赫赛汀联合丝裂霉素C对人膀胱癌T24细胞生长的抑制作用

目的 探讨赫赛汀(Herceptin,HER)联合丝裂霉素C(MMC)对HER-2/neu基因高表达人膀胱癌细胞株生长的抑制作用.方法 应用免疫细胞化学法、逆转录-聚合酶链反应(RT-PCR)法检测膀胱癌T24细胞株HER-2/neu的表达;采用噻唑蓝(MTT)比色法测定不同浓度HER(10、20、40、80、160μg/L)、MMC(4、8、16、32、64μg/L)及联合用药对人膀胱癌T24细胞株体外生长的抑制率并进行比较.结果 应用免疫细胞化学方法及RT-PCR法检测证实HER-2/neu在膀胱尿路上皮癌T24细胞株高表达;单用HER于72 h出现细胞抑制(72 h时各浓度组分别与48 h时比较,均P<0.05);HER和MMC联用在24、48、72 h基本上均表现为协同作用(q值1.264～3.473),在96 h呈相加作用(q值0.913～1.138).结论 HER-2/neu在膀胱尿路上皮癌T24细胞株高表达;HER单药对T24细胞有轻度抑制作用,且起效慢(72 h);与MMC联合应用能协同抑制T24细胞生长.     

茶多酚诱导膀胱癌T24细胞凋亡及上调PTEN表达

目的 探讨茶多酚（TP）抑制膀胱癌细胞生长的可能分子机制。方法 采用MTT法和流式细胞术，观察膀胱癌细胞系T24经不同浓度TP处理后细胞生长及PTEN蛋白表达的改变。结果TP以剂量依赖的方式抑制膀胱癌细胞的生长，加入0、50、100、200、400μg／mL TP的T24细胞抑制率分别为0％、11．2％、33.4％、36．9％、67．5％。流式细胞仪直方图上可见亚二倍体峰，癌细胞出现凋亡，凋亡率分别为6．8％、25．1％、28．6％、36．6％、41．1％；同时，随TP作用浓度的增加，G／S阻滞细胞逐渐增多，细胞分裂增殖指数（PI）降低；而细胞PTEN蛋白表达水平由（37.66±0．49）逐渐增加至（163．92±3．36）（P〈0．01）。结论 TP对T24细胞生长具有抑制作用，其机制可能是通过上调PTEN蛋白表达影响细胞周期和诱导细胞凋亡。     

比较雷帕霉素和吡柔比星抑制膀胱癌T24细胞生长活性的实验研究

目的对单独使用雷帕霉素（RPM）和吡柔比星（THP）抑制膀胱癌T24细胞生长活性的作用进行比较,探究雷帕霉素在膀胱肿瘤患者中的应用前景。方法建立空白对照组,将雷帕霉素和吡柔比星分别调整至10μg/mL、0.8μg/100μL,作用于膀胱癌T24细胞,处理24h后分别使用MTT法、流式细胞仪、RT-PCR和划痕法探索比较在此浓度下两种药物对膀胱癌T24细胞的影响;在体内实验,BALB/c裸鼠种植转移性人膀胱癌构建荷瘤模型。随机分为RPM（2mg/kg）、THP（0.015mg/cm2）组和空白对照组（生理盐水）,观察RPM和TPH对肿瘤生长及转移的影响。结果 RPM和THP分别在10μg/mL、0.8μg/100μL质量浓度下均对膀胱癌T24细胞生长活性具有明显抑制作用,同时此浓度下RPM和THP抑制T24细胞增殖的作用无明显差异（P〉0.05）;RPM组下调血管生长因子（VEGF）的作用明显强于THP组（P〈0.05）;体内实验中,RPM和THP均显著抑制肿瘤的生长及转移。结论雷帕霉素（RPM）和吡柔比星（THP）均具有良好的抑制T24细胞生长的作用,但在此浓度下THP的细胞毒性较雷帕霉素更强,并且雷帕霉素（RPM）明显抑制膀胱癌T24细胞的生长活性的作用为治疗膀胱癌治疗提供了实验参考,表现出良好的临床应用前景。     

