Adenoviral p53 gene transfer in human bladder cancer cell lines: cytotoxicity and synergy with cisplatin

Mutations of the tumor suppressor gene p53 are common in bladder cancer. To determine whether p53 gene transfer would lead to decreased viability of bladder cancer cells, we studied the effect of p53 gene transfer in human bladder cancer cell lines with either mutant or wild-type p53. Bladder cancer cell lines 5637 and J82 (which express only mutant p53) and 253J-BV (which expresses wild-type p53) were transduced with vectors containing the β-galactosidase gene (Ad5-lacZ), wild-type human p53 gene (Ad5CMV-p53), or no foreign gene (DL312 or Ad5-polyA). X-gal staining of cells exposed to Ad5-lacZ showed that the adenoviral vector was capable of transducing each of the cell lines. Increases in p53, p21^waf1/cip1 and bax protein were demonstrated following exposure to Ad5CMV-p53, and there was a dose-dependent increase in the number of apoptotic cells. Cell viability was decreased in all three cell lines, although J82 was less sensitive than either 5637 or 253J-BV. To determine whether cisplatin increases sensitivity of J82 cells to Ad5CMV-p53, we performed median effect analysis for cisplatin combined with Ad5CMV-p53 or DL312. The combination index for cisplatin plus Ad5CMV-p53 revealed synergy, whereas cisplatin and DL312 were only additive. These results suggest that forced p53 gene expression is cytotoxic to human bladder cancer cells with either p53 mutant or wild-type background, and that combination with cisplatin is a potential method for overcoming resistance.     

p21WAF1/CIP1 gene is inactivated in metastatic prostatic cancer cell lines by promoter methylation

INTRODUCTION: p21WAF1/CIP1 may act as a tumour suppressor gene (TSG) and loss of the p21WAF1/CIP1 gene has been reported in several solid tumours. The aim of this study was to see whether p21WAF1/CIP1 was expressed in metastatic prostate cancer cell lines and to determine if there was methylation of the p21WAF1/CIP1 promoter. METHOD: PC3, LNCaP and DU145 metastatic prostate cancer cell lines, 1542NP normal prostate, and RD rhabdomyosarcoma cell lines were cultured in the demethylating agent 5-Aza-2 deoxycytidine (5-Aza-CdR). p21WAF1/CIP1 mRNA expression was analysed by RT-PCR. DNA from untreated cell lines was modified with sodium bisulphite and promoter sequencing was performed. RESULTS: p21WAF1/CIP1 was expressed at low or undetectable levels in metastatic prostate cancer cell lines but expression was reactivated by treatment with 5-Aza-CdR. Sequence analysis of the promoter region revealed several sites of methylation at the 5' end of a CpG island in the PC3, LNCaP and DU145 cell line DNA but not in the normal prostate control DNA. Most notably the Sis-inducible element (SEI)-1-a STAT1-binding site, was methylated. CONCLUSIONS: In this study, we show that p21WAF1/CIP1 expression in metastatic prostate cancer cell lines is enhanced as a result of demethylation of the DNA. Furthermore, several cytosine residues in the promoter region are methylated, including critical binding sites. The inhibition of the STAT1-signalling pathway by methylation of the promoter may inactivate the p21WAF1/CIP1 TSG in prostate cancer.     

The growth inhibitory effect of p21 adenovirus on androgen-dependent and -independent human prostate cancer cells

OBJECTIVE: To assess the potential of p21 as a gene therapy treatment for prostate cancer, by introducing p21 into both androgen-dependent (AD) and -independent (AI) human prostate cancer cell lines via a recombinant adenoviral vector, Ad5CMV-p21, carrying human p21 cDNA. MATERIALS AND METHODS: The LNCaP, DU145 and PC-3 human prostate cancer cell lines were cultured and infected with Ad5CMV-p21. Cell growth, cell-cycle progression and tumorigenicity were then assessed by thymidine incorporation into cellular DNA, and cell number, flow cytometry, and tumour growth after inoculating the cells into nude mice. RESULTS: Growth was inhibited in Ad5CMV-p21 viral-infected AD and AI prostate cancer cells. The effects were dose-dependent, regardless of the androgen status of the cell lines. Flow cytometric analysis showed that Ad5CMV-p21 arrested cell-cycle progression at G1/S with no appreciable effect on the levels of apoptotic cells. The tumorigenicity of cancer cells infected with Ad5CMV-p21 was greatly reduced in athymic mice. CONCLUSIONS: These results suggest that Ad5CMV-p21 may be a new therapeutic agent for human prostate cancer gene therapy.     

