Anti-Tumor Prostaglandins Facilitate Mineralization by Human Osteoblasts

We reported in 1981 that prostaglandin D2 (PGD2) selectively inhibits tumor cell growth (1). It was verified by Dr. Fukushima’s group in 1985 (2) that a metabolite of PGD2, Δ12-PGJ2 (9-deoxy-Δ9,12-13,14- dihydro-PGD2) was the active form of this PG. Recently we have found that PGD2 and PGA1 derivatives (3,4), which are called the anti-tumor PGs, facilitate mineralization in human osteoblasts. Considering that carcinogenesis enhances bone resorption in general, the concept that anti-tumor PGs stimulate mineralization is an attractive one. I will present data on the stimulative effect of these cyclopentenone PGs and their derivatives on mineralization in human osteoblasts, and discuss a possible mechanism.