Figure 4.

Increased AMPK activity in ALDH+ cells contributes to their survival. (A and B) ATP level in ALDH FACS‐sorted cells from either CRC#2 (A), or from a colorectal cancer cell line, Colo205 (B). C, Increased AMPK activity in ALDH+ cells. CRC#2 tumor cells were FACS sorted into 4 fractions based on their ALDH activity: −Hi < −Lo< +Lo< +Hi. Proteins from equal numbers of ALDH FACS‐sorted cells were analyzed by Western Blot. The antibodies used for immunoblotting are indicated on the right. (D and E) AMPK inhibitors preferentially target ALDH+ cells. Equal numbers of ALDH FACS‐sorted cells from CRC#2 were treated with 5 μM or 10 μM Compound C, or 10 μM Iodotubercidin, for 24 h. Cellular ATP was then quantified and normalized against DMSO (Control)‐treated samples as a reflection of cell viability. All error bars are standard deviation obtained from 3 different experiments