A plasmid, viral or linear DNA molecule containing a nucleic acid sequence
derived from the promoter region of the hCol1.alpha.2 gene, which is
selectively transported into the nuclei of cells in the osteoblast
lineage. The sequence can be used independently as a nuclear entry
sequence only, and/or as a nuclear entry sequence without regard to
position, in a vector or linear DNA that directs gene expression and
nuclear entry. The disclosure further includes a chimeric DNA sequence
derived by the addition of osteoblast-specific enhancer sequences to the
nuclear entry sequence/promoter sequence, to increase osteoblast-specific
expression while retaining osteoblast-specific nuclear import. An
enhancer sequence is derived from the promoter region of the human Core
Binding Factor alpha 1 (Cbfa1/Runx2) gene. The Cbfa1/Runx2 promoter can
be added to the sequence derived from, or alternatively, comprising the
promoter region of the hCol1.alpha.2 gene. Also provided are methods of
use of the novel sequences.