Genetic detection of bladder cancer by microsatellite analysis of p16, RB1 and p53 tumor suppressor genes

PURPOSE: We investigated the incidence of genetic alterations in urine specimens from patients with bladder cancer. MATERIALS AND METHODS: A total of 28 cytological urine specimens were assessed for microsatellite alternations, and 15 microsatellite markers were located on p53, RB1 and p16 regions. In 15 patients DNA from tumor specimens was also available. RESULTS: Loss of heterozygosity was detected in 26 of 28 patients (93%) in at least 1 microsatellite marker. Allelic losses were found in 18 patients (64%) for the p16 locus, in 8 (29%) for the RB1 locus and in 17 (61%) for the p53 region. In contrast, no microsatellite alterations were found in the normal group without evidence of bladder cancer. In 11 cases genetic alterations in the cytological urine specimens were not detectable in the corresponding tumor specimen, suggesting heterogeneity of bladder cancer. CONCLUSIONS: The detection of loss of heterozygosity in cytological urine specimens may be a prognostic indicator of early detection of bladder cancer. Our results suggest that microsatellite analysis of urine specimens represents a novel, potentially useful, noninvasive clinical tool to detect bladder cancer.     

p53 nuclear accumulation is not associated with decreased disease-free survival in patients with node positive transitional cell carcinoma of the bladder

PURPOSE: Although the majority of patients with node positive transitional cell carcinoma of the bladder have disease progression, a definitive subset is cured by surgery only. Nuclear accumulation of p53 has been associated with disease progression in patients with superficial transitional cell carcinoma and decreased survival in those with muscle invasive disease. We determined whether p53 status would predict survival in a cohort with nodal metastasis. MATERIALS AND METHODS: We explored the comprehensive database of all 199 radical cystectomies performed at our institution between July 1988 and September 1999. The 59 patients in this database with node positive pathology comprise our study. We performed immunohistochemical analysis of specimens using the MAB1801 antibody with greater than 20% lymph node and primary tumor nucleus staining deemed positive. Additional covariates measured included patient age, sex, pathological disease stage, adjuvant chemotherapy and nodal stage. Disease-free survival curves were generated for the various covariates and compared using the log rank test. The Cox proportional hazards technique was used to determine covariate adjusted p53 survival. RESULTS: In the cohort overall median disease-free survival was only 21 months, although 18% of patients were disease-free at 5 years. There was evidence of p53 nuclear accumulation in 54% of cases and complete agreement of nodal with bladder p53 nuclear accumulation. No significant baseline differences were noted in the covariates with respect to p53 nuclear accumulation. For stratum specific disease-free survival univariate and multivariate analyses revealed that only pathological stages p0-p2b versus p3-p4 (hazards ratio 2.86, p = 0.03), and nodal stages N2 versus N1 and N3 versus N1 (hazards ratio 3.84, p = 0.01 and hazards ratio 13.3, p = 0.0002, respectively) were significantly associated with prolonged disease-free survival, while p53 nuclear accumulation was not. CONCLUSIONS: Despite credible evidence for p53 nuclear accumulation prognostication in patients with in situ and invasive transitional cell carcinoma, this marker is not predictive of disease-free survival in node positive disease.     

p53 and microvessel density in primary resection specimens of superficial bladder cancer

