Selective apoptosis of lung cancer cells with talc

Abstract

To the Editors: Lung cancer is the leading cause of cancer deaths worldwide, with adenocarcinoma being the most common cell type. The majority of patients with lung cancer present at an advanced stage of disease with only 15% being amenable to surgery for cure; treatment is, therefore, palliative. For patients with malignant effusions due to pleural metastasis, chemical pleurodesis is one method by which to prevent recurrence. While there are many intrapleural sclerosing agents, most data pertaining to pleurodesis have been reported with tetracycline derivatives, bleomycin and talc 1. A number of studies have demonstrated superior efficacy of talc over other sclerosing agents commonly used for the palliation of malignant pleural effusions 2, and talc is the preferred pleurodesis agent according to a survey of chest physicians 3. Despite talc's wide clinical use, the exact mechanisms for its efficacy as well as its apoptotic effects on lung cancer cells in vitro have not been studied. The objectives of our study were to determine if talc caused apoptosis of lung cancer cells, and to compare talc against other commonly administered intrapleural sclerosing agents by extending the experiments to include bleomycin and doxycyline. The lung adenocarcinoma cell line (LAC, A549) was purchased from American Type Culture Collection (Rockville, MD, USA). Human pleural mesothelial cells (PMC) characterised by classic cobblestone morphology, cytokeratin and without factor VIII antigen were isolated from pleural fluid obtained via thoracentesis from patients with symptomatic transudative pleural effusions secondary to congestive heart failure, and …