The Novel Use of IL-28 as an Effective Radiosensitizer in Pancreatic Cancer.

Abstract

Pancreatic cancer is the second most common gastrointestinal cancer in the world, yet the five-year survival outcome rate of less than 5% urges for improvement in medical interventions of pancreatic cancer. Currently, high dose radiation therapy (RT) is used as an adjuvant treatment; however, the high level of RT required to treat advanced neoplasms leads to high incidence rates of side effects. In recent years, the utilization of cytokines as radiosensitizing agents has been studied, in order to reduce the amount of radiation required. However, few studies have examined IL-28 regarding its potential as a radiosensitizer. This study is the first to utilize IL-28 as a radiosensitizing agent in pancreatic cancer. MiaPaCa-2, a widely used pancreatic cancer cell line was used in this study. Clonogenic survival and cell proliferation assays were used to evaluate growth and proliferation of MiaPaCa-2 cells. Caspase-3 activity assay was used to evaluate apoptosis of MiaPaCa-2 cells and RT-PCR was used to study the possible molecular mechanisms. Our results showed that IL-28/RT enhanced RT-induced inhibition of cell proliferation and promoted apoptosis of MiaPaCa-2 cells. Furthermore, compared to RT alone, we found that IL-28/RT up-regulated the mRNA expression of TRAILR1 and P21, while down-regulating mRNA expression of P18 and survivin in MiaPaCa-2 cells. IL-28 has the potential to be used as a radiosensitizer for pancreatic cancer and warrants further investigation.