7182

NR2C2

OBJECTIVES: Aberrant expression of testicular orphan receptor 4 (TR4) has been shown to regulate biological processes near solid tumors. However, the role of TR4 in non-small cell lung cancer (NSCLC) patient prognosis and the development of NSCLC cancer cells are unclear. METHODS: Immunohistochemical analysis was used to evaluate the correlation between TR4 expression and clinicopathological characteristics in 291 cases of NSCLC specimens. A knockdown and overexpression of TR4 was performed to assess the role of TR4. Transwell and colony formation assays were completed to investigate the metastatic and proliferative abilities. Quantitative real-time PCR, Western blotting and immunofluorescence staining were carried out to analyze the epithelial-to-mesenchymal transition (EMT) phenotype. RESULTS: Immunohistochemical evaluation of clinical samples revealed that most of the lung cancer tissues were strongly positive for TR4, whereas the tissues that stained weakly positive or negative for TR4 expression were shown in the paired normal tissues. Moreover, higher levels of TR4 expression were significantly associated with higher lymph node metastases, TNM stages, tumor thrombus in vena and poor prognosis. We observed that downregulation and up-regulation of TR4 with stable cell transfection significantly influence the proliferation, invasive and metastatic abilities of NSCLC lines. In addition, aberrant TR4 expression could modulate the expression levels of several EMT related markers. CONCLUSIONS: Collectively, our results show TR4 expression in NSCLC samples is significantly associated with poor clinicopathological features, and TR4 plays an important role in the metastatic capacity of NSCLC cells by EMT regulation.CI - Copyright (c) 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Seminoma is the most common testicular germ cell tumor worldwide and mainly occurs in 15-35-year-old young men. Early studies have indicated that testicular nuclear receptor 4 (TR4) first cloned from testis is involved in the invasion and metastasis of several human tumors; however, little attention is paid to the function of TR4 in seminoma. Our immunohistochemical (IHC) staining results showed that patients with advanced stage tumors tended to have higher expression of TR4. Importantly, there was a significant association between elevated TR4 expression and reduced overall survival in seminoma patients. In vitro MTS, western blot and transwell assays, after manipulating TR4 expression in Tcam-2 cells, revealed that TR4 induced epithelial-to-mesenchymal transition (EMT) and promoted Tcam-2 cell proliferation and invasion. Mechanism dissection demonstrated that AKT3, a critical component in the signaling pathway, played a crucial role in mediating TR4-promoted Tcam-2 cell proliferation and invasion. We further revealed that TR4 modulated AKT3 at the transcriptional level via chromatin immunoprecipitation and luciferase assays. Meanwhile, addition of the AKT3 siRNA blocked the function of TR4. Overall, these findings first elucidate that TR4 is a novel prognostic marker and plays a critical role in the metastatic capacity of Tcam-2 cells by EMT regulation and, consequently, targeting TR4-AKT3 pathway may serve as a potential therapeutic approach for seminoma.CI - (c) 2017 The Authors. cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese cancer Association.

Transforming growth factor-beta (TGF-beta) is major inducer of epithelial-to-mesenchymal transition (EMT), which associates with cancer cell metastasis and resistance to chemotherapy and targeted drugs, through both transcriptional and non-transcriptional mechanisms. We previously reported that, in cancer cells, heightened mitogenic signaling allows TGF-beta-activated Smad3 to interact with poly(RC) binding protein 1 (PCBP1) and together they regulate many alternative splicing events that favors expression of protein isoforms essential for EMT, cytoskeletal rearrangement, and adherens junction signaling. Here we show that the exclusion of TGF-beta-activated kinase 1 (TAK1) variable exon 12 requires another RNA-binding protein, Fox-1 homolog 2 (Rbfox2), which binds intronic sequences in front of exon 12 independently of the Smad3-PCBP1 complex. Functionally, exon 12-excluded TAK1E12 and full-length TAK1FL are distinct. The short isoform TAK1E12 is constitutively active and supports TGF-beta-induced EMT and nuclear factor kappa B (NF-kappaB) signaling, whereas the full-length isoform TAK1FL promotes TGF-beta-induced apoptosis. These observations offer a harmonious explanation for how a single TAK1 kinase can mediate the opposing responses of cell survival and apoptosis in response to TGF-beta. They also reveal a propensity of the alternatively spliced TAK1 isoform TAK1E12 to cause drug resistance due to its activity in supporting EMT and NF-kappaB survival signaling.