H19 in normal development and neoplasia

Since our previous review (De Groot and Hochberg, 1993), a large number of studies regarding the role of genomic imprinting in normal development, and in non-neoplastic and neoplastic diseases has been reported. Although a number of very interesting but more general reviews have been published (Feinberg, 1993; Tycko, 1994; Surani, 1994; Ohlsson et al., 1994a; Nicholls, 1994; Langlois, 1994; Efstratiadis, 1994; Barlow, 1994; Brenton et al., 1995; Deal, 1995; Barlow, 1995; Sapienza, 1995; Feinberg et al., 1995; Latham et al., 1995; Franklin et al., 1996; John and Surani, 1996; Leighton et al., 1996), the new data justify an update on genomic imprinting, in particular on H19 and its putative role in normal development and especially neoplastic growth. Data will be discussed which were thought to support the idea that H19 acts as a tumor suppressor gene. We propose that these data are in favor of the hypothesis that H19 acts as an oncofetal gene. We will describe different aspects of H19, including its possible link with the insulin-like growth factor-2 (igf2 for mouse and IGF2 for human).