TY  - JOUR
A1  - Ceteci, Fatih
A1  - Xu, Jiajia
A1  - Ceteci, Semra
A1  - Zanucco, Emanuele
A1  - Thakur, Chitra
A1  - Rapp, Ulf R.
T1  - Conditional Expression of Oncogenic C-RAF in Mouse Pulmonary Epithelial Cells Reveals Differential Tumorigenesis and Induction of Autophagy Leading to Tumor Regression
JF  - Neoplasia
N2  - Here we describe a novel conditional mouse lung tumor model for investigation of the pathogenesis of human lung cancer. On the basis of the frequent involvement of the Ras-RAF-MEK-ERK signaling pathway in human non-small cell lung carcinoma (NSCLC), we have explored the target cell availability, reversibility, and cell type specificity of transformation by oncogenic C-RAF. Targeting expression to alveolar type II cells or to Clara cells, the two likely precursors of human NSCLC, revealed differential tumorigenicity between these cells. Whereas expression of oncogenic C-RAF in alveolar type II cells readily induced multifocal macroscopic lung tumors independent of the developmental state, few tumors with type II pneumocytes features and incomplete penetrance were found when targeted to Clara cells. Induced tumors did not progress and were strictly dependent on the initiating oncogene. Deinduction of mice resulted in tumor regression due to autophagy rather than apoptosis. Induction of autophagic cell death in regressing lung tumors suggests the use of autophagy enhancers as a treatment choice for patients with NSCLC.
KW  - Human lung-cancer
KW  - K-RAS
KW  - Induced senescence
KW  - Gene-expression
KW  - In-vivo
KW  - Kinase pathway
KW  - P53
KW  - Activation
KW  - Model
KW  - Adenocarcinomas
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134347
VL  - 13
IS  - 11
ER  - 
TY  - JOUR
A1  - Hohenauer, Tobias
A1  - Berking, Carola
A1  - Schmidt, Andreas
A1  - Haferkamp, Sebastian
A1  - Senft, Daniela
A1  - Kammerbauer, Claudia
A1  - Fraschka, Sabine
A1  - Graf, Saskia Anna
A1  - Irmler, Martin
A1  - Beckers, Johannes
A1  - Flaig, Michael
A1  - Aigner, Achim
A1  - Höbel, Sabrina
A1  - Hoffmann, Franziska
A1  - Hermeking, Heiko
A1  - Rothenfusser, Simon
A1  - Endres, Stefan
A1  - Ruzicka, Thomas
A1  - Besch, Robert
T1  - The neural crest transcription factor Brn3a is expressed in melanoma and required for cell cycle progression and survival
JF  - EMBO Molecular Medicine
N2  - Pigment cells and neuronal cells both are derived from the neural crest. Here, we describe the Pit-Oct-Unc (POU) domain transcription factor Brn3a, normally involved in neuronal development, to be frequently expressed in melanoma, but not in melanocytes and nevi. RNAi-mediated silencing of Brn3a strongly reduced the viability of melanoma cell lines and decreased tumour growth in vivo. In melanoma cell lines, inhibition of Brn3a caused DNA double-strand breaks as evidenced by Mre11/Rad50-containing nuclear foci. Activated DNA damage signalling caused stabilization of the tumour suppressor p53, which resulted in cell cycle arrest and apoptosis. When Brn3a was ectopically expressed in primary melanocytes and fibroblasts, anchorage-independent growth was increased. In tumourigenic melanocytes and fibroblasts, Brn3a accelerated tumour growth in vivo. Furthermore, Brn3a cooperated with proliferation pathways such as oncogenic BRAF, by reducing oncogene-induced senescence in non-malignant melanocytes. Together, these results identify Brn3a as a new factor in melanoma that is essential for melanoma cell survival and that promotes melanocytic transformation and tumourigenesis.
KW  - oncogene-induced senescence
KW  - BRN-3A
KW  - DNA
KW  - DNA damage
KW  - tumourigenesis
KW  - P53
KW  - in-vitro
KW  - neural crest factors
KW  - family
KW  - apoptosis
KW  - melanoma
KW  - BRAF mutations
KW  - domain
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122193
SN  - 1757-4676
VL  - 5
ER  -