MicroRNAs implicated in self-renewal and metastases are markedly reduced in 3D spheres. A) Higher expression of relative Let-7 microRNA levels was seen in 2D vs. 3D sphere culture. RNA was extracted from 293T cells cultured in 2D and 3D conditions and subjected to real time PCR using miRNA primers from Ambion. B) H-Ras and HMGA2, two known targets of Let-7 microRNAs, were expressed higher in 3D than 2D cells by western blot. C) MicroRNAs known to regulate EMT are expressed at very low levels in 3D culture. RNA was extracted from 293T cells cultured in 2D and 3D conditions and subjected to quantitative PCRarray from SABiosciences.