Figure 4

Tumorosphere formation and anchorage independent growth capabilities of MSDACs in alternated culture conditions. (A) Representative microphotographs showing growth trends, monolayer differentiation or cell aggregation, tumorosphere formation, and phenotype conversions in three different clones of MSDACs maintained in serum-free stem cell medium for three generations: SF-SCM-1(3G), SF-SCM-1(3G) cells transferred and maintained in growth medium with FBS for three generations (SF-SCM-1(3G) → GM-FBS(3G), or the MSDACs reintroduced in SF-SCM for three generations (SF-SCM-1(3G) → GM-FBS(3G) → SF-SCM-2(3G). (B) Parental SH-SY5Y cells maintained in growth medium or SF-SCM are used as controls. (C) Representative microphotographs of soft agar colony forming assay showing anchorage-independent growth signatures of MSDACs maintained in serum-free stem cell medium for three generations, transferred and maintained in growth medium with FBS for three generations or reintroduced in SF-SCM for three generations. FBS, fetal bovine serum; MSDACs, metastatic site-derived aggressive cells; SF-SCM, serum-free stem cell medium.