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As required by NCI, the Philadelphia NTROI investigators have instituted a general data sharing plan to disseminate important findings to the scientific community. In addition, intra- and inter-team data sharing is accomplished through a secure web-based system as well as regular meetings of Team investigators.

Data-Sharing through publically available results:

Wang S, El-Deiry WS. Requirement of p53 targets in chemosensitization of colonic carcinoma to death ligand therapy. Proc Natl Acad Sci U S A. 2003 Dec 9;100(25):15095-100. Epub 2003 Nov 26.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) exhibits specific tumoricidal activity and is under development for cancer therapy. Mismatch-repair-deficient colonic tumors evade TRAIL-induced apoptosis through mutational inactivation of Bax, but chemotherapeutics including Camptosar (CPT-11) restore TRAIL sensitivity. However, the signaling pathways in restoring TRAIL sensitivity remain to be elucidated. Here, we imaged p53 transcriptional activity in Bax-/- carcinomas by using bioluminescence, in vivo, and find that p53 is required for sensitization to TRAIL by CPT-11. Small interfering RNAs directed at proapoptotic p53 targets reveal TRAIL receptor KILLER/DR5 contributes significantly to TRAIL sensitization, whereas Bak plays a minor role. Caspase 8 inhibition protects both CPT-11 pretreated wild-type and Bax-/- HCT116 cells from TRAIL-induced apoptosis, whereas caspase 9 inhibition only rescued the wild-type HCT116 cells from death induced by TRAIL. The results suggest a conversion in the apoptotic mechanism in HCT116 colon carcinoma from a type II pathway involving Bax and the mitochondria to a type I pathway involving efficient extrinsic pathway caspase activation. In contrast to Bax-/- cells, Bak-deficient human cancers undergo apoptosis in response to TRAIL or CPT-11, implying that these proteins have nonoverlapping functions. Our studies elucidate a mechanism for restoration of TRAIL sensitivity in MMR-deficient Bax-/- human cancers through p53-dependent activation of KILLER/DR5 and reconstitution of a type I death pathway. Efforts to identify agents that up-regulate DR5 may be useful in cancer therapies restoring TRAIL sensitivity.

Wang W, El-Deiry WS. Bioluminescent molecular imaging of endogenous and exogenous p53-mediated transcription in vitro and in vivo using an HCT116 human colon carcinoma xenograft model. Cancer Biol Ther. 2003 Mar-Apr;2(2):196-202.

Real-time p53 activity in tumor cells was detected non-invasively both in vitro and in vivo by bioluminescent imaging. HCT116 colon cancer cells were stably transduced with PG13-luc, a p53 reporter with a Firefly luciferase gene under the control of 13 p53 response elements, together with a Renilla luciferase gene under an MMLV long terminal repeat promoter. Basic conditions for both in vivo and in vitro imaging were explored. Signals from as few as three thousand cells in a 96-well plate were detected following addition of D-luciferin, a substrate of Firefly luciferase at a concentration of 100 microg/ml. Bioluminescence from fifteen thousand cells with PG13-luc inoculated subcutaneously was detected following intravenous injection of D-luciferin at a dose of 100 mg/kg. Intraperitoneal injection serves as an alternative and effective route for D-luciferin delivery, although the maximal luminescent intensity was 4-10 times lower than that from intravenous injection. Bioluminescence from Renilla luciferase constitutively expressed in tumor cells was also imaged both in vitro and in vivo and served as an internal control to monitor the physiological state of the cells or tumor volume. Infection of the cells with adenovirus carrying p53 increased the bioluminescent intensity both in vitro and in vivo. Non-invasive imaging of p53 transcriptional activity provides a practical way to monitor the p53 response in cell culture and in animal models.

Data-Sharing within the Philadelphia NTROI:

Requires secure log-in and passwords

Data-Sharing between NTROI Teams in Pennsylvania, Massachusetts, and California:

Requires secure log-in and passwords