OBJECTIVE: To investigate the significance of expression of COX-2, p21, Ki67 and HPV in nasal inverted papilloma. METHOD: Detecting COX-2, p21, Ki-67 in 30 cases of nasal inverted papilloma (NIP), 20 cases of nasal polyps (NP) and 10 cases of normal nasal mucosa (NM) by two step immunohistochemical method, and HPV virus by flow-through hybridization method. RESULT: The positive expression rate of COX-2 and Ki-67 in NIP, NP and NM group was decreased in turn, COX-2 had significant difference in the groups(χ2 = 30.00, P< 0. 05); the positive expression rate of Ki-67 had significant differences between NIP and NM group (χ2 = 8. 533, P<0. 05). The expression of COX-2 in NIP tissues was positively correlate with that of Ki-67 by using Spearman rank correlation analysis (r=0.78, P<0.05). Expression of p21 were not observed in NIP group. The positive rate of HPV was 26. 67% in 30 cases of NIP, all of HPV16 type. CONCLUSION COX-2, Ki-67 and HPV infection have certain correlation with the occurrence of NIP. The occurrence of NIP has relationship with inflammatory reaction mediated by COX-2. Ki-67 can well reflect the proliferation activity of tumor cells, and can be used to measure the proliferation rate of nasal inverted papilloma. The COX-2 and Ki-67 have a synergistic role in the pathogenesis of NIP. p21 has no significant relationship with the incidence of NIP. HPV infection is related to the pathogenesis of NIP, but not as a;major factor in the pathogenesis of NIP.
Case-Control Studies ; Cyclin-Dependent Kinase Inhibitor p21 ; biosynthesis ; Cyclooxygenase 2 ; biosynthesis ; Humans ; Ki-67 Antigen ; biosynthesis ; Nasal Mucosa ; Nasal Polyps ; Nose Neoplasms ; genetics ; virology ; Papilloma, Inverted ; genetics ; virology ; Papillomavirus Infections

OBJECTIVETo explore the effect of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell proliferation and cell cycle of gastric carcinoma cells, and its possible molecular mechanism.

METHODSControl siRNA and AEG-1 siRNA were transfected into gastric carcinoma SGC-7901 cells. 48 h after transfection, the cells were divided into 3 groups including untransfected, siRNA control and AEG-1 siRNA transfection groups. Expressions of AEG-1 mRNA and protein in the 3 group cells were detected by real-time quantitative PCR and Western blot. The changes of cell proliferation were examined using CCK-8 kit, and the cell cycle distribution was detected by flow cytometry. Finally, expressions of cell proliferation and cell cycle related proteins were detected by Western blot.

RESULTSReal-time quantitative PCR and Western blot demonstrated that compared with the untransfected and siRNA control groups, expressions of AEG-1 mRNA and protein were significantly down-regulated in the AEG-1 siRNA transfection group (P < 0.05), but there was no significant difference between the untransfected and siRNA control groups (P > 0.05). Furthermore, in vivo experiment confirmed a significant down-regulation of AEG-1 protein in the AEG-1 siRNA transfection group (P < 0.05). In addition, AEG-1 siRNA obviously inhibited the proliferation of SGC-7901 cells at different time points after transfection with AEG-1 siRNA. The percentage of cells in G0/G1 phase in the AEG-1 siRNA transfection group [(61.26 ± 1.25)%] was significantly higher than those in the untransfected group [(46.17 ± 1.91)%] and siRNA control group [(46.46 ± 1.96)%], and there was a significant difference between them (all P < 0.001). Furthermore, the result of Western blotting revealed that down-regulation of AEG-1 expression evoked the down-regulation of cdk2 and cyclin D1 expressions and elevation of p21 expression in vitro and in vivo.

CONCLUSIONSThe inhibition of cell proliferation and cell cycle arrest mediated by down-regulation of AEG-1 expression may be closely associated with the changes of expression of cell cycle related proteins including cdk2, cyclin D1 and p21.

