Variations in the organization and expression of human histone genes in normal diploid and tumor cell lines
The organization and expression of human histone genes were examined in W138 normal human diploid fibroblasts, SV40 transformed W138 cells, A549 epithelial lung carcinoma cells, two adeno-carcinoma cell lines (LOVO and HT29) and three leukemia cell lines (HL60, KG1 and K562). Analysis of the restriction enzyme digests of total genomic DNAs by hybridization with a series of cloned human histone sequences indicated polymorphic organization of at least a subset of the moderately reiterated human histone genes in these cells. Quantitative and qualitative differences were also observed in the representation of histone mRNAs by Northern blot analysis using cloned human histone genes as hybridization probes. However, there was no apparent correlation between variations in the representation of transcripts from various copies of the histone genes, variations in histone gene organization, and the extent of tumor progression.