BACKGROUND: Altered cell cycle regulation may underlie the development and/or progression of human malignancies. The purpose of this study is to determine if the oncogenesis of soft tissue sarcomas could be better explained by examining the components involved in G1 phase progression. METHODS: Sixty-seven soft tissue sarcomas were studied for the immunohistochemical expression of cdk4, cyclin D1, retinoblastoma (Rb) and p16 proteins. For Rb and p16, samples showing either negative or heterogeneous (<80% of tumor cells) staining were considered to be altered. RESULTS: The cdk4 protein was observed in 64 cases (95.5%). Cyclin D1 was expressed in 14 cases (20.9%). The Rb expression was altered in 48 (71.6%). Sixty-three (94%) sarcomas demonstrated altered p16 expressions. All of the samples displayed altered expressions of either Rb or p16. A high percentage of the tumors with altered Rb were observed in relapsed patients (p<0.05). CONCLUSIONS: Disturbance in the cell cycle regulatory system involving the Rb/p16/cdk4/cyclin D1 pathway appears to be relatively frequent in soft tissue sarcomas and may play an important role in the tumorigenesis of these tumors. It is noteworthy that the reduced Rb expression correlates with tumor relapse, suggesting its prognostic significance.
Carcinogenesis ; Cell Cycle ; Cyclin D1* ; Cyclin-Dependent Kinase 4 ; Cyclins* ; G1 Phase ; Humans* ; Recurrence ; Retinoblastoma ; Retinoblastoma Protein* ; Sarcoma*

This study was purposed to explore the expression of P27(kip1)and cyclin G in patients with acute leukemia (AL) and its correlation. The reverse polymerase chain reaction (RT-PCR) was used to analyse the expression of P27(kip1) and cyclin G mRNA in 89 AL patients and 10 normal persons; Western blot was used to analyze the expression of P27(kip1) and cyclin G protein in 39 AL patients and 10 normal persons. The results showed that the cyclin G mRNA and protein expressions in new diagnosed/relapsed cases of AL were significantly higher than those in patients with remission and normal controls (p < 0.05 and p < 0.01), but there was no difference between remission cases and normal controls (p > 0.05). The expression of P27(kip1) mRNA in newly diagnosed/relapsed patients with AL was not significantly different from patients with remission and normal controls (p > 0.05), while the P27(kip1) protein expression in remission cases of AL and normal controls was significantly higher than that in new diagnosed/relapsed cases (p < 0.05), but there was no difference between remission cases and normal controls (p > 0.05). The expression of P27(kip1) negatively and lowly correlated with the expression of cyclin G in patients with AL. It is concluded that the low expression of P27(kip1) and the high expression of cyclin G in patients with AL may have some correlation with genesis and development of AL and may be an indication for poor prognosis of AL.
Adult ; Cyclin G1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Female ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Male

OBJECTIVETo confirm the unscheduled in vivo and in vitro expression models of cyclin B1 in cancer cells so as to study the different profiles of cyclin B1 in G(1)-phase immortal cells under different culture states and culture conditions.

METHODSMultiparameter flow cytometry (FCM) was used to correlate the expression of cyclin B1 with the position in cell cycle of immortal cells in vivo and in vitro using the MOLT-4 cell line as control. Cells which belonged to G(1)-phase were sorted by FCM according DNA diploidy, and then the expression of cyclin B1 was examined by confocal microscope to confirm the results. For further analysis, different subgroups in G(1) phase were sorted according to the fluorescent intensity of cyclin E, and then the exact period in G(1) phase when cyclin B1 was expressed, were assayed by Western blot.

RESULTSUnscheduled expression of cyclin B1 expressed in G(1)-phase was found not only in synchronized leukemia cells MOLT-4 and in vivo transformed T-7 cells, but also in vivo tumor cells detached from clinical samples. In the synchronized growing cells, cyclin B1 was mainly detected in the early G(1) phase, while in transformed T7 cells, cyclin B1 was mainly detected in the late G(1) phase.

CONCLUSIONThe limitation of detecting cyclin B1 is due to its unscheduled expression, rending cyclin B1 being detected at different time-spots in the G(1) phase. This phenomenon may be related to the adjustment between the loss of control in cell proliferation and cell apoptosis, thereby leading to tumorigenesis.

