Enhanced sensitivity to mitomycin C by abating heat shock protein 70 expression in human bladder cancer cell line of BIU-87 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Bladder cancer is a relatively common tumor in the urinary system, in which mitomycin C (MMC)-based chemotherapy or combination chemotherapy has been mainly used to treat patients with advanced bladder cancer. The prognosis of patients with advanced bladder cancer is still extremely poor in spite of recent therapeutic advances. To improve the prognosis, the sensitivity of tumor cells to mitomycin C by the induction of apoptosis with the abating heat shock protein 70 (HSP70) expression in human bladder cancer cell lines of BIU-87 was investigated.</p><p><b>METHODS</b>HSP70 expression was abated in BIU-87 cells by HSP mRNA antisense oligomers. MTT assay and the clone-forming test were used for evaluating the sensitivity of cells to MMC. Apoptosis was assessed using both fluorescent microscopy after staining the cells with Hoechst 33258 and DNA fragment ladder agarose electrophoresis. Thirty-two male six-week-old BALB/c nude mice, at the beginning of the experiment, were used to evaluate the effect of antisense oligomers (ASO) on the tumor formation in vivo.</p><p><b>RESULTS</b>HSP70 expression in BIU-87 was effectively abated by HSP70 mRNA antisense oligomers. The percentage of apoptotic cells in ASO group was greater than in sense oligomers (SO) [P < 0.05, (18.31 +/- 2.89)% vs (1.89 +/- 0.74)%], nonsense oligomers (NO) [P < 0.05, (18.31 +/- 2.89)% vs (1.78 +/- 0.92)%] and blank groups [P < 0.05, (18.31 +/- 2.89)% vs (1.87 +/- 0.84)%], while the sensitivity of tumor cells to mitomycin C was enhanced. The in vivo tumor inhibition rate of ASO plus MMC (> 50%) was more than that of ASO or MMC group alone (all P < 0.05).</p><p><b>CONCLUSIONS</b>The abating level of HSP70 expression can strengthen the sensitivity of BIU-87 to MMC. One of this effect might be related to the induction of apoptosis by abating HSP70 expression.</p>

The significance of the expression of cyclooxygenase-2 in bladder transitional cell carcinoma tissues / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of cyclooxygenase-2 (COX-2) in bladder transitional cell carcinoma tissues, and understand its clinical significance.</p><p><b>METHODS</b>Reversal transcription polymerase chain reaction (RT-PCR) was used to assess the expression of COX-2 mRNA in 52 cases of bladder transitional cell carcinoma tissues and 17 cases of normal bladder tissues far from neoplasm; Western blot was used to assess the expression of COX-2 protein in 49 cases of bladder cancerous tissues and 17 cases of normal tissues.</p><p><b>RESULTS</b>Positive expression of COX-2 mRNA was detected in 83% (43/52) of bladder cancer tissues and in 29% (5/17) of normal tissues by RT-PCR and there was significant difference in expression of COX-2 mRNA between cancer tissues and normal tissues. Western blot analysis showed that expression of COX-2 protein was correlation with the stage and grade of cancer.</p><p><b>CONCLUSION</b>COX-2 is overexpressed in bladder transitional cell carcinoma. COX-2 maybe play a certain role in carcinogenesis and progression of bladder cancer and turn into a useful target of chemoprevention of bladder cancer.</p>

The heat shock protein 70 antisense oligomers enhance the sensitivity of bladder cancer cell EJ to mitomycin C / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate whether the heat shock protein (HSP) 70 antisense oligomers can enhance the sensitivity of bladder cancer cell EJ to mitomycin C.</p><p><b>METHODS</b>The HSP70 mRNA of EJ cells was blocked by the 10 micromol/L HSP70 antisense oligomers, while its effect on cell growth was evaluated by methyl thiazolyl tetrazolium (MTT) and colony forming ability test.</p><p><b>RESULTS</b>The HSP70 expressions in HSP70 antisense treated group were lower than the corresponding sense and nonsense treated groups (P < 0.01). While, the increased sensitivity of EJ to mitomycin C was found in antisense treated group, compared with the corresponding sense and nonsense treated groups (P < 0.01).</p><p><b>CONCLUSION</b>The sensitivity of bladder cancer cell EJ to mitomycin C was enhanced by the blockage of the HSP70 expression.</p>