Open AccessTetraarsenic hexoxide induces G2/M arrest, apoptosis, and autophagy via PI3K/Akt suppression and p38 MAPK activation in SW620 human colon cancer cells
Author(s) -
Arulkumar Nagappan,
Won Sup Lee,
Jeong Won Yun,
Jing Lü,
Shih-Chieh Chang,
Jong Ju Jeong,
Gon Sup Kim,
JinMyung Jung,
Soon Chan Hong
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0174591
Subject(s) - protein kinase b , pi3k/akt/mtor pathway , programmed cell death , cancer cell , microbiology and biotechnology , apoptosis , p38 mitogen activated protein kinases , ly294002 , biology , cancer research , mapk/erk pathway , kinase , chemistry , signal transduction , cancer , biochemistry , genetics
Tetraarsenic hexoxide (As 4 O 6) has been used in Korean folk medicines for the treatment of cancer, however its anti-cancer mechanisms remain obscured. Here, this study investigated the anti-cancer effect of As 4 O 6 on SW620 human colon cancer cells. As 4 O 6 has showed a dose-dependent inhibition of SW620 cells proliferation. As 4 O 6 significantly increased the sub-G1 and G2/M phase population, and Annexin V-positive cells in a dose-dependent manner. G2/M arrest was concomitant with augment of p21 and reduction in cyclin B1, cell division cycle 2 (cdc 2) expressions. Nuclear condensation, cleaved nuclei and poly (adenosine diphosphate‑ribose) polymerase (PARP) activation were also observed in As 4 O 6 -treated SW620 cells. As 4 O 6 induced depolarization of mitochondrial membrane potential (MMP, ΔΨm) but not reactive oxygen species (ROS) generation. Further, As 4 O 6 increased death receptor 5 (DR5), not DR4 and suppressed the B‑cell lymphoma‑2 (Bcl-2) and X-linked inhibitor of apoptosis protein (XIAP) family proteins. As 4 O 6 increased the formation of AVOs (lysosomes and autophagolysosomes) and promoted the conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3)-I to LC3-II in a dose- and time- dependent manner. Interestingly, a specific phosphoinositide 3-kinase (PI3K)/Akt inhibitor (LY294002) augmented the As 4 O 6 induced cell death; whereas p38 mitogen-activated protein kinases (p38 MAPK) inhibitor (SB203580) abrogated the cell death. Thus, the present study provides the first evidence that As 4 O 6 induced G2/M arrest, apoptosis and autophagic cell death through PI3K/Akt and p38 MAPK pathways alteration in SW620 cells.