Apoptosis ; physiology ; Cell Line, Transformed ; Cyclin B ; biosynthesis ; Cyclin B1 ; Flow Cytometry ; G1 Phase ; physiology ; Humans ; Tumor Cells, Cultured

PURPOSE: Cyclin D1 plays critical roles in the progression of cells through the G1 phase of the cell cycle, which has been implicated as a putative protooncogene, while p53 protein affects different phase checkpoint pathways in the normal cell cycle, which mutations occur in poor prognosis of cancer. We attempted to determine their significance for tumor behavior and prognosis of transitional cell carcinoma(TCCa) of the bladder in human. MATERIALS AND METHODS: Formalin fixed-paraffin embedded tissue specimens from 102 patients with TCCa of the urinary bladder were examined. Nuclear expression was detected by immunohistochemical analysis with a standard avidin-biotin immunoperoxidase method, using the monoclonal antibody cyclin D1 and p53(DO7). RESULTS: Cyclin D1 and p53 protein immunostaining of the nucleus was observed in 49 tumors(48.0%) and 55 tumors(53.9%) respectively. Overexpression of cyclin D1 showed significant inverse correlation with the histological grade and significant correlation with recurrence. Overexpression of p53 protein showed a significant correlation with the histological grade and stage(p<0.01). 65.3% (32 out of 49 tumors), of the cyclin D1 positive tumors exhibited expression for p53 protein(p<0.05). Patients with TCCa coexpressing cyclin D1 and p53 protein had a significantly poorer prognosis than those expressing neither cyclin D1 nor p53 protein(p<0.001). CONCLUSIONS: Cyclin D1 in bladder TCCa is closely related to early tumor differentiation and associated with recurrence. Simultaneous overexpression of both cyclin D1 and p53 protein is related to more aggressive tumor behavior and poorer prognosis. This indicates that cyclin D1 evaluation may be a further useful element for selecting subgroup of patients who should be treated with more aggressive therapies.
Carcinoma, Transitional Cell* ; Cell Cycle ; Cyclin D1* ; Cyclins* ; Formaldehyde ; G1 Phase ; Humans ; Prognosis ; Recurrence ; Urinary Bladder*

PURPOSE: Cyclins, and their associated cyclin dependent kinases, regulate progression of the cell cycle through the G1 phase and into the S-phase during the DNA replication process. Cyclin E regulation is an important event in cell proliferation. Despite its importance, abnormalities of these genes and their protein products have yet to be found in lits asoociation with lung cancer. MATERIALS AND METHODS: The relationships between expression of cyclin A, cyclin B1, cyclin D1, cyclin D3, and cyclin E and clinicopathologic factors were investigated in 103 cases with non-small cell carcinomas, using immunohistochemical analysis. RESULTS: The positive immunoreactivity was observed in 51 cases (50%) for cyclin A, 33 cases (32%) for cyclin B1, 83 cases (81%) for cyclin D1, 19 cases (18%) for cyclin D3, and 11 cases (11%) for cyclin E. Expression of cyclin E was significant for lymph node metastasis (p=0.004, Chi-square test). There was no relationship between cyclin A, B1, D1, and E and histological typing, tumor size, lymph node metastasis, or pathological tumor, node and metastasis staging. CONCLUSION: These findings suggest that the expression of cyclin E played a role, to some degree, in the lymph node metastasis.
Adenocarcinoma ; Carcinoma, Squamous Cell ; Cell Cycle ; Cell Proliferation ; Cyclin A ; Cyclin B1 ; Cyclin D1 ; Cyclin D3 ; Cyclin E ; Cyclin-Dependent Kinases ; Cyclins ; DNA Replication ; G1 Phase ; Lung ; Lung Neoplasms ; Lymph Nodes ; Neoplasm Metastasis

