Human Creatine Kinase-B complementary DNA Nucleotide Sequence, Gene Expression in Lung Cancer, and Chromosomal Assignment to Two Distinct Loci

Using a small cell lung cancer (SCLC) cDNA library, we obtained clones for the creatine kinase-B (CK-B) gene and determined the nucleotide sequence for the protein coding and 3 ' untranslated region (3 ' UT). The human translated protein spans 381 residues and the amino acid homology with rabbit CK-B is> 98%. We have demonstrated that a nucleic acid probe encompassing the protein coding region will also hybridize to CK-M sequences while a probe derived from the 3 ' UT region is CK-B specific. When a B-isoenzyme specific sequence is hybridized to Eco RI cut genomic DNA, two independent restriction fragment poly-morphisms are detected. We have subsequently localized these two CK-B homologous sequences to chromosomes 14q32 and 16. Finally, we show that increased levels ofCK-B seen in SCLC are not accompanied by gene amplification or rearrangement, but reflect a greatly enhanced level ofCK-B specific mRNA that is not seen in non-SCLC lines thus far examined