Recombinant Adenoviruses Expressing TRAIL Demonstrate Antitumor Effects on Non-Small Cell Lung Cancer (NSCLC)

Abstract

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in a variety of malignant cells, but not in normal cells. This preferential toxicity to the abnormal cells renders TRAIL potentially a very powerful therapeutic weapon against cancer. However, a requirement for large quantities of TRAIL to suppress tumor growth in vivo is one of the major factors that has hindered it from being widely applied clinically. To overcome this, we constructed a replication-deficient adenovirus that carries a human full-length TRAIL gene (Ad-TRAIL) and tested its efficacy against a lung cancer model system in comparison to that of the recombinant soluble TRAIL protein. To investigate the antitumor activity and therapeutic value of the Ad-TRAIL on the non-small cell lung cancer (NSCLC), four NSCLC cell lines, namely, YTMLC, GLC, A549, and H460 cells, were used. TRAIL protein expression was determined by Western blotting and flow cytometry. Cell viability was analyzed by proliferation assay, and DNA ladder and cell-cycle analysis were used to identify apoptosis. To further evaluate the effect of Ad-TRAIL in vivo, YTMLC cells were inoculated to the subcutis of nude mice. The Ad-TRAIL was subsequently administered into the established tumors. Tumor growth and the TRAIL toxicity were evaluated after treatment. YTMLC cells infected with Ad-TRAIL showed decreased cell viability and a higher percentage of apoptosis. Similar, Ad-TRAIL treatment also significantly suppressed tumor growth in vivo. TRAIL gene therapy provides a promising therapy for the treatment of NSCLC.