Growth-Modulating Effect of Hyaluronic Acid on Cultured Tawa Sarcoma Cells

Abstract

I examined the effect in vitro of hyaluronic acid on the proliferation of cultured Tawa sarcoma (CTS) cells using conditioned medium to control growth activity.
CTS cells were obtained from tumorigenic ascites of rat peritoneal cavities which contained Tawa sarcoma (TS) cells. CTS cells were subcultured in vitro in Dulbecco's modified Eagle medium (DME) supplemented with 5% fetal calf serum (complete DME). The conditioned media were supernatants obtained by cultivation of CTS cells for 1 to 7 days in complete DME. New CTS cells were then cultured in these media. Various concentration (0.01-100μg/ml) of hyaluronic acid were added to these CTS cell cultures, the cells were incubated for 48 hours, and the number of cells were counted.
When CTS cells were cultured in media which had been conditioned for 1 to 4 days, the number of cells increased in relation to the conditioning time. However, the addition of hyaluronic acid depressed cell growth in all these conditioned media. In contrast, when CTS cells were cultured in media which had been conditioned for 5 to 7 days, little increase was seen in the number of cells. However, in these cases, cell growth was increased by the addition of hyaluronic acid.
These results indicate that the growth of CTS cells can be regulated by media which have been conditioned by CTS cells. Furthermore, the addition of hyaluronic acid depresses actively proliferating cells, while it accelerates the growth of inactive cells.