Cytotoxic effects of camptothecin and cisplatin combined with tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) in a model of primary culture of non-small cell lung cancer

Abstract

Background: The cytokine tumor-necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) has been shown to preferentially induce apoptosis in cancer cells. A previous study of our group demonstrated that non-small cell lung cancer cell lines can be sensitized to Apo2L/TRAIL-induced apoptosis by chemotherapeutic agents. The aim of the present study was the evaluation of these results in a model of primary culture of non-small cell lung cancer.

Materials and methods: Lung cancer tissue and normal lung tissue obtained from 8 patients who underwent operation were cultured and treated with Apo2L/TRAIL alone and in combination with cisplatin and the topoisomerase I inhibitor camptothecin for different periods. Metabolic activity of the tissue was measured by alamar blue. Markers for apoptosis were determined by immunohistochemistry and Western blot. Expression of Apo2L/TRAIL receptors in primary lung cancer and normal lung tissue was evaluated by semi-quantitative RT-PCR. Statistics were performed using nonparametric repeated measures Anova with Dunnett's correction.

Results: Treatment with cisplatin, camptothecin and the combination of camptothecin and Apo2L/TRAIL demonstrated significant reduction of metabolic activity in tumor and normal lung tissue. In addition, the combination of camptothecin plus Apo2L/TRAIL revealed greater cytotoxic activity in cancer tissue compared with normal lung tissue. Importantly, no toxic activity of Apo2L/TRAIL alone in normal lung tissue was observed.

Conclusion: Our results obtained in a model of primary culture of lung cancer suggest that the combination of Apo2L/TRAIL and camptothecin might present an effective strategy for the treatment of non-small cell lung cancer.