Immunoreactivity of bcl-2, p53 and EGFr is associated with tumor stage, grade and cell proliferation in superficial bladder cancer. Finnbladder III Group

Progress in the Research and Targeted Therapy of ErbB/HER Receptors in Urothelial Bladder Cancer

Bladder cancer is a lethal malignancy and a majority of bladder cancer arise from urothelial cells. Infiltration and metastasis are barriers for the radical cystectomy to achieve favored outcome and are the main cause of death. Systemic therapy, including chemotherapy, targeted therapy, and immunotherapy, is fundamental for these patients. erbB/HER receptors are found to be overexpressed in a subgroup of urothelial carcinoma, targeting erbB/HER receptors in these patients was found to be an efficient way in the era of genetic testing. To evaluate the role of erbB/HER receptors in bladder cancer, we reviewed the literature and ongoing clinical trials as regards to this topic to unveil the context of erbB/HER receptors in bladder cancer, which probably help to solidate the theoretical basis and might instruct further research.

Therapeutic potential of sepantronium bromide YM155 in gemcitabine-resistant human urothelial carcinoma cells

Survivin is overexpressed in transitional cell carcinoma (TCC), the most common type of bladder cancer. Previous reports demonstrated that knockdown of survivin by siRNA induced apoptosis of TCC cells. The present study evaluated the therapeutic effects of sepantronium bromide (YM155), a novel small molecule survivin inhibitor under clinical trials, on TCC cells in vitro. BFTC905, a grade III TCC cell line derived from a patient of blackfoot disease in Taiwan, was the most gemcitabine-resistant cell line when compared to BFTC909, TSGH8301 and T24 in cytotoxicity assay, resulting from upregulation of securin and bcl-2 after gemcitabine treatment. YM155 caused potent concentration‑dependent cytotoxicity in 4 TCC cell lines (IC50s ≤20 nM), but exhibited no cytotoxicity in survivin-null primary human urothelial cells. For BFTC905 cells, addition of gemcitabine and/or cisplatin, the standard TCC chemotherapy regimen, to YM155 did not exert additive cytotoxic effects. Molecular analyses indicated that YM155 inhibited the proliferation of BFTC905 cells by increasing p27kip1, suppressing Ki-67, and inducing quiescence. In addition, YM155 elicited apoptosis manifested with DNA fragmentation through suppressing the expression of survivin, securin and bcl-2. Furthermore, YM155 induced autophagy in BFTC905 cells as autophagic inhibitor, 3-methyladenine, attenuated YM155-induced LC3B-II levels and reversed the cytotoxicity of YM155. mTOR inhibitors sirolimus and everolimus did not increase YM155-induced expression of LC3B-II nor augment YM155-induced cytotoxicity. These results indicate that YM155 exerts its lethal effect on BFTC905 cells via apoptotic and autophagic death pathways and suggest that YM155 may be a potential drug for the therapy of gemcitabine-resistant bladder cancer.

Biomarkers in bladder cancer: translational and clinical implications

Bladder cancer is associated with high recurrence and mortality rates. These tumors show vast heterogeneity reflected by diverse morphologic manifestations and various molecular alterations associated with these disease phenotypes. Biomarkers that prospectively evaluate disease aggressiveness, progression risk, probability of recurrence and overall prognosis would improve patient care. Integration of molecular markers with conventional pathologic staging of bladder cancers may refine clinical decision making for the selection of adjuvant and salvage therapy. In the past decade, numerous bladder cancer biomarkers have been identified, including various tumor suppressor genes, oncogenes, growth factors, growth factor receptors, hormone receptors, proliferation and apoptosis markers, cell adhesion molecules, stromal factors, and oncoproteins. Recognition of two distinct pathways for urothelial carcinogenesis represents a major advance in the understanding and management of this disease. Nomograms for combining results from multiple biomarkers have been proposed to increase the accuracy of clinical predictions. The scope of this review is to summarize the major biomarker findings that may have translational and clinical implications.

The significance of p53 and bcl-2 overexpression and other prognostic factors in transitional cell carcinoma of the bladder

The aim of this study was to investigate the expression of bcl-2 and p53 oncoproteins in a series of transitional cell bladder carcinomas and its relation to traditional prognostic indicators and patients' survival. Specimens from 59 patients who underwent transurethral resection from March 1992 to February 1997 were included in this study. Tumors were graded based on WHO grades 1-3 and staged according to the 1997 TNM classification. Three patients lost to follow-up were excluded from the analysis. We could not establish a statistically significant relation between bcl-2 and p53 and other parameters such as sex, age, stage and grade. Tumor grade and stage were the most important factors for predicting tumor recurrence and aggressiveness. Only sex seems to significantly affect the statistics of the risk of death (p<0.05). Women had quadruple risk of death compared to men.

