Figure 4

Establishment of the primary tumor cell line OS-RH-2011/5. The original tumor tissue was collected and directly cultivated into medium (P1*). After 26 days, cells were split and 3.75 × 10⁶ cells were injected subcutaneously into the left flank of six athymic BALB/c Nu/Nu mice. After three weeks, four of six mice developed a tumor mass, which was removed when reaching a volume of 1.500 mm³. Tumor cells were then passaged in culture (P2*), split after 20 days and again injected into the flank of six mice. After two weeks, all mice developed a tumor mass, which was removed and re-cultured (P3*)