The possible anticancer activity of combination (M + E + F) of metformin (M), efavirenz (E), and fluoxetine (F) was investigated in normal HDF cells and HCT116 human colon cancer cells. Metformin increased cellular FOXO3a, p-FOXO3a, AMPK, p-AMPK, and MnSOD levels in HDFs but not in HCT116 cells. Cellular ATP level was decreased only in HDFs by metformin. Metformin increased ROS level only in HCT116 cells. Transfection of si-FOXO3a into HCT116 reversed the metformin-induced cellular ROS induction, indicating that FOXO3a/MnSOD is the key regulator for cellular ROS level. Viability readout with M, E, and F alone decreased slightly, but the combination of three drugs dramatically decreased cell survival in HCT116, A549, and SK-Hep-1 cancer cells but not in HDF cells. ROS levels in HCT116 cells were massively increased by M + E + F combination, but not in HDF cells. Cell cycle analysis showed that of M + E + F combination caused cell death only in HCT116 cells. The combination of M + E + F reduced synergistically mitochondrial membrane potential and mitochondrial electron transport chain complex I and III activities in HCT116 cells when compared with individual treatments. Western blot analysis indicated that DNA damage, apoptosis, autophagy, and necroptosis-realated factors increased in M + E + F-treated HCT116 cells. Oral administration with M + E + F combination for 3 weeks caused dramatic reductions in tumor volume and weight in HCT116 xenograft model of nude mice when compared with untreated ones. Our results suggest that M + E + F have profound anticancer activity both in vitro and in vivo via a cancer cell-specific ROS amplification (CASRA) through ROS-induced DNA damage, apoptosis, autophagy, and necroptosis.

β-amyloid is an important factor in the pathophysiology of Alzheimer's disease.This study investigates β-amyloid's role in the regulation of nociception in mice. Pretreated once, 2 weeks prior to testing with β-amyloid, male ICR mice were examined on various nociceptive tests. Pretreatment with β-amyloid reversed the nociceptive effects induced by intraperitoneally administered acetic acid (writhing response) and intraplantar injection of 5% formalin into the hind paw. β-amyloid pretreatment also elevated the threshold for nociception in the mechanical von Frey test. Additionally, p-CREB and p-ERK levels in the spinal cord and the adrenal gland increased after formalin injection. Pretreatment with β-amyloid attenuated formalin-induced overexpression of p-CREB and p-ERK in the spinal cord and the adrenal gland. Our results suggest that chemical and mechanical nociception appear to be altered in β-amyloid-treated animals. Furthermore, the reduction of nociception by β-amyloid in the formalin pain model appears to be mediated, at least in part, by the suppression of p-CREB and p-ERK level in the spinal cord and the adrenal gland.