生长因子对大鼠肝星状细胞间质胶原酶基因表达的调节作用

目的 了解转化生长因子—β(TGF—β)、表皮生长因子(EGF)、血小板衍生生长因子(PDGF)对大鼠肝星状细胞间质胶原酶(MMP13)基因表达的影响。方法 在培养的肝星状细胞系中加入TGF—β(1μg／L)、EGF(100μg／L)和PDGF(200μg／L)，于不同的时间点(8、24、48、72h)收集细胞，提取总RNA；用逆转录定量多聚酶链反应(PCR)方法测定MMP13的基因表达水平。结果 TGF-β组肝星状细胞MMP13基因表达水平在8、24、48、72h4个时间点均明显低于对照组。EGF组肝星状细胞MMP13的基因表达水平在8、24、48h均明显高于对照组；24h达高峰，为对照组的3倍。PDGF组肝星状细胞MMP13的基因表达水平在8、24、48、72h均明显高于对照组；48h达高峰，为对照组的3倍。结论 TGF—β可抑制大鼠肝星状细胞MMP13基因的表达；而EGF、PDGF可增强肝星状细胞MMP13基因的表达。     

胡椒碱对人膀胱癌 T24细胞增殖及侵袭作用的研究

目的：探讨不同浓度胡椒碱对膀胱癌 T24细胞增殖和侵袭作用的影响。方法用不同浓度的胡椒碱（5、10、20、40、80、160μmol／L）处理体外培养的膀胱癌 T24细胞,然后通过 MTT实验、Transwell 实验、Western blot 等方法检测 bax 和 bcl-2的表达以及 T24细胞的增殖和凋亡情况。结果胡椒碱作用于 T24细胞24 h 后,IC50值为38．73μmol／L,并且呈剂量依赖性。随着胡椒碱浓度的增加,T24细胞活性被抑制作用明显增加,且抑凋亡蛋白 bcl-2的表达量减少,促凋亡蛋白 bax 的表达量增加。结论胡椒碱对膀胱癌 T24细胞具有抑制增殖及促进其凋亡的作用。     

氧化苦参碱抑制人肝癌细胞EGF和EGFR表达的研究

目的:探讨氧化苦参碱对人肝癌细胞EGF及EGFR表达的影响。方法:将肝癌细胞株BEL-7402在37℃、5%CO2条件下培养、传代。按氧化苦参碱浓度分为1000μg/ml、500μg/ml、250μg/ml3组,对照组不加氧化苦参碱,每组设6个平行孔,每孔加入细胞1×105/ml,培养24h、48h和72h,分别进行EGF及EGFR的免疫组化染色。结果:不同浓度的氧化苦参碱均抑制EGF和EGFR在人肝癌细胞的表达,随着培养时间的延长,EGF和EGFR表达阳性率下降显著,在1000μg/ml组24h、48h和72h的EGF和EGFR阳性率均较500μg/ml组和250μg/ml组同时段的阳性率下降显著(P〈0.05,P〈0.01)。500μg/ml组和250μg/ml组同时段的阳性率无明显差异。结论:氧化苦参碱对EGF和EGFR的抑制途径可能是其抗肝癌机制之一。     

