measured by MTT assay, apoptosis rate was detected by flow cytometry (FCM), the expression of cell cycle-associated cyclin E mRNA was measured by RT-PCR. The results showed that IFN-alpha (2,000 U/L) could cause apoptosis, after being treated by various concentrations of IFN-alpha, the growth of U937 cells was inhibited significantly, the apoptosis rate was 25.82% - 70.54% (P < 0.01), the cycle-associated cyclin E mRNA expression decreased, the growth of U937 cells was significantly inhibited, the suppression of U937 by IFN-alpha was both in time-and dose-dependent manner. It is concluded that IFN-alpha has apparent anti-proliferation and apoptosis-inducing effects on U937 cells. These results will provide strong laboratory evidence for IFN-alpha clinical application in leukemia therapy.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Cyclin E ; biosynthesis ; genetics ; Humans ; Interferon-alpha ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; U937 Cells

OBJECTIVETo explore the effect of transforming growth factor alpha (TGFalpha) on the expression of cyclin E and D1 in gastric carcinoma cells.

METHODSHuman gastric adenocarcinoma SGC7901 cells were cultured routinely and synchronized at G(0)/G(1) phase in serum-free RPMI-1640. The percentage of the cells at G(0)/G(1) phase was detected by propidium iodide staining and flow cytometry (FCM), and the synchronized cells were cultured in RPMI-1640 supplemented with 2.5% calf serum and treated with 10, 30, and 50 microg/L TGFalpha for 5 h. The expression of cyclin E and D1 in SGC7901 cells was detected by immunofluorescent staining and FCM.

RESULTSThe percentage of the cells at G(0)/G(1) phase increased from 54% in routine culture to 72% in the serum-free RPMI-1640 culture. TGFalpha treatment of the cells synchronized at G(0)/G(1) phase induced significant increment of cyclin E and D1 expressions (P<0.001), and at the dose of TGFalpha of 50 microg/L, their expressions increased by 25.18% and 27.52%, respectively (P<0.001).

CONCLUSIONTGFalpha can increase the expression of cyclin E and D1 in gastric carcinoma cells to promote their cell cycle progress.

Adenocarcinoma ; metabolism ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cyclin D1 ; biosynthesis ; Cyclin E ; biosynthesis ; Flow Cytometry ; Fluorescent Antibody Technique ; Humans ; Stomach Neoplasms ; metabolism ; pathology ; Transforming Growth Factor alpha ; pharmacology

OBJECTIVETo investigate the expression of pRb and E2F-1, and the association between their expression and the activity of telomerase (hTERT) or cyclin E in human ameloblastoma (AB), and to explore the clinical biological characteristics of AB.

METHODSThe expressions of pRb, E2F-1, cyclin E and hTERT mRNA in human AB were detected by in situ hybridization or immunohistochemistry (SP method).

RESULTSThe positive expression ratio of pRb in the cell nucleus of AB was 20.4% (11/54). The positive ratio of E2F-1, cyclin E and hTERT mRNA was 92.6% (50/54), 66.7% (36/54) and 94.4% (51/54), respectively. With AB recurrence and malignant transformation, the expression of hTERT, E2F-1, cyclin E was up-regulated. hTERT and cyclin E or E2F-1 mRNA had high positive relation (Spearsman'r(s) = 1.000, P = 0.0001).

CONCLUSIONSThe regulatory pathway of Rb/E2F-1 is associated with the cell proliferation and in differentiation of AB. The activity or release of telomerase may be related to the lower expression of Rb and higher expression of E2F-1, and is up-regulated in G(1) late phase by cyclin E.

Adolescent ; Adult ; Aged ; Ameloblastoma ; metabolism ; pathology ; Child ; Cyclin E ; biosynthesis ; E2F1 Transcription Factor ; biosynthesis ; Female ; Humans ; Jaw Neoplasms ; metabolism ; pathology ; Male ; Middle Aged ; RNA, Messenger ; biosynthesis ; Retinoblastoma Protein ; biosynthesis ; Telomerase ; genetics ; metabolism