Animals ; Cell Adhesion Molecules ; biosynthesis ; genetics ; Cell Cycle Checkpoints ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase 2 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Down-Regulation ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Stomach Neoplasms ; metabolism ; pathology ; Transfection

Natural isoflavones and flavones are important dietary factors for prostate cancer prevention. We investigated the molecular mechanism of these compounds (genistein, biochanin-A and apigenin) in PC-3 (hormone-independent/p53 mutant type) and LNCaP (hormone-dependent/p53 wild type) prostate cancer cells. A cell growth rate and apoptotic activities were analyzed in different concentrations and exposure time to evaluate the antitumor activities of genistein, biochanin-A and apigenin. The real time PCR and Western blot analysis were performed to investigate whether the molecular mechanism of these compounds are involving the p21 and PLK-1 pathway. Apoptosis of prostate cancer cells was associated with p21 up-regulation and PLK-1 suppression. Exposure of genistein, biochanin-A and apigenin on LNCaP and PC-3 prostate cancer cells resulted in same pattern of cell cycle arrest and apoptosis. The inhibition effect for cell proliferation was slightly greater in LNCaP than PC-3 cells. In conclusion, flavonoids treatment induces up-regulation of p21 expression, and p21 inhibits transcription of PLK-1, which promotes apoptosis of cancer cells.
Antineoplastic Agents/*pharmacology ; Apigenin/pharmacology ; *Apoptosis ; Cell Cycle/drug effects ; Cell Cycle Proteins/biosynthesis/*genetics/metabolism ; Cell Line, Tumor ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21/biosynthesis/*metabolism ; Flavonoids/*pharmacology ; Gene Expression Regulation, Neoplastic/drug effects ; Genistein/pharmacology ; Humans ; Male ; Prostatic Neoplasms/genetics/metabolism/*pathology ; Protein Kinase Inhibitors/pharmacology ; Protein-Serine-Threonine Kinases/biosynthesis/*genetics/metabolism ; Proto-Oncogene Proteins/biosynthesis/*genetics/metabolism ; Transcription, Genetic/drug effects

OBJECTIVECytotoxin-associated protein (CagA) of H. pylori has been confirmed to be closely associated with gastric inflammation and tumorigenesis, but the mechanism behind it is little understood. In this study, we try to determine roles of CagA(+) strain in activating PI3K/Akt1 signaling pathway, and affecting expression of p21(WAF1/CIP1) and p27(KIP1), and also in releasing IL-8 in host cells.

METHODSAkt1 phosphorylation and IL-8 levels of CagA(+) and CagA⁻ strain infected AGS cells were detected by ELISAs. Two quantitative RT-PCRs were established to measure p21(WAF1/CIP1) and p27(KIP1) mRNA levels in the CagA(+) and CagA⁻ strain infected cells. LY294002, an inhibitor of PI3K/Akt pathway, was used to define effect of the pathway in IL-8 release.

RESULTSCagA(+) strain could induce an obvious elevation of Akt1 phosphorylation in the infected AGS cells while CagA? strain failed to do so. The CagA(+) H. pylori strain infected AGS cells showed significant drops both in p21(WAF1/CIP1) and p27(KIP1) mRNA levels, whereas the CagA⁻ H. pylori strain caused a remarkable increase in p21(WAF1/CIP1) mRNA without affecting p27(KIP1) gene transcription in the AGS cells. Both the CagA(+) and CagA⁻ H. pylori strains enabled AGS cells to produce close elevated levels of IL-8, and the LY294002 block resulted in unexpected elevations of IL-8 levels.

CONCLUSIONSCagA can activate PI3K/Akt1 pathway that plays an inhibitory role in IL-8 release in H. pylori infected AGS cells. Activation of PI3K/Akt1 pathway and subsequent negative regulation of p21(WAF1/CIP1) and p27(KIP1) expression might be involved in CagA-associated carcinogenesis.