核心蛋白聚糖对膀胱癌细胞生长抑制机制的研究

目的 探讨核心蛋白聚糖（DCN）对膀胱癌细胞生长的影响。方法 以膀胱癌T24细胞株为研究对象，采用MTT法检测不同浓度、不同时间的DCN对T24细胞存活率的作用，采用流式细胞术分析DCN对T24细胞周期及凋亡的影响，采用ELISA和Western blot法检测DCN对转化生长因子-β1（TGF-β1）和P21蛋白表达的影响。结果 与其他浓度相比，40、50 μg/mL DCN作用72 h时对T24细胞的抑制作用最强，差异有统计学意义（P<0.05），且G1期细胞达到最高值，S期细胞达最低值（P<0.001）。5、10、20、30、40、50 μg/mL DCN作用72 h后均能促进T24细胞凋亡，且在40 μg/mL时达到最大值(P<0.001)；与0 μg/mL相比，5、10、20、30、40、50 μg/mL DCN作用72 h对TGF-β1表达均有抑制作用, 最明显的抑制作用浓度为40 μg/mL(P<0.001)；与0 μg/mL相比，40 μg/mL DCN能促进P21蛋白上调（P<0.001）。结论 DCN在体外能够抑制膀胱癌T24细胞生长，诱导其凋亡，其可能的作用机制为下调TGF-β1及上调P2l蛋白表达。     

环氧化酶-2抑制剂塞来昔布对膀胱癌T24细胞杀伤作用的研究

目的：体外观察塞来昔布对人膀胱癌T24细胞株的抑制作用,并探讨其可能的机制。方法i采用MTT法检测塞来昔布对T24细胞的生长抑制作用;采用Hoechst 33258染色观察细胞凋亡形态;采用Western印迹法检测塞来昔布作用前后T24细胞COX-2蛋白的表达变化;采用RT—PCR法检测塞来昔布作用前后T24细胞Bcl-2及Bax基因的表达变化。结果：塞来昔布（≥100μmol／L）作用24h及48h后能明显抑制T24细胞的生长并诱导凋亡;塞来昔布100μmol／L作用,24h及48h后,T24细胞COX-2蛋白表达量下降,Bcl-2基因表达亦下调,而Bax基因在塞来昔布作用24h后变化不明显,48h后表达上调。结论：塞来昔布能抑制T24细胞增殖并诱导其凋亡,可能与下调Bcl-2、上调Bax基因表达有关。     

Smac基因促丝裂霉素诱导膀胱癌细胞凋亡的研究

目的 探讨Smac基因的表达对于丝裂霉素(MMC)诱导膀胱癌细胞凋亡的影响。方法 脂质体介导Smac基因转染膀胱癌T24细胞3d后，用低剂量丝裂霉素诱导凋亡启动，噻唑蓝(MTT)比色分析检测癌细胞生长活性，吖啶橙-溴化乙锭荧光染色法及流式细胞术法检测细胞凋亡；免疫组织化学法和逆转录聚合酶链反应检测Smac基因的表达。结果 T24细胞在低剂量丝裂霉素的诱导下发生凋亡，两种方法检测细胞凋亡率，用0．05g／L丝裂霉素处理的T24细胞凋亡率分别为20，50％和18．84％，而经过转染Smac后用0，05g／L丝裂霉素处理的T24细胞凋亡率分别为36，40％和33．52％，差异有统计学意义(P＜0．05)。结论 促凋亡基因Smac在膀胱癌细胞中的活化表达可以明显增强细胞在刺激信号下的凋亡。     

重组人肝再生增强因子抑制大鼠肝星状细胞c-jun基因表达的研究

目的探讨重组人肝再生增强因子(hALR)对大鼠肝星状细胞c-jun基因表达的影响。方法在培养的肝星状细胞系中加入200、20、2 μg／L三种浓度的hALR,于8、24、48、72 h四个时间点收集细胞,提取总RNA;用逆转录-聚合酶链反应(RT-PCR)方法测定c-jun的基因表达水平。结果对照组肝星状细胞有c-jun的明显表达;不同浓度的hALR 3组肝星状细胞c-jun基因表达水平在8、24、48、72 h四个时间点均明显低于对照组;2μg／L组为对照组的60％-64％,20μg／L组为对照组的41％-43％,200 μg／L组为对照组的29％-35％。与对照组比较差异有显著性(P<0.01)。结论hALR对大鼠肝星状细胞c-jun基因表达有明显的抑制作用。     

Changes in epidermal growth factor receptor expression in human bladder cancer cell lines following interferon-alpha treatment

