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Updated: Aug 8, 2026
Evaluating the Effectiveness of Cancer Drug Sensitization In Vitro and In Vivo
Published on: February 6, 2015
Comparing the effect of ATRA, 4-HPR, and CD437 in bladder cancer cells
Changping Zou1, Jianwei Zhou, Linxin Qian
1Department of Obstetrics and Gynecology, University of Arizona, Tucson, AZ 85724, USA. zou@email.arizona.edu
Abstract:
Clinical trials have explored the use of natural and synthetic retinoids for the prevention of bladder cancer recurrence. Natural retinoids have been shown to inhibit bladder cancer growth. Here, we compared the effects of natural and synthetic retinoids in bladder cancer cells. Bladder cancer cell lines were treated with all-trans-retinoid acid (ATRA), N-4-hydroxyphenyl-retinamide (4-HPR) and 6-[3-(1-adamantyl)-4 hydroxyphenyl]-2-naphthalene carboxylic acid (CD437). Their effects on cell growth, apoptosis, cell cycle, gene expression, and retinoid acid receptors (RARs) and the JWA-retinoid response gene were assessed. Most of the bladder cancer cells were resistant to ATRA (1 and 10 microM). 4-HPR inhibited cell growth by 90% at 10 microM; however, CD437 showed the same effect at 1 microM. 4-HPR and CD437 increased G1 and decreased S phase. The three retinoids differentially affected p53, RARs, and JWA. Only CD437 increased Caspase 3 expression. The results demonstrated that 4-HPR and CD437 were more potent growth inhibitors and apoptosis inducers than ATRA. However, 4-HPR was effective at a concentration at least 10 microM. The in vitro results suggested the higher dose of 4-HPR in chemoprevention trial be considered.
Insights
Synthetic retinoids, 4-HPR and CD437, show greater potential than natural retinoids for preventing bladder cancer recurrence by inhibiting cell growth and inducing apoptosis. Higher doses of 4-HPR may be beneficial in chemoprevention trials.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Natural and synthetic retinoids are investigated for bladder cancer recurrence prevention.
- Retinoids have demonstrated inhibitory effects on bladder cancer growth.
- Understanding the differential effects of various retinoids is crucial for optimizing chemoprevention strategies.
Purpose of the Study:
- To compare the efficacy of natural and synthetic retinoids in inhibiting bladder cancer cell growth and inducing apoptosis.
- To evaluate the impact of all-trans-retinoid acid (ATRA), N-4-hydroxyphenyl-retinamide (4-HPR), and CD437 on cell cycle, gene expression, and retinoid receptors.
- To identify potent retinoid compounds for potential use in bladder cancer chemoprevention.
Main Methods:
- Bladder cancer cell lines were treated with ATRA, 4-HPR, and CD437.
- Assays were performed to assess cell growth, apoptosis, cell cycle progression, and gene expression.
- Expression levels of p53, retinoid acid receptors (RARs), and the JWA-retinoid response gene were analyzed.
- Caspase 3 activity was measured as an indicator of apoptosis.
Main Results:
- Most bladder cancer cells were resistant to ATRA at tested concentrations.
- 4-HPR and CD437 significantly inhibited cell growth, with CD437 being more potent (1 microM vs. 10 microM for 4-HPR).
- Both 4-HPR and CD437 induced G1 cell cycle arrest and decreased S phase, indicating reduced proliferation. CD437 uniquely increased Caspase 3 expression, suggesting stronger apoptotic effects.
Conclusions:
- Synthetic retinoids 4-HPR and CD437 are more effective growth inhibitors and apoptosis inducers than ATRA in bladder cancer cells.
- CD437 demonstrated higher potency than 4-HPR in vitro.
- The findings suggest that higher doses of 4-HPR should be considered for future bladder cancer chemoprevention trials.