Prognostic value of EGF receptor and tumor cell proliferation in bladder cancer: therapeutic implications

Changes in growth factor receptor expression may confer a growth advantage on tumour cells. Epidermal growth factor-receptor (EGF-R) has been associated with the genesis of bladder tumours. We sought a link between EGF-R expression and MIB-1 cell proliferation and examined their prognostic value in the progression of bladder cancer. Fresh frozen samples from 113 transitional cell carcinomas (TCC) of the bladder and 10 healthy bladders were studied by immunohistochemistry, using monoclonal antibodies for EGF-R expression and MIB-1 for cell proliferation. Qualitative and quantitative immunostaining were analyzed in relation to time to progression and compared with clinical and pathologic parameters for prognostic significance in univariate and multivariate analysis (stepwise logistic regression). EGF-R stained more intensively in invasive tumours. Median nuclear over-expression of MIB-1 was 28%. Progression free survival rate estimates (log rank test) were significantly lower in patients EGF-R positive and with MIB-1 score above 28% (P < 0.0001, P < 0.0001, respectively). Multivariate analysis indicated that MIB-1 immunostaining was the most significant independent variable and EGF-R expression had no additional prognostic value over clinical stage and grade and cell proliferation. The MIB-1 proliferation index is a stronger predictor of bladder tumour progression than is EGF-R over-expression. This marker yield significant prognostic information in addition to stage and grade and may be of value for the clinical management of superficial and invasive bladder carcinomas. The pattern of EGF-R immunostaining and its association with tumour progression makes it a candidate for antigrowth factor therapy.

[Comparative study of the expression of p53, Ki-67, bcl-2 and CK20 in superficial transitional carcinoma of the bladder: correlation with recurrence, histological grade, and clinical stage]

OBJECTIVE

We examined the presence of p53, Ki-67, bcl-2 and CK20, as detected by immunohistochemistry, and correlated with the classic variables (grade, stage and recurrence).

MATERIAL AND METHOD

The authors evaluated 57 superficial transitional cell carcinomas. Biopsy specimens examined included non recurrent transitional cell carcinomas (n = 36) and recurrent transitional cell carcinomas (n = 21). Association of bcl-2, p53, Ki-67 y CK20 index immunoreactivity with tumor grade, clinical stage and tumor recurrence was examined.

RESULTS

Ki-67 and p53 expression were related to the degree of differentiation and recurrence of the disease. bcl-2 and CK20 were not correlated with grade, stage and recurrence of the disease.

CONCLUSIONS

Positivity for Ki-67 and p53 increase with grade of the disease. P53 and Ki-67 are predictors of tumor recurrence for patients with superficial transitional cell carcinoma.

AgNOR/P53 expression compared with different grades in bladder carcinoma

OBJECTIVE

The aim of this study is to assess the relation between silver-strained nucleolar organizer regions (AgNOR)/P53 expression and urothelial neoplasm of the bladder which graded according to the WHO/ISUP tumor grading system.

METHODS

Transurethral resection materials (TUR) and cystectomy specimens from 52 patients with bladder urothelial carcinomas were stained by AgNORs and analyzed immunohistochemically using an avidinbiotin peroxidase method for p53 staining and also silver for AgNORs.

RESULTS

Nuclear p53 accumulation was determined in two of 5 LMP cases (%40), in 10 of 22 LGC (%45.4), and in 8 of 25 HGC (%32). Positivity of p53 accumulation was observed in 20 (%57.7) of all cases. There was no statistically significant relationship between AgNOR score of p53(+) and p53(-) cases. There was no correlation between LGC and LMP, also between LGC and HGC (p > 0.05), but a meaningful relationship was found between LMP and HGC (p = 0.03). Association between P53 and grade, AgNOR value and grade, p53 and AgNOR was found statistically insignificant.

CONCLUSIONS

Although we found a statistically significant correlation between AgNOR count of LMP and HGC, this study did not show a satisfying correlation between AgNOR, p53 and any grade of urothelial carcinoma.

