Identification of a transcriptional profile associated with in vitro invasion in non-small cell lung cancer cell lines

Abstract

Although much has been learned about basic mechanisms of cell invasion, the genes whose expression is required for this process by malignant cell lines have remained obscure. We assessed invasion through Matrigel using EGF as a chemoattractant and gene expression profiles using oligonucleotide microarrays for 22 non-small cell lung cancer cell lines. The expression of 22 genes were significantly correlated (p < 0.001) with the measured invasion index. Cluster analysis demonstrated that gene expression profiles classify the cell lines into low and high invasive subgroups. Considering invasiveness as a dichotomous variable, Bayesian analysis was used to identify genes that have the highest probability of being differentially expressed between the high and low invasion groups. This analysis identified 16 genes whose expression was associated with invasiveness. "Leave one out" cross validation was 91% accurate. Nine genes were identified in both correlation and Bayesian analyses. Seven of the nine genes were negatively associated with invasion and four of those genes are plasma membrane proteins. The two genes with the highest inverse association with invasion, TACSTD1 and CLDN3, are involved with cell adhesion and cell-cell interactions, respectively. Interestingly, the gene with the highest positive association with invasion, SERPINE1 (PAI-1), is a protease inhibitor. These and the other genes identified by both analyses represent targets for further study to assess their importance in non-small cell lung cancer invasion and metastasis.

The plasminogen activator inhibitor “paradox” in cancer

“…On the other hand wild-type PAI-1 increased cell motility in chemotaxic assays for human MDA-MB-435 breast carcinoma cells, while a non-protease inhibitory P14 (T333R) PAI-1 mutant did not [99]. Interestingly, in a microarray analysis of 22 non-small cell lung cancer cell lines, 16 genes were positively and 7 negatively associated with invasiveness: the gene with the highest positive association with invasion was the protease inhibitor PAI-1 [101], further strengthening the notion that PAI-1 effects on invasion are not mediated by modulating mere proteolytic activities. In a cutaneous healing model (epidermal monolayer scraping), injury site closure was inhibited by anti-sense down-regulation of PAI-1 synthesis (by 80-85%), or addition of PAI-1 neutralizing antibodies; these data strongly indicate that PAI-1 was required for efficient long-term planar motility of keratinocytes.…”

Functional Expression and Mutations of c-Met and Its Therapeutic Inhibition with SU11274 and Small Interfering RNA in Non–Small Cell Lung Cancer

“…H661 did not have any significant expression of c-Met. Next, we examined the level of c-Met gene expression using the Affymetrix HG-U133A gene chip expression data obtained on the cell lines as reported previously (25). The c-Met gene expression for the H1993 cells was assessed using microarray data from the Affymetrix HG-U95Av2 gene chip.…”

SCUBE3 is an endogenous TGF-β receptor ligand and regulates the epithelial-mesenchymal transition in lung cancer

“…We have previously reported that Slug promotes tumor invasion and acts as an independent prognostic marker in lung adenocarcinoma (Shih et al, 2005). Another TGF-b upregulated gene, PAI-1 (SERPINE1), which is involved in the extracellular matrix remodeling, cell migration and tumor angiogenesis (Stefansson et al, 2003;Providence and Higgins, 2004;Binder and Mihaly, 2008), is also an independent predictor of cancer relapse and poor survival in patients with breast, lung, ovarian and oral squamous cell carcinoma (Kuhn et al, 1999;Foekens et al, 2000;Hundsdorfer et al, 2004;Lader et al, 2004;Werle et al, 2004). MMP-2 and MMP-9 have also been reported to promote tumor invasion and metastasis and act as prognostic factors in non-small cell lung cancer Figure 6 SCUBE3 is cleaved by purified recombinant MMP-2 and MMP-9 in vitro.…”