PURPOSE: p53 Regulates angiogenesis in fibrosarcoma and correlative studies suggest a similar role for muscle invasive bladder cancer. We evaluated the associations of p53 status and microvessel density with pathological features and clinical outcomes in a large population of patients with superficial bladder cancer. In addition, we assessed the correlation of p53 status with microvessel density, which would suggest the regulation of angiogenesis by p53. MATERIALS AND METHODS: We stained 84 primary bladder resection specimens, including 55 stage pTa, 29 stage pT1, 27 grade 1, 35 grade 2 and 22 grade 3 samples, for p53, CD31 and CD34. The relationships of p53 or microvessel density and tumor stage-grade or clinical recurrence-progression were analyzed by analysis of variance and pairwise comparison analysis for least significant difference, and Pearson correlation coefficients. Only patients with no previous biopsy were included in analysis to preclude interference by granulation tissue related neovascularization. The 4 samples with significant inflammation were also excluded from study. RESULTS: At a mean followup of 33 months (range 1 to 93) 34 of 84 patients (40.4%) experienced 1 or more tumor recurrences and 10 (11.9%) had stage and/or grade progression. Statistically significant associations were observed of p53 immunostaining and microvessel density with tumor stage and grade (p <0.05). However, the association of p53 status with microvessel density was weak and not statistically significant. Similar results were observed for the CD31 and CD34 based estimates of microvessel density. Neither p53 status nor microvessel density correlated with recurrence or progression. CONCLUSIONS: Our study confirms the strong association of p53 and microvessel density with the well established prognostic factors of grade and stage in superficial bladder cancer, supporting other evidence of an important role for p53 and angiogenesis in the tumor biology of this disease. However, our data argue against a primary role of p53 in the regulation of angiogenesis in superficial bladder cancer. This study, which to our knowledge is the first to focus on primary resection specimens, suggests that other genetic or environmental factors may contribute to the regulation of angiogenesis in superficial bladder cancer.     

Prognostic implications of p53 gene mutations in bladder tumors

PURPOSE: Alterations in the p53 gene related to neoplastic progression were studied in tumor tissue samples from patients with transitional cell carcinoma and correlated with classic staging parameters. On this basis, biological characterization of the tumor was performed to establish subgroups of patients at high risk and those with a more favorable prognosis. MATERIALS AND METHODS: This observational, analytical and cross-sectional study included 115 patients divided into 4 homogeneous groups of 1-control, 2-primary superficial transitional cell carcinoma, 3-recurrent superficial transitional cell carcinoma, and 4-infiltrative transitional cell carcinoma. DNA was obtained from tumor tissue samples and polymerase chain reaction-single strand conformational polymorphism analysis was performed on exons 5 to 9 of the p53 gene. Samples showing mutations were submitted to automatic sequencing. Statistics included bivariate analysis and logistic regression. RESULTS: Of the tumors the 63.8% were superficial and 37.2% were infiltrative transitional cell carcinoma. Of the infiltrative tumors 23.5% (8 of 34) resulted from recurrent transitional cell carcinoma. Mutations were found in samples from 46.8% of patients, all with bladder tumors. There was a trend toward increasing appearance of mutations as the size of the tumor, number of tumor implants, degree of dedifferentiation and stage of local infiltration increased. The presence of mutations in p53 was 2.5 times greater in infiltrative tumors than in low stage and 4.3 times greater in moderate to high grade than in low grade tumors. All mutations found were point mutations and 79.25% provoked severe alterations in protein structure. CONCLUSIONS: Mutations in the p53 gene are mainly point mutations that aggregate in hot spots, and provoke genetic instability and substantial changes that alter p53 function, implying a trend to tumor progression and dissemination (with a greater proportion of mutations in high stage high grade tumors). Since a large percentage of bladder tumors are under staged, analysis of p53 gene mutations could be useful as a factor for prognosis and therapeutic decisions.     

Prognostic value of p53 for high risk superficial bladder cancer with long-term followup

