Apoptosis and its clinical significance for bladder cancer therapy.
Department of Urology, Belfast City Hospital, Belfast.BJU International (Impact Factor: 3.53). 02/1999; 83(1):1-10.
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ABSTRACT: To investigate Ki-67 and p21Waf1/Cip1 expression and apoptosis, before and after treatment, in tumour biopsies obtained from patients with superficial bladder cancer who underwent vinorelbine intravesical therapy. Twenty patients with high-risk superficial bladder cancer (including one or more of the following parameters: tumour diameter > 3 cm, histological grade 3, or multicentric tumours) were treated 1-6 times (weekly) with intravesical vinorelbine (50 mg/mL) instillations. Transurethral tumour marker biopsies were obtained one week before the first instillation of the drug and one week after the last. The biopsies were immunostained for Ki-67 and p21Waf1/Cip1 with monoclonal antibodies, on tissue sections derived from paraffin-embedded samples obtained before and after vinorelbine treatments. In addition, apoptosis was determined using a terminal deoxynucleotidyl transferase-mediated dUTP biotin nick-end labelling (TUNEL) technique. There were no significant differences in the cell proliferation marker Ki-67 in biopsies taken before or after treatment. However, p21Waf1/Cip1 showed significantly higher expression in biopsies obtained after vinorelbine treatment, with median (range) values of 40 (20-90)% before and 70 (50-80)% after (P < 0.001, paired nonparametric Wilcoxon test). The apoptotic index was significantly higher after vinorelbine therapy, with median (range) values of 0.89 (0.06-3.8)% before and 2.25 (0.17-18.7)% after treatment (P < 0.001, paired nonparametric Wilcoxon test). Despite the brief treatment and few patients there was a clinical response in nine patients, together with low toxicity in all. The intravesical treatment of tumours with vinorelbine affects p21Waf1/Cip1 expression without blocking cell proliferation, although increasing apoptosis. The preliminary results suggest that vinorelbine may be useful for treating superficial bladder tumours, and thus a phase II study is warranted.
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ABSTRACT: Bcl-2 is an important determinant of transitional cell carcinoma of the bladder recurrence and progression as well as a factor in patient response to chemotherapy or radiotherapy. We determined Bcl-2 down-regulation after antisense oligonucleotide therapy and synergism with mitomycin C in transitional cell carcinoma of the bladder. Bcl-2 protein was quantified using flow cytometry and immunohistochemistry in 4 bladder cancer cell lines, in bladder washings from 6 patients with carcinoma in situ and in 16 patient tumor samples. The synergistic effects of antisense oligonucleotides G3139 and 2009, and mitomycin C were investigated in 4 cell lines, while 2009 down-regulation was examined in 20 tumor explants in an ex vivo model. Bcl-2 protein expression was found in all 4 cell lines and in 5 of the 6 cell populations derived from patients with carcinoma in situ. Of the 16 tumors 7 were classified positive by frozen section immunohistochemistry and quantitative flow cytometry. G3139 and 2009 down-regulated Bcl-2 protein expression in all 4 cell lines and 2009 down-regulated Bcl-2 protein expression in half of the Bcl-2 positive tumor specimens. There was only evidence in 1 cell line, T24/83, that Bcl-2 protein expression down-regulation enhanced mitomycin C induced apoptotic cell death. Bcl-2 was expressed in a significant proportion of bladder tumors and in carcinoma in situ. Therefore, antisense oligonucleotides represent a viable strategy for Bcl-2 protein down-regulation. However, it may not always translate into an increased level of mitomycin C induced apoptosis in transitional cell carcinoma of the bladder.
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