[The quantitative analysis of cyclin D1 expression in RA-treated and non-RA-treated ectomesenchymal cells in vitro]

To elucidate the alteration of Cyclin D1 protein between RA-treated and the non-RA-treated ectomesenchymal cells in embryonic mice.

Ectomesenchymal cells in the developing orofacial processes were explanted from embryonic BALB/c mice on generation day 12(15) (the 15th hour of the 12th day). Primary cells were cultured using the tissue mass method. The variants of growth curves were examined in the RA-treated and normal groups. Protein of Cyclin D1 was detected using immunohistochemistry. The positive degree of Cyclin D1 staining was analyzed using image analysis.

The findings showed that the growth of ectomesenchymal cells was inhibited dramatically. Cyclin D1 expressed strongly in normal ectomesenchymal cells. However, its expression decreased evidently after RA-treated. There was significant difference between the test group and the normal group (P < 0.01).

Low expression of Cyclin D1 may contribute to the inhibition of ectomesenchymal cells. It is necessary for Cyclin D1 to express appropriately during the normal meiosis of ectomesenchymal cells.