PURPOSE: The risk of muscle invasive disease in a high risk patient with superficial bladder cancer is up to 50%. Identifying patients at risk for progression remains an unsolved problem. A suggested prognosticator is mutations in the p53 tumor suppressor gene. We determined the value of p53 mutation, as demonstrated by mutation analysis, in a clinically selected group of high risk patients with superficial bladder cancer. MATERIALS AND METHODS: p53 Mutation analysis was performed by automated sequencing of bladder wash samples of 105 patients with high risk superficial bladder cancer. The mutation and WT groups were subsequently compared with regard to mortality, progression, disease worsening and the recurrence-free period. RESULTS: A total of 29 patients had a mutation and 76 had WT. Median followup was 58.3 months (range 3 to 161). A total of 13 patients died of bladder cancer, including 6 of 29 with a mutation and 7 of 76 patients in the WT group. p53 Mutation had no significant prognostic value for decreased survival, progression or disease worsening. Recurrence-free survival was significantly lower in the WT group. CONCLUSIONS: We observed a trend toward a worse clinical outcome in high risk patients with a p53 mutation in the bladder wash. However, no significant differences were seen in clinical outcome parameters. Based on these data we conclude that the prognostic value of a p53 mutation is insufficient for individual policy making.     

STRUCTURAL ALTERATION OF p53 PROTEIN IN PATIENTS WITH MUSCLE INVASIVE BLADDER TRANSITIONAL CELL CARCINOMA

PURPOSE: Recent data imply that 3-dimensional (D) p53 protein modeling provides more specific information on its function in patients with pancreatic adenocarcinoma. In addition to immunohistochemical and single strand conformational polymorphism analysis, we performed 3-D p53 protein modeling and correlated our results with the disease-free survival of patients with muscle invasive transitional cell carcinoma of the bladder who underwent surgery. MATERIALS AND METHODS: We identified 43 patients and analyzed p53 status in each by immunohistochemical testing, single strand conformational polymorphism and DNA sequencing with 3-D protein modeling. Median followup was 38 months (range 4 to 92). The results of each analysis were compared and correlated with cancer specific survival. Statistical analysis was performed using the log rank test on Kaplan-Meier survival curves. RESULTS: The population included 30 men and 13 women 35 to 84 years old (median age 65). Nuclear over expression of p53 protein was observed in 26 of the 43 cases (60%). Lymph node involvement did not correlate with p53 over expression. Significantly more patients with lymph node metastasis died of cancer. Median survival in the 26 patients with p53 over expression was 28 months versus 57 in those with negative staining (p = 0.25). Mutation analysis by single strand conformational polymorphism revealed no abnormality in 24 patients (56%) with a median survival of 28 months, whereas we noted abnormal mutational analysis in 19 (44%) with a median survival of 38 months (p = 0.33). Of 19 single strand conformational polymorphism positive cases DNA sequencing showed mutation near the DNA binding site in 10 (53%), mutation away from the site in 6 (32%) and no mutation in 3 (17%). No survival difference was detected in cases with mutation away and near the DNA binding site, respectively (p = 0.69). CONCLUSIONS: In this group of patients treated with radical cystectomy for muscle invasive bladder transitional cell carcinoma, analysis of p53 protein and the p53 gene by immunohistochemical testing, single strand conformational polymorphism and mutational analysis did not correlate with cancer specific survival.     

膀胱癌p53蛋白核蓄积的临床意义

为探讨不同病理分期膀胱癌p53蛋白核蓄积与肿瘤恶性进展的关系．采用免疫组织化学方法检测122例获随访结果的膀胱癌患者的p53表达，用多变量相关分析，Logistic回归分析和Kaplan-Meier法分析。发现p53蛋白核反应与肿瘤临床病理分期及淋巴结转移呈正相关(P=0.003)；Kaplan—Meier生存分析显示肿瘤局限于膀胱内(P1，P2和P3a)，p53蛋白阳性染色者复发率显著高于阴性者，5年生存率明显低于阴性者。本研究证明p53蛋白核蓄积表示肿瘤呈恶性进展，病人预后较差。     

Absence of the p53 tumor suppressor gene promotes osteogenesis in mesenchymal stem cells

Objective

Osteosarcoma arises predominantly in the metaphyseal growth plate of children during the growth spurt years. These tumors develop during physiological growth from an expanding cell population, suggesting that the transformed cell is a bone-forming progenitor. An absence of the p53 oncogene has been implicated in the origin and progression of osteosarcoma, and because mesenchymal stem cells (MSCs) are the physiological osteogenic progenitor cell population, we hypothesized that a p53^−/− mutation would enhance bone differentiation of MSC in a mouse model of in vitro osteogenesis.