Intimal hyperplasia is defined as the abnormal migration and proliferation of vascular smooth muscle cells (VSMCs) with deposition of extracellular matrix. However, the cell cycle regulatory mechanisms of injury-induced VSMC proliferation are largely unknown. To examine the expression kinetics of cell cycle regulatory factors which is known to be worked positively or negatively, we used rat balloon injury model. Marked induction of proliferating cell nuclear antigen (PCNA), G1/S cyclin-dependent kinase (cdk2), and its regulatory subunit (cyclin E) occurred between 1 and 3 days after balloon arterial injury, and this was sustained for up to 7 days and then declined. However, the induction of the negative regulators, p21 and p27, occurred between 3 and 5 days of injury, peaked after 7 and 14 days and was then sustained. VSMC proliferation after balloon catheter injury of the rat iliac artery is associated with coordinated expression of positive (cdk2, cyclin E and PCNA) and negative (p21, p27) regulators. Cell cycle regulators such as cdk2, cyclin E, p21, p27 may be suitable targets for the control of intimal hyperplasia.
Animals ; Arteries/*pathology ; Balloon Dilatation/*adverse effects ; Blotting, Western ; CDC2-CDC28 Kinases/biosynthesis ; Cell Cycle ; Cell Cycle Proteins/biosynthesis ; Cell Division ; Cyclin E/biosynthesis ; Cyclins/biosynthesis ; Endothelium, Vascular/pathology ; Extracellular Matrix/metabolism ; Hyperplasia/pathology ; Iliac Artery/pathology ; Immunohistochemistry ; Male ; Myocytes, Smooth Muscle/*cytology ; Proliferating Cell Nuclear Antigen/biosynthesis ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't ; Time Factors ; Tumor Suppressor Proteins/biosynthesis

OBJECTIVETo investigate the effects of ginsenoside Rh2 (GS-Rh2) on growth inhibition and cell cycle of Eca-109 esophageal carcinoma cell line in culture.

METHODThe effects of GS-Rh2 on cell growth inhibition was detected by MTT assay. Cell cycle was analyzed by flow cytometry (FCM). Cell morphology was observed by a light microscope after HE staining. The protein expression of cell cycle components (cyclinE, CDK2, p21WAF1) were examined by immunocytochemistry and Western blot. The mRNA expression were examined by semiquantitative RT-PCR.

RESULTGS-Rh2 inhibited the proliferation of Eca-109 cells in dose and time-dependent manners. The inhibition rate was about 50% after 1-day treatment with 20 microg x mL(-1) GS-Rh2 x 20 microg x mL(-1) GS-Rh2 induced the mature differentiation and morphological reversion. With increasing dose of GS-Rh2 treatment, the cell number of G0/G1 phase was increased, whereas it decreased at S and G2/M phase. There was significant difference between 10, 20 microg x mL(-1) GS-Rh2 groups and the corresponding group without GS-Rh2 treatement. After treating cells by 20 microg x mL(-1) GS-Rh2 for 1, 2, 3 days individually, the protein and mRNA expression of both cyclinE and CDK2 reduced, while the expression of p21WAF1 enhanced gradually.

CONCLUSIONGS-Rh2 could arrest Eca-109 cells at G0/G1 phase and induce cell differentiation tending to normal. Furthermore, GS-Rh2 had an effect on expression of cell cycle components (cyclinE, CDK2 and p21WAF1) to inhibit Eca-109 cell proliferation.

Carcinoma, Squamous Cell ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclin E ; biosynthesis ; genetics ; Cyclin-Dependent Kinase 2 ; biosynthesis ; genetics ; Cyclin-Dependent Kinase Inhibitor p21 ; biosynthesis ; genetics ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Esophageal Neoplasms ; metabolism ; pathology ; Ginsenosides ; administration & dosage ; isolation & purification ; pharmacology ; Humans ; Panax ; chemistry ; Plants, Medicinal ; chemistry ; RNA, Messenger ; biosynthesis ; genetics ; Time Factors

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 confirm the relations between the expression of cyclin E, p16ink4, ki67 and HPV16/18 infection using cervical exfoliated cells, and evaluate the usefulness of cyclin E, p16ink4 and ki67 as biomarkers for screening of cervical carcinomas.

METHODSThe expression of cyclin E, p16ink4 oncoproteins and ki67 proliferative activity was evaluated immunohistochemically in 78 cervical exfoliated epithelial specimens. Human papillomavirus type16 and 18 (HPV16/18) infection was assessed by polymerase chain reaction (PCR) using type specific primers.

RESULTSCyclin E, p16ink4 and ki67 were all overexpressed in cervical preneoplasia and neoplasia cells, compared with little expressed in ASCUS (P less than 0.005). Overexpression of cyclin E was observed in CIN, (P less than 0.01), p16ink4 and ki67 overexpressed in invasive carcinoma(100 percent and 90.9 percent respectively). The degree of p16ink4 and ki67 expression correlated well with the degree of cervical neoplasia (P less than 0.005). HPV16 infection was assessed at all stages of cervical neoplasia samples, and a significant relationship with the degree of cervical epithelial lession was observed at the same time. The expression level of p16ink4 and ki67 seemed to be more closely associated with HPV16 infection than cyclin E did (rs=1.0 vs rs=0.4). HPV18 was found positive in only 1 case in CIN1 and in 4 cases in CIN2-3. Therefore no significance was found on statistical analysis (P less than 0.005).

