N-(4-HYDROXYPHENYL)RETINAMIDE PREVENTS DEVELOPMENT OF T-LYMPHOMAS IN AKR J MICE/

N-(4-Hydroxyphenyl)retinamide (4-HPR), a synthetic retinoic acid deriv ative, has chemopreventive effects on several types of cancer. We rece ntly showed that 4-HPR is a potent inducer of apoptosis in malignant, but not normal, T-lymphoid cells in vitro. To test 4-HPR's effect in v ivo, we used the virus-induced T-lymphoma in AKR/J mice as a model sys tem. The AKR/J mice were fed 4-HPR at 0, 1 or 2 mmole/kg diet, and the animals were monitored as to tumor development, plasma level of 4-HPR , body weight, appetite, and general health. Our results show that in a 19-week period, 4-HPR prevented T-lymphoma development by 40% and 50 % of animals fed 1 and 2 mmole 4-HPR/kg diet, respectively. In the pla sma, 4-HPR reached micromolar levels without causing any observable de leterious side-effects. Thus, 4-HPR is potentially useful in chemoprev ention of lymphoid cancers.