Curcumin alters gene expression-associated DNA damage, cell cycle, cell survival and cell migration and invasion in NCI-H460 human lung cancer cells in vitro

Lung cancer is the most common cause of cancer mortality and new cases are on the increase worldwide. However, the treatment of lung cancer remains unsatisfactory. Curcumin has been shown to induce cell death in many human cancer cells, including human lung cancer cells. However, the effects of curcumin on genetic mechanisms associated with these actions remain unclear. Curcumin (2 mu M) was added to NCI-H460 human lung cancer cells and the cells were incubated for 24 h. Total RNA was extracted from isolated cells for cDNA synthesis, labeling, microarray hybridization and flour-labeled cDNA hybridized on chip. Localized concentrations of fluorescent molecules were detected and quantified using Expression Console software (Affymetrix) with default RMA parameters. GeneGo software was used for the key genes involved and their possible interaction pathways. The results showed that similar to 170 genes were significantly upregulated and 577 genes were significantly downregulated in curcumin-treated cells. Specifically, the up- and downregulated genes included CCNE2, associated with DNA damage; ID3, associated with cell survival and 146 genes with a >2- to 3-fold change including the TP53INP1 gene, associated with DNA damage; CDC6, CDCA5,TAKMIP2, CDK14, CDK5,CDCA76, CDC25A, CDC5L and SKP2, associated with cell cycle; the CARD6, ID1 and ID2 genes, associated with cell survival and the BRMSIL, associated with cell migration and invasion. Additionally, 59 downregulated genes exhibited a >4-fold change, including the DDIT3 gene, associated with DNA damage; while 97 genes had a >3- to 4-fold change including the DDIT4 gene, associated with DNA damage; the CCPGI gene, associated with cell cycle and 321 genes with a >2- to 3-fold including the GADD45A and CGREFI genes, associated with DNA damage; the CCPGI gene, associated with cell cycle, the TNFRSFIOB, GASS, TSSCI and TNFRSF11B gene, associated with cell survival and the ARHAP29 and CADM2 genes, associated with cell migration and invasion. In conclusion, gene alterations provide information regarding the cytotoxic mechanism of curcumin at the genetic level and provide additional biomarkers or targets for the treatment of human lung cancer.