Antigens, Bacterial ; genetics ; physiology ; Bacterial Proteins ; genetics ; physiology ; Cell Line ; Cyclin-Dependent Kinase Inhibitor p21 ; biosynthesis ; Cyclin-Dependent Kinase Inhibitor p27 ; Gastric Mucosa ; cytology ; enzymology ; microbiology ; Helicobacter pylori ; metabolism ; pathogenicity ; physiology ; Humans ; Interleukin-8 ; secretion ; Intracellular Signaling Peptides and Proteins ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Transcription, Genetic ; Virulence

OBJECTIVETo investigate the mechanism by which recombinant adenovirus (Ad)-mediated mutations of hypoxia inducible factor 1alpha (Ad-HIF-1alpha-Ala564-Ala803) regulates cell apoptosis.

METHODSLoVo cells were infected with recombinant Ad-HIF-1alpha-Ala564-Ala803 and control virus Ad-lacZ under normoxia condition. Real-time PCR was used to detect HIF-1alpha and p21WAF1/CIP1 mRNA expressions at different time points. Western blotting was employed to verify HIF-1alpha and p21WAF1/CIP1 protein expression. Hoechst 33342 flourescein staining was performed to observe the ratio of apoptotic LoVo cells.

RESULTSThe expression levels of HIF-1alpha mRNA and protein increased after infection with Ad-HIF-1alpha- Ala564-Ala803, accompanied by an increase in p21WAF1/CIP1 mRNA and protein expressions. The apoptotic ratio was significantly higher in LoVo cells infected with recombinant Ad-HIF-1alpha-Ala564-Ala803 (16.2%) than in the control cells (5.5%, P=0.00).

CONCLUSIONHIF-1alpha may induce cell cycle arrest by up-regulating p21WAF1/CIP1 expressions to promote LoVo cell apoptosis.

Adenoviridae ; genetics ; Apoptosis ; genetics ; physiology ; Blotting, Western ; Cell Line, Tumor ; Colonic Neoplasms ; genetics ; metabolism ; pathology ; Cyclin-Dependent Kinase Inhibitor p21 ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; biosynthesis ; genetics ; Mutagenesis, Site-Directed ; Mutation ; RNA, Messenger ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection

OBJECTIVETo investigate the roles of p53 in cell cycle changes on human embryo lung fibroblasts (HELF) induced by benzo(a) pyrene[ B(a) P], and relationships between p53 and p21, E2F-1.

METHODSCells transfected with p53 siRNA plasmid (p53-H) and CMV vector (HELF/CMV) were cultured with serum-free R/MINI-1640 for 48 hours, then treated with 2 micromol/L B(a)P for 24 hours. Flow cytometry assay was used for detecting the cell cycle alteration after being exposed to B(a)P. Changes of p53 and p21 expressions were checked using Western blot assay, and the cytoplasmic and nuclear extraction was used to observe the subcellular localizations of p53 and p21. The immunofluorescence assay was used to check changes of E2F-1 expression and the distribution of E2F-1 in nuclear and cytoplasm after exposed to B (a)P. p53siRNA plasmid and the chemical inhibitor of p53 [pifithrin-alpha (PFT)] were used to observe effects of p53 in B(a)P induced cell cycle changes and the relationships of p53 and p21, E2F-1.

RESULTSAfter 2 micromol/L B(a)P exposure, the ratio of G1 phase cells (71 +/- 5)% was decreased to (39 +/- 4)% (P < 0.05). p53, p21 and E2F-1 expressions were increased significantly, and over expressed proteins were mostly located in nuclear after B(a)P treatment. When p53 expression was inhibited by p53 siRNA or PFT, the decreases of G1 phase in response to B(a)P treatment still existed, and over expression of p21 induced by B(a)P was attenuated, especially in nuclear, but E2F-1 over expression was not changed significantly.

