Establishing a lung cancer stem cell culture using autologous intratumoral fibroblasts as feeder cells.

Human LCSCs (lung cancer stem cells) were first isolated from lung cancer patients and cultured using serum-free culture methods. To recreate the intratumoural microenvironment to sustain LCSC growth, autologous intratumoral fibroblasts were used as feeder cells. In this study, we investigated the growth and maintenance of pluripotency in prolonged LCSCs culture on autologous intratumoural fibroblasts. LCSCs isolated from three clinical samples all showed vigorous growth on feeder cells for 16 weeks of continuous cultures with a doubling time of 41-47 h. The cells continued expressing stem cell marker CD133 and remained undifferentiated. Pluripotency was demonstrated by tumour formation in immunodeficient mice. In a feeder-free culture system, growth of LCSCs spheres was retarded and would cease when the diameter reached 100 μm if immediate passage was not performed. Moreover, spontaneous differentiation was more frequently seen in a serum-free culture system. In conclusion, we have successfully established a culture system using autologous intratumoural fibroblast cells as feeder cells for prolonged culture of undifferentiated LCSCs in vitro.