apoptosis executioner caspase-3 and apoptosis. 3TSR/hTSP-1 (2mM) still demonstrated a potent apoptosis-inducing effect even inthe presence of high concentrations of VEGF (50 ng/ml). 3TSR/hTSP-1 reduced endogenous Akt activity significantly, and partiallyattenuated the phosphorylation of AKT473 and cFLIP(L) expressionstimulated by VEGF, which suggests modulation of cell survivalthrough modulation of PI3kinase/Akt signaling.

CONCLUSIONS: Extrinsic and intrinsic signaling pathways play anindependent role in 3TSR/hTSP-1-mediated apoptosis in endothe-lial cells. Akt signaling is also involved in the regulation of 3TSR/hTSP-1-mediated apoptosis in microvascular endothelial cells cul-tured in low serum or stimulated by VEGF.

Induction of apoptosis in human follicular thyroidcancer cells by the histone Deacetylase inhibitorsTSA and FK228Wen T Shen MD, Mariwil G Wong BS, Electron Kebebew MD,Quan-Yang Duh MD, FACS, Orlo H Clark MD, FACSUniversity of California, San FranciscoSan Francisco, CA

INTRODUCTION: The histone deacetylase (HDAC) inhibitors area heterogeneous group of compounds that alter the chromatin struc-ture of neoplastic cells, causing cell-cycle arrest, redifferentiation, andapoptosis. TSA and FK228 are structurally different HDAC inhibi-tors that have been used for the treatment of several cancers in labo-ratory and clinical trials. The effects of TSA and FK228 on apoptosishave not been fully characterized or quantitated. We studied theeffects of TSA and FK228 on apoptosis in a human follicular thyroidcancer cell line (FTC-236).

METHODS: We treated FTC-236 cells with TSA (25-100 ng/ml) andFK228 (0.1-1 ng/ml). Apoptosis was measured at 24 and 48 hours aftertreatment using annexin V-FITC labeling and flow cytometry. RNA wasextracted at 24 and 48 hours and real-time PCR was performed tomeasure gene expression levels of bcl-2 and bcl-xl, two pro-survival pro-teins that function in the regulation of apoptosis.

RESULTS: At 48 hours after treatment, 6.4% of TSA-treated FTC-236 cells underwent apoptosis; 25.7% of FK228-treated cells underwentapoptosis in the same time period (p � 0.05). Bcl-2 gene expression wasdown-regulated by 17% inTSA-treated cells and 46% in FK228-treatedcells (p � 0.05). Bcl-xl gene expression was down-regulated by 58% inTSA-treated cells and 90% in FK228-treated cells (p � 0.05).

CONCLUSIONS: TSA and FK228 have differing effects on apopto-sis and pro-survival gene expression in FTC-236 cells. A better un-derstanding of the effects of HDAC inhibitors on apoptosis willallow clinicians to design treatment regimens based on the geneticprofiles and tumor behavior of the targeted malignancies.

The role of defective mismatch repair in smallbowel adenocarcinoma in celiac diseaseD Dean Potter MD, Joseph Murray MD, John Donohue MD, FACS,Lawrence Burgart MD, David Nagorney MD, FACS,Jon van Heerden MD, FACS, Matthew Plevak BS,Alan Zinsmeister PhD, Stephen Thibodeau PhDMayo ClinicRochester, MN

INTRODUCTION: Celiac Disease (CD) is associated with an in-creased risk of small bowel (SB) adenocarcinoma. The aims of thisstudy were to investigate the molecular basis and assess outcomes ofSB adenocarcinoma in CD.

METHODS: We performed a retrospective case control study of 18biopsy-proven CD patients with SB adenocarcinoma, 51 age- andgender-matched control patients, and 40 age-, gender-, and stage-matched control patients with SB adenocarcinoma treated at ourinstitution from 7/1960 to 11/2002. Mismatch Repair (MMR) sta-tus was assessed by microsatellite instability (MSI) and hMLH1 andhMSH2 protein expression by immunohistochemistry.

RESULTS: One CD patient was excluded due to postmortem di-agnosis of cancer. High frequency MSI (MSI-H) was identified in8/11 (73%) tumors in the CD group and 2/22 (9%) in the controlgroups. Expression of hMLH1 was lost in 6/8 and 2/2 MSI-H tu-mors in the CD and control groups, respectively. One MSI-H tumorlost hMSH2 expression in the CD group. CD patients presentedwith lower stage cancer compared to controls (P � 0.018). Survivalwas improved in the CD group when compared to stage-matchedcontrols (5-year survival 64% versus 24%, P � 0.025), and was notassociated with stage in the CD group.

CONCLUSIONS: CD patients with SB adenocarcinoma had re-markably high incidence of defective MMR and better survival com-pared to stage-matched controls. CD patients presented with earlierstage cancers and stage was not a strong prognostic indicator. Im-proved survival and earlier presentation of SB adenocarcinoma inCD may be biologically linked to defective MMR.

Intra-operative analysis of lumpectomy margins:How effective and at what cost?Dominique Coco MD, Juan Cendan MD, FACS,Edward M Copeland III, MD, FACSUniversity of Florida College of MedicineGainesville, FL

INTRODUCTION: Breast conservation therapy (BCT) for Stage I-IIbreast cancer and DCIS requires obtaining tumor-free margins toprevent recurrence. Although assessing margins intra-operatively hasnot been widely accepted, the University of Florida (UF) has beenperforming frozen sections (FS) on margins of all patients undergo-ing BCT in an attempt to reduce the number of additional operation.This study reviews the effectiveness of this method and calculates theadditional cost required.

METHODS: Operative and pathology reports and financial state-ments were retrospectively reviewed on 75 patients who had BCTbetween January 2001 and February 2003 at UF in Gainesville.

S86 Surgical Oncology J Am Coll Surg