Methods

Clonal MSC populations were derived from p53^−/− mice. P53^−/− and wild-type cells were placed in osteogenic culture and assessed via Alizarin Red quantification and alkaline phosphatase staining. The osteogenic marker genes Cbfa1, osteopontin, and osteocalcin were assessed by quantitative real time polymerase chain reaction during differentiation.

Results

Bone nodule formation and alkaline phosphatase staining was accelerated and enhanced in the p53^−/− cells. The early and intermediate osteogenic markers, Cbfa1 and osteopontin, were upregulated in p53^−/− MSCs compared with wild-type cells during osteogenesis. The terminal osteogenic marker gene osteocalcin was paradoxically lower in p53^−/− MSCs indicating impaired terminal differentiation.

Conclusion

The p53^−/− mutation enhances and accelerates early osteogenesis in MSCs, but prevents terminal differentiation toward a mature osteocyte phenotype. These findings may have important implications for the regulation of the MSC compartment during the derivation of osteosarcoma in children.     

Immunoexpression of p53 protein and proliferating cell nuclear antigen in penile carcinoma.

PURPOSE: We examined p53 protein and proliferating cell nuclear antigen immunoexpression as prognostic factors to the outcome of squamous cell carcinoma of the penis in 50 patients. MATERIALS AND METHODS: Penectomy and lymphadenectomy were performed in 14 patients with clinically positive nodes while 36 with cN0 disease were treated with penectomy and kept under surveillance that resulted in subsequent lymphadenectomy due to nodal relapse in 8. Of 21 patients with confirmed nodal metastases 18 died of disease. Immunohistochemical reactions were performed via the avidin-biotin-immunoperoxidase method and the results were compared with tumor pT stage, grade, nodal status and cause specific death. RESULTS: In univariate analysis proliferating cell nuclear antigen staining showed association only with nodal metastasis (p = 0.04) while p53 staining exhibited correlation with tumor pT stage (p = 0.0005), grade (p = 0.02), lymphatic spread (p = 0.02) and cause specific survival (p = 0.003). Multivariate analysis showed that p53 immunoreactivity was the only factor with prognostic significance for disease progression and cause specific survival. Tumor pT stage, grade and proliferating cell nuclear antigen staining had no significance for nodal metastases and cause specific death. CONCLUSIONS: Proliferating cell nuclear antigen staining had no prognostic value for disease progression. Since p53 over expression was associated with tumor progression and cause specific death, perhaps it should be evaluated in staging and therapeutic planning for patients with squamous cell carcinoma of the penis.     

Association of p53 tumor suppressor gene with paraclinical and clinical modalities of gliomas patients in Malaysia

Summary Background. Alteration of the tumor suppressor gene p53 is considered to be a critical step in the development of human cancer. Changes in this gene have been detected in a wide range of human tumours, including gliomas. In glioma, the presence of p53 gene alterations has been associated with worse prognosis.Methods. Forty-seven Malaysian adult glioma patients of the Malay race were prospectively studied over a period of 3 years where the presence of p53 mutation using cold-SSCP method and their clinical and paraclinical response were correlated.Findings. Among these glioma patients, p53 mutations were detected in 12 tumors, an incidence rate of 25.5%. Mutations were found in 2 patients of grade II, and 5 patients both in grade III and grade IV. The sequencing results revealed the presence of base-substitutions (7) (58.3%) and frameshifts mutations (5) (41.7%). Of the base-substitutions, 57.1% were transversions and 42.9% were transitions.Interpretation. Our analysis shows that 3 factors were associated with p53 mutations i.e. grade, site and consistency of tumour using univariate analysis although multivariate analysis revealed no positive on predictors of mutation. In conclusion, although p53 genetic alterations are involved in glioma patients in Malaysia, it has no impact on prognosis.     

