transforming-growth-factor-alpha and Adenocarcinoma-of-Lung

Epithelial-mesenchymal transition (EMT) is a cellular process during which epithelial cells acquire mesenchymal phenotypes. Cancer cells undergo EMT to acquire malignant features and TGF-β is a key regulator of EMT. Here, we demonstrate for the first time that TGF-β could elicit EMT in a mouse lung adenocarcinoma cell line. TGF-β signaling activation led to cell morphological changes corresponding to EMT and enhanced the expression of mesenchymal markers and EMT-associated transcription factors in CMT64 lung cancer cells. RNA-sequencing analyses revealed that TGF-β increases expression of Tead transcription factors and an array of Tead2 target genes. TGF-β stimulation also resulted in alternative splicing of several genes including Cd44, tight junction protein 1 (Tjp1), and Cortactin (Cttn). In parallel with EMT, TGF-β enhanced cell growth of CMT64 cells and promoted tumor formation in a syngeneic transplantation model. Of clinical importance, the expression of TGF-β-induced genes identified in CMT64 cells correlated with EMT gene signatures in human lung adenocarcinoma tissue samples. Furthermore, TGF-β-induced gene enrichment was related to poor prognosis, underscoring the tumor-promoting role of TGF-β signaling in lung adenocarcinoma. Our cellular and syngeneic transplantation model would provide a simple and useful experimental tool to study the significance of TGF-β signaling and EMT.

Topics: Adenocarcinoma of Lung; Animals; Binding Sites; Cell Line, Tumor; Computational Biology; Epithelial-Mesenchymal Transition; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Immunohistochemistry; Mice; Protein Binding; Transcriptome; Transforming Growth Factor alpha; Transforming Growth Factor beta

Aberrant expression of miR-374a has been reported in several types of human cancers, including lung cancer. However, the functional significance and molecular mechanisms underlying the role of miR-374a in lung cancer remain largely unknown. We found that the expression of miR-374a was significantly downregulated in lung adenocarcinoma tissues compared to adjacent normal lung tissues in samples included in The Cancer Genome Atlas. Functional studies revealed that overexpression of miR-374a led to inhibition of lung adenocarcinoma cell proliferation, migration and invasion and that miR-374a negatively regulated transforming growth factor-alpha (TGFA) gene expression by directly targeting the 3'-UTR of TGFA mRNA. Treating lung adenocarcinoma cells with TGF-α neutralizing antibody resulted in suppression of cell proliferation and invasion, which mimicked the action of miR-374a. Additionally, TGFA gene expression was significantly higher in tumor tissues compared to adjacent normal tissue and high TGFA gene expression strongly correlated with poor survival in patients with lung adenocarcinoma. Taken together, our studies suggest that miR-374a suppresses lung adenocarcinoma cell proliferation and invasion via targeting TGFA gene expression. Our findings may provide novel treatment strategies for lung adenocarcinoma patients.

Topics: 3' Untranslated Regions; Adenocarcinoma; Adenocarcinoma of Lung; Antibodies, Neutralizing; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Lung; Lung Neoplasms; MicroRNAs; Transforming Growth Factor alpha

To observe the effects of hepatocyte growth factor (HGF) derived from tumor microenvironment and/or afatinib on the growth of human lung adenocarcinoma H1975 cells and explore the potential mechanisms by which HGF induces primary resistance to afatinib.. The effects of HGF, TGF-α and afatinib on the growth of H1975 cells were evaluated by MTT assay. The HGF concentrations of normal human fetal lung fibroblasts MRC-5 cells and human lung adenocarcinoma H1975 cells co-cultured or separately cultured were determined by ELISA assay. Western blot was used to detect the expressions of EGFR and Met signal pathway-related proteins and epithelial-mesenchymal transition (EMT) markers in H1975 cells treated with HGF and/or afatinib.. The MTT assay showed that H1975 cells were hyposensitive to afatinib in the presence of HGF. The ELISA assay showed that HGF production by H1975 cells was less than 0.1 ng/2.0×10(6) cells, but HGF production by MRC-5 cells was (151.37 ± 2.07)ng/2.0×10(6) cells incubated for 48 h. When H1975 cells and MRC-5 cells were co-cultured for 72 h, the concentration of HGF in the culture supernatant was (61.13 ± 16.21)ng/ml. In the presence of HGF, the expression of p-Met, p-Akt and p-ERK proteins in the H1975 cells was markedly up-regulated. afatinib inhibited p-EGFR, but did not affect the expression of p-Met, p-Akt and p-ERK proteins. In the presence of afatinib, HGF up-regulated the expression of vimentin and down-regulated the expression of E-cadherin.. HGF secreted by stromal cells in the tumor micro-environment may confer resistance to afatinib in H1975 cells by activation of the Met/PI3K/Akt and Met/MAPK/ERK signaling pathways, and is involved in the epithelial-mesenchymal transition process.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Afatinib; Antineoplastic Agents; Cadherins; Cell Line, Tumor; Cell Proliferation; Cells, Cultured; Coculture Techniques; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; ErbB Receptors; Fibroblasts; Hepatocyte Growth Factor; Humans; Lung; Lung Neoplasms; MAP Kinase Signaling System; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-met; Quinazolines; Signal Transduction; Transforming Growth Factor alpha; Tumor Microenvironment; Vimentin