CULTURE OF RETINOBLASTOMA CELLS FROM CLINICAL SPECIMENS - GROWTH-PROMOTING EFFECT OF 2-MERCAPTOETHANOL

Establishment of new tumor cell lines is an important first step for biological studies of tumor cells. High success rates in establishing retinoblastoma cell lines have been reported when feeder-layer culture but not liquid-culture techniques were used. Liquid culture is, however, essential for studies in which feeder-layer cells are undesirable. In a previous study, we formulated a medium (RB-- medium), the components of which were almost identical to those of a soft-agar medium developed for colony formation of established retinoblastoma cell lines, in which one cell line from 12 primary retinoblastoma specimens was established. In this study, another medium (RB++ medium), RB-- medium to which 20 muM 2-mercaptoethanol and 375 muM asparagine were added, was tested for its ability to grow retinoblastoma cells from clinical specimens. In the RB++ medium, 6 cell lines from 16 primary sites, 2 from 2 intraocular-recurrent and 3 from 3 metastatic retinoblastomas grew for over a year. The major reason for the apparent improvement of the RB-medium on the RB-- medium was demonstrated to be the addition of 2-mercaptoethanol.