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 evaluate the correlation of p27 protein expression in the cytoplasm with the clinicopathologic features of nasopharyngeal carcinoma (NPC).

METHODSImmunohistochemistry was employed to examine P27 protein expression in the cytoplasm of NPC samples and nasopharyngeal (NP) tissue samples. The differential expression of P27 protein between NPCs and NPs and the correlation of cytoplasmic P27 protein expression with the clinicopathologic parameters of NPC patients was analyzed. RESULTS Immunohistochemistry indicated significantly down-regulated t p27 protein expression in NPC tissues compared to that in NP tissues (P=0.047). The reduction of P27 expression was inversely correlated with T classification of NPC (P=0.033). Although cytoplasmic p27 protein expression was not significantly correlated with lymph node metastasis (P=0.157) or clinical stages of NPC (P=0.090), an obvious trend of inverse correlations between them was noted.

CONCLUSIONDown-regulated cytoplasmic p27 protein expression may promote the carcinogenesis of NPC and can be an unfavorable prognostic factor for survival of NPC patients.

Carcinoma ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Cytoplasm ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; metabolism ; pathology ; Prognosis

BACKGROUND/AIMS: The cyclin-dependent kinase inhibitors (CDKI) including p21, p27, and p57 of the kinase inhibitor protein (KIP) family are negative regulators of cell cycle progression and potentially act as tumor suppressor. Tumor behavior and growth are influenced by the extent of tumor cell proliferation. The aim of this study was to evaluate the expression of KIP family CDKI in gastric cancer tissue, and to examine the relationship between these expression and various clinicopathological parameters including tumor cell proliferation. METHODS: We conducted an immunohistochemical analysis of p21, p27, and p57 expression in 109 gastric cancer tissues. Tumor cell proliferation was assessed by immunohistochemistry with antibody against Ki-67. RESULTS: Negative expression of p21, p27, and p57 was demonstrated in 45.9%, 65.1%, and 57.8% of cancer tissues, respectively. Negative expression of p21 correlated with larger tumor size, poor differentiation, depth of invasion, lymph node metastasis and advanced TNM stage (p=0.048, 0.041, 0.001, 0.005, and 0.001 respectively). Negative expression of p21 correlated with poor survival (p=0.037). Tumors with negative p21 expression had higher Ki-67 expression than those with positive p21 expression (p=0.024). No significant correlation could be observed between status of p27 and p57 expression and various clinicopathological parameters including survival and tumor cell proliferation. CONCLUSIONS: These results suggest that negative expression of p21 may play an important role in carcinogenesis by stimulating tumor cell proliferation, and may help in predicting the prognosis of gastric cancer.
Adult ; Aged ; Cell Division ; Cyclin-Dependent Kinase Inhibitor Proteins/*metabolism ; Cyclin-Dependent Kinase Inhibitor p21/metabolism ; Cyclin-Dependent Kinase Inhibitor p27/metabolism ; Cyclin-Dependent Kinase Inhibitor p57/metabolism ; English Abstract ; Female ; Humans ; Male ; Middle Aged ; Stomach Neoplasms/*metabolism/mortality/pathology ; Survival Rate

OBJECTIVETo investigate the expression, localization and interrelationship of P27(kip1) and cyclin D3 in non-Hodgkin's lymphoma (NHL).

METHODSThe expressions of P27(kip1), cyclin D3 and index Ki-67 was detected in 100 NHL and 20 reactive lymph nodes by immunohistochemical technique. The expression and localization of P27(kip1) and cyclin D3 in 3 NHL cell lines were detected by Western blot, double immunolabelling and laser scanning confocal microscopy, respectively.

RESULTSIn general the expression of P27(kip1) in NHL was lower than in control group, and was negatively related to the tumor aggressiveness and proliferating activity; the expression of cyclin D3 in NHL was higher than in control group, and was positively related to the tumor aggressiveness and proliferating activity. There was a negative correlation between P27(kip1) and cyclin D3. Nevertheless, anomalous high P27(kip1) expression was found in a few NHL tissues with high expression of cyclin D3 and Ki-67. Overexpression and colocalization of P27(kip1) and cyclin D3 was found in Raji cell line.