CONCLUSIONCyclin E, p16ink4 and ki67 should be regarded as useful biomarkers of HPV-related cervical neoplasias, and be used for screening patients at high risk for developing cervical carcinomas. Moreover, cyclin E might be a significant cytologic marker for the primary screening of cervical carcinomas.

Adult ; Aged ; Cervical Intraepithelial Neoplasia ; metabolism ; pathology ; virology ; Cervix Uteri ; cytology ; metabolism ; virology ; Cyclin E ; biosynthesis ; Cyclin-Dependent Kinase Inhibitor p16 ; biosynthesis ; DNA, Viral ; genetics ; Female ; Host-Pathogen Interactions ; Human papillomavirus 16 ; genetics ; physiology ; Human papillomavirus 18 ; genetics ; physiology ; Humans ; Immunohistochemistry ; Ki-67 Antigen ; biosynthesis ; Middle Aged ; Papillomavirus Infections ; metabolism ; pathology ; virology ; Polymerase Chain Reaction ; Uterine Cervical Neoplasms ; metabolism ; pathology

Cyclin E2 is present in solid tumors, while its expression and clinical value in acute leukemia is unknown. This study was aimed to investigate the expression of cyclin E2 and survivin gene in bone marrow cells from patients with acute leukemia and their relationship. Reverse transcription polymerase chain reaction was used for detection of the expression of cyclin E2 and survivin mRNA in 84 adult patients with acute leukemia which included 16 cases of relapse, 60 cases of de novo acute leukemia, 8 cases of continuously complete remission, and 20 normal persons as controls. The results showed that (1) positive expression of cyclin E2 (70.24%) in acute leukemia patients was significantly higher than that (0%) in controls, positive expression of survivin (72.62%) in acute leukemia patients was higher than that (30%) in control. (2) the expression of cyclin E2 positively correlated with that of survivin in acute leukemia patients. (3) remission rate in cyclin E2-positive patients (55.81%) was lower than that (88.24%) in cyclin E2-negative patients, the rate of cyclin E2 expression in relapse group was the highest among the three groups; while that in continuously complete remission group was the lowest among the three groups. (4) positive rate of cyclin E2 expression (59.32%) in patients with acute myelocytic leukemia was lower than that (96%) in patients with acute lymphocytic leukemia, no correlation between cyclin E2 expression and white blood cell counts of patients was found. It is concluded that the overexpression of cyclin E2 has been confirmed for the first time to positively correlate with the expression of the survivin in acute leukemia patients, and implicate the poor prognosis. Cyclin E2 may be used as a marker for examination of minimal residual disease.
Acute Disease ; Adolescent ; Adult ; Cyclin E ; biosynthesis ; genetics ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; Leukemia ; metabolism ; Leukemia, Myeloid, Acute ; metabolism ; Male ; Microtubule-Associated Proteins ; biosynthesis ; genetics ; Middle Aged ; Neoplasm Proteins ; biosynthesis ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; metabolism ; RNA, Messenger ; biosynthesis ; genetics

AIMTo study the antitumor mechanism of 3-substituted aryl oxindole (PH II-7) and determine its effects on cell cycle distribution of tumor cells.

METHODSThe cell cycle distributions were determined with FACS. The cell cycle regulation-related proteins of K562 lysates were analyzed with Western Blot. The inhibition of PH II-7 on DNA synthesis of tumor cells were estimated though 3H-thymidine incorporation and the tyrosine kinase activity of EGFR of A431 lysates was measured with ELISA.

RESULTSPH II-7 effected cell cycle distribution of several tumor cells, including multidrug resistant tumor cell lines, and accumulation of cells in the G0-G1 stages was observed. The cell cycle regulation-related proteins CDK2, Rb and c-myc were inhibited by PH II-7 in a dose dependent manner, whereas the expression of CyclinE was increased after exposure to PH II-7. Furthermore, PH II-7 2.0 mg.L-1 was shown to inhibit the incorporation of 3H-thymidine into DNA, and 21.89%-41.29% of the PTK activity of EGFR in A431 lysates was inhibited by PH II-7 2-8 mg.L-1 in a dose-dependant manner.

CONCLUSIONPH II-7, a new anti-tumor agent, blocks the transition of cell cycle of tumor cells from G1 to S phase by inhibition CDK2.

Antineoplastic Agents ; pharmacology ; CDC2-CDC28 Kinases ; metabolism ; Cell Cycle ; drug effects ; Cell Cycle Proteins ; metabolism ; Cyclin E ; metabolism ; Cyclin-Dependent Kinase 2 ; DNA, Neoplasm ; biosynthesis ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Humans ; Indoles ; chemical synthesis ; pharmacology ; K562 Cells ; pathology ; Proto-Oncogene Proteins c-myc ; metabolism ; Retinoblastoma Protein ; metabolism