Compared to other target cells examined for gene therapy, vascular smooth muscle cells (VSMCs) have the unique advantages including proximity to blood stream and relative abundance in vasculature. With an ultimate goal of developing VSMC-based therapies for cardiovascular disorders, we explored the utility of VSMC as a target cell for ex vivo gene therapy using a set of retroviral vectors.

Cultured VSMCs were transduced with replication-defective recombinant retroviruses harboring LacZ, nlsLacZ, mVEGF, mGM-CSF or bacterial CAT reporter. The VSMCs were examined for G418-selection, transduction efficiency, the level of transgene expression, and longevity of gene expression.

VSMCs were readily transduced with different kinds of retroviral vectors. The bacterial neo r gene-transduced VSMCs were successfully selected with G418. The G418-selected VSMCs could express the transduced genes at a level comparable to NIH3T3. The level of transgene expression did not appear to be affected by the increasing number of passages.

The results demonstrate an efficient transduction of VSMCs by retroviral vectors in vitro and an sustained expression of retrovirally transduced genes in VSMCs. VSMCs could be one of the ideal target cells for ex vivo cardiovascular gene therapy employing retroviral vector.