CONCLUSIONSUnder expression of P27(kip1) and overexpression of cyclin D3 may play a role in the occurrence and development of NHL. Anomalous high P27(kip1) expression and its interaction with cyclin D3 may be another mechanism for tumor genesis of NHL.

Cell Line, Tumor ; Cyclin D3 ; Cyclin-Dependent Kinase Inhibitor p27 ; genetics ; metabolism ; Cyclins ; genetics ; metabolism ; Humans ; Lymphoma, Non-Hodgkin ; genetics ; metabolism ; pathology

Carcinoma, Hepatocellular ; metabolism ; pathology ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Neoplasm Staging ; Phosphorylation ; S-Phase Kinase-Associated Proteins ; metabolism

The purpose of this study was to elucidate the apoptosis, apoptotic pathway of HL-60 cells induced by proteasome inhibitor MG132 and its effect on allogeneic mixed lymphocyte reaction. Apoptosis of HL-60 cells was detected by flow cytometry, the expression of P21, P27 and P53 proteins in HL-60 cells treated with MG132 was assayed by Western blot. The HL-60 cells were treated with 1 µmol/L MG132 for 48 h, and irradiated by 75 Gy of (60)Co γ-ray, but their antigenicity was preserved. The effect of irradiated HL-60 cells treated with MG132 on proliferation of peripheral blood mononuclear cells (PBMNC) was measured by CCK-8 method. The results showed that the apoptotic rate of MG132-treated HL-60 cells increased in dose-and time-dependent manner. No significant changes in MG132-induced apoptosis were observed after inhibiting caspase-8 and caspase-9 pathway. The expression of P21 and P27 protein increased after treatment of HL-60 cells with MG132. CCK-8 test showed that HL-60 cells induced with low-dose of MG132 displayed the enhancing effect on proliferation of PBMNC. It is concluded that high dose of MG132 can induce the apoptosis of HL-60 cells, and has direct killing effect on HL-60 cells, but this inducing apoptotic effect on HL-60 cells can not be realized through caspase-8 and caspase-9 pathway. The P21 and P27 protein may be involved in MG132 induced HL-60 cell apoptosis. Low dose of MG132 promotes the proliferation of PBMNC in healthy individuals and enhance the immunity of organism.
Apoptosis ; drug effects ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; HL-60 Cells ; Humans ; Leupeptins ; pharmacology ; Proteasome Inhibitors ; pharmacology

OBJECTIVETo investigate the effect of Shenkang Injection (SI) on hypertrophy and expressions of p21 and p27 in glomerular mesangial cells of rats cultured in high glucose fluid.

METHODSCultured rat glomerular mesangial cells were divided into 6 groups: the normal control group, mannitol-treated group, high glucose-treated group, high, middle and low dose SI treated groups. The synthesis of cell protein and DNA were determined with incorporation of 3H-TdR and 3H-Leu. The changes of p21 mRNA and expressions of p21 and p27 protein were determined by reverse transcriptase polymerase chain reaction and Western blot.

RESULTSHigh glucose caused incorporation of 3H-TdR reduced, incorporation of 3H-Leu increased. SI could decrease incorporation of 3H-Leu, increase incorporation of 3H-TdR. Compared with the high glucose-treated group, SI could inhibit the overexpression of p2l mRNA and protein,p27 protein induced by high glucose.

CONCLUSIONSI could inhibit hypertrophy of glomerular mesangial cells cultured in high glucose partly through inhibiting overexpressions of p2l mRNA, p21 and p27 protein.

Animals ; Cell Enlargement ; Cells, Cultured ; Culture Media ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Glucose ; pharmacology ; Mesangial Cells ; cytology ; drug effects ; metabolism ; Rats

OBJECTIVETissue kallikrein cleaves kininogen substrate to produce vasoactive kinin peptides that have been implicated in the proliferation of vascular smooth muscle cells. We investigated the effects of adenovirus-mediated human tissue kallikrein (Ad-hKLK1) gene delivery on the proliferation of vascular smooth muscle cells of SHR (VSMCs(SHR)) induced by platelet derived growth factor-BB (PDGF-BB).

