NSCLC-SP cells have cancer stem cell-like properties in vitro.

(A) Growth curve on 10,000 H1650-SP or MP cells were generated using MTT cell proliferation assay in regular growth medium [22]. (B) SP or MP cells from H1650 cell line were plated in serum free medium supplemented with EGF and bFGF for 10 days. The average (±SD) number of spheres from 1000 cells is plotted. (C) H1650-SP cells resulted in larger and more colonies compared to MP cells when plated at the density of 1000 cells per 60 mm plate. (D) Cell viability was assayed after 21 days of plating via MTT assay. (E) SP or MP cells were plated on Matrigel and grown in endothelial growth medium (Lonza) overnight. SP cells gave rise to angiogenic like tubules effectively. (F) Real time qPCR analysis on SP and MP cells performed for CD31 mRNA expression. (G) CD31 expression on angiogenic tubules as visualized by immunofluorescence.