Supplementary Fig. S1 - Generation of inducible TPL2 transgenic (iTPL2 TG) mice. Supplementary Fig. S2 - Percentage of tumor-free for iTPL2 TG mice ON DOX Supplementary Fig. S3 - Detection of transgene TPL2 expression using an antibody against HA epitope tag (A) and three different antibodies against TPL2 (B) in an iTPL2 wt (#100) TG-driven KA-like cSCC ON DOX. Supplementary Fig. S4 - A, effects on TPL2-related signaling pathways with the treatments of indicated inhibitors in stable cell lines, overexpressing either control vector (Vector), TPL2-WT, or TPL2-IN, by western blot. Supplementary Fig. S5 - Western blot analyses of normal mouse skin samples Supplementary Fig. S6 - For In vitro kinase assay Supplementary Fig. S7 -Co-immunofluorescence of TPL2 Supplementary Fig. S8 - Quantification of each staining with iTPL2 TG-driven cSCC
ARTICLE ABSTRACT
Squamous cell carcinoma (SCC) and keratoacanthoma (KA; SCC/KA) research has been hampered mainly by our lack of understanding the underlying genetic and epigenetic alterations associated with SCC/KA development, as well as the lack of animal models that faithfully recapitulate histopathologic features of human SCC/KA. Here, we show that TPL2 overexpression induced both cell transformation in immortalized human keratinocytes and SCC and KA-like cutaneous SCC (cSCC) development in mice. Mechanistically, activation of TPL2 downstream signaling pathways such as MEK/ERK MAPK, mTOR, NF-κB, and p38 MAPK leads to TPL2-mediated cell transformation in immortalized human keratinocytes and tumorigenesis in mice. Most importantly, TPL2 overexpression is required for iTPL2 TG–driven SCC and KA-like cSCC tumor maintenance, validating TPL2 as a possible drug target for the treatment of SCC/KA. Finally, we verified that TPL2 is overexpressed in human cutaneous metastatic SCC and KA clinical specimens compared with normal skin. Taken together, our results establish TPL2 as an oncogenic driver in SCC/KA development. Cancer Res; 76(22); 6712–22. ©2016 AACR.