Induction of TrkA receptor by retinoic acid in leukaemia cell linesXie, Ping1; Cheung, William M.W.1; Ip, Fanny C.F.1; Ip, Nancy Y.1; Leung, Mun-Fai1,2Neuroreport: 24 March 1997 - Volume 8 - Issue 5 - p 1067–1070 Molecular Neuroscience Abstract Author Information TO explore the potential involvement of neurotrophins in the actions of retinoic acid (RA) on leukaemia differentiation, we examined the ability of RA to regulate the expression of neurotrophins and Trk receptors in several leukaemia cell lines. Expression of TrkA was dramatically induced by RA at both the mRNA and protein level in leukaemia cell lines K562 and KG-1. Furthermore, while no expression of trkB and trkC was detected, constitutive expression of nerve growth factor (NGF), neurotrophin-3 and neurotrophin-4/5 could be detected in leukemia cells. Our findings suggested that NGF/trkA may potentially be involved in the RA-induced differentiation of leukemia cells. 1Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 2Corresponding Author: Mun-Fai Leung ACKNOWLEDGEMENTS: This study was supported by Hong Kong Research Grant Council grant HKUST 569/95M. We would like to thank Amy K. Y. Fu, Apple H. Chu and Kwok-On Lai for their stimulating discussion and their help in preparing the cDNA fragments used in this study. Received 9 December 1996; accepted 23 January 1997 © Lippincott-Raven Publishers.