p53, p21/WAF1, pRb的表达与T1G3膀胱癌预后的关系

目的　探讨p5 3,p2 1/WAF1和pRb的异常表达在T1G3 膀胱癌预后判断中的价值。　方法　对 4 7例T1G3 膀胱癌患者进行术后随访 ,采用p5 3,p2 1/WAF1和pRb单克隆抗体对手术标本行免疫组化染色。将肿瘤进展情况与染色结果和与预后相关的临床指标进行分析。　结果　 39例手术保留膀胱的患者总进展率为 5 9% ,其中 9例发生远处转移。 8例行膀胱全切术的患者 1例于术后 2年发现肺转移。肿瘤细胞核p5 3,p2 1/WAF1和pRb蛋白的异常表达率分别为 6 6 .7%、5 1.4 %和 71.8%。多因素分析显示 ,p5 3、pRb同时异常表达 (P <0 .0 5 )和p5 3、p2 1/WAF1、pRb三者同时异常表达(P <0 .0 1)与肿瘤进展显著相关。　结论　p5 3,p2 1/WAF1和pRb的表达与T1G3 膀胱癌患者的预后密切相关     

人骨肉瘤中p53、p21~(WAF1/CIP1)和增殖细胞核抗原的表达及相互关系

目的 探讨细胞周期相关基因p21~(WAF1/CIP1)、p53和增殖细胞核抗原(PCNA)在人骨肉瘤中的表达和相互关系.方法 应用LSAB法,对40例骨肉瘤、20例骨软骨瘤患者的病变组织和20例正常人骨组织分别以p53、p21~(WAF1/CIP1)、PCNA蛋白的单克隆抗体作免疫组织化学检测.结果 骨肉瘤组织中p53、p21~(WAF1/CIP1)、PCNA蛋白的阳性反应率和阳性反应强度均明显高于骨软骨瘤和正常骨组织,其差异有统计学意义(P<0.05).p53标记指数与p21~(WAF1/CIP1)标记标数以及p21~(WAF1/CIP1)与PCNA标记指数间呈正相关(t值分别为2.93和4.20,P<0.01).结论 骨肉瘤组织中有p53、p21p21~(WAF1/CIP1)和PCNA的过表达,其表达的强度与肿瘤的恶性程度和预后相关.     

Evaluation of p21WAF1/CIP1 and cyclin D1 expression in the progression of superficial bladder cancer

Immunoreactivity of p21^WAF1/CIP1 and cyclin D₁ proteins was assessed in a cohort of 207 patients with superficial (pTa-pT₁) bladder cancer followed up for a mean of 4.9 years. The results of the immunostainings were compared with T category, WHO grade, tumor cell proliferation rate (MIB-1 score), the expressions of p53 and bcl-2 as well as survival. Sixty-eight percent and 75% of the tumors were p21^WAF1/CIP1 positive (≥5% of cells positive) and cyclin D₁ positive (≥10% of cells positive), respectively. The p21^WAF1/CIP1 expression was related to cyclin D₁ immunolabelling (P < 0.001) but not to the other variables studied. The expression of cyclin D₁ was inversely associated with T category (P=0.001), WHO grade (P=0.006), MIB-1 score (P=0.014), p53 expression (P=0.001), and bcl-2 (P=0.011) immunoreactivity. In univariate analysis, T category (P=0.0001), WHO grade (P < 0.0001), MIB-1 score (P < 0.0001), bcl-2 (P=0.0092), p53 (P=0.0016) and p21^WAF1/CIP1 (P=0.009) expressions were significant prognostic factors with regard to tumor progression, whereas cyclin D₁ was without any prognostic significance (P=0.1). Out of 123 p21 positive tumors 21 progressed, whereas only 2 out of 58 p21 negative tumors progressed. In multivariate analysis, the MIB-1 score was the only independent predictor of cancer-specific survival (P=0.03), whereas tumor grade (P=0.002) and cyclin D₁ expression (P=0.04) were independent predictors of tumor recurrence. Only the WHO grade (P=0.04) retained its prognostic value indicating the risk of progression. We suggest that in superficial bladder cancer p21^WAF1/CIP1 and cyclin D₁ immunohistochemistry provide no additional prognostic information compared with already established prognostic factors for predicting the risk of progressive disease. Received: 13 September 1999 / 22 March 2000     

p53, p21 and mdm2 expression vs the response to radiotherapy in transitional cell carcinoma of the bladder

