Detection and Clinical Significance of Circulating Tumor Cells in Patients Undergoing Radical Cystectomy for Urothelial Bladder Cancer.

INTRODUCTION: Estimation of prognosis is patients undergoing radical cystectomy is often unreliable, as occult disease remains undetected by conventional diagnostic tools. The purpose of this study was to evaluate the feasibility and the clinical significance of a polymerase chain reaction assay to detect cytokeratin 7 (CK7) mRNA expression in peripheral blood cells of patients undergoing radical cystectomy for clinically nonmetastatic bladder cancer. PATIENTS AND METHODS: From 2005 to 2009, 59 patients undergoing radical cystectomy and pelvic lymph node dissection were prospectively investigated. Peripheral blood was collected prior to surgery, and a nested polymerase chain reaction assay was developed to identify patients with circulating cells expressing CK7 mRNA. Preoperative, histopathologic data and clinical outcome were compared with CK7 findings. RESULTS: CK7 expression was detected in 23 (38.9%) of 59 patients and correlated to T stage and lymph node status. After a median follow-up of 42 months, 29 patients experienced a recurrence, whereas 36 died. The presence of CK7-positive cells was significantly associated with an increased risk for recurrence and decreased survival as compared with patients who were CK7-negative (P < .001 and P < .001, respectively; hazard ratios of 8.77 and 5.2 for recurrence and overall death, respectively). The detection of CK7-positive cells was an independent predictor of recurrence and death in a multivariable analysis. CONCLUSION: The detection of CK7 mRNA in the circulating cells of patients undergoing radical cystectomy for urothelial cancer identifies those with significantly increased risk of cancer recurrence and death.

Celecoxib for the prevention of nonmuscle invasive bladder cancer: results from a matched control study.

OBJECTIVES: New targets and approaches are under investigation for the treatment of nonmuscle invasive bladder cancer (NMIBC). Preclinical data suggest cyclooxygenase-2 (COX-2) as a promising target. Celecoxib, a COX-2 selective inhibitor, inhibits tumor development and enhances survival, both in vitro and in vivo models of bladder cancer. Therefore, we conducted a pilot study of celecoxib to prevent recurrence in patients with intermediate risk NMIBC. METHODS: Treatment with celecoxib was administered orally for 12 months and compared with a contemporary series of patients treated with intravesical mitomycin C (MMC), given weekly for 4 weeks and then monthly for 11 months. Primary endpoints were time to first recurrence and adverse events. RESULTS: From 2003 through 2006, 58 patients were treated with celecoxib and compared with 66 patients receiving MMC. After a median follow up of 75 months, 49 patients were disease free, including 23 (34.85%) in the MMC group and 26 (44.8%) in the celecoxib group. Median disease-free interval was 67 months [95% confidence interval (CI) 35.8 to NA] versus 41 months (95% CI 27.1-67.1; log-rank p = 0.25) for patients treated with MMC and celecoxib, respectively. In the multivariate analysis, treatment was not found to be an independent predictor for recurrence [hazard ratio (HR) 0.76, 95% CI 0.47-1.22, p = 0.25). Overall, 45 AEs were recorded in 35/124 patients. There were no differences between the two groups. CONCLUSIONS: Our data support a clinical benefit of celecoxib and encourage future trials in which COX-2 inhibitors may be tested in selected patients with NMIBC.

The interaction of celecoxib with MDR transporters enhances the activity of mitomycin C in a bladder cancer cell line.

BACKGROUND: An in vitro model was developed to understand if celecoxib could synergize with Mitomycin C (MMC), commonly used for the prevention of non-muscle invasive bladder cancer recurrence, and eventually elucidate if the mechanism of interaction involves multi drug resistance (MDR) transporters. METHODS: UMUC-3, a non COX-2 expressing bladder cancer cell line, and UMUC-3-CX, a COX-2 overexpressing transfectant, as well as 5637, a COX-2 overexpressing cell line, and 5637si-CX, a non COX-2 expressing silenced 5637 cell line, were used in the present study. The expression of COX-2 and MDR pumps (P-gp, MDR-1 and BCRP) was explored through western blot. The anti-proliferative effect of celecoxib and MMC was studied with MTT test. Three biological permeability assays (Drug Transport Experiment, Substrate Transporter Inhibition, and ATP cell depletion) were combined to study the interaction between MDR transporters and celecoxib. Finally, the ability of celecoxib to restore MMC cell accumulation was investigated. RESULTS: The anti-proliferative effect of celecoxib and MMC were investigated alone and in co-administration, in UMUC-3, UMUC-3-CX, 5637 and 5637si-CX cells. When administered alone, the effect of MMC was 8-fold greater in UMUC-3. However, co-administration of 1 µM, 5 µM, and 10 µM celecoxib and MMC caused a 2,3-fold cytotoxicity increase in UMUC-3-CX cell only. MMC cytotoxicity was not affected by celecoxib co-administration either in 5637, or in 5637si-CX cells. As a result of all finding from the permeability experiments, celecoxib was classified as P-gp unambiguous substrate: celecoxib is transported by MDR pumps and interferes with the efflux of MMC. Importantly, among all transporters, BCRP was only overexpressed in UMUC-3-CX cells, but not in 5637 and 5637si-CX. CONCLUSIONS: The UMUC-3-CX cell line resembles a more aggressive phenotype with a lower response to MMC compared to the wt counterpart. However, the administration of celecoxib in combination to MMC causes a significant and dose dependent gain of the anti-proliferative activity. This finding may be the result of a direct interaction between celecoxib and MDR transporters. Indeed, BCRP is overexpressed in UMUC-3-CX, but not in UMUC-3, 5637, and 5637si-CX, in which celecoxib is ineffective.

Bicalutamide failure in prostate cancer treatment: involvement of Multi Drug Resistance proteins.

Prolonged bicalutamide treatment induced pathology regression although relapses with a more aggressive form of prostate cancer have been observed. This failure could be due to androgen receptor mutation. In the present work we hypothesized an alternative mechanism responsible for bicalutamide failure involving activity of ATP-binding cassette (ABC) pumps such as P-glycoprotein, Breast Cancer Receptor Protein (BCRP), and Multi Resistant Proteins (MRPs) that extrude the androgen antagonist from the cell membrane. As experimental models androgen-dependent (LnCap) and androgen-independent (PC-3) prostate cancer cell lines have been employed. Bicalutamide has been tested in the cell lines mentioned above in the absence and in the presence of MC18, our potent P-glycoprotein/BCRP/MRP1 inhibitor. The results displayed that bicalutamide antiproliferative effect at 72 h was ameliorated in LnCap cells (EC(50) from 51.9+/-6.1 microM to 17.8+/-2.6 microM in the absence and in the presence of MC18, respectively) and restored in PC-3 cells (EC(50) from 150+/-2.4 microM to 60+/-3.5 microM in the absence and in the presence of MC18, respectively). Moreover, we established the contribution of each transporter employing stable transfected cells (MDCK) overexpressing P-glycoprotein or BCRP or MRP1 pump. The results displayed that P-glycoprotein and BCRP were involved in bicalutamide efflux while MRP1 was unable to bind the antiandrogen drug.