Gu X, Song X, Dong Y, Cai H, Walters E, Zhang R, Pang X, Xie T, Guo Y, Sridhar R, Califano JA. Vitamin E succinate induces ceramide-mediated apoptosis in head and neck squamous cell carcinoma in vitro and in vivo.
Clin Cancer Res 2008;
14:1840-8. [PMID:
18347187 DOI:
10.1158/1078-0432.ccr-07-1811]
[Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE
Vitamin E succinate (alpha-TOS) inhibits the growth of cancer cells without unacceptable side effects. Therefore, the mechanisms associated with the anticancer action of alpha-TOS, including ceramide-mediated apoptosis, were investigated using head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo.
EXPERIMENTAL DESIGN
Five different human HNSCC cell lines (JHU-011, JHU-013, JHU-019, JHU-022, and JHU-029) were treated with alpha-TOS, and its effects on cell proliferation, cell cycle progression, ceramide-mediated apoptosis, and ceramide metabolism were evaluated. The anticancer effect of alpha-TOS was also examined on JHU-022 solid tumor xenograft growth in immunodeficient mice.
RESULTS
Alpha-TOS inhibited the growth of all the HNSCC cell lines in vitro in a dose- and time-dependent manner. Thus, JHU-013 and JHU-022 cell lines were more sensitive to alpha-TOS than the other cell lines. Cellular levels of ceramide, sphingomyelinase activity, caspase-3, and p53 were elevated with increasing time of exposure to alpha-TOS. The degradation of poly(ADP-ribose) polymerase protein in JHU-022 cells treated with alpha-TOS provided evidence for apoptosis. The amounts of nuclear factor kappaB, Bcl-2, and Bcl-X(L) proteins were reduced in the cells treated with alpha-TOS for 6 hours. The levels of caspase-9, murine double minute-2, and IkappaB-alpha proteins were unchanged after alpha-TOS treatment. I.p. administration of alpha-TOS slowed tumor growth in immunodeficient mice.
CONCLUSIONS
Alpha-TOS showed promising anticancer effects to inhibit HNSCC growth and viability in vivo and in vitro. The induction of enzymes involved in ceramide metabolism by alpha-TOS suggests that ceramide-mediated apoptosis may expand therapeutic strategies in the treatment of carcinoma.
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