The cell cycle is the set of events that is responsible for the duplication of the cells. Recent studies indicate that cell cycle regulatory proteins, mainly the cyclins and cyclin-related genes, can be critical targets during oncogenesis. The genes and gene products normally control specific events in the cell cycles, particularly during the late G1 and early S phase and G2/M phase. A large body of date implicates cyclins in oncogenesis. The first evidence came from human cyclin A in oncogenesis. Cyclin A is expressed from the late G1 phase through the M-phase of the cell cycle. Cyclin A is known as positive regulator of cell cycle and participates in the tumorigenesis. Overexpression of cyclin A has been reported in several cancers. Ki-67 is a nuclear protein expressed during the cell cycle except in Go. The labeling index of Ki-67 in the tumor cell nuclei has been used as a good prognostic factor. In this study, we compared labeling index of cyclin A and Ki-67 to assess the feasibility between them with 30 cases of cervical intraepithelial neoplasia(CIN) and 20 cases of invasive squamous cell carcinoma(SCC)by immunohistochemistry. The results were as follow; 1. Cyclin A expressed in normal parabasal cells and their labeling index was 0.8+/-0.4%, while in CIN and invasive SCC 65.5+/-9.4% and 86.5+/-12.3% respectively. Ki-67 expressed in normal parabasal cells as 1.3+/-0.7% while in CIN and invasive SCC as 77.8+/-12.9% and 92.2+/-17.6% respectively. 2. In CIN, the expression of cyclin A increased according to the grades of the CIN as 32.5+/-5.7%, 75.8+/-9.0%, and 83.2+/-13.4% in CIN I, II and III respectively. The expression of the Ki-67 also increased according to the grades of the CIN as 51.8+/-9.8%, 87.9+/-11.3%, and 93.6+/-17.5% respectively in CIN I, II and III. 3. There was no differences of cyclin A and Ki-67 expressions according to the histologic types of invasive SCC. Above results suggests that the cyclin A labeling index could be used as a marker of tumor progression in the uterine cervical carcinoma as Ki-67.
Carcinogenesis ; Cell Cycle ; Cell Cycle Proteins ; Cell Nucleus ; Cyclin A* ; Cyclins* ; G1 Phase ; Humans ; Immunohistochemistry ; Nuclear Proteins ; S Phase

PURPOSE: Cyclins are groups of proteins that play a role as a major regulator of the G1 restriction point promoting inactivation of the retinoblastoma protein. The cyclin D1 gene, CCND1, is amplified in approximately 20% of breast carcinomas and the protein is reportedly overexpressed in 60~80% of all cases. Cyclin D1 overexpression was strongly correlated to estrogen receptor positivity and better histologic grade in breast cancer. The aim of this study was to correlate cyclin D1 overexpression using a well characterized antibody with estrogen receptor status and other clincopathologic parameters. METHODS: From March 1989 to December 1994, 85 patients with primary breast carcinoma were the subject in this study. We analyzed cyclin D1 expression by immnohistochemical staining using cyclin D1 antibody, cells were considered positive according to distinct nuclear staining. The correlation between cyclin D1 expression was compared with important clinicopathologic parameters (tumor size, axillary lymph node status, p53 expression, c-erbB2 expression, histologic grade, estrogen receptor status). RESULTS: Cyclin D1 expression was detected in 37 cases (43.5%). Cyclin D1 expression was high in patients with tumors that expressed estrogen receptor (58.5% vs 26.5%, P=0.019). Cyclin D1 was mainly overexpressed in the histologic grade I and II (75.0%), as compared with 65.2% in cyclin D1 negative tumor, however there was no statistical significance (P=0.067). There were no significant correlation with tumor size, axillary lymph node status, p53 expression, or c-erbB2 expression (P>0.05). CONCLUSION: Cyclin D1 expression in estrogen receptor (ER) positive patients was significantly higher than that seen in ER negative patients. There was a negative correlation between cyclin D1 and tumor histologic grade, however it was not statistically significant. Tumor size, axillary lymph node status, p53 expression, and c-erbB2 expression were not correlated with cyclin D1.
Breast Neoplasms* ; Breast* ; Cyclin D1* ; Cyclins* ; Estrogens* ; G1 Phase Cell Cycle Checkpoints ; Genes, bcl-1 ; Humans ; Lymph Nodes ; Retinoblastoma Protein

PURPOSE: Growth inhibitory effects of lipid soluble components of the Korean red ginseng and the antineoplastic mechanism against human melanoma cell lines were investigated. To examine molecular mechanism of growth inhibitory effects of GX-PE, we analyzed the effect of GX-PE on cell cycle progression and expression of cell cycle regulatory factors such as retinoblastoma gene product (Rb), p27 (Kip1), p21 (WAF1), cdk2, cdk4 and cyclin D1 which are known to regulate cell cycle progression. MATERIALS AND METHODS: Petroleum ether extract of the Korean red ginseng (GX-PE) was added to cultures of three human melanoma cell lines, SK-MEL-1, SK-MEL-2, and SK-MEL-5. Proliferation was measured by 3H-thymidine incorporation assay. Cell cycle and expression of cell cycle regulatory factors were analyzed by flow cytometry and Western blotting, respectively. RESULTS: Growth of melanoma cells was inhibited by GX-PE in proportion to the concentration. GX-PE significantly inhibited cell cycle progression at G1 phase. GX-PE increased expression of negative cell cycle regulators, i.e., p27 (Kip1) in SK-MEL-2 and p21 (WAF1) and Rb in SK-MEL-1. CONCLUSION: These results suggest that GX-PE inhibits proliferation of melanoma cells at a G1-S transition point of the cell cycle. The effect of GX-PE is most likely due to induction of negative cell cycle regulatory factors.
Blotting, Western ; Cell Cycle* ; Cell Line* ; Cyclin D1 ; Ether ; Flow Cytometry ; G1 Phase ; Genes, Retinoblastoma ; Humans* ; Melanoma* ; Panax* ; Petroleum

