ABSTRACT
Long-term primary culture of mammalian cells has been always difficult due to unavoidable senescence. Conventional methods for generating immortalized cell lines usually require manipulation of genome which leads to change of important biological and genetic characteristics. Recently, conditional reprogramming (CR) emerges as a novel next generation tool for long-term culture of primary epithelium cells derived from almost all origins without alteration of genetic background of primary cells. CR co-cultures primary cells with inactivated mouse 3T3-J2 fibroblasts in the presence of RHO-related protein kinase (ROCK) inhibitor Y-27632, enabling primary cells to acquire stem-like characteristics while retain their ability to fully differentiate. With only a few years' development, CR shows broad prospects in applications in varied areas including disease modeling, regenerative medicine, drug evaluation, drug discovery as well as precision medicine. This review is thus to comprehensively summarize and assess current progress in understanding mechanism of CR and its wide applications, highlighting the value of CR in both basic and translational researches and discussing the challenges faced with CR.
ABSTRACT
BACKGROUND@#The incidence of lung cancer is gradually increased, and the cystic fibrosis transmembrane conductance regulator (CFTR) has recently demonstrated to have an implication in the deoncogenesis and malignant transformation of many types of cancers. The aim of this study is to investigate impacts of CFTR on the malignant features of lung adenocarcinoma A549 cells.@*METHODS@#The capacity of cell proliferation, migration, invasion and clonogenicity of non-small cell lung cancer A549 cells were detected by CCK8 cell proliferation assay, cell scratch assay, Transwell cell invasion assay and clone formation assay, respectively. Meanwhile, the effect of CFTR gene on the expression of cancer stem cell related transcriptional factors was also detected by immunoblotting (Western blot) assay.@*RESULTS@#An overexpression of CFTR gene in A549 cells significantly inhibited the malignant capacity of A549 cells, including potencies of cell proliferation, migration, invasion and colony formation; while knockdown of CFTR gene expression by RNA interference in A549 cells resulted in an opposite effect seen in above cells overexpressing CFTR gene. Mechanistically, immunoblotting assay further revealed that the ectopic expression of CFTR gene led an inhibitory expression of stem cell-related transcriptional factors SOX2 and OCT3/4, and cancer stem cell surface marker CD133 in A549 cells, while a knockdown of CFTR expression yielded a moderately increased expression of these gene. However, an alteration of CFTR gene expression had neither effect on the expression of putative lung cancer stem cell marker aldehyde dehydrogenase1 (ALDH1), nor the frequency of ALDH1A-positive cells in A549 cells, as ascertained by the immunoblotting assay and cytometry analysis, respectively.@*CONCLUSIONS@#The CFTR exhibited an inhibitory role in the malignancy of lung adenocarcinoma A549 cells, suggesting that it may be a novel potential target for lung cancer treatment. However, its functions in other lung adenocarcinoma cell lines and its underlying molecular mechanisms require further investigation.