miRNA expression profiles of HBE cells at different stages

To identify miRNAs involved in ST-induced cell transformation, we used microarray chips containing 856 miRNA probes to define miRNA expression profiles in 16HBE,16HBER and 16HBERST cells. we created HBE cells at different stages of the cell transformation process (Pang et al., 2008). In brief, primary human bronchial epithelial cells were immortalized by expressing SV40 LT and hTERT (named as HBELH cells). HBER cells were created by introduction of an oncogenic version of H-Ras into HBELH cells. In agreement with previous studies, the expression of the oncogene H-Ras led to an increase in cell proliferation; however these cells (HBER) were unable to grow in soft agar or form tumors in immunodeficient mice. Subsequently, HBERST cells generated by the additional introduction of SV40 ST into HBER cells grew in an anchorage independent fashion and formed tumors in immunodeficient mice. Therefore, these cell lines represent distinct stages of immortalized cells (HBELH), pre-transformed cells (HBER) and transformed cells (HBERST). And then, the different miRNA expression profiles of HBE cells at different stages were assayed by miRNA microarray.