RNA干扰下调p53抑制因子iASPP表达对膀胱癌细胞的影响

Objective To discuss the effects of silencing of iASPP gene on human bladder cancer cells. Methods RNAi silencing of iASPP gene in bladder cancer cell 5637 and T24 cells were used by lentiviral mediated interfering short hairpin RNAs. Cell proliferation was tested by MTT assay, and rate of colony was tested by colony formation assay. Cell cycles were tested by using fluorescence-activated cell sorting. Results Down-regulation of iASPP could inhibit the growth and proliferation of human bladder cancer cells (P＜0.05). iASPP know-down could decrease the colony formation of 5637 and T24 cells (P＜0, 05). Knocking down of iASPP in 5637 and T24 cells showed cell arrested at G1. Conclusions Silencing of iASPP gene could inhibit proliferation and colony formation of bladder cancer, iASPP might be an important target for gene therapy of bladder cancer.     

RNA干扰下调p53抑制因子iASPP表达对膀胱癌细胞的影响

Objective To discuss the effects of silencing of iASPP gene on human bladder cancer cells. Methods RNAi silencing of iASPP gene in bladder cancer cell 5637 and T24 cells were used by lentiviral mediated interfering short hairpin RNAs. Cell proliferation was tested by MTT assay, and rate of colony was tested by colony formation assay. Cell cycles were tested by using fluorescence-activated cell sorting. Results Down-regulation of iASPP could inhibit the growth and proliferation of human bladder cancer cells (P＜0.05). iASPP know-down could decrease the colony formation of 5637 and T24 cells (P＜0, 05). Knocking down of iASPP in 5637 and T24 cells showed cell arrested at G1. Conclusions Silencing of iASPP gene could inhibit proliferation and colony formation of bladder cancer, iASPP might be an important target for gene therapy of bladder cancer.     

Anaplastic ependymomas: Clinical features and tumour suppressor gene p53 analysis

Summary We analyzed seven cases of anaplastic ependymoma, focusing on neuro-imaging, histopathology, and mutations of the tumour suppressor gene p53. Five of the seven tumours were supratentorial. All had both cystic and solid components, with fragment calcifications detectable on CT scan. The solid parts of the tumours were imaged as heterogenous hypo- or iso-intense areas with moderate enhancement on T1-weighted magnetic resonance images. Vascularity was not prominent on angiograms except for one case. Histologically, in addition to the WHO criteria, loss of typical cellular architecture, endothelial proliferation, and necrosis were commonly found. A mutation in Exon 5 of the tumour suppressor gene p53 was detected in one anaplastic ependymoma out of five tumours (two benign and three anaplastic ependymomas) examined by PCR-SSPC analysis of genomic DNA followed by direct sequencing. Anaplastic ependymoma typically presents as a calcified cystic tumour in the supratentorial parenchyma or transependyma. Mutations of p53 deserve further investigation to examine their possible role in the oncogenesis and malignant transformation of ependymoma.     

甲状腺癌中p53基因248位密码子突变及其蛋白过度表达的临床意义

对５４例甲状腺癌标本分别用ＤＮＡ聚合酶链反应－限制性片段长度多态性分析（ＰＣＲ－ＲＦＬＰ）法检测ｐ５３基因第２４８位密码子的突变及免疫组化法检测ｐ５３蛋白，并用时序检验分析ｐ５３基因突变和ｐ５３蛋白表达与甲状腺癌的关系。结果发现，甲状腺癌中１５例（２７８％）有ｐ５３基因突变和３０例（５５６％）有ｐ５３蛋白过度表达，临床分期晚、分化程度低的甲状腺癌突变率较高，ｐ５３抑癌基因突变和ｐ５３蛋白阳性的病例有较高的复发率和死亡率。表明ｐ５３基因突变及其蛋白过度表达在甲状腺癌的发生和发展过程中起重要作用，是预后不良的标志。     