Appraisal of differentiation markers in urothelial cells

The expression, subcellular localization, and supramolecular organization of structural and differentiation-related proteins were studied in differentiating superficial cells during regeneration of the rat urothelium. Cytokeratin 17 and epidermal growth factor receptor were expressed in undifferentiated cells, whereas in differentiated superficial cells, this expression ceased. beta-Actin was expressed in undifferentiated and in differentiated cells, but subcellular localization markedly changed by its withdrawal from apical region during differentiation. In differentiating cells, cytokeratin 20 was first observed as diffusely arranged spots distributed throughout the cytoplasm; later, it became organized as a network in the apical part of the cells. Urothelium specific proteins, uroplakins, were weakly expressed at early states of differentiation, but only in terminally differentiated cells did they organize into asymmetric unit membrane plaques. These findings show that in some cases, expression is a sufficient marker of cell differentiation. In other cases, however, the specific subcellular localization and supramolecular organization of proteins should be considered. It is evident that choosing the appropriate methods is crucial for precise evaluation of the urothelial differentiation states.

Biologic differences between noninvasive papillary urothelial neoplasms of low malignant potential and low-grade (grade 1) papillary carcinomas of the bladder

We investigated the expression of oncogenes p53, c-erbB-2, and bcl-2 and cell proliferative activity in 62 newly diagnosed superficial pTa papillary bladder tumors. Based on the 1998 World Health Organization/International Society of Urological Pathology (WHO/ISUP) and 1999 WHO classifications, 19 were urothelial neoplasias of low malignant potential (LMP) and 43 low-grade (grade 1) papillary carcinomas. All the patients underwent transurethral resection and were followed up to 97 months; 42 had recurrences. Initial biopsies were tested for p53, c-erbB-2, and bcl-2 proteins using DO7, CB11, and bcl-2 124 monoclonal antibodies. Cell proliferation was assessed by MIB-1 mAb and mitotic count. LMP had significantly lower MIB-1 (p = 0.002) and p53 immunopositivity (p = 0.03), mitotic count (p = 0.006), and recurrence rates (p = 0.04) than did grade 1 cases, whereas no difference was observed for c-erbB-2 and bcl-2 expression. The median disease-free survival for LMP was 76 months but only 15 months for grade 1 cases (p = 0.002). Although the cohort is small, the results indicate that the distinction between LMP and low-grade (grade 1) papillary urothelial neoplasias, as proposed by the 1998 WHO/ISUP and 1999 WHO classifications, reflects different biologic activity and clinical behavior; however, a long-term follow-up is advisable also for patients with LMP.

Clinical sensitivity of p53 mutation detection in matched bladder tumor, bladder wash, and voided urine specimens

BACKGROUND

Mutations in the p53 tumor suppressor gene may correlate with an increased risk of recurrence and disease progression in patients with bladder carcinoma. The ability to accurately and sensitively detect p53 mutations in cytology specimens may be of benefit in the treatment of bladder carcinoma patients with superficial, minimally invasive disease.

METHODS

Genomic DNA was isolated from 49 cases, each of which was comprised of matched bladder tumor tissue, bladder wash, and voided urine specimens obtained concurrently at a single institution. The genomic DNA was analyzed for mutations in the p53 tumor suppressor gene using a p53 mutation detection assay. Automated dideoxy sequencing of mutant specimens also was performed.

RESULTS

Of the 49 cases, 29 (59%) showed no evidence of p53 mutations in the tumor, bladder wash, or voided urine specimens. Of the remaining 20 cases, 19 showed evidence of mutations in the tumor. Of these 19 p53 mutant bladder tumors, 16 (84%) were detected in the matched bladder wash and 16 (84%) were detected in the matched voided urine specimens. One case resulted in the detection of mutant p53 in the voided urine and the bladder wash, but not in the tumor. Analysis of the results between tumor tissue and bladder wash or tumor and voided urine showed 84.2% sensitivity, 96.8% specificity, and 91.8% accuracy. Sequence analysis of the mutant cases showed that the mutations detected in the tumor tissue were the same mutations detected in the bladder wash and the voided urine specimens.

CONCLUSIONS

Both voided urine and bladder wash specimens from patients with bladder carcinoma were found to provide a high rate of clinical accuracy for the determination of the p53 gene status in patients with bladder tumors.

