Identification of epidermal Pdx1 expression discloses different roles of Notch1 and Notch2 in murine KrasG12D-induced skin carcinogenesis in vivo
Mazur, Pawel K., Grüner, Barbara M., Nakhai, Hassan, Sipos, Bence, Zimber-Strobl, Ursula, Strobl, Lothar J., Radtke, Freddy, Schmid, Roland M. and Siveke, Jens T.. (2010) Identification of epidermal Pdx1 expression discloses different roles of Notch1 and Notch2 in murine KrasG12D-induced skin carcinogenesis in vivo. PL o S One, Vol.5 (No.10). ISSN 1932-6203
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Official URL: http://dx.doi.org/10.1371/journal.pone.0013578
The Ras and Notch signaling pathways are frequently activated during development to control many diverse cellular processes and are often dysregulated during tumorigenesis. To study the role of Notch and oncogenic Kras signaling in a progenitor cell population, Pdx1-Cre mice were utilized to generate conditional oncogenic KrasG12D mice with ablation of Notch1 and/or Notch2.
Surprisingly, mice with activated KrasG12D and Notch1 but not Notch2 ablation developed skin papillomas progressing to squamous cell carcinoma providing evidence for Pdx1 expression in the skin. Immunostaining and lineage tracing experiments indicate that PDX1 is present predominantly in the suprabasal layers of the epidermis and rarely in the basal layer. Further analysis of keratinocytes in vitro revealed differentiation-dependent expression of PDX1 in terminally differentiated keratinocytes. PDX1 expression was also increased during wound healing. Further analysis revealed that loss of Notch1 but not Notch2 is critical for skin tumor development. Reasons for this include distinct Notch expression with Notch1 in all layers and Notch2 in the suprabasal layer as well as distinctive p21 and β-catenin signaling inhibition capabilities.
Our results provide strong evidence for epidermal expression of Pdx1 as of yet not identified function. In addition, this finding may be relevant for research using Pdx1-Cre transgenic strains. Additionally, our study confirms distinctive expression and functions of Notch1 and Notch2 in the skin supporting the importance of careful dissection of the contribution of individual Notch receptors.
|Item Type:||Journal Article|
|Subjects:||Q Science > QP Physiology
R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)
|Divisions:||Faculty of Science > Life Sciences (2010- ) > Biological Sciences ( -2010)
Faculty of Science > Life Sciences (2010- )
|Library of Congress Subject Headings (LCSH):||Notch proteins, GTPase-activating protein, Carcinogenesis, Skin -- Tumors|
|Journal or Publication Title:||PL o S One|
|Publisher:||Public Library of Science|
|Official Date:||22 October 2010|
|Access rights to Published version:||Open Access|
|Funder:||Deutsche Krebshilfe [German Cancer Aid], Lustgarten Foundation, Deutsche Forschungsgemeinschaft (DFG)|
|Grant number:||107195 (DK), RFP05-14 (LF), RFP06-12 (LF), SI 1549/1-1 (DFG)|
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