PURPOSE: We examined the regulation of epidermal growth factor (EGF) receptor (EGFR) expression in human bladder cancer cell lines by interferon-alpha (IFN-alpha), the ability of IFN-alpha to inhibit cell proliferation and the sensitivity of IFN-alpha pretreated cells to EGF. MATERIALS AND METHODS: Cell proliferation was determined using crystal violet colorimetric and clonogenic assays. EGFR expression was measured by flow cytometry using specific antibody or ligand binding approaches. RESULTS: After IFN-alpha (100 IU/ml) treatment cell surface EGFR expression was upregulated in 6 of 11 and down-regulated in 2 of 11 bladder cancer cell lines. The over expression of cell surface EGFR peaked within 48 to 96 hours and increased by 35% to 241% in individual cell lines. High level cell surface EGFR correlated with intracellular EGFR expression. Cell growth inhibition by IFN-alpha coexisted with EGFR over expression in the 6 lines. IFN-alpha treated cells remained sensitive to EGF treatment. CONCLUSIONS: IFN-alpha transiently up-regulates EGFR expression and inhibits in vitro growth in some human bladder cancer cells. IFN-alpha does not prevent EGFR from binding EGF or signal transduction via the EGF-EGFR pathway. This may have clinical implications for improving treatment based on EGFR targeting in select patients with bladder cancer.     

Antitumor effect of ascorbic acid, lysine, proline, arginine, and green tea extract on bladder cancer cell line T-24

AIMS: Bladder cancer, the fourth highest incident cancer in men and tenth in women, is associated with a high rate of recurrence, even when treated in situ, and prognosis is poor once the cancer metastasizes to distant sites. Based on anticancer properties, we investigated the effect of a mixture of lysine, proline, arginine, ascorbic acid, and green tea extract on human bladder cancer cells T-24 by measuring: proliferation, matrix metalloproteinase (MMP) expression, and cancer cell invasive potential. METHODS: Human bladder cancer cells T-24 (ATCC) were grown in McCoy medium supplemented with 10% fetal bovine serum, penicillin (100 U/mL) and streptomycin (100 mg/mL) in 24-well tissue culture plates. At near confluence, the cells were treated with the nutrient mixture dissolved in media and tested at 0, 10, 50, 100, 500, and 1000 microg/mL in triplicate at each dose. Cells were also treated with PMA 200 ng/mL to study enhanced MMP-9 activity. Cell proliferation was evaluated by MTT assay, MMP activity by gelatinase zymography, and invasion through Matrigel. RESULTS: Nutrient mixture inhibited the T-24 cell secretion of MMP-2 and -9, with virtual total inhibition of MMP-2 at 500 microg/mL and MMP-9 at 100 microg/mL. The nutrient mixture significantly reduced the invasion of human bladder cancer cells T-24 through Matrigel in a dose-dependent fashion, with 95% inhibition at 500 microg/mL and 100% at 1000 microg/mL nutrient mixture (P < 0.001). CONCLUSION: Our results suggest that our nutrient mixture is an excellent candidate for therapeutic use in the treatment of bladder cancer, by inhibiting critical steps in cancer development and spread, such as MMP secretion and invasion.     

Inhibition of the epidermal growth factor receptor in bladder cancer cells treated with the DNA-damaging drug etoposide markedly increases apoptosis