[Molecular biology in bladder cancer]

Progress of molecular biology with regard to etiopathogeny of tumours in general, and cancer of the bladder in particular, is taking place at such a vertiginous pace that practising urologists find themselves overwhelmed in terms of their ability to learn and keep updated in so complex a subject. The understanding of certain molecular factors with critical influence on the formation, growth and progression of a tumour of the bladder, is forcing us to make unbiased assessments on the role they will play in the evolution and survival of this neoplasia. It is anticipate they will be much more reliable than traditionally established morphological factors such as grade and stage. We also include a literature review with an analysis and elucidation of the role played by oncogenes, tumor suppressor genes, vascular density markers, telomerase etc., in the formation and growth of cancer of the bladder and their likely relationships with already established clinico-pathological factors.

DNA ploidy and p53 protein expression in superficial transitional cell carcinoma of the bladder

Superficial transitional cell carcinoma of the bladder (STCCB) is a heterogeneous group of neoplasias with an unpredictable clinical course. In recent years many techniques have been used in order to predict the behaviour of these tumours at individual patient level. The aim of this study was to investigate in imprints from tumour biopsies the DNA ploidy and p53 protein expression in a group of 80 STCCB (pTa-pT1) patients in relation to histological grade and recurrence status. The DNA content was studied in Feulgen-stained imprints by the image analysis technique using a SAMBA 2005 analyser. In order to investigate p53 protein expression an avidin-extravidin immunocytochemical technique was used. According to our measurements a strong correlation was observed between recurrence status and DNA ploidy status (P < 0.001). No statistical difference was found in DNA ploidy status and grade of malignancy (P = 0.68). A statistically significant difference was found in p53 protein expression between recurrent and nonrecurrent tumours (P < 0.001). No statistically significant difference was found among tumours of grade I, grade II and grade III (P = 0.42). These results could provide useful information on the potential behaviour of STCCB.

The role of bcl-2, p53, and ki-67 index in predicting tumor recurrence for low grade superficial transitional cell bladder carcinoma

PURPOSE

We assess the prognostic significance of bcl-2 expression, p53 mutation and ki-67 index for low grade, superficial transitional cell bladder carcinoma.

MATERIALS AND METHODS

The medical records of 93 cases of primary, low grade (24 G1, 69 G2), superficial (70 pTa, 23 pT1) transitional cell carcinoma of the bladder were reviewed. Association of bcl-2, p53 and ki-67 index immunoreactivity with tumor grade and stage was examined. Prognostic significance of tumor grade, pathological stage, bcl-2 expression, p53 mutation and ki-67 index in predicting tumor recurrence was assessed.

RESULTS

Of the tumors 60 (70%) had p53 mutation and 9 (10.5%) expressed bcl-2. These 2 markers did not relate to tumor grade or pathological stage. Median ki-67 index was 10.9% and positively correlated with tumor grade. Recurrence was noted in 34.9% of patients with a median followup of 26 months (range 1 to 84). The ki-67 index was the only significant prognostic indicator in univariate and multivariate analyses. This marker can further distinguish grade 2 tumors with a favorable prognosis from those with an unfavorable outcome.

CONCLUSIONS

The ki-67 labeling index is an independent predictor of tumor recurrence for patients with primary superficial, low grade bladder cancers.

Mutation of cell cycle regulators and their impact on superficial bladder cancer

Early cytogenetic studies in bladder cancer identify regions of chromosomal gain or loss that can be candidate loci for oncogenes and tumor suppressor genes. Oncogenes with potential prognostic significance identified in bladder cancer the RAS family, epidermal growth factor receptor, ERBB-2, MDM2, and cyclin D1. The TP53 gene has been the most thoroughly characterized tumor suppressor gene in bladder cancer, with correlation of TP53 alterations with type of carcinogenic exposure, tumor stage and grade, as well as prognosis. Studies evaluating alterations of the retinoblastoma pathway have identified the retinoblastoma gene, RB, p161NK4A/CDKN2, and E2F-1 as tumor suppressor genes with potential prognostic significance in patients with bladder cancer. Better understanding of the genetic mechanisms underlying bladder tumor development and progression will allow better prevention, diagnosis, and treatment strategies.

Current concepts in the role of intravesical instillations in the therapy and prophylaxis of superficial transitional-cell cancer of the bladder. The Finnbladder Research Group

A survey on superficial, local urinary bladder cancer, its prognostic factors, and instillation treatments is presented on the basis of experience with approximately 1,000 patients over a period of 20 years, experimental investigations, and the literature. Personal opinions and practical recommendations are presented in 11 conclusive theses.