TY - JOUR TI - The Flavonol Isoquercitrin Promotes Mitochondrial-Dependent Apoptosis in SK-Mel-2 Melanoma Cell via the PI3K/AKT/mTOR Pathway AU - Won, Yeong-Seon AU - Kim, Jeong-Ho AU - Lizardo, Rona Camille M. AU - Min, Hye-Ji AU - Cho, Hyun-Dong AU - Hong, Seong-Min AU - Seo, Kwon-Il T2 - Nutrients AB - Isoquercitrin (IQ), a major flavonol present in Prunus mume fruit, has gained much attention in recent studies because of its superior bioavailability and physiological effects. In this study, the anti-cancer mechanism of IQ against human melanoma, particularly its effect on the mitochondria-mediated apoptosis, was investigated. Treatment with IQ at 25 μM concentration effectively inhibited the proliferation of SK-MEL-2 skin cancer cells while the same concentration did not exhibit cytotoxicity against human keratinocytes HaCaT. Morphological analysis and clonogenic assay also showed that IQ can alter the growth and long-term survival of SK-MEL-2 cells. IQ also induced apoptosis in the melanoma cells as manifested in the nuclear morphology changes, DNA fragmentation, increase in the apoptosis rate (17.69% at 25 μM) and accumulation of sub-G1 cell cycle phase population (19.55% at 25 μM). Western blot analysis revealed the involvement of the mitochondrial apoptosis signaling pathway in the anti-cancer property of IQ. Treatment with IQ resulted in the decrease in the levels of procaspase-8 and -9, and Bcl-2 protein, and an increase in the expression of cleaved PARP and Bax. Moreover, AIF and Endo G protein expression increased, indicating a caspase-independent mitochondrial-mediated apoptosis. The anti-proliferative activity of IQ against SK-MEL-2 can also be attributed to the downregulation of the PI3K/AktmTOR signaling pathway. These findings showed that IQ can be developed into a chemopreventive therapeutic agent against the melanoma cells. DA - 2020/12// PY - 2020 DO - 10.3390/nu12123683 DP - www.mdpi.com VL - 12 IS - 12 SP - 3683 LA - en UR - https://www.mdpi.com/2072-6643/12/12/3683 Y2 - 2020/12/04/22:23:21 KW - flavonol KW - human melanoma KW - isoquercitrin KW - mitochondrial-mediated apoptosis KW - natural chemopreventive agent ER -