Rearrangement and co-amplification of L-myc and rlf in primary lung cancer.

We have recently characterized a gene fusion and chimeric protein product formed by L-myc and part of a novel gene named rlf in two small-cell lung cancer (SCLC) cell lines. The rlf-L-myc fusion gene is formed by intrachromosomal rearrangements placing the regulatory region and (at least) the first exon of rlf upstream of the L-myc gene. In the characterized cases the fusion gene has also been involved in DNA amplification. Here we report on a similar in vivo rearrangement involving rlf and L-myc in a primary SCLC tumor. In addition, we have found co-amplification of L-myc and rlf without visible rearrangements in either gene in three other SCLC tumors, confirming the physical linkage of these loci.