| First Author | Thiem S | Year | 2016 |
| Journal | Cancer Res | Volume | 76 |
| Issue | 8 | Pages | 2277-87 |
| PubMed ID | 26837764 | Mgi Jnum | J:231629 |
| Mgi Id | MGI:5771962 | Doi | 10.1158/0008-5472.CAN-15-3089 |
| Citation | Thiem S, et al. (2016) Stomach-Specific Activation of Oncogenic KRAS and STAT3-Dependent Inflammation Cooperatively Promote Gastric Tumorigenesis in a Preclinical Model. Cancer Res 76(8):2277-87 |
| abstractText | About 5% to 10% of human gastric tumors harbor oncogenic mutations in the KRAS pathway, but their presence alone is often insufficient for inducing gastric tumorigenesis, suggesting a requirement for additional mutagenic events or microenvironmental stimuli, including inflammation. Assessing the contribution of such events in preclinical mouse models requires Cre recombinase-mediated conditional gene expression in stem or progenitor cells of normal and transformed gastric epithelium. We therefore constructed a bacterial artificial chromosome containing transgene (Tg), comprising the regulatory elements of the trefoil factor 1 (Tff1) gene and the tamoxifen-inducible Cre recombinase (CreERT2)-coding sequence. The resulting Tg(Tff1-CreERT2) mice were crossed with mice harboring conditional oncogenic mutations in Kras or Braf The administration of tamoxifen to the resulting adult Tg(Tff1-CreERT2);Kras(LSL-G12D/+) and Tg(Tff1-CreERT2);Braf(LSL-V600E/+) mice resulted in gastric metaplasia, inflammation, and adenoma development, characterized by excessive STAT3 activity. To assess the contribution of STAT3 to the spontaneously developing gastric adenomas in gp130(F/F) mice, which carry a knockin mutation in the Il6 signal transducer (Il6st), we generated Tg(Tff1-CreERT2);Stat3(fl/fl);gp130(F/F) mice that also harbor a conditional Stat3 knockout allele and found that tamoxifen administration conferred a significant reduction in their tumor burden. Conversely, excessive Kras activity in Tg(Tff1-CreERT2);Kras(LSL-G12D/+);gp130(F/F) mice promoted more extensive gastric inflammation, metaplastic transformation, and tumorigenesis than observed in Tg(Tff1-CreERT2);Kras(LSL-G12D/+) mice. Collectively, our findings demonstrate that advanced gastric tumorigenesis requires oncogenic KRAS or BRAF in concert with aberrant STAT3 activation in epithelial precursor cells of the glandular stomach, providing a new conditional model of gastric cancer in which to investigate candidate therapeutic targets and treatment strategies. Cancer Res; 76(8); 2277-87. (c)2016 AACR. |
