J. A. Yi1, E. E. Moore1,2, A. Banerjee1, K. El-Kasmi1, C. C. Barnett1,2 1University Of Colorado Denver,Aurora, CO, USA 2Denver Health Medical Center,Aurora, CO, USA
Introduction: Pathological studies have demonstrated that hypoxia inducible factor-1α (HIF1α) is a marker of advanced malignancy in pancreatic cancer patients. HIF1α is a transcription factor that regulates multiple cellular processes including oxygen transport, angiogenesis, metabolism, cell adhesion, and inflammation. We hypothesize that HIF1α activity is important for the development of hepatic metastases in pancreatic adenocarcinoma.
Methods: The Pan02 murine pancreas adenocarcinoma cell line was modified using short-hairpin RNA targeting HIF1α via lentiviral transduction to create Pan02-SH+ cells lacking HIF1α activity. Knockdown of HIF1α activity by >80% was confirmed using polymerase chain reaction prior to injection of the tumor cells. C57/Bl6 mice underwent splenic injection of 200,000 Pan02 or Pan02-SH+ cells followed by hemisplenectomy to create intraabdominal metastatic tumor dissemination. After 4 weeks, mice were euthanized for necropsy performed by blinded observers. Tumor volume was calculated as (height x width2). Statistical analysis was performed using Student’s t-test and Fisher’s exact test, with significance determined to be α<0.05.
Results: Abrogating HIF1α activity of the tumor cells resulted in a decreased number of hepatic metastases (p=0.0397) and decreased hepatic tumor volume (Pan02 mean volume=1275 mm3 ± 236.08, Pan02-SH+ mean volume=16.4 mm3 ± 13.98; p=0.0007). There was no significant difference in non-hepatic intraabdominal metastases by count (p=0.1347) or by tumor volume (Pan02 mean volume=1193.8 mm3 ± 264.97, Pan02-SH+ mean volume=358.6 mm3 ± 278.55; p=0.0616) with HIF1α shRNA knockdown.
Conclusion: HIF1α activity is important for the development of hepatic metastases in pancreatic adenocarcinoma. This was reflected by both reduced number of malignant lesions and tumor volume in the liver. Non-hepatic metastases were not significantly decreased by reduction of HIF1α activity. HIF1α may represent an important target in hepatic directed therapy for pancreatic adenocarcinoma.
