Grants and Contracts Details
Description
Our research focuses on complementary and alternative medicines (CAM) that possess anti-
cancer properties. In the proposed study, we will analyze the mechanism of action of
Withaferin-A (WA), a CAM based herbal used extensively in African and Asian countries for the
treatment of various ailments, including cancer. Our preliminary in vitro data suggest WA
targets colon cancer cells by down-regulating cleaved NOTCH1, pAkt, pS6K, p4E-BPI, and Bcl-
2, and simultaneously promoting caspase-3 activation and PARP cleavage. Based on these
results, we hypothesize WA will effectively inhibit colon cancer growth due to its ability to
inactivate Notch-1/Akt/mTOR-mediated pro-survival signaling, and induce apoptosis in colon
cancer cells. To address our hypothesis, we propose: study the mechanism(s) of WA-mediated
Notch-i/AktImTOR inhibition in colon cancer (Aim 1), and determine the in vivo efficacy of WA
and its chemosensitization effect on colon cancer xenografts that over-express either Akt or
mTOR (Aim 2). For our in vitro studies, we will use RT-PCR, Western Blotting, SiRNA
strategies, immunoprecipitation, cell viability assays, apoptotic assays, kinase assays, transient
transfection, gene transcription assays, pharmacological blocking, and immunocytochemistry to
clarify the impact of WA on the Notch-1/AktImTOR signaling axis. For our in vivo studies, colon
cancer cells will be stably transfected with either constitutively active Aid or mTOR. Using these
transfectants, xenografts will be formed in nude mice, and the effect of WA on the tumor bearing
animal models will be studied. Additionally, to determine the chemosensitization effect of WA on
tumor bearing animal models, we will treat mice with WA and a sub-lethal dose of 5-Fluorouracil
(5-FU). Necroscopy, histopathology, and immunohistochemical (Notch-i, Aid, mTOR, cyclin
Dl, Par-4 and Bid) analyses will be performed on the tumor sections following the termination of
the study. Additionally, HFLC will be performed to determine serum concentrations of WA in the
nude mice models. Our long term ~goal is to encourage the use of CAMs in a clinical
environment, where these agents can be best used for their chemopreventive and
chemotherapeutic properties. Our preliminary data indicate WA is one such compound, and is a
viable candidate for investigating its clinical potency against colon cancer cells.
Status | Finished |
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Effective start/end date | 3/4/10 → 5/31/11 |
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