AIM We have previously reported that inducible over-expresaion of Bak may prolong cell cycle in G1 phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27KIP1 plays an important role in...AIM We have previously reported that inducible over-expresaion of Bak may prolong cell cycle in G1 phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27KIP1 plays an important role in this process. MEHODS In order to elucidate the exact function of p27KIP1 in this process, a zinc inducible p27KIP1 stable transfectant and transient p27KIP1- GFP fusion transfectant were constructed. The effects of inducible p27KIP1 on cell growth, cell cycle arrest and apoptosis were examined in the mock, control pMD vector, and pMD-KIP1 transfected HCC-9204 cells. RESULTS This p27KIP1-GFP transfectant may transiently express the fusion gene. The cell growth was reduced by 35% at 48 h of p27KIP1 induction with zinc treatment as determined by trypan blue exclusion assay. These differences remained the same after 72 h of p27KIP1 expression, p27KIP1 caused cell cycle arrest after 24 h of induction, with 40% increase in G1 population. Prolonged p27KIP1 expression in this cell line induced apoptotic cell death reflected by TUNEL assay. Fourty-eight h and 72 h of p27KIP1 expression showed a characteristic DNA ladder on agarose gel electrophoresis.展开更多
Background RhoA/ Rho kinase （ROCK） pathway is involved in pulmonary arterial hypertension （PAH） and pulmonary artery smooth muscle cell （PASMC） proliferation. Inhibition of ROCK has been proposed as a treatment ...Background RhoA/ Rho kinase （ROCK） pathway is involved in pulmonary arterial hypertension （PAH） and pulmonary artery smooth muscle cell （PASMC） proliferation. Inhibition of ROCK has been proposed as a treatment for PAH. But the mechanism of RhoA/ROCK pathway and its downstream signaling in proliferation of human PASMCs is unclear. We investigated the effect of fasudil, a selective ROCK inhibitor, on platelet-derived growth factor （PDGF） induced human PASMC proliferation, and the possible association between RhoA/ROCK and extracellular signal-regulated kinase （ERK）,p27KiP1.Methods Human PASMCs were cultured with the stimulation of 10 ng/ml PDGF, and different concentrations of fasudil were added before the addition of mitogen. Cell viability and cell cycle were determined with MTT and flow cytometry respectively. ROCK activity, ERK activity and protein expression of proliferating cell nuclear angigen （PCNA） and p27Kip1 were measured by immunoblotting.Results By MTT assay, PDGF significantly increased the OD value that represented human PASMC proliferation, and pretreatment with fasudil significantly reversed this effect in a dose-dependent manner. After PDGF stimulation, the percentage of cells in S phase increased dramatically from 15.6% to 24.3%, while the percentage in G0/G1 phase was reduced from 80.6% to 59%. And pretreatment with fasudil reversed the cell cycle effect of PDGF significantly in a dose-dependent manner. PDGF markedly induced ROCK activity and ERK activity with a peak at 15 minutes, which were significantly inhibited by fasudil. In addition, fasudil significantly inhibited PDGF-induced PCNA expression and fasudil also upregulated p27Kip1 expression in human PASMCs, which decreased after PDGF stimulation.Conclusion RhoA/ROCK is vital for PDFG-induced human PASMC proliferation, and fasudil effectively inhibited PDGF-induced human PASMC proliferation by up-regulation of p27Kip1, which may be associated with inhibition of ERK activity.展开更多
