Comet assay measures of DNA damage are predictive of bladder cancer cell treatment sensitivity in vitro and outcome in vivo.

Bladder cancer patients suffer significant treatment failure, including high rates of recurrence and poor outcomes for advanced disease. If mechanisms to improve tumour cell treatment sensitivity could be identified and/or if tumour response could be predicted, it should be possible to improve local-control and survival. Previously, we have shown that radiation-induced DNA damage, measured by alkaline Comet assay (ACA), correlates bladder cancer cell radiosensitivity in vitro. In this study we first show that modified-ACA measures of cisplatin and mitomycin-C-induced damage also correlate bladder cancer cell chemosensitivity in vitro, with essentially the same rank order for chemosensitivity as for radiosensitivity. Furthermore, ACA studies of radiation-induced damage in different cell-DNA substrates (nuclei, nucleoids and intact parent cells) suggest that it is a feature retained in the prepared nucleoids that is responsible for the relative damage sensitivity of bladder cancer cells, suggestive of differences in the organisation of DNA within resistant vs. sensitive cells. Second, we show that ACA analysis of biopsies from bladder tumours reveal that reduced DNA damage sensitivity associates with poorer treatment outcomes, notably that tumours with a reduced damage response show a significant association with local recurrence of non-invasive disease and that reduced damage response was a better predictor of recurrence than the presence of high-risk histology in this cohort. In conclusion, this study demonstrates that mechanisms governing treatment-induced DNA damage are both central to and predictive of bladder cancer cell treatment sensitivity and exemplifies a link between DNA damage resistance and both treatment response and tumour aggression.

Successful use of steroids and ureteric stents in 24 patients with idiopathic retroperitoneal fibrosis: a retrospective study.

BACKGROUND/AIMS: Retroperitoneal fibrosis (RPF) is a chronic inflammatory disorder causing obstructive nephropathy and renal failure. We reviewed our management of this condition. METHOD: All patients with RPF treated at a single center over a 15-year period were identified. A full review of notes and computer records was undertaken. RESULTS: Data was available on 27 patients, 3 of which were excluded from later analysis. Diagnosis was based on clinical history and cross-sectional imaging. Retroperitoneal biopsy was undertaken in 3 patients. 96% had significant renal impairment at presentation with a mean serum creatinine of 688 micromol/l. 46% required emergency hemodialysis. All patients were treated with a combination of ureteric stents and/or steroids with an excellent clinical response. The mean best creatinine reached by the cohort was 136 micromol/l, and renal function remained stable in the long term. No patients required chronic dialysis. Ureteric stents were removed within 12 months and low-dose steroids were continued for a mean of 34 months. Recurrent disease was observed in 25% of patients, who all responded well to further steroid therapy. Mean duration of follow-up was 76 months. CONCLUSIONS: RPF is very effectively treated by a combination of ureteric stents and steroids, with excellent long-term results using this approach. Continued follow-up is advised because of the possibility of recurrent disease.

The increased risk of urinary stone disease in betel quid chewers.

The chewing of betel quid is a common practice in many countries of the world, particularly in Southeast Asia. The quid consists of a preparation of areca nut, betel leaf and calcium hydroxide "lime" paste ("chuna"). For the first time, we present a study that links its use to urinary stone disease. Eight patients (seven male and one female) who presented to our Stone Unit with recurrent urinary stones were included in the study. All were from the Indian subcontinent and were found to regularly chew betel. The patients underwent metabolic screening including blood, random urine and 24-h urine tests, quantitative chemical analysis of their calculi (where possible) and each completed a 7-day Diet Diary on his/her free, home diet. The study demonstrated a high incidence of hypercalciuria, a tendency to pass an alkaline urine and low urinary citrate excretion among the patients. Together these urinary risk factors increase the probability of developing both calcium phosphate-containing and calcium oxalate-containing stones. In support of this hypothesis, the patients were found to form stones consisting mainly of calcium phosphate but mixed with calcium oxalate. It is concluded that the use of calcium hydroxide "chuna" in the betel quid is the major contributor to the cause of urinary stones in its users. Moreover, the development of urinary lithiasis in such patients may be a precursor to milk-alkali syndrome in those individuals whose chewing habit is more extensive than in the patients in this study and who do not seek to decrease their habit over the long term.