OBJECTIVE: To identify, in a retrospective study, possible molecular markers predictive of radioresponsiveness in patients with transitional cell carcinoma (TCC) of the bladder. PATIENTS AND METHODS: Patients with T2-T4a TCC treated with preoperative radiotherapy and cystectomy were included in the study if their cystectomy specimen was pT3b (in 42) or pT0 (in 17). Because treatment schedules changed over time, radiotherapy was given either as 2 Gy x 23 over 4-5 weeks with cystectomy 4-5 weeks later (in 23), or as 4 Gy x 5 during 1 week with cystectomy in the following week (in 36 patients). Protein expression of p53, mdm2 and p21 (CDKN1 A/WAF1/CIP1/SDI1) was assessed immunohistochemically in biopsies taken before radiotherapy. RESULTS: There was no difference in protein expression when comparing all patients with pT0 and pT3b. However, for patients receiving 46 Gy, increased p53 expression (but not p21 or mdm2) predicted the absence of residual tumour (P = 0.005): six of seven patients with > 50% p53 expression had pT0 in the cystectomy specimen, whereas 10 of 12 patients with < or = 5% expression had pT3b. Over-expression of p53 correlated with longer overall (P = 0.045) and cancer-specific survival (P = 0.020). CONCLUSION: The expression of mdm2 or p21 did not predict radioresponsiveness in patients with TCC of the bladder. The role of p53 remains unclear; the view that p53 over-expression confers radioresistance in bladder cancer is not supported.     

Prognostic significance of histopathological grading and immunoreactivity for p53 and p21/WAF1 in grade 2 pTa transitional cell carcinoma of the urinary bladder

OBJECTIVE: At present, there are no predictors of tumour behaviour for grade (G) 2 pTa transitional cell carcinomas (TCC) of the bladder. Here we analyse the prognostic relevance of histopathological grading and the immunohistochemical detection of p53 and p21/WAF1. METHODS: 70 patients were newly diagnosed with G2 pTa TCC of the bladder based on transurethral resection specimens. Two pathologists, blinded with respect to the clinical outcome, confirmed the initial grade and subclassified the G2 lesions into G2a and G2b carcinomas based on the degree of nuclear atypia and the number of mitoses. Immunoreactivity for p53 and p21/WAF1 was evaluated semiquantitatively. RESULTS: There were 52 G2a and 18 G2b tumours, mean follow-up was 49.2 months. Of all patients, 31.4% remained tumour-free, 48.6% recurred with the same tumour grade and stage, and 20.0% showed tumour progression. Patients with G2a tumours developed tumour progression in 13% in contrast to 39% with G2b lesions (p = 0.037). Of 21 p53-positive tumours, 33% (7/21) developed progressive disease, whereas 14% (7/49) of p53-negative patients showed tumour progression (p = 0.102). Neither p21/WAF1 expression alone nor the combination of p53 and p21/WAF1 correlated with clinical outcome. CONCLUSION: The more detailed grading system but not p53 or p21/WAF1 immunohistochemistry was found to be an independent prognostic factor for tumour progression.     

Biological evaluation of undifferentiated carcinoma of the esophagus

Background Patients with undifferentiated carcinoma of the esophagus (UEC) are rare and have a poor prognosis compared with those with differentiated squamous cell carcinomas (DECs). We compared clinicopathological and biological features of UEC and DEC, with emphasis on markers for epithelial cell origin, proliferation, and cell-cell adhesion. Methods Seven patients with UEC were compared with 21 with DEC. Immunohistochemical studies were performed by using monoclonal antibodies to cytokeratin, epithelial membrane antigen, p53, p21^WAF1/CIP1, Ki-67, E-cadherin, desmoglein-1, and thrombomodulin. Results Patients with UEC had a poorer prognosis because of hematogenous metastasis at the time of presentation (mean survival, 6.5±6.2 vs. 35.5±28.9 months;P<.05). Immunohistochemical findings for cytokeratin and epithelial membrane antigen suggest that some UECs had epithelial origins. The following immunohistochemical profile of UEC was consistent with its highly malignant properties: (1) reduced or negative expression of cell-cell adhesion molecules such as E-cadherin, desmoglein-1, and thrombomodulin, (2) high positive rate for p53 and Ki-67, and (3) negative expression of p21^WAF1/CIP1. Conclusions The immunohistochemical findings for UEC showed its high cell-proliferative activity and a high potential for metastasis. Clinical features of UEC were supported by the results of immunohistochemical findings.     

