Over expression of 5-aminolevulinic acid synthase 2 increased protoporphyrin IX in nonerythroid cells.

Protoporphyrin IX has been used as an efficient sensitizer in photodynamic diagnosis, photodynamic therapy, and sonodynamic therapy. The level of protoporphyrin IX is very important for diagnostic or therapy effects. 5-aminolevulinic acid synthase 2 (ALAS2) is the key enzyme upstream of protoporphyrin IX synthesis. To increase protoporphyrin IX accumulation, ALAS2 over-expression transgenic mice were generated. Plasmid containing alas2 gene was transfected in colonic carcinoma cell lines. Both in tissues of transgenic mice and in colonic carcinoma cells, the amount of protoporphyrin IX accumulation did increase. In addition, the level of heme, which is down stream of protoporphyrin IX did not change. Overexpression ALAS2 in nonerythriod cells may become a novel approach to cause protoporphyrin IX accumulation.