Mitochondrial depolarization and apoptosis associated with sustained activation of c-jun-N-terminal kinasein the human multiple myeloma cell line U266 induced by 2-aminophenoxazine-3-one

Downregulation of CUEDC2 prevents doxorubicin‑induced cardiotoxicity in H9c2 cells

Treatment with doxorubicin (DOX), which is an effective anticancer agent, is limited by cardiotoxicity. CUE domain-containing 2 (CUEDC2) serves a role in numerous cellular processes. The present study aimed to elucidate the potential function of CUEDC2 in DOX-induced cardiotoxicity. Cell Counting kit-8 assay demonstrated that DOX induced cytotoxicity of H9c2 cells in a dose-dependent manner. Flow cytometry demonstrated that downregulation of CUEDC2 reduced the levels of DOX-induced reactive oxygen species. Furthermore, compared with in the DOX-treated group, the activity of superoxide dismutase was increased in the DOX + small interfering RNA (si)CUEDC2 group; whereas, the malondialdehyde content was reduced in the DOX + siCUEDC2 group. In addition, flow cytometric analysis indicated that mitochondrial membrane potential was maintained following the depletion of CUEDC2. Furthermore, CUEDC2 downregulation significantly inhibited DOX-induced apoptosis. The expression levels of proapoptotic genes, including B-cell lymphoma 2 (Bcl-2)-associated X protein, cleaved caspase-3 and cytochrome c were inhibited by the depletion of CUEDC2. Conversely, the expression levels of the anti-apoptotic gene Bcl-2 were elevated in the CUEDC2 knockdown group. Downregulation of CUEDC2 also increased phosphorylation of protein kinase B and forkhead box O3a, and decreased the expression of Bcl-2-like protein 11 according to western blot analysis. Taken together, the present study demonstrated that CUEDC2 downregulation prevented DOX-induced cardiotoxicity in H9c2 cells. Therefore, CUEDC2 may be a promising target for the prevention of DOX-induced cardiotoxicity.

Prevention of carcinogenesis and development of gastric and colon cancers by 2-aminophenoxazine-3-one (Phx-3): direct and indirect anti-cancer activity of Phx-3

2-Aminophenoxazine-3-one (Phx-3), an oxidative phenoxazine, exerts strong anticancer effects on various cancer cell lines originating from different organs, in vitro. This article reviews new aspects for the prevention of carcinogenesis and development of gastric and colon cancers by Phx-3, based on the strong anticancer effects of Phx-3 on gastric and colon cancer cell lines (direct anticancer effects of Phx-3 for preventing development of cancer), the bacteriocidal effects of Phx-3 against Helicobacter pylori associated with carcinogenesis of gastric cancer (indirect anticancer effects for preventing carcinogenesis of gastric cancer), and the proapoptotic activity of Phx-3 against human neutrophils involved in the incidence of ulcerative colitis associated with a high colon cancer risk (indirect anticancer effects for preventing carcinogenesis of colon cancer).