OBJECTIVE: To investigate the effect of the epidermal growth factor receptor (EGFR) on the induction of apoptosis by the chemotherapeutic agent etoposide (VP16), and to examine the effect of combining VP16 with gefitinib to see if the cell-survival mechanism can be prevented. MATERIALS AND METHODS: The bladder cancer cell lines RT4 and T24, representing low- and high-malignancy grades respectively, were treated with VP16 (10 or 50 microM) and the level of apoptosis determined using a commercial kit. EGFR receptor activity was determined by western blotting using antibodies against phosphorylated EGFR. The EGFR was either activated by heparin-binding (HB)-EGF (1 nM) or inhibited with the specific EGFR inhibitor gefitinib (1 or 5 microM). The pan-caspase inhibitor Z-VAD (30 microM) was used to test the involvement of caspase activity. RESULTS: Treatment of T24 bladder cancer cells with VP16 (50 microM) for 48 h induced phosphorylation of the EGFR and activation of the EGFR prevented the apoptosis induced by VP16. Thus, treatment of T24 cells with 50 microM VP16 for 48 h resulted in 19% apoptosis. However, activation of the EGFR with HB-EGF (1 nM) with VP16 (50 microM) significantly reduced the level of apoptosis by 25% (P < 0.05) showing that activating the EGFR has a cell-survival function. Inhibiting the EGFR with gefitinib (5 microM) blocked the VP16-induced activation of the EGFR. Combined treatment with gefitinib and VP16 resulted in 45% apoptotic cells, i.e. more than double the percentage of apoptotic cells with VP16 alone. This was found in both T24 and RT4 cells. Gefitinib used alone (1 and 5 microM) generated no apoptosis in the cells. Treatment of T24 cells with Z-VAD showed that apoptosis induced by both VP16 alone and VP16 with gefitinib was caspase-mediated. CONCLUSION: These results suggest that activation of the EGFR induced a cell-survival function when bladder cancer cells were treated with the DNA-damaging drug VP16, and that combined treatment with VP16 and the EGFR inhibitor gefitinib might improve the efficacy of treatment.     

Inhibition of tumor implantation by intravesical gemcitabine in a murine model of superficial bladder cancer

PURPOSE: We determined if a single intravesical instillation of gemcitabine (2',2'-difluorodeoxycytidine) could prevent the implantation of urothelial cancer cells in the bladder wall of mice, and if 4 weekly treatments could eliminate early implanted bladder cancer in this model. MATERIALS AND METHODS: Tumor implantation and orthotopic bladder tumors were induced in mice by electrocautery of the bladder wall and subsequent instillation of MB49 bladder cancer cells. In the first experiment the tumor cell suspension was left in place for 30 minutes, immediately followed by bladder irrigation and a single intravesical instillation of 250 or 500 microg gemcitabine for 10, 30, 60 or 120 minutes. In the second experiment dwell time was 2 hours, bladders were not irrigated after tumor cell instillation and mice were treated with 4 weekly instillations starting 24 hours after tumor cell implantation. The animals were monitored for side effects and bladder cancer signs, and autopsied at the end of followup. RESULTS: A single intravesical instillation of 500 microg gemcitabine (10 mg/ml) for 30 minutes decreased tumor outgrowth significantly from 90% (control) to 30% (chi-square test p = 0.022). Gemcitabine at 250 microg and prolonged instillations of 500 microg during 60 or 120 minutes were less effective. In the second experiment a short dwell time (30 minutes) was effective at 500 microg doses, resulting in an outgrowth decrease in 89% (control) to 30% of mice, whereas longer instillations (greater than 120 minutes) resulted in significantly reduced tumor outgrowth (11% at 250 microg). The apparent loss of efficacy as a factor of time could not be fully explained. Prolonged bladder distention caused by increased bladder volume due to diuresis may have resulted in trauma and caused enhanced susceptibility to tumor implantation. In the second experiment prolonged instillations (greater than 120 minutes) at 250 microg or higher doses (500 microg) were effective with 11% and 30% outgrowth, respectively. CONCLUSIONS: If given early (within 30 minutes.) after tumor cell seeding, gemcitabine is effective for preventing tumor cell implantation and the resulting tumor outgrowth.     

Matrix metalloproteinases (MMPs) in bladder cancer: the induction of MMP9 by epidermal growth factor and its detection in urine

