Frequent Loss of Imprinting of the H19 Gene is Often Associated with Its Overexpression in Human Lung Cancers

Accumulating evidence suggests that deregulation of the insulin-like growth factor II (IGF2) and H19 genes at 11p15, due to loss of imprinting (LOI), plays a role in the oncogenesis of Wilms' tumors. We previously reported LOI of IGF2 in carcinomas of the lung, a common cancer of adults. We show here that LOI of H19 is also a frequent event in lung cancer development, and correlated with hypomethylation of the promoter region. Furthermore, the present study also revealed that overexpression of H19 is often associated with LOI of H19 in lung cancers retaining both parental alleles, showing a contrast to LOI in Wilms' tumors. Interestingly, in contrast to frequent LOI of the imprinted genes at 11p15, LOI was not observed for the remaining gene known to be imprinted in man, SNRPN at 15q12.