The expression of oncoproteins in transitional cell carcinoma: its correlation with pathological behavior,cell cycle and drug resistance

OBJECTIVE: To investigate the relationship of oncoproteins with histological grade, tumor stage, cell cycle and multidrug resistance (MDR) in bladder cancer. METHODS: The expression of various oncoproteins (p21, EGFR1, erbB-2, c-jun, c-myc, bcl-2, Bax) and suppressor gene products (WT-1, RB gene, p53) was studied in normal urothelium, transitional cell carcinoma (TCC) cell lines and their MDR sublines by using specific antibodies and an indirect immunofluorescence flow-cytometric method. RESULTS: The total increased rate of measured oncoproteins in TCC cell lines was 62.7%. There was no difference in the expression rate of oncoproteins between low-grade/stage TCC cell lines and high-grade/stage TCC cell lines. All of these TCC cell lines have aneuploidy and increased proliferative activity in the cell cycle, but a correlation with oncoprotein expression was not seen. They had a low expression rate of c-myc, Bax and RB gene when compared to normal urothelium. On the contrary, the expressions of p21, EGFR1, erbB-2, bcl-2, WT-1 and p53 oncoproteins were significantly higher than in normal urothelium (p < 0.05). A long-term cultured MDR subline of TCC8702 (TCC8702/ADR1000) demonstrated a generally decreasing expression of oncoproteins in addition to p53. CONCLUSIONS: The p21, EGFR1, erbB-2, bcl-2, WT-1 and p53 oncoproteins were increased in TCC cells compared to normal urothelium. Oncoprotein expression is related to tumorigenesis of TCC cells, but no correlation was seen between the incidence and tumor differentiation and cell cycle. These oncoproteins decreased gradually in the process of generation of MDR in addition to p53. It indicates that the p53 oncogene is closely related to the acquired MDR of TCC cells.     

RNA激活技术上调p21WAF1/CIP1基因表达对胆囊癌细胞增殖、侵袭与迁移能力的影响

目的利用RNA激活技术上调人胆囊癌细胞(GBC-SD)中p21基因的表达,观察其对GBS-SD细胞体外增殖、侵袭和迁移能力的影响。方法将与p21基因启动子DNA序列互补的双链RNA分子(dsRNA)转染入人胆囊癌细胞中,采用RT-PCR法和Western blot分别检测p21基因mRNA及蛋白的表达情况;MTT法检测细胞增殖活性;Transwell小室法检测RNAa后细胞侵袭、迁移能力的变化。结果 dsRNA转染GBC-SD细胞72h后能显著上调p21基因mRNA和蛋白的表达,与空白组和对照组比较,转染dsp21后,GBC-SD细胞的增殖活性明显受到抑制,细胞侵袭及迁移能力明显下降。结论 RNAa技术能有效上调p21基因的表达并抑制细胞的增殖活性,降低其侵袭及迁移能力,为胆囊癌疾病的基因治疗提供依据。     

膀胱癌多发或复发的克隆起源

目的 探讨人膀胱移行上皮癌多发性、复发性的细胞克隆起源。方法 采用ｐ５３基因突变的ＰＣＲ－ＳＳＣＰ分析及ＤＮＡ测序检测６例患者１４个表浅、低分级原发加多发或复发的膀胱移行上皮癌标本及ｐ２１＾ＷＡＦ１／ＣＩＰ１蛋白的表达。结果 在１４个膀胱移行上皮癌标本均有ｐ５３基因的点突变,同一例患者所有标本的点突变分别在同一位点上;１４个膀胱移行上皮癌标本中仅有５个有ｐ２１＾ＷＡＦ１／ＣＩＰ１蛋白的表达。结论     

