Expression in lung cancer of a transcribed sequence at the DNF15S2 locus at chromosome 3P21

The short arm of chromosome 3 undergoes genetic loss in virtually all small cell lung cancers (SCLC). The most frequently deleted region includes the DNF15S2 locus (mapped to 3p21), suggesting that a putative recessive SCLC gene might be located nearby. Using a DNA probe subcloned from the DNF15S2 locus, we identified a 3.0 kb mRNA species and isolated corresponding partial cDNA clones. Analysis of the nucleic acid sequence showed it to be the same as a recently published transcribed gene isolated from this chromosomal 3p21 region. To determine whether this gene might represent a "recessive oncogene" we examined a large number of SCLC and other human tumors and found no evidence for DNA rearrangements or inactivation of RNA expression. We discuss the significance of this transcribed gene and the DNF15S2 locus in tumorigenesis.