Background: Lung cancer is the leading cause of cancer-related death in China. Mutation analysis reveals that LKB1 inactivation is present in 30% of non-small-cell lung cancer (NSCLC), indicating its role as a tumor suppressor. However, the molecular mechanism is still not clear. Our study attempted to establish LKB1 stable knockdown NSCLC cell line, detect alterations in gene expression and identify the genes regulated by LKB1.
Methods: LKB1 stable knockdown H1299 cell line was established using a lentiviral short hairpin RNA. To identify the knockdown effect, LKB1 mRNA and protein expression level were evaluated with quantitative real-time PCR and Western blotting. We treated the cell lines with 2-deoxyglucose to determine if LKB1 protein function was impacted. Gene microarray analysis was performed to detect the gene expression alterations in LKB1 stable knockdown H1299 cells.
Results: LKB1 mRNA and protein expression were significantly suppressed in LKB1 stable knockdown H1299 cell line. 2-DG treatment had little impact on the phosphorylation of AMPK, which is the downstream target of LKB1, indicating the loss of function of LKB1. The microarray data showed that LKB1 knockdown resulted in expression alterations of 1243 kinds of genes, including those involved in cell migration, cell proliferation and cell apoptosis.
Conclusions: The establishment of LKB1 stable knockdown H1299 cell line provides us with a great tool to investigate various genes regulated by LKB1 through microarray. The discovery of cell proliferation and migration-related genes regulated by LKB1 is critical for unraveling molecular mechanisms of LKB1's role in the development and metastasis of lung cancer.