Human CD34(+) cells do not express glutathione S-transferases alpha

The expression of glutathione S-transferases alpha (GST alpha) in human hematopoietic CD34(+) cells and bone marrow was studied using RT-PCR and immunoblotting. The GSTA1 protein conjugates glutathione to the stem cell selective alkylator busulfan. This reaction is the major pathway of elimination of the compound for the human body. Human hematopoietic CD34(+) cells and bond marrow do not express GSTA1 message, which was present at high level in liver an organ relatively resistant to busulfan toxicity in comparison to bone marrow. Similarly baboon CD34(+) cells and dog bone marrow donor express GSTA1. Human GSTA1 may be useful as a chemoprotective selectable marker in human stem cell gene therapy.