Epothilone B is a more potent antiangiogenic than paclitaxel in a human tumor-based angiogenesis model

S90

Surgical Oncology

J Am Coll Surg

MET and HGF predict outcome in colorectal cancer Udai S Kammula MD, Eleanor Kuntz BS, Zhaoshi Zeng MD, Jinru Shia MD, Ron Landmann MD, Philip Paty MD, FACS, Martin Weiser MD Memorial Sloan-Kettering Cancer Center New York, NY INTRODUCTION: MET, a receptor tyrosine kinase, and its ligand, hepatocyte growth factor (HGF), are critical in cellular proliferation, motility, and invasion. We hypothesize that elevated MET and HGF gene expression predicts metastatic spread and poor survival in colorectal (CR) cancer patients. METHODS: In 60 primary CR adenocarcinomas, MET and HGF mRNA was quantified with Real-Time RT-PCR. Using random primed cDNA and gene-specific PCR, specimen threshold cycle was measured and standard curves generated. Tumor mRNA levels were extrapolated, normalized to 18S RNA and compared to pooled matched normal mucosa. Median follow-up for survival analysis was 6 years. RESULTS: When compared with normal tissue, a ⬎ 2 fold elevation in MET mRNA was seen in 69% of tumors with 48% having ⬎ 10 fold increases. Elevated HGF mRNA was noted in 47% of tumors with 19% having a ⬎ 10 fold increase. MET and HGF mRNA levels were correlated (p ⫽ 0.01). 33 patients had low expression of both genes (LOW MET/HGF) while 27 patients had high expression of both (HIGH MET/HGF). HIGH MET/HGF was associated with nodal and distant metastases(Table). Further, HIGH MET/HGF gene expression predicted poor survival (RR ⫽ 2.3, p ⬍ 0.05). The HIGH MET/HGF cohort had median survival of 3 years while the LOW MET/HGF group did not reach their median survival.

Factor

All patients Grade

T stage

N stage M stage AJCC stage

1 2 3 1 2 3 4 0 1/2 0 1 1/2 3/4

High MET/HGF n (%)

Low MET/HGF n (%)

27 (100) 1 (4) 23 (85) 3 (11) 1 (4) 5 (19) 18 (67) 3 (11) 9 (33) 18 (67) 15 (56) 12 (44) 5 (19) 22 (81)

33 (100) 1 (3) 24 (72) 8 (24) 1 (3) 8 (24) 21 (64) 3 (9) 21 (64) 12 (36) 26 (79) 7 (21) 18 (55) 15 (45)

p Value

Relative Risk

— 0.57

— —

0.96

—

0.02

1.9

0.05

2.1

0.004

1.8

CONCLUSIONS: Over-expression of MET and HGF identifies a metastatic phenotype. These molecular markers may be exploited for identifying tumors with aggressive biology and are potential therapeutic targets.

Epothilone B is a more potent antiangiogenic than paclitaxel in a human tumor-based angiogenesis model James M Lewis MD, P Johnstone Maxwell IV MD, Catherine T Anthony PhD, Brian M Gebhardt PhD, Jessica L Thompson PhD, John Rothermel PhD, Paul McSheehy PhD, Yi-Zarn Wang MD, FACS, Eugene A Woltering MD, FACS Louisiana State University Health Sciences Center New Orleans, LA INTRODUCTION: We have previously shown that Epothilone B, a microtubule stabilizer, is a potent antiangiogenic in an intact human tumor-based angiogenesis assay. Clinical studies have demonstrated Epothilone B can be effective in patients resistant to the microtubule stabilizer paclitaxel. METHODS: We hypothesized that equimolar doses of Epothilone B would be more potent than paclitaxel in our in vitro human tumor angiogenesis assay. To evaluate our hypothesis discarded portions of eleven fresh human tumors were obtained. Tumor fragments were embedded in fibrin-thrombin clots in 96 well plates. Drug-treated wells contained a control nutrient media supplemented with Epothilone B or paclitaxel at equimolar (10-6 to 10-10 M) concentrations. Wells were assessed over time and evaluated for onset of neovessel invasion (%I) and the degree of subsequent angiogenic development (angiogenic index, AI). Epothilone B (10-8 M) and paclitaxel (10-8 M) were compared at a statistical significance level of 5%. RESULTS: At doses of 10-6 M, both Epothilone B and paclitaxel completely inhibited angiogenesis. Epothilone B was statistically superior to paclitaxel in its ability to block angiogenic initiation in 4 of 11 (36%) of the cases studied, and demonstrated a numerical advantage in 9 out of the 11 (82%) cases. Epothilone B was statistically superior to paclitaxel in prohibiting subsequent angiogenic proliferation in 5/11(45%) tumors, and showed a numerical advantage in 8/11 (73%) specimens. CONCLUSIONS: At equimolar, clinically relevant (10-8M) drug doses, Epothilone B exhibits statistical and numerical advantage over paclitaxel’s ability to inhibit human tumor-derived angiogenesis.

IFN-gamma production by adoptively transferred CD8ⴙ T lymphocytes and host cells contributes to successful tumor immunotherapy Steven Finkelstein MD, Christopher Klebanoff BS, Paul Antony MD, Luca Gattinoni MD, David Heimann MD, Christian Hinrichs MD, Leroy Hwang PhD, Douglas Palmer BA, Paul Spiess BA, Steven Rosenberg MD, PhD, Nicholas Restifo MD National Institutes of Health Bethesda, MD INTRODUCTION: Adoptively transferred antigen-specific CD8⫹ T-cells can specifically produce IFN-gamma in response to tumor stimulation. We hypothesized that IFN-gamma production solely by adoptively transferred T-cells was required for anti-tumor efficacy. METHODS: A murine model with analogous components to the treatment of patients was established. CD8⫹ T-cell receptor gp100-specific transgenic mice (Pmel-1) were crossed with IFN-gamma knockout mice