AIM: To investigate p27 expression in hepatocellular carcinoma (HCC), adjacent nontumoral and normal liver tissues, and to verify whether the subcellular localization of p27 was altered in HCC.METHODS: The level of p2...AIM: To investigate p27 expression in hepatocellular carcinoma (HCC), adjacent nontumoral and normal liver tissues, and to verify whether the subcellular localization of p27 was altered in HCC.METHODS: The level of p27 in tumoral, nontumoral, and normal liver tissues were assessed by immunohistochemical (IHC) analysis. Parallel immunostaining was done for proliferating cell nuclear antigen (PCNA) to evaluate cell proliferation.RESULTS: The labeling index (LI) of p27 in tumoral lesions was significantly lower than that in adjacent nontumoral lesions (t=2.444, P=0.017) and normal controls (t=-2.268,P=0.029). The LI of p27 significantly decreased in patients with massive type (t=-2.227, P=0.037) and infiltration (t=2.197, P=0.036). The prognosis of patients with higher p27 LI was longer than that of patients with lower p27 LI (P=0.0247, log-rank test). The LI of PCNA was significantly higher in HCC than that in adjacent nontumoral lesions (t=2.092, P=0.041) and normal controls (t=-3.533, P=0.002).There was no significant correlation between p27 expression and cell proliferation in tumor samples. The level of p27 in the cytoplasmic fraction was higher in tumoral and nontumoral liver tissues, and was associated with clinical stage (t=-2.520, P=0.029) and the degree of invasion (t=2.640, P=0.019). Survival analysis showed that p27 was an independent prognosis marker for HCC patients.CONCLUSION: These results suggest that p27 underexpressing in patients with HCC is closely associated with infiltration, metastasis, and prognosis. Alterations in the subcellular localization of p27 protein may occur early during hepatocarcinogenesis.展开更多
文摘AIM We have previously reported that inducible over-expresaion of Bak may prolong cell cycle in G1 phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27KIP1 plays an important role in this process. MEHODS In order to elucidate the exact function of p27KIP1 in this process, a zinc inducible p27KIP1 stable transfectant and transient p27KIP1- GFP fusion transfectant were constructed. The effects of inducible p27KIP1 on cell growth, cell cycle arrest and apoptosis were examined in the mock, control pMD vector, and pMD-KIP1 transfected HCC-9204 cells. RESULTS This p27KIP1-GFP transfectant may transiently express the fusion gene. The cell growth was reduced by 35% at 48 h of p27KIP1 induction with zinc treatment as determined by trypan blue exclusion assay. These differences remained the same after 72 h of p27KIP1 expression, p27KIP1 caused cell cycle arrest after 24 h of induction, with 40% increase in G1 population. Prolonged p27KIP1 expression in this cell line induced apoptotic cell death reflected by TUNEL assay. Fourty-eight h and 72 h of p27KIP1 expression showed a characteristic DNA ladder on agarose gel electrophoresis.
文摘目的:探讨SPY1(Speedy A1)和p27^(kip1)(cyclin-dependent kinase inhibitor 1B,p27)在子宫内膜癌中的表达情况及其临床意义。方法:采用生物医学信息数据库分析子宫内膜癌中SPY1、p27^(kip1) mRNA表达水平;采用免疫组织化学染色法及蛋白质印迹法检测子宫内膜癌及正常子宫内膜组织中SPY1、p27^(kip1)蛋白的表达水平,并分析其表达与患者临床病理参数、激素受体、癌症基因组图谱分子分型的关系,以及两者之间的相关性。通过Kaplan-Meier法绘制生存曲线,应用Cox比例风险模型分析影响子宫内膜癌患者的预后因素。结果:SPY1在子宫内膜癌组织中的蛋白质表达水平显著高于不典型增生的子宫内膜及正常子宫内膜组织(P=0.009),p27kip1在子宫内膜癌组织中的蛋白质表达水平显著低于不典型增生的子宫内膜及正常子宫内膜组织(P=0.001);SPY1蛋白表达与肿瘤病理分级(P=0.023)、国际妇产科协会(The International Federation of Gynecology and Obstetrics,FIGO)癌分期(P=0.003),肌层浸润深度(P=0.010)及淋巴结转移(P<0.001)有关,p27kip1蛋白表达与肿瘤病理分级(P=0.001)、FIGO癌分期(P=0.001)及淋巴结转移(P<0.001)有关;SPY1与p27kip1表达呈负相关(r=−0.563,P<0.001);Kaplan-Meier预后分析表明SPY1高表达患者生存率低于低表达患者(P<0.05),p27kip1高表达患者的生存率高于低表达患者(P<0.05)。Cox单因素及多因素分析表明FIGO癌分期(P=0.023)、病理分级(P<0.001)、淋巴结转移(P<0.001)及p27kip1表达(P<0.001)可作为子宫内膜癌患者的独立预后指标。结论:子宫内膜癌组织中SPY1蛋白呈高表达,p27kip1蛋白呈低表达,且两者之间呈负相关,可用于评估子宫内膜癌的发生和发展。
基金This study was supported by grants from the National Natural Science Foundation of China （No. 30972958）, Beijing Natural Science Foundation （No. 7112046）, Beijing Municipal Education Commission （No. PXM2011_014226 07 000060）.