PURPOSE: Cyclins are groups of proteins that play a role as a major regulator of the G1 restriction point promoting inactivation of the retinoblastoma protein. The cyclin D1 gene, CCND1, is amplified in approximately 20% of breast carcinomas and the protein is reportedly overexpressed in 60~80% of all cases. Cyclin D1 overexpression was strongly correlated to estrogen receptor positivity and better histologic grade in breast cancer. The aim of this study was to correlate cyclin D1 overexpression using a well characterized antibody with estrogen receptor status and other clincopathologic parameters. METHODS: From March 1989 to December 1994, 85 patients with primary breast carcinoma were the subject in this study. We analyzed cyclin D1 expression by immnohistochemical staining using cyclin D1 antibody, cells were considered positive according to distinct nuclear staining. The correlation between cyclin D1 expression was compared with important clinicopathologic parameters (tumor size, axillary lymph node status, p53 expression, c-erbB2 expression, histologic grade, estrogen receptor status). RESULTS: Cyclin D1 expression was detected in 37 cases (43.5%). Cyclin D1 expression was high in patients with tumors that expressed estrogen receptor (58.5% vs 26.5%, P=0.019). Cyclin D1 was mainly overexpressed in the histologic grade I and II (75.0%), as compared with 65.2% in cyclin D1 negative tumor, however there was no statistical significance (P=0.067). There were no significant correlation with tumor size, axillary lymph node status, p53 expression, or c-erbB2 expression (P>0.05). CONCLUSION: Cyclin D1 expression in estrogen receptor (ER) positive patients was significantly higher than that seen in ER negative patients. There was a negative correlation between cyclin D1 and tumor histologic grade, however it was not statistically significant. Tumor size, axillary lymph node status, p53 expression, and c-erbB2 expression were not correlated with cyclin D1.
Breast Neoplasms* ; Breast* ; Cyclin D1* ; Cyclins* ; Estrogens* ; G1 Phase Cell Cycle Checkpoints ; Genes, bcl-1 ; Humans ; Lymph Nodes ; Retinoblastoma Protein

Fibroblasts are major cellular components of gingiva and periodontal ligament. They regulate the healing process after surgery or injury. Recently, many natural medicines, whose advantages are less side effects and possibility of long-term use, have been studied for their capacity, their anti-bacterial and anti-inflammatory effects and regenerative potential of periodontal tissues. Sophorae radix have been traditionally used as an antibacterial and anti-inflammatory drug in oriental medicine. The purpose of present study was to investigate the effects of Sophorae radix extract on cell cycle progression and its molecular mechanism in human gingival fibroblasts. Sophorae radix extracts(100microgram/ml) notably increased cell proliferation and cell activity in the human gingival fibroblasts as compared to non-supplemented controls. There was an increase in the S phase and a decrease in the G1 phase in 100microgram/ml of Sophorae radix extracts group as compared to non-supplemented controls. The level of cyclin E and cdk 2 protein in test group was higher than that of control groups. But that of cyclin D, cdk 4, and cdk 6 was not distinguished from controls. The level of p53 protein in test group was lower than that of controls, whereas that of p21 was not different. The level of pRB protein in test group was higher than that of controls, whereas that of p16 was lower. These results indicate that the increase of cell proliferation by Sophorae radix extracts may be due to the increased expression of cyclin E and cdk 2, and the decreased expression of p53 and p16 in human gingival fibroblasts.
Cell Cycle Proteins* ; Cell Cycle* ; Cell Proliferation ; Cyclin D ; Cyclin E ; Cyclins ; Fibroblasts* ; G1 Phase ; Gingiva ; Humans* ; Medicine, East Asian Traditional ; Periodontal Ligament ; S Phase ; Sophora*