METHODSPrimary VSMCs(SHR) were isolated and cultured from thoracic aorta of male SHR. The VSMCs(SHR) proliferation induced by PDGF-BB was accessed by cell counting and methyl thiazolyl tetrazolium (MTT). Western blot was used to determine the protein expression of hKLK1, the cycle-independent kinase inhibitors p27(Kip1) and p21(Cip1). The mRNA expressions of bradykinin B1 receptor and B2 receptor were detected by RT-PCR in VSMCs(SHR).

RESULTSProliferation of VSMCs(SHR) induced by PDGF-BB was significantly inhibited post transfection of Ad-hKLK1 (20-100 MOI) in a MOI-dependent manner. The peak inhibition titer of Ad-hKLK1 was 100 MOI with peak inhibition rate of 39.3% (cell counting, n = 3, P < 0.01), 30.2% (MTT, n = 3, P < 0.01) and 36.4% (peak stunning rate of cell-cycle in phase G(0)/G(1)). The inhibitory effects of proliferation and cell-cycle caused by hKLK1 gene delivery could be abolished by Hoe140, a bradykinin B2 receptor antagonist. The protein expression of p27(Kip1) and p21(Cip1) increased significantly after the hKLK1 gene delivery, whereas Hoe140 nearly completely blocked these effects (n = 3, P < 0.001, respectively). PDGF-BB also significantly upregulated the mRNA expression of B2 receptor but not B1 receptor in VSMCs(SHR).

CONCLUSIONThe hKLK1 gene delivery could inhibit PDGF-BB induced proliferation in VSMCs(SHR) through Bradykinin B2 receptor and up-regulate expression of p27(Kip1) and p2l(Cip1).

Animals ; Cell Division ; drug effects ; Cell Proliferation ; drug effects ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Humans ; Kallikreins ; genetics ; pharmacology ; Male ; Muscle, Smooth, Vascular ; cytology ; drug effects ; Rats ; Rats, Inbred SHR ; Recombination, Genetic

OBJECTIVETo investigate the biological function of RIG-G gene by establishing a cell line stably expressing RIG-G protein.

METHODSEctopic RIG-G gene was transfected into U937 cells by using Tet-off expression system. Changes before and after RIG-G expression were detected for cell growth, cell morphology, cell surface antigen and cell cycle regulating proteins.

RESULTSRIG-G protein arrested the cells at G0/G1 phase and inhibited cell growth by increasing the cell cycle inhibitors P21 and P27. As compared to that in control group, the proportion of cells at G0/G1 phase in RIG-G-expressing cell group increased from (43.9 +/- 5.6)% to (63.9 +/- 2.3)% (P < 0.01). The rate of growth inhibition was (68.7 +/- 0.2)%. In addition, an increase in CD11C expression [(61.3 +/- 1.1)% vs. (18.0 +/- 0.4)% (P < 0.01)] and in cells with morphologic features of partial differentiation (smaller cell size, reduced nucleus-cytoplasm ratio, notched nucleus and coarse chromatin) was also observed in RIG-G-expressing cells.

CONCLUSIONSRIG-G has potential abilities to inhibit cell proliferation and promote cell differentiation.

Cell Cycle ; genetics ; Cell Differentiation ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; genetics ; metabolism ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; physiology ; Plasmids ; genetics ; Transfection ; U937 Cells

OBJECTIVETo study the effect of all-trans retinoic acid (ATRA) on U937 cell growth and its mechanism.

METHODSCell cycle was detected by flow cytometry (FCM), expressions of cell cycle associated protein and the p27 related protein were detected by Western blot. The binding of P27 and Skp2 was detected by immunoprecipitation.

RESULTSFCM displayed that ATRA could inhibit the proliferation of U937 cells. At 72 h on 1 micromol/L ATRA treatment, 72% of the cells were arrested at G0/G1 phase. Western blot displayed that ATRA could decrease the expression of cyclin A, up-regulate the expression of p21 and p27, and down-regulate the expression of p27 related proteins Skp2. p27 could bind with Skp2 in U937 cells as detected by immunoprecipitation.

CONCLUSIONATRA may arrest the proliferation of U937 cells through the reduction of Skp2 expression, and finally the induction of the accumulation of p27.

Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Humans ; S-Phase Kinase-Associated Proteins ; metabolism ; Tretinoin ; pharmacology ; U937 Cells