Fig. 1

A CIC-like cell population is expanded in MSTO-211H MM spheroids. a MSTO-211H cells were cultured for 4 days under conventional adherent (upper) or sphere-forming conditions. b Total RNA was isolated from adherent cells or spheroids, and the expression of SOX2, SNAIL2, ZEB1, and ZEB2 was determined by real-time PCR. Each mRNA level was normalized to that of endogenous GAPDH. c ALDH activity of adherent cells or spheroids was determined by ALDEFLUOR assay. Cell populations that disappeared with a specific ALDH inhibitor, diethylaminobenzaldehyde (DEAB), were gated as ALDH^bright cells. d Total RNA was isolated from the ALDH^bright or ALDH^dim cells sorted from spheroids, and the expression of SNAIL2, ZEB1, SOX2, OCT3/4, and NANOG was determined by RT-PCR. e Anti-CD122 (TM-β1; 500 μg/body) was intraperitoneally injected into NOD/SCID mice to deplete NK cells before tumor implantation. After 7 days, MSTO-211H cells (1 × 10³ cells) cultured under adherent (open circle) or spheroid (closed circle) conditions were subcutaneously injected into the mice. The tumor growth in vivo was measured every 3–4 days (n = 3). Data are presented in triplicate as the mean ± s.d. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001