文摘Background RhoA/ Rho kinase （ROCK） pathway is involved in pulmonary arterial hypertension （PAH） and pulmonary artery smooth muscle cell （PASMC） proliferation. Inhibition of ROCK has been proposed as a treatment for PAH. But the mechanism of RhoA/ROCK pathway and its downstream signaling in proliferation of human PASMCs is unclear. We investigated the effect of fasudil, a selective ROCK inhibitor, on platelet-derived growth factor （PDGF） induced human PASMC proliferation, and the possible association between RhoA/ROCK and extracellular signal-regulated kinase （ERK）,p27KiP1.Methods Human PASMCs were cultured with the stimulation of 10 ng/ml PDGF, and different concentrations of fasudil were added before the addition of mitogen. Cell viability and cell cycle were determined with MTT and flow cytometry respectively. ROCK activity, ERK activity and protein expression of proliferating cell nuclear angigen （PCNA） and p27Kip1 were measured by immunoblotting.Results By MTT assay, PDGF significantly increased the OD value that represented human PASMC proliferation, and pretreatment with fasudil significantly reversed this effect in a dose-dependent manner. After PDGF stimulation, the percentage of cells in S phase increased dramatically from 15.6% to 24.3%, while the percentage in G0/G1 phase was reduced from 80.6% to 59%. And pretreatment with fasudil reversed the cell cycle effect of PDGF significantly in a dose-dependent manner. PDGF markedly induced ROCK activity and ERK activity with a peak at 15 minutes, which were significantly inhibited by fasudil. In addition, fasudil significantly inhibited PDGF-induced PCNA expression and fasudil also upregulated p27Kip1 expression in human PASMCs, which decreased after PDGF stimulation.Conclusion RhoA/ROCK is vital for PDFG-induced human PASMC proliferation, and fasudil effectively inhibited PDGF-induced human PASMC proliferation by up-regulation of p27Kip1, which may be associated with inhibition of ERK activity.
文摘AIM: To investigate p27 expression in hepatocellular carcinoma (HCC), adjacent nontumoral and normal liver tissues, and to verify whether the subcellular localization of p27 was altered in HCC.METHODS: The level of p27 in tumoral, nontumoral, and normal liver tissues were assessed by immunohistochemical (IHC) analysis. Parallel immunostaining was done for proliferating cell nuclear antigen (PCNA) to evaluate cell proliferation.RESULTS: The labeling index (LI) of p27 in tumoral lesions was significantly lower than that in adjacent nontumoral lesions (t=2.444, P=0.017) and normal controls (t=-2.268,P=0.029). The LI of p27 significantly decreased in patients with massive type (t=-2.227, P=0.037) and infiltration (t=2.197, P=0.036). The prognosis of patients with higher p27 LI was longer than that of patients with lower p27 LI (P=0.0247, log-rank test). The LI of PCNA was significantly higher in HCC than that in adjacent nontumoral lesions (t=2.092, P=0.041) and normal controls (t=-3.533, P=0.002).There was no significant correlation between p27 expression and cell proliferation in tumor samples. The level of p27 in the cytoplasmic fraction was higher in tumoral and nontumoral liver tissues, and was associated with clinical stage (t=-2.520, P=0.029) and the degree of invasion (t=2.640, P=0.019). Survival analysis showed that p27 was an independent prognosis marker for HCC patients.CONCLUSION: These results suggest that p27 underexpressing in patients with HCC is closely associated with infiltration, metastasis, and prognosis. Alterations in the subcellular localization of p27 protein may occur early during hepatocarcinogenesis.