Multivariate analysis of clinical parameters of synchronous primary superficial bladder cancer and upper urinary tract tumor

PURPOSE: We determined the incidence and characteristic of synchronous upper urinary tract tumors (UUTTs) in patients with primary superficial bladder carcinoma and evaluated the characteristics of bladder tumors related to UUTTs. MATERIALS AND METHODS: We performed a retrospective study of 1,529 patients with primary superficial bladder carcinoma who underwent initial examination of the upper urinary tract with excretory urography. Data were analyzed by multivariate analysis using logistic regression. Variables evaluated and related to the incidence of UUTT were multiplicity, carcinoma in situ, bladder tumor size, localization of tumor in the bladder, and tumor grade and stage. RESULTS: A total of 28 patients (1.8%) had simultaneous bladder tumor and UUTT. UUTTs showed no preferred location and 17.9% were multiple. Of UUTTs 46% were invasive and almost 87% were grade 2 or 3. The only significant variable related to UUTT was bladder tumor in the trigone (RR 5.8, 95% IC 2.18 to 15.9, p <0.0005). Of 147 tumors located in the trigone 11 (7.5%) were associated with UUTT, corresponding to 41% of the UUTTs first diagnosed. If multiplicity and tumors in the trigone (551 cases) had been considered, 66.7% of tumors would have been diagnosed. CONCLUSIONS: Synchronous UUTT and superficial bladder tumor are uncommon but 46% are invasive. Considering the possible examination of the upper urinary tract only in patients with tumor in the trigone or with multiple bladder tumors 41.4% or 69% of UUTTs, respectively, would have been diagnosed. Patients with tumor in the trigone are at almost 6-fold higher risk for a synchronous tumor in the upper urinary tract.     

Cost-effectiveness of a modified care protocol substituting bladder tumor markers for cystoscopy for the followup of patients with transitional cell carcinoma of the bladder: a decision analytical approach.

PURPOSE: Decision analysis models were established to determine the cost-effectiveness of a plan alternating a bladder tumor marker with cystoscopy and cytology at 3-months intervals or modified care versus followup cystoscopy and cytology every 3 months or standard care. MATERIALS AND METHODS: We performed a comprehensive literature review for bladder tumor markers using 1966 to current MEDLINE data and other search engines. Statistical performance data on tumor markers were calculated by hierarchical Bayes meta-analysis with 95% confidence intervals used for the model. Other basic assumptions included cost data on tumor markers, cytology, cystoscopy, transurethral bladder resection and cystectomy as well as recurrence and progression rates from the literature. Decision trees were built with computer software using a 12 and a 24-month model with linear recurrence and progression rate assumptions. RESULTS: Overall specificity for common tumor markers was 73% to 90% and sensitivity was 49% to 77%. As expected, sensitivity increased for higher disease grades and stages. The modified care protocol was more cost-effective than standard care for the 1 and 2-year followups. On 1-year 1-way sensitivity analysis for cost only tumor marker cost, recurrence and progression rates achieved a threshold at which the modified care protocol was as or more expensive as standard care. Modified care was more cost-effective at a tumor marker cost of less than $264. On 2-way sensitivity analysis there was no significant impact of parameters at a wide range of tumor marker costs, recurrence and progression rates. CONCLUSIONS: Using a modified followup protocol in transitional cell carcinoma cases with an initial tumor occurrence using a urine based tumor marker alternating with cystoscopy and/or cytology is cost-effective for a wide range of marker sensitivities, specificities and costs, cystoscopy and/or cytology cost, a 20% to 80% yearly recurrence and a 2% to 40% yearly progression rate. This protocol should be evaluated in a prospective randomized trial to determine whether the financial and emotional benefits outweigh any potential drawbacks.     