OBJECTIVES: To investigate the matrix metalloproteinases (MMPs) 2 and 9 in bladder cancer cell lines stimulated with epidermal growth factor (EGF), and to investigate the presence of gelatinases in the urine of patients with bladder tumours, in relation to the stage and grade of tumour and the EGF receptor (EGFR) status. PATIENTS, SUBJECTS AND METHODS: Conditioned media from cultured tumour cells were analysed by zymography. Urine samples from 28 patients with transitional cell carcinoma and 12 normal volunteers were also analysed. Western blotting was used to verify the bands of gelatinolytic activity. The EGFR status of the tumours was assessed by immunohistochemistry. RESULTS: MMP9 was induced by EGF in the RT112 but not the RT4 bladder tumour cell line, whereas MMP2 production was unaffected by EGF. Gelatin zymography of urine samples from patients with bladder tumours showed high levels of MMP activity, with 78% positive for MMP9 and 28% positive for MMP2. The total gelatinolytic and MMP9 activity were significantly higher in patients with high-stage invasive tumours than in those with superficial tumours (P < 0.05), and were higher than in normal controls. Gelatinolytic activity at 130 and 200 kDa in urine was identified as MMP9 and MMP2. There was no significant relationship of urinary MMP9 activity to EGFR status of the tumour. CONCLUSION: EGF induces MMP9 but not MMP2 in bladder cells. Analysis of urinary gelatinases is a useful noninvasive technique and both total gelatinase and MMP9 activity are associated with high stages of bladder tumours.     

Dual epidermal growth factor receptor and vascular endothelial growth factor receptor inhibition with vandetanib sensitizes bladder cancer cells to cisplatin in a dose‐ and sequence‐dependent manner

OBJECTIVE

To investigate the activity of the combination of vandetanib and cytotoxic agents using in vitro models of bladder cancer, as modern chemotherapy regimens are built around cisplatin, with gemcitabine or a taxane such as docetaxel also commonly added in combination for the treatment of advanced bladder cancer.

MATERIALS AND METHODS

Human bladder cancer cells HTB3, HT1376, J82, RT4, CRL1749, T24, SUP and HTB9 were cultured. The activity of gefitinib (ZD1839) and vandetanib (ZD6474) was assessed in these eight bladder cancer cell lines with a tetrazolium‐based assay of cell viability. RT4 bladder cancer cells, determined to have moderate cisplatin resistance and also moderate sensitivity to vandetanib, were treated with vandetanib and cisplatin. RT4 and T24 cells were treated with six different regimens. The apoptosis and cell‐cycle analysis were studied by flow cytometry. Expression of p21 and p27 was detected by Western blotting. Fluorescence in situ hybridization (FISH) analysis of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 was performed for all cell lines.

RESULTS

At equal concentrations, vandetanib was a more potent inhibitor of cell viability, compared to gefitinib. At vandetanib concentrations of ≤2 µM, the combination with cisplatin was synergistic, especially in the treatment sequence of cisplatin followed by vandetanib, and additive with vandetanib followed by cisplatin. An analysis of the cell‐cycle distribution showed that vandetanib treatment induced G1 arrest at high concentrations, but not at lower concentrations. High‐concentration treatment was associated with increased levels of the cyclin‐dependent kinase p27. FISH analysis showed that there was a low level of genomic gain, and no gene amplification. Mutational analysis of exons 18, 19, and 21 of EGFR in each cell line revealed no mutation.

CONCLUSION

Vandetanib has synergistic activity when given at low concentration with cytotoxic chemotherapy. The addition of vandetanib to cisplatin‐based chemotherapy regimens merits further study.     

Heparin-binding epidermal growth factor-like growth factor functionally antagonizes interstitial cystitis antiproliferative factor via mitogen-activated protein kinase pathway activation

OBJECTIVE

To delineate the mechanism underlying the potential functional relationship between interstitial cystitis antiproliferative factor (APF) and heparin‐binding epidermal growth factor‐like growth factor (HB‐EGF), as APF has previously been shown to decrease the proliferation rate of normal bladder epithelial cells and the amount of HB‐EGF produced by these cells.

MATERIALS AND METHODS

APF‐responsive T24 transitional carcinoma bladder cells were treated with high‐pressure liquid chromatography‐purified native APF with or without HB‐EGF to determine the involvement of signalling pathways and proliferation by Western blot analysis, p38 mitogen‐activated protein kinase (MAPK) and extracellular signal‐regulated kinase (Erk)/MAPK assays, and 3‐(4,5‐dimethylthiazolyl‐2)‐2,5‐diphenyltetrazolium bromide (MTT) assay.