Rupture and perforation of urinary reservoirs made from bowel.

A review of the literature involving the rupture or perforation of urinary reservoirs made from the bowel indicates that this complication is perhaps not as rare as commonly perceived. It is a severe complication for which a high index of suspicion needs to be maintained. Physicians attending to patients with such urinary reconstructions should be aware that the diagnosis is often difficult to confirm without resorting to exploratory laparotomy and in particular that a negative cystogram can be misleading. A practical suggestion to help alert these physicians to the possibility of a ruptured urinary reconstruction is that such patients should carry a medical card stating the type of reservoir they have along with their special circumstances. From the reported experiences, it is, however, clear that in carefully selected cases and with vigilant monitoring, some patients may be managed non-operatively.

Overexpression of vimentin: role in the invasive phenotype in an androgen-independent model of prostate cancer.

The androgen-sensitive LNCaP prostate cancer cell line is less invasive than hormone-insensitive lines. CL1, an aggressive, hormone-insensitive LNCaP subline derived by continuous passaging in hormone-depleted medium, was compared with the parental cell line by cDNA microarray analysis. The gene coding for the intermediate filament protein vimentin was found to be highly up-regulated in the CL1 subline. This difference was confirmed by Northern and Western blots and visualized by immunofluorescence microscopy. To assess the contribution of vimentin to the invasive phenotype, LNCaP cells were stably transfected to overexpress vimentin, and the CL1 cells were transfected with vimentin antisense construct. The invasiveness of the transfected cells was tested using an in vitro invasion assay. We were able to demonstrate that decreasing vimentin expression in the constitutively vimentin-expressing CL1 cells led to a significant decrease in their invasiveness but that forcing expression of vimentin in the LNCaP cells did not augment their invasiveness. These findings imply that vimentin expression contributes to the invasive phenotype but cannot confer it alone.

ETS proteins and MMPs: partners in invasion and metastasis.

Binding sites for the ETS domain family of transcription factors are found in the promoters of the matrix metalloproteinase (MMP) family of matrix degrading enzymes. Evidence is accumulating that both these groups of molecules are important in the process of angiogenesis in addition to matrix degradation. Furthermore, they are both expressed in tumor tissue as well as in the normal surrounding stroma. These factors along with various sites at which they may be regulated collectively makes them attractive targets to consider for therapeutic intervention in the processes of invasion and metastasis.

Role of gadolinium-enhanced magnetic resonance imaging in retroperitoneal fibrosis.

PURPOSE: To determine if the gadolinium-enhancement characteristics of magnetic resonance images (MRI) differ for acute and chronic benign retroperitoneal fibrosis (RPF). METHOD: Seven male subjects, 3 with newly diagnosed nontreated RPF (acute group) and 4 with long-standing stable RPF (chronic group) who had been treated with steroids, ureteric stents or both, underwent MRI examinations with gadolinium enhancement. Patients in the acute group were examined again after treatment. Mean dynamic gadolinium-enhancement ratios (both dynamic and delayed) were calculated for each group. RESULTS: The initial mean dynamic enhancement ratio for the acute group (mean 1.86, range 1.80-1.95) was significantly different (p = 0.005) from that of the chronic group (mean 1.37, range 1.26-1.61). The mean dynamic enhancement ratio for the acute group after treatment (4-8 months duration) was 1.40 (range 1.26-1.51). The mean delayed enhancement ratio (RPF/psoas muscle signal intensity) for the acute group was 1.41 (range 1.38-1.43, data from 2 patients) and for the chronic group was 1.29 (range 1.13-1.44). CONCLUSION: Dynamic gadolinium enhancement was useful in differentiating newly diagnosed RPF from treated chronic disease and may have a role in assessing disease activity, monitoring response to treatment and detecting relapse.