CONCLUSIONB(a)P could induce cell cycle changes through p53 independent pathways. And p53 could regulate p21 expression positively, but not E2F-1.

Benzo(a)pyrene ; toxicity ; Cell Cycle ; drug effects ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p21 ; drug effects ; DNA Damage ; E2F1 Transcription Factor ; biosynthesis ; Fibroblasts ; Flow Cytometry ; Gene Expression ; Humans ; Lung ; cytology ; drug effects ; metabolism ; Mechanotransduction, Cellular ; drug effects ; RNA, Messenger ; genetics ; Tumor Suppressor Protein p53 ; genetics ; metabolism

Tropomyosin-related kinase A (TrkA) plays an important role in cell survival, differentiation, and apoptosis in various neuronal and nonneuronal cell types. Here we show that TrkA overexpression by the Tet-On system mimics NGF-mediated activation pathways in the absence of nerve growth factor (NGF) stimulation in U2OS cells. In addition, p53 upregulation upon DNA damage was inhibited by TrkA, and p21 was upregulated by TrkA in a p53-independent manner. TrkA overexpression caused cell death by interrupting cell cycle progression, and TrkA-induced cell death was diminished in the presence of its specific inhibitor GW441756. Interestingly, TrkA-mediated cell death was strongly related to gammaH2AX production and poly (ADP-ribose) polymerase cleavage in the absence of DNA damage inducer. In this study, we also reveal thatgammagammaH2AX production by TrkA is blocked by TrkA kinase inhibitors K-252a and GW441756, and it is also significantly inhibited by JNK inhibitor SP600125. Moreover, reduction of cell viability by TrkA was strongly suppressed by SP600125 treatment, suggesting a critical role of JNK in TrkA-induced cell death. We also found that gammaH2AX and TrkA were colocalized in cytosol in the absence of DNA damage, and the nuclear localization of gammaH2AX induced by DNA damage was partly altered to cytosol by TrkA overexpression. Our results suggest that the abnormal cytosolic accumulation of gammaH2AX is implicated in TrkA-induced cell death in the absence of DNA damage.
Anthracenes/pharmacology ; Apoptosis/drug effects/*genetics ; Carbazoles/pharmacology ; Cell Cycle/drug effects/genetics ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21/*biosynthesis/genetics ; Cytosol/drug effects/enzymology/ultrastructure ; DNA Damage/drug effects/genetics ; Doxorubicin/pharmacology ; Histones/*metabolism ; Humans ; Indole Alkaloids/pharmacology ; MAP Kinase Kinase 4/antagonists & inhibitors ; Nerve Growth Factor/antagonists & inhibitors/metabolism ; Phosphorylation/drug effects ; Protein Binding ; *Protein Transport/drug effects/genetics ; Receptor, trkA/antagonists & inhibitors/*genetics/metabolism ; Signal Transduction ; Transfection

OBJECTIVETo investigate the effect of curcumin (Cur) on histone deacetylase (HDAC1) and P21(WAF1/CIP1), a cyclin dependent kinase inhibitor, in HepG2 cells for exploring the mechanism of Cur in anti-cancer.

METHODThe HDAC1, P21(WAF1/CIP1) proteins and P21(WAF1/CIP1) mRNA were extracted from human hepatoma cells treated with or without Cur of different concentrations at different time points. Western blot analysis was performed to determine the levels of HDAC1 and P21(WAF1/CIP1) proteins, respectively. RT-PCR was performed to detect the level of P21(WAF1/CIP1) mRNA.

RESULTThe IC50 of concentration treated by Cur was 25 micromol x L(1) on HepG2 cell. The level of HDAC1 was obviously inhibited by Cur, and decreased at 4 hours at IC, and lasted for 48 h in a time-dependent manner. The inhibition of HDAC1 was significant at the Cur concentration of 12.5 micromol x L(-1) but there was no difference between 50 and 100 micromol x L(-1). The levels of P21(WAF1/CIP1) mRNA and protein were up-regulated by Cur in dose and time-dependent manner, and the change of mRNA and protein was detected at 8 hours and lasted for 48 hours.

