# STUDIES ON EXPERIMENTAL BLADDER TUMORS

> **NIH NIH R01** · UNIVERSITY OF NEBRASKA MEDICAL CENTER · 1991 · $119,392

## Abstract

A reliable, highly reproducible model of bladder cancer in Fischer rats
using the carcinogen N-[4-(5-nitro-2-furyl)-2-thiazolyl] formamide (FANFT)
was developed.  The natural history and the reversibility or
irreversibility of early lesions were determined.  It was also demonstrated
that the carcinogenic process could be divided into 2-stages with
properties similar to the classical murine skin carcinogenesis model of
initiation and promotion.  FANFT fed for 6 weeks was used as initiator and
sodium saccharin and DL-tryptophan demonstrated promoting properties in
this model.  We propose to evaluate this model with regard to other
criteria for initiation and promotion in urinary bladder carcinogenesis
including irreversibility of initiation, reversal of order of
administration of initiator and promoter, and length of time that promotion
administration is required.  The possible co-carcinogenicity of sodium
saccharin and L-tryptophan will be evaluated.  Mechanisms involved in
initiation and promotion will be evaluated.  Induction of bladder
epithelial proliferation appears to be a prerequisite for initiation.
Moreover, increasing the level of cell proliferation enhances the
effectiveness of a given dose of initiator.  Attempts will be made using
increased proliferation to develop a model requiring a single dose of
orally administered initiator.  The anti-promoting activity of
13-cis-retinoic acid will be evaluated.  A marker of abnormal cell
proliferation in this model is the appearance of pleomorphic microvilli on
cell surfaces as detected by scanning electron microscopy.  Development of
a short term assay for evaluating chemicals for activity toward the bladder
will be attempted using pleomorphic microvilli as a marker.  Identification
of other markers, particularly histochemical assays for use in evaluating
the carcinogenic and differentiation process in the bladder, will be
attempted.

## Key facts

- **NIH application ID:** 3170409
- **Project number:** 3R01CA032513-08S2
- **Recipient organization:** UNIVERSITY OF NEBRASKA MEDICAL CENTER
- **SAM.gov UEI:** G15AG3BLLMH4
- **Principal Investigator:** SAMUEL M COHEN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $119,392
- **Award type:** 3
- **Project period:** 1981-09-19 → 1992-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3170409

## Citation

> US National Institutes of Health, RePORTER application 3170409, STUDIES ON EXPERIMENTAL BLADDER TUMORS (3R01CA032513-08S2). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3170409. Licensed CC0.

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