The predictive value of muscularis mucosae invasion and p53 over expression on progression of stage T1 bladder carcinoma

PURPOSE: We determine the significance of muscularis mucosae invasion and nuclear p53 over expression on the progression of stage T1 transitional cell bladder cancer. MATERIALS AND METHODS: The pathological findings in 149 cases of T1 tumors diagnosed between 1973 and 1996 were reviewed. Diagnosis was stage T1 in 94 tumors in which the muscular layer was clearly identifiable and disease-free. Mean followup was 64.9 months (range 5 to 288). T1 bladder cancers were subclassified into 2 groups, with (T1b) or without (T1a) muscularis mucosae invasion. The p53 nuclear antibody immunoreactivity was determined with antibody D07 and a cutoff point at 15%. RESULTS: T1 subclassification was possible in all 94 patients. Of all tumors 37.2% expressed p53 nuclear over expression. Univariate statistical analysis showed that p53 expression (p <0.05) and tumor invasion depth (p <0.001) significantly correlated with progression. However, on multivariate analysis only invasion depth (p <0.0001) and associated carcinoma in situ (p <0.03) remained independently significant as predictors of progression. CONCLUSIONS: In our study the depth of tumor invasion was a significant independent predictor of progression in patients with T1 bladder cancer. This result suggests that the depth of invasion in stage T1 should be included in the histopathological report.     

膀胱癌组织中nm23蛋白和p53蛋白的表达及其意义

目的　探讨肿瘤抑制基因nm2 3、p5 3蛋白在膀胱癌组织中的异常表达及其与肿瘤病理分级、浸润程度和淋巴结转移等肿瘤的病理特征的关系。方法　应用免疫组织化学ABC方法检测 4 0例膀胱癌组织标本中nm2 3、p5 3蛋白的表达水平。 结果　膀胱癌组织中nm2 3和 p5 3蛋白表达的阳性率分别为 5 0 .0 %和 4 7.3%。nm2 3蛋白表达与病理分级和浸润程度呈正相关 ,而与膀胱癌的淋巴结转移呈负相关 (P <0 .0 5 )。p5 3蛋白表达与膀胱癌的浸润程度和分化程度呈正相关 ,而与肿瘤的淋巴结转移无关(P >0 .0 5 )。结论　nm2 3、p5 3蛋白的表达在膀胱癌的浸润转移中起重要作用 ,p5 3表达与膀胱癌组织浸润、分化程度有关 ,膀胱癌的淋巴结转移可能与多基因异常改变有关。     

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.     

联合评估凋亡相关蛋白Survivin和突变型p53在膀胱移行细胞癌中的表达及意义

目的：探讨凋亡相关蛋白Survivin和突变型p53在膀胱移形细胞癌（BTCC）中的表达及其临床意义。方法：应用SP免疫组织化学法检测50例BTCC及10例正常膀胱黏膜组织石蜡切片中Survivin和p53表达的情况,结合临床资料进行分析。结果：Survivin在BTCC的肿瘤标本中的阳性表达率为76％（38／50）,而正常对照组中无一例呈阳性表达;Survivin的表达与BTCC的组织学分级、预后显著相关（二者均P〈0．05）,但与临床病理分期无关（P〉0．05）;p53在13TCC肿瘤标本中的阳性表达率为68％（34／50）,与对照组阳性表达率30％（3／10）相比有统计学意义（P〈0．05）。p53的表达与BTCC组织学分级、临床分期及复发相关（均P％0．05）;相关性分析表明,BTCC肿瘤组织中Survivin的表达与p53表达呈正相关（r=0．317,P〈0．05）。结论：Survivin在BTCC组织中选择性表达,与BTCC的分化程度及复发密切相关;p53蛋白在BTCC中的表达与分级、分期及复发相关,联合评估Survivin和p53蛋白对于判断BTCC预后有重要临床指导意义。