Figure 6. Inhibition of mTOR signaling sensitized leukemic cells to chemotherapy under hypoxic conditions mimicking BM microenvironment. Exponentially growing REH cells were cultured with or without MSC for 48 h under normoxia (21% O₂) and then were grown under normoxic (21% O₂) or hypoxic (1% O₂) conditions in the presence or absence of 20nM everolimus and/or 1ng/ml Vcr. After 48 h, effects on cell growth and apoptosis induction were determined by viable cell count and annexin V flow cytometry. *p = 0.01–0.03