Reactive oxygen species and PI3K/Akt signaling play key roles in the induction of Nrf2-driven heme oxygenase-1 expression in sulforaphane-treated human mesothelioma MSTO-211H cells.
The nuclear factor erythroid-derived 2 related factor 2 (Nrf2)/heme oxygenase (HO)-1 induction plays cytoprotective roles against oxidative injury, apoptosis, and anticancer therapy; however, little is known about its regulation in human mesothelioma MSTO-211H cells. In this study, we investigated Nrf2/HO-1 induction in response to sulforaphane and determined the signaling pathways involved in this process. Sulforaphane treatment decreased cell viability and triggered a rapid and transient increase in the intracellular ROS levels. Pretreatment with N-acetylcysteine (NAC) prevented sulforaphane-induced cytotoxicity. Erk1/2 was activated within 1h of sulforaphane addition, whereas Akt phosphorylation was suppressed until the first 8h, and was then maintained at an elevated level until 72h, displaying a biphasic regulatory feature. Nrf2 protein levels in both nuclear and whole cell lysates were increased after sulforaphane treatment and were decreased by pretreatment with NAC, actinomycin D and cycloheximide. Activation of the Nrf2/HO-1 system after sulforaphane treatment was suppressed by pretreatment with NAC or Ly294002, a PI3K inhibitor. Knockdown of Nrf2 with siRNA decreased cell viability and attenuated sulforaphane-induced HO-1 up-regulation. Overall, our results indicate that ROS generation and/or activation of PI3K/Akt signaling regulate cell survival and Nrf2-driven HO-1 expression in sulforaphane-treated MSTO-211H cells.
Soonchunhyung Environmental Health Center for Asbestos-related Disease, College of Medicine, Soonchunhyang University, Cheonan Hospital, Cheonan 330-090, Republic of Korea.
Yoon-Jin
YJ
Lee
Hyang-Yun
HY
Jeong
Yong-Bae
YB
Kim
Yong-Jin
YJ
Lee
Seong Youn
SY
Won
Jung-Hyun
JH
Shim
Moon-Kyun
MK
Cho
Hae-Seon
HS
Nam
Sang-Han
SH
Lee
D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017879:Isothiocyanates; D008654:Mesothelioma / Q000378:metabolism*; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013454:Sulfoxides; D013861:Thiocyanates / Q000008:administration & dosage / Q000633:toxicity
D051547:Heme Oxygenase-1; D017879:Isothiocyanates; D051267:NF-E2-Related Factor 2; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D017382:Reactive Oxygen Species; D013454:Sulfoxides; D013861:Thiocyanates; C495635:NFE2L2 protein, human; C016766:sulforaphane