Background & objective: Since three-dimensional culture simulates in vivo microenvironment better than planar culture, the biological character of cells in three-dimensional culture model are more similar with that of living tissues. This study was to establish three-dimensional culture models that represent different stages of nasopharyngeal caicinogenesis, and provide information to elucidate the related molecular events.
Methods: Non-tumor nasopharyngeal biopsy specimens were used to culture for normal nasopharyngeal epithelial cells. Early and late passages of normal nasopharyngeal epithelial cell line NPNE2 from nasopharyngeal biopsy specimens, immortalized nasopharyngeal epithelial cell line NP69SV40T, nasopharyngeal carcinoma (NPC) cell line SUNE-1 and its high metastatic subclone 5-8F were cultured in Matrigel to establish three-dimensional models.
Results: The cells grew out of non-tumor nasopharyngeal biopsy specimens displayed the morphologic characteristics as epithelia, and could proliferate in vitro for 8-10 passages before senescence. Immunocytochemical staining of cytokeratin revealed that the cells were of epithelial origin. All of the cells, except late passages of NPNE2 cells, could proliferate in the three-dimensional culture system. NPNE2 and NP69SV40T cells mainly developed reticular structures in morphology, and formed few clones with clear and smooth edges as well as tight intercellular junctions. SUNE-1 and 5-8F cells formed clones with irregular morphology, unclear edge, and loose intercellular junctions. In addition, the clones formed by 5-8F cells also developed a lot of pseudopodia, but developed no reticular structure. Late passages of NPNE2 cells formed no clone and reticular structure in the three-dimensional culture.
Conclusions: Normal nasopharyngeal epithelial cells can be successfully cultured in vitro from naspharyngeal biopsy specimens. The three-dimensional culture models, established with normal nasopharyngeal epithelial cells, immortalized nasopharyngeal epithelial cells, and NPC cells, may represent the different stages of nasopharyngeal carcinogenesis.