维生素K3诱导乳腺癌细胞凋亡作用及调控因素的观察

目的：观察维生素K3（VitK3）对乳腺癌MCF-7细胞的凋亡诱导作用,探讨其可能机制.方法：采用噻唑蓝比色实验（MTT法）检测不同浓度VitK3对MCF-7细胞增殖的影响,观察过氧化氢酶（Catalase）对VitK3作用的影响;采用流式细胞技术（FCM）检测细胞的凋亡;应用RT-PCR检测VitK3作用前后核转录因子RelA、凋亡相关基因Bcl-2、Bax和细胞周期蛋白依赖性激酶抑制物p21 CIP1/WAF1、p27KIP1 mRNA表达的变化.结果：（1）VitK3对MCF-7细胞的生长有明显的抑制作用,Catalase能降低VitK3的生长抑制作用;（2）VitK3能够诱导MCF-7细胞发生凋亡并随浓度的增加而增强;（3）VitK3作用后,Rcla、Bax、p21 CIP1/WAF1在mRNA水平表达增强.结论：VitK3能够诱导MCF-7细胞发生调亡,细胞周期停滞和Bax表达增加是其可能的作用机制.     

Chondrocyte p21<Superscript>WAF1/CIP1</Superscript> Expression Is Increased by Dexamethasone but Does Not Contribute to Dexamethasone-Induced Growth Retardation In Vivo

It has been shown that cell cycle genes play an important role in the coordination of chondrocyte proliferation and differentiation. The inhibitory effects of glucocorticoids (GCs) on chondrocyte proliferation are consistent with GCs disrupting cell cycle progression and promoting cell cycle exit. Cyclin-dependent kinase inhibitors (CDKIs) force cells to exit the cell cycle and differentiate, and studies have shown that expression of the CDKI p21^CIP1/WAF1 is increased in terminally differentiated cells. In this study, p21 mRNA and protein expression was increased during chondrocyte differentiation and after exposure to dexamethasone (Dex, 10⁻⁶ M) in murine chondrogenic ATDC5 cells. In 4-week-old mice lacking a functional p21 gene, Dex caused a reduction in body weight compared to saline control null mice, but this was consistent with the reduction in body weight observed in Dex-treated wild-type littermates. In addition, p21 ablation had no effect on the reduction in width of the growth plate or reduced mineral apposition rate in Dex-treated mice. However, an alteration in growth rate and epiphyseal structure is evident when comparing p21^−/− and wild-type mice. These findings suggest that p21 does not directly contribute to GC-induced growth retardation in vivo but is involved in the maintenance of the growth plate.     

Expression of cyclin kinase inhibitor p21/WAF1 protein in pituitary adenomas: correlations with endocrine activity,but not cell proliferation

Summary.  p21/WAF1 blocks cell cycle progression through inhibition of cyclin/cyclin-dependent kinases (cdks) complexes and, simultaneously, has been associated with cell cycle exit and the process of differentiation. In this series, the expression of p21/WAF1 was assessed immunohistochemically in 47 cases of pituitary adenomas in relation to endocrine activity and cell proliferation. To evaluate cell proliferation, a monoclonal antibody, MIB-1, against Ki-67 antigen was used in all of the available cases. The study revealed positive p21/WAF1 staining in 24 cases of 26 functioning parenchymas, whereas 14 cases of 21 non-functioning parenchymas stained negative. The MIB-1 index ranged from less than 1% to 5.1% (mean: less than 1.7%) in functioning adenomas, and from less than 1% to 3.6% (mean: less than 1.6%) in non-functioning adenomas. Regardless of endocrine activity, p21/WAF1 positivity did not correlate with the MIB-1 index. Double staining techniques revealed the co-expression of p21/WAF1/GH or p21/WAF1/PRL in functioning adenomas. In 22 cases of p21/WAF1-positive functioning adenomas, p21/WAF1 immunoreactivity was seen in the cytoplasma as well as nuclei. These results indicate that in pituitary adenomas, p21/WAF1 expression is associated with endocrine activity, but not with cell proliferation. Taken together with recent findings demonstrating that cytoplasmic p21/WAF1 acts as an inhibitor of apoptosis, it is possible that pituitary adenomas expressing cytoplasmic p21/WAF1 have resistance against DNA-damaging agents such as ionizing radiation.     

