Survival of salivary gland cancer stem cells requires mTOR signaling

摘要

a Immunofluorescence staining of primary human salivary gland mucoepidermoid carcinoma or xenograft tumors generated from UM-HMC-3A cells. ALDH1 is stained in green, p-mTOR is stained in red and DAPI is stained in blue. Scale bars represent 25 µm. b Graphs depicting the correlation of survival of MEC patients after surgery and expression of pS6K1 and p-mTOR (n = 17; five fields per slide). c Western blots for AKT, p-S473-AKT, mTOR, p-S2448-mTOR, S6K1, p-T421/S424-S6K1, and Bmi-1 in ALDHhighCD44high or ALDHlowCD44low cells sorted from UM-HMC-1, UM-HMC-3A or UM-HMC-3B cells. Alternatively, ALDHhighCD44high cells (i.e., cancer stem-like cells) were exposed to 2 ng/ml rapamycin or vehicle control for 24 h. d Western blots for AKT, p-S473-AKT, mTOR, p-S2448-mTOR, S6K1, p-T421/S424-S6K1, Bmi-1 in ALDHhighCD44high, ALDHhighCD44low, ALDHlowCD44high, or ALDHlowCD44low cells sorted from UM-HMC-3A cells. Experiments were performed three independent times to verify reproducibility of the data.