An integrated expression profiling reveals target genes of TGF-β and TNF-α possibly mediated by microRNAs in lung cancer cells

• Published in: PloS one 2013-02, Vol.8 (2), p.e56587-e56587
• Main Authors: Saito, Akira, Suzuki, Hiroshi I, Horie, Masafumi, Ohshima, Mitsuhiro, Morishita, Yasuyuki, Abiko, Yoshimitsu, Nagase, Takahide
• Format: Article
• Language: English
• Subjects: Adenocarcinoma; Adenocarcinoma - genetics; Adenocarcinoma - metabolism; Adenocarcinoma - pathology; Adenocarcinoma of Lung; Autocrine signalling; Biochemistry; Biology; Cancer; Cell Line, Tumor; Cell morphology; Chemokines; Computer Simulation; Cytokines; Cytology; Epithelial cells; Epithelial-Mesenchymal Transition - genetics; Extracellular matrix; Gelatin; Gene expression; Gene Expression Regulation, Neoplastic; Genes; Genotype & phenotype; Growth factors; HMGN2 Protein - genetics; HMGN2 Protein - metabolism; Humans; Invasiveness; JNK protein; Kinases; Lung cancer; Lung diseases; Lung Neoplasms - genetics; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Lysis; Medicine; Mesenchyme; Metastasis; MicroRNAs; MicroRNAs - genetics; MicroRNAs - metabolism; miRNA; Paracrine signalling; Phosphorylation; Ribonucleic acid; RNA; Signal Transduction; Smad protein; Smad2 protein; Smad2 Protein - metabolism; TNF inhibitors; Transforming Growth Factor beta - genetics; Transforming Growth Factor beta - metabolism; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; Tumor necrosis factor-TNF; Tumor necrosis factor-α
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0056587

EMT (epithelial-mesenchymal transition) is crucial for cancer cells to acquire invasive phenotypes. In A549 lung adenocarcinoma cells, TGF-β elicited EMT in Smad-dependent manner and TNF-α accelerated this process, as confirmed by cell morphology, expression of EMT markers, capacity of gelatin lysis and cell invasion. TNF-α stimulated the phosphorylation of Smad2 linker region, and this effect was attenuated by inhibiting MEK or JNK pathway. Comprehensive expression analysis unraveled genes differentially regulated by TGF-β and TNF-α, such as cytokines, chemokines, growth factors and ECM (extracellular matrices), suggesting the drastic change in autocrine/paracrine signals as well as cell-to-ECM interactions. Integrated analysis of microRNA signature enabled us to identify a subset of genes, potentially regulated by microRNAs. Among them, we confirmed TGF-β-mediated induction of miR-23a in lung epithelial cell lines, target genes of which were further identified by gene expression profiling. Combined with in silico approaches, we determined HMGN2 as a downstream target of miR-23a. These findings provide a line of evidence that the effects of TGF-β and TNF-α were partially mediated by microRNAs, and shed light on the complexity of molecular events elicited by TGF-β and TNF-α.