EXPRESSION OF NUCLEAR LAMINS IN HUMAN TISSUES AND CANCER CELL-LINES AND TRANSCRIPTION FROM THE PROMOTERS OF THE LAMIN A C AND B1 GENES/

We have examined the expression of lamins A, B1, and C in human tissue s and cancer cell lines and the function of the lamin A/C and B1 gene promoters in transfected cells. Northern analysis and immunoblotting d emonstrated that lamin A/C mRNA and protein were not detectable in som e human cell lines whereas lamin B1 was always present. Sequencing of approximately 2.6 kb of the lamin A/C and 1.6 kb of the lamin B1 genes 5' to the translation initiation sites showed that they did not conta in typical TATA boxes near the transcription start sites. The lamin B1 and A/C proximal promoter regions were transcribed in transfected HeL a, Raji, and NT2/D1 cell lines even if the cells did not contain detec table endogenous lamin A/C mRNA or protein. These results show that, s imilar to most cytoplasmic intermediate filament genes, transcriptiona l regulatory elements in the promoters of the human nuclear lamin A/C and B1 genes do not control their cell type-specific expression in cul ture lines. (C) 1997 Academic Press.