Introduction and Objectives: Intravesical chemotherapy has
been proven effective in preventing recurrence of low-risk
non-muscle invasive bladder cancer (NMIBC). BCG is recognised as the best conservative treatment for intermediate
and high risk NMIBC. Maintenance for at least one year is
required to ameliorate the efficacy of adjuvant therapy.
Discomfort and toxicity often cause interruption of adjuvant
therapy, BCG particularly. Almost 50% of the patients
undergoing BCG does not complete one year. A biomarker of
urothelium damage would be helpful for timely detection of
toxicity in order to ameliorate patient’s tolerance and
compliance. The aim of the present study was to evaluate the
gene expression of Fibronectin (FN) in bladder washing in
relation with local toxicity due to adjuvant intravesical therapy.
Patients and Methods: Out of 26 asymptomatic patients
undergoing intravesical prophylaxis with mitomycin (40
mg/40 ml), epirubicin (80 mg/50 ml) or BCG Connaught (81
mg/50 ml) and 10 volunteers as control group, 62 samples of
bladder washing were collected before, during and after
therapy. The samples were analyzed by isolation of cellular
RNA using a miRNeasy Mini Kit (Qiagen®). FN gene
expression was analyzed by RT-PCR. The ΔΔCt method after
normalization with endogenous reference 18s rRNA was
adopted. An average Ct value for each RNA was obtained for
triplicate reactions. Local toxicity was classified into 3 grades:
0-1. mild (no medical therapy); 2. moderate (medical therapy);
3. severe (instillation postponed for 1-2 weeks or intravesical
solution of hyaluronic acid and chondroitin sulphate
administered). Results: FN gene expression, compared to
controls, was increased 1.1 fold after TUR and before
intravesical therapy. During therapy it remained unchanged
(1.0 fold). However it was increased 1.1 fold in absence of
local toxicity, but to a median value of 3.6 fold in presence of
severe toxicity. Particularly, the mean values, compared to
controls, were 2.4 (range: 0.3-6.1), 1.1 (range: 0.1-2.3), 9.3
(range: 0.2-45.2), before therapy, in absence and in presence
of local toxicity, respectively. Of interest, patients receiving
intravesical hyaluronic acid and chondroitin sulphate solution
showed a median FN gene expression of 0.2 fold (range 0.1-
0.7), decreasing from 3 to 0.6 and from 4 to 0.2 fold in two
patients contemporary with symptomatic relief. Discussion:
Few studies have correlated the gene expression of FN to
bladder urothelial damage, in interstitial cystitis (1). FN plays
an important role on BCG activity (2). A marker of topical
toxicity would be helpful to improve the tolerance and to
reduce the drop-out rates of intravesical therapy. The
measurement in bladder washing is a simple and direct
evaluation of urothelial FN gene activity. This method avoids
all the bias due to the evaluation of FN protein expression in
urine. The overexpression of FN gene indicates the presence
of urothelial damage and activation of repairing processes.
Normal and downexpression indicate the absence or healing
of urothelial damage. Preliminarily, our study shows a
significant correlation between FN gene expression on bladder
washing and local toxicity. Furthermore, FN seems to be
reduced by the intravesical administration of intravesical hyaluronic acid and chondroitin sulphate solution. Conclusion:
FN gene expression in bladder washing emerges as a simple
and promising marker of urothelial damage. Further and larger
studies should be justified.
Acknowledgements: We wish to thank IBSA for unrestricted grant
and the GSTU Foundation for administrative support.
1 Blalock EM et al: Gene expression analysis of urine
sediment: evaluation for potential noninvasive markers of
interstitial cystitis/bladder pain syndrome. J Urol 187: 725,
2012.
2 Eissa S et al: Diagnostic value of fibronectin and mutant p53
in the urine of patients with bladder cancer: impact on
clinicopathological features and disease recurrence 27: 1286,
2010