Osteogenic properties of various HeLa cell lines and the BMP family genes expression

Heterotopic ossicles were induced in thigh muscles of immunosuppressed mice by implantation of suspension of several HeLa cell lines. These ossicles are the object of our research on osteoporosis. It was found that various HeLa cell lines differ in their potential to induce osteogenesis. In the previous paper we demonstrated the involvement of bone morphogenetic proteins (BMP-4 and BMP-6) secreted by HeLa cells in this phenomenon. In the present paper we try to find out the reason of the heterogeneity of various cell lines regarding the differences in their osteoinductive potencies. By the use of semiquantitative RT-PCR the differences in mRNA expression for several isoforms of BMP proteins in examined HeLa cell lines were found. The presence or absence of some of the BMP isoforms seems to be correlated with the quantity of heterotopically induced mineralised tissues. This was measured by weighing the deposited mineral after digestion of soft tissues surrounding the induced ossicles. This finding is supporting the thesis on high and uncontrolled heterogeneity of various HeLa cell lines used all over the world.