Differential involvement of the Fas receptor/ligand system in p53-dependent apoptosis in human prostate cancer cells

BACKGROUND: The objective of this study was to characterize the involvement of the Fas receptor/ligand system in p53-dependent apoptosis in human prostate cancer cells. METHODS: The effects of adenovirus-mediated p53 gene transfer (Ad5CMV-p53) into human prostate cancer LNCaP, DU145, and PC3 cells on their growth, apoptosis and Fas receptor/ligand expression were examined by the MTT assay, DNA fragmentation assay, and Northern blot analysis, respectively. The sensitivity of these cells to an agonistic anti-Fas receptor antibody (CH11) and the effects of an antagonistic anti-Fas ligand antibody (4H9) on Ad5CMV-p53-induced apoptosis were analyzed by the MTT assay and DNA fragmentation assay. RESULTS: Ad5CMV-p53 treatment resulted in substantial growth inhibition, induction of apoptosis and up-regulation of Fas receptor as well as Fas ligand mRNA expression in LNCaP, DU145 and PC3 cells. Despite the abundant expression of Fas receptor in all of these cells, CH11 induced apoptosis only in PC3 cells. Furthermore, 4H9 partially blocked the apoptosis induced by Ad5CMV-p53 in PC3 cells, but not in LNCaP and DU145 cells. CONCLUSIONS: The Fas receptor/ligand system is differentially involved in p53-dependent apoptosis in prostate cancer cells; therefore, reintroduction of wild-type p53 into prostate cancer cells may induce apoptosis through Fas receptor/ligand interaction as well as through an alternative pathway.     

Preclinical study of adenoviral p53 gene therapy for esophageal cancer

An alteration of the p53 gene function is a major factor in the development of esophageal cancer. Recently, p53 gene therapy has been applied for clinical studies in lung cancer and head and neck cancer. However, no preclinical studies have yet demonstrated an anticancer effect of adenoviral-mediated wild-type p53 gene therapy on esophageal cancer. We herein evaluated the effect of p53 adenoviral gene therapy on human esophageal squamous cell carcinoma to test the ability of clinical application. A normal esophageal epithelial cell line (EN53F) and two human esophageal cancer cell lines (ECGI-10 and T.Tn) with a p53 alteration were used. The transduction efficiency, p53 protein expression, p21 protein expression, the induction of apoptosis, and growth suppression were assessed by using the recombinant adenoviral vector Ad5CMV-p53. The transduction efficiency was 60%–80% at 100 plaque-forming units (PFU)/cell and 80%–100% at 300 PFU/cell. A significant growth suppression following an Ad5CMV-p53 infection was observed in both cancer cell lines. A Western blot analysis confirmed the presence of both exogenous p53 protein expression and p21 protein induction. Apoptotic cell death was observed with TUNEL staining. T.Tn xenografts in nude mice transduced with Ad5CMV-p53 demonstrated significant growth suppression. These data suggest that Ad5CMV-p53 may thus be a potentially effective therapeutic agent for locally advanced esophageal cancer. Received: July 19, 2000 / Accepted: January 9, 2001     

P27KIP1和P53及P21WAF1/CIP1表达与胃癌临床病理及预后的关系

目的研究P27KIP1、P53、P21WAF1/CIP1蛋白表达与胃癌临床病理及预后的关系。方法应用免疫组织化学SP法检测90例胃癌组织中P27KIP1、P53、P21WAF1/CIP1的表达。结果90例胃癌组织中P27KIP1、P53、P21WAF1/CIP1阳性表达率分别为48.9%、56.7%、51.1%;随肿瘤分化程度降低、浸润深度加深、恶性程度增加,P27KIP1、P21WAF1/CIP1阳性表达率逐渐降低(P<0.05),P53阳性表达则相反;P27KIP1与P53、P21WAF1/CIP1表达显著相关(P<0.05);P27KIP1、P21WAF1/CIP1表达与胃癌预后密切相关(P<0.05),P53表达与患者术后生存无显著相关(P>0.05)。结论P27KIP1、P53、P21WAF1/CIP1异常表达可加速细胞周期转化,促进胃癌的发生,其蛋白检测尤其是P27KIP1、P21WAF1/CIP1蛋白检测可作为判断胃癌恶性程度、预测肿瘤转移和预后的重要参考指标。