[Frontiers in Bioscience 11, 2007-2016, September 1, 2006]

Comparing the effect of ATRA, 4-HPR, and CD437 in bladder cancer cells

Changping Zou 1, Jianwei Zhou 2, Linxin Qian 2, Jean M. Feugang 1, Jia Liu 2, Xinru Wang 2, Sheng Wu 2, Hong Ding2, Changchun Zou 1, Monica Liebert 3, and H. Barton Grossman 4

1 Department of Obstetrics and Gynecology, University of Arizona, 2 The Key Laboratory of Reproductive Medicine and Department of Urology, the First Affiliated Hospital, Nanjing Medical University, 3 American Urology Association, 4 Departments of Urology, University of Texas M.D. Anderson Cancer Center

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Methods
3.1. Bladder cancer cell lines and retinoids
3.2.Effects of retinoids on cell proliferation in monolayer cultures
3.3. Cell cycle analysis by propidium iodide (PI) staining
3.4. Analysis of apoptosis induced by ATRA, 4HPR or CD437
3.5. Analysis of nuclear retinoic acid receptors by real time Q RT-PCR
3.6. Western blot analysis
3.7. Immunofluorescence microscopy
4. Results
4.1. Growth inhibitory effect of different retinoids on human bladder cancer cell lines
4.2. Cell cycle analysis in bladder cancer cells
4.3. Retinoid-induced apoptosis
4.4. Expression and induction of nuclear retinoid receptor
4.5. Modulation of gene expression by ATRA, 4-HPR, and CD437
4.6. JWA gene expression detected by immunofluorescence staining
5. Disscussion
6. Conclusion
7. Acknowledge
8. References

1. 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 mM). 4-HPR inhibited cell growth by 90% at 10 mM; however, CD437 showed the same effect at 1 mM. 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 mM. The in vitro results suggested the higher dose of 4-HPR in chemoprevention trial be considered.