RESULTS

Cyclic stretch induced the secretion of HB‐EGF from T24 cells overexpressing the HB‐EGF precursor, resulting in enhanced proliferation. T24 cells treated with APF had increased p38MAPK activity and suppressed cell growth, events that were both reversed by treatment with a p38MAPK‐selective inhibitor. Activation of Erk/MAPK by HB‐EGF was inhibited by APF, and APF did not stimulate p38MAPK in the presence of soluble HB‐EGF or when cells overexpressed constitutively secreted HB‐EGF. Lastly, APF inhibitory effects on cell growth were attenuated by HB‐EGF.

CONCLUSIONS

These results indicate that HB‐EGF and APF are functionally antagonistic and signal through parallel MAPK signalling pathways in bladder cells.     

COX-2 inhibition demonstrates potent anti-proliferative effects on bladder cancer in vitro

PURPOSE: The purpose of this work was to determine the in vitro effect of Rofecoxib and specific COX 1 and COX 2 inhibitors in regards to cell growth and apoptotic and necrotic activity. INTRODUCTION AND OBJECTIVE: Rofecoxib (Vioxx) is a nonsteroidal anti-inflammatory agent (NSAID) that selectively inhibits cyclooxygenase-2 (COX-2). The inducible isoform of COX-2 is overexpressed in many gastrointestinal and genitourinary tract tumors. We hypothesized that in vitro treatment with both COX-1 and COX-2 inhibitors would significantly reduce cellular proliferation of bladder cancer cells by apoptotic pathways. MATERIALS AND METHODS: Two human bladder cancer cell lines were grown in culture using standard techniques and treated with Rofecoxib at doses ranging from 125 microg/well serially diluted down to 8.0 microg/well. Catechin (COX 1 inhibitor) and NS398 (COX 2 inhibitor) were used at doses of 50 and 100 microM. Cell viability was measured by MTT at 24 and 72 h. Apoptosis was evaluated by the Annexin V FITC Assay. Statistical analysis was performed by ANOVA. RESULTS: Rofecoxib, Catechin, and NS398 all exhibited significant inhibition of cell growth when compared to the nontreated controls. Significant changes in apoptotic activity were observed in all agents tested in both the T24 and the TCCSUP cells. CONCLUSIONS: Selective COX-2 inhibition, using the well-tolerated and commercially available Rofecoxib (VIOXX) and specific COX 1 and 2 inhibitors, reduced the growth of human bladder cancer in vitro by apoptotic mechanisms. Further in vivo and human studies are warranted to evaluate the safety and clinical utility of this agent in patients with bladder cancer.     

PI-3K和p38MAPK通路在EGF诱导PC-3细胞环氧化酶-2表达上调中的作用

目的:研究p38丝裂原激活蛋白激酶(p38MAPK)和磷脂酰肌醇-3激酶(PI/3K)通路在表皮生长因子(EGF)诱导的激素非依赖性前列腺癌(hormone-refractory prostate cancer,HRPC)PC-3细胞环氧化酶2(cyclooxygen-ase-2,COX-2)表达上调中的作用。方法:MTT法检测EGF(0μg/L)、EGF(10μg/L)、EGF(10μg/L)+PI-3K阻断剂(LY294002,20μmol/L)、EGF(10μg/L)+p38MAPK阻断剂(SC203580,20μmol/L)处理后的细胞增殖情况。RT-PCR和Western印迹测定上述处理24h后PC-3细胞COX-2的表达变化,ELISA测定细胞培养液中前列腺素E2(PGE2)的变化。结果:LY294002和SC203580明显抑制EGF刺激后的PC-3细胞增殖(P<0.05)及EGF诱导的COX-2上调和PGE2生成(P<0.05)。结论:PI-3K通路和p38MAPK通路可能参与了EGF诱导的PC-3细胞COX-2的表达上调。