CONCLUSIONCur can inhibit the level of HDAC1 and enhance the expression of P21(WAF1/CIP1) protein and mRNA, and the results suggest that inhibiting HDAC1 and increasing P21(WAF1/CIP1) may be one of the possible mechanisms of anti-cancer by Cur.

Blotting, Western ; Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Curcuma ; chemistry ; Curcumin ; administration & dosage ; isolation & purification ; pharmacology ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; metabolism ; Dose-Response Relationship, Drug ; Gene Expression Regulation, Neoplastic ; drug effects ; Histone Deacetylase Inhibitors ; Histone Deacetylases ; metabolism ; Humans ; Liver Neoplasms ; genetics ; metabolism ; pathology ; Plants, Medicinal ; chemistry ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors

OBJECTIVEThe aim of this study was designed to investigate the effect of TSA on human umbilical vein endothelial cells and to reveal its possible mechanisms and relationship between apoptosis and activity of telomerase reverse transcriptase.

METHODSsulforhodamine B method was employed to determine the growth rate of umbilical vein endothelial cells. The cell apoptotic rate was measured by flow cytometry (FCM). The hTERT and p21(Waf1) mRNA expression before and after TSA treatment were detected by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). The quantitative of hTERT protein expression in cells were detected by flow cytometry. After transfection, the cell telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA) and early apoptosis was measured by Annexin V/PI stain and flow cytometry.

RESULTSAfter being treated with TSA, the proliferation of umbilical vein endothelial cells was inhibited. Slight apoptosis and cell cycle arrest were detected. However, the same concentration of TSA induced serious apoptosis in HeLa cells. Up-regulation of hTERT mRNA expression was observed within 48 h after TSA treatment, but the change of p21(Waf1) expression was not significant. The umbilical vein endothelial cells hTERT protein expression level was increased within 24 h. After transfection of the dominant negative, wild type and control hTERT plasmid, a significant difference of telomerase activity in these cells was observed by PCR-TRAP-ELISA assay. WT-hTERT-transfected cells were more resistant to apoptosis induced by trichostatin A.

CONCLUSIONHuman umbilical vein endothelial cells could be resistant to apoptosis induced by high concentrate TSA, and hTERT might play an important role in this process.

Apoptosis ; drug effects ; Blotting, Western ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; metabolism ; Endothelial Cells ; cytology ; drug effects ; metabolism ; Enzyme Inhibitors ; pharmacology ; Enzyme-Linked Immunosorbent Assay ; methods ; Flow Cytometry ; Gene Expression ; drug effects ; HeLa Cells ; Humans ; Hydroxamic Acids ; pharmacology ; Plasmids ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Telomerase ; genetics ; metabolism ; Transfection ; Umbilical Veins ; cytology

To investigate the effect of Protein kinase B on the expression and location of p21 in mouse early development. Immunopreciptation technology was used to detect the localization of p21 and Western blotting was used to analyze the expression of p21 after microinjecting mRNA of WT-PKB, myt-PKB and PKB-KD to mouse eggs. There was no obvious difference between the three kinds of mRNA in the expression of p21. But the cell localization altered. The p21 retain in cytoplasm after microjecting myt-PKB. In mouse fertilized egg PKB/Akt controls the cell cycle by changing the cell localization of p21.
Animals ; Cell Nucleus ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; biosynthesis ; Cytoplasm ; metabolism ; Female ; Fluorescent Antibody Technique ; Male ; Mice ; Microinjections ; Mutation ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; RNA, Messenger ; administration & dosage ; genetics ; metabolism ; Time Factors ; Zygote ; cytology ; growth & development ; metabolism