TY  - JOUR
A1  - Ceteci, Fatih
A1  - Ceteci, Semra
A1  - Zanucco, Emanuele
A1  - Thakur, Chitra
A1  - Becker, Matthias
A1  - El-Nikhely, Nefertiti
A1  - Fink, Ludger
A1  - Seeger, Werner
A1  - Savai, Rajkumar
A1  - Rapp, Ulf R.
T1  - E-Cadherin Controls Bronchiolar Progenitor Cells and Onset of Preneoplastic Lesions in Mice
JF  - Neoplasia
N2  - Although progenitor cells of the conducting airway have been spatially localized and some insights have been gained regarding their molecular phenotype, relatively little is known about the mechanisms regulating their maintenance, activation, and differentiation. This study investigates the potential roles of E-cadherin in mouse Clara cells, as these cells were shown to represent the progenitor/stem cells of the conducting airways and have been implicated as the cell of origin of human non-small cell lung cancer. Postnatal inactivation of E-cadherin affected Clara cell differentiation and compromised airway regeneration under injury conditions. In steady-state adult lung, overexpression of the dominant negative E-cadherin led to an expansion of the bronchiolar stem cells and decreased differentiation concomitant with canonical Wnt signaling activation. Expansion of the bronchiolar stem cell pool was associated with an incessant proliferation of neuroepithelial body-associated Clara cells that ultimately gave rise to bronchiolar hyperplasia. Despite progressive hyperplasia, only a minority of the mice developed pulmonary solid tumors, suggesting that the loss of E-cadherin function leads to tumor formation when additional mutations are sustained. The present study reveals that E-cadherin plays a critical role in the regulation of proliferation and homeostasis of the epithelial cells lining the conducting airways.
KW  - injury
KW  - lung cancer
KW  - stem cells
KW  - clara cell
KW  - gene expression
KW  - basal cell
KW  - in vivo
KW  - epithelium
KW  - airway
KW  - renewal
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135407
VL  - 14
IS  - 12
ER  - 
TY  - JOUR
A1  - Zanucco, Emanuele
A1  - Götz, Rudolf
A1  - Potapenko, Tamara
A1  - Carraretto, Irene
A1  - Ceteci, Semra
A1  - Ceteci, Fatih
A1  - Seeger, Werner
A1  - Savai, Rajkumar
A1  - Rapp, Ulf R.
T1  - Expression of B-RAF V600E in Type II Pneumocytes Causes Abnormalities in Alveolar Formation, Airspace Enlargement and Tumor Formation in Mice
JF  - PLOS ONE
N2  - Growth factor induced signaling cascades are key regulatory elements in tissue development, maintenance and regeneration. Perturbations of these cascades have severe consequences, leading to developmental disorders and neoplastic diseases. As a major function in signal transduction, activating mutations in RAF family kinases are the cause of human tumorigenesis, where B-RAF V600E has been identified as the prevalent mutant. In order to address the oncogenic function of B-RAF V600E, we have generated transgenic mice expressing the activated oncogene specifically in lung alveolar epithelial type II cells. Constitutive expression of B-RAF V600E caused abnormalities in alveolar epithelium formation that led to airspace enlargements. These lung lesions showed signs of tissue remodeling and were often associated with chronic inflammation and low incidence of lung tumors. The inflammatory cell infiltration did not precede the formation of the lung lesions but was rather accompanied with late tumor development. These data support a model where the continuous regenerative process initiated by oncogenic B-RAF-driven alveolar disruption provides a tumor-promoting environment associated with chronic inflammation.
KW  - obstructive pulmonary-disease
KW  - lung-cancer
KW  - somatic mutations
KW  - epithelial-cells
KW  - mouse models
KW  - protein
KW  - kinase
KW  - inflammation
KW  - activation
KW  - pathway
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137061
VL  - 6
IS  - 12
ER  -