Purpose: To evaluate agonistic TRA-8 monoclonal antibody to human death receptor 5 (DR5) and gemcitabine in vitro and in an orthotopic pancreatic cancer model. Experimental Design: Pancreatic cancer cell lines were screened for DR5 expression, cytotoxicity, and apoptosis induced by TRA-8, gemcitabine, or gemcitabine and TRA-8. An orthotopic model of pancreatic cancer was established in severe combined immunodeficient mice. Mice were treated with TRA-8, gemcitabine, or a combination for one or two cycles of therapy. Tumor growth (ultrasound) and survival were analyzed. Results: All five pancreatic cancer cell lines showed DR5 protein expression and varying sensitivity to TRA-8 -mediated cytotoxicity. MIA PaCa-2 cells were very sensitive to TRA-8, moderately resistant to gemcitabine, with additive cytotoxicity to the combination. S2-VP10 cells were resistant to TRA-8 and sensitive to gemcitabine with synergistic sensitivity to the combination. Combination treatment in vitro produced enhanced caspase-3 and caspase-8 activation. A single cycle of therapy produced comparable efficacy for single-agent TRA-8 and the combination of TRA-8 and gemcitabine, with significant reduction in tumor size and prolonged survival compared with gemcitabine alone or control animals. With two cycles of therapy, TRA-8 and combination therapy produced enhanced inhibition of tumor growth compared with single-agent gemcitabine or untreated animals. However, the combination regimen showed enhanced survival as compared with single-agent TRA-8. Conclusions: Pancreatic cancer cell lines express varying levels of DR5 and differ in their sensitivity to TRA-8 and gemcitabine-induced cytotoxicity. TRA-8 with two cycles of gemcitabine therapy produced the best overall survival.

Purpose: Evaluate the response of human pancreatic cancer cell lines and orthotopic tumors to TRA-8, an agonistic antibody to death receptor 5, in combination with irinotecan (CPT-11). Experimental Design: MIA PaCa-2 and S2VP10 cells were treated withTRA-8 and/or CPT 11. Cell viability was determined by ATP assay. JC-1 mitochondrial depolarization and Annexin V assays confirmed cell death by apoptosis. Immunoblotting was used to evaluate protein changes. MIA PaCa-2 cells were injected into the pancreas of severe combined immunodeficient mice. Mice underwent abdominal ultrasound to quantitate tumor size before and after treatment with twice weekly injections of 200 Ag TRA-8 and/or 25 mg/kg CPT-11 for one or two treatment cycles, each lasting 2 weeks. Results: MIA PaCa-2 cells were more sensitive to TRA-8 and showed additive cytotoxicity, whereas S2VP10 cells showed synergistic cytotoxicity when treated with TRA-8 and CPT-11. Cell death occurred via apoptosis with increased cleavage of caspase-3, caspase-8, and caspase-9 and proapoptotic proteins Bid and poly(ADP)ribose polymerase after combination treatment compared with either agent alone. XIAP and Bcl-XL inhibitors of apoptosis were down-regulated. After a single cycle of in vivo combination therapy, tumor sizes had diminished significantly (P < 0.001) at 8 days posttreatment compared with no treatment, CPT-11, and TRA-8; and there was a 50-day increase in survival with combination treatment over untreated controls (P = 0.0002), 30 days over TRA-8, and a 36-day increase over CPT-11 monotherapy (P = 0.0003). With two cycles of TRA-8/CPT-11 treatment, mean survival time increased significantly (P < 0.001) to 169 days versus untreated controls, TRA-8 or 121, or 108 days, respectively). Conclusions: Combination TRA-8 and CPT-11 therapy produced enhanced cytotoxicity and survival in the MIA PaCa-2 orthotopic model of pancreatic cancer.

Superficial inferior epigastric artery (SIEA) flap breast reconstruction has advantages over deep inferior epigastric perforator flap (DIEP) and muscle sparing transverse rectus abdominus myocutaneous flap (TRAM) reconstructions with less donor site morbidity and less complicated flap dissection. Not all patients have an adequate SIEA and superficial inferior epigastric vein (SIEV) to support free tissue breast reconstruction, and dissection of the SIEA in all patients can be time consuming. Preoperative computed tomography (CT) angiograms can be used to identify the SIEA and SIEV in patients planning to undergo free abdominal tissue breast reconstruction and direct more efficient dissection in patients with a large SIEA. Retrospective analysis of free abdominal tissue flap breast reconstruction from a single plastic surgeon was performed. All patients undergoing free abdominal tissue breast reconstruction had a preoperative CT angiogram using a protocol for the evaluation of the abdominal wall perforating arteries. CT scans were reviewed by the surgeon preoperatively and evaluated for the presence, caliber, and image quality of the SIEA and SIEV. All patients, regardless of CT angiogram findings, had operative dissection and evaluation of the SIEA and SIEV. A total of 177 free flaps were performed on 113 patients who underwent preoperative CT angiogram and free abdominal tissue breast reconstruction. Of them, 64 patients had bilateral breast reconstruction. Twelve SIEA flaps (10.6%) were performed on 12 patients. During preoperative CT angiographic evaluation, 49 patients (43%) were noted to have at least one visible SIEA, whereas only 24 of those patients (21%) were felt to have an SIEA of adequate caliber. No flaps were lost during the postoperative period. All 12 SIEA flaps performed had an adequate SIEA when observed on preoperative CT angiogram. Overall, 50% of patients found to have at least one adequate SIEA on CT angiogram had a single breast reconstructed with an SIEA flap. If the SIEA was not visualized on CT angiogram, no usable SIEA was found during surgery. Preoperative CT angiogram of the abdominal wall perforating arteries can help predict which patients may have adequate anatomy for an SIEA-based free flap. This information may help direct more efficient dissection of the abdominal flaps by selecting out patients who do not have an adequate SIEA.

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