The N-myc gene, first detected by its homology to the second exon of the c-myc gene, is amplified and/or expressed in tumours or cell lines derived from neuroblastoma, retinoblastoma and SCLC.
The translocated c-myc gene should provide a probe to the chromosome 3p14 region, which appears to be important not only in renal cell carcinoma but also in small cell carcinoma of the lung.
The presence of myb transcripts in SCLC suggests that the myb gene may have a specific role in the initiation or maintenance of an important human epithelial tumor.
Northern blot analysis, using human HLA-A,B, and beta 2m cDNA probes, showed that almost all SCLC lines tested had markedly decreased amounts of HLA and beta 2m mRNA, but both gene products could be induced with interferon treatment of SCLC lines.
Examination of the structure of prepro-GRP transcripts found in SCLC reveals three types of prepro-GRP mRNA which differ in the structure of a putative GRP-associated peptide in the pro-GRP precursor.
Six cell lines (3 adenocarcinomas, 2 squamous cell carcinomas and 1 small cell carcinoma) expressed EGF receptor gene and its product to a significant level without gene amplification, and the other three cell lines were found to be negative as regards expression.
Organization of the L-myc gene was determined by comparing its sequence to those of the L-myc psi gene and an L-myc cDNA clone derived from a human small cell lung carcinoma.