Tumor fibroblast–derived epiregulin promotes growth of colitis-associated neoplasms through ERK
Clemens Neufert, Christoph Becker, Özlem Türeci, Maximilian J. Waldner, Ingo Backert, Katharina Floh, Imke Atreya, Moritz Leppkes, Andre Jefremow, Michael Vieth, Regine Schneider-Stock, Patricia Klinger, Florian R. Greten, David W. Threadgill, Ugur Sahin, Markus F. Neurath
Clemens Neufert, Christoph Becker, Özlem Türeci, Maximilian J. Waldner, Ingo Backert, Katharina Floh, Imke Atreya, Moritz Leppkes, Andre Jefremow, Michael Vieth, Regine Schneider-Stock, Patricia Klinger, Florian R. Greten, David W. Threadgill, Ugur Sahin, Markus F. Neurath
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Research Article Oncology

Tumor fibroblast–derived epiregulin promotes growth of colitis-associated neoplasms through ERK

Abstract

Molecular mechanisms specific to colitis-associated cancers have been poorly characterized. Using comparative whole-genome expression profiling, we observed differential expression of epiregulin (EREG) in mouse models of colitis-associated, but not sporadic, colorectal cancer. Similarly, EREG expression was significantly upregulated in cohorts of patients with colitis-associated cancer. Furthermore, tumor-associated fibroblasts were identified as a major source of EREG in colitis-associated neoplasms. Functional studies showed that Ereg-deficient mice, although more prone to colitis, were strongly protected from colitis-associated tumors. Serial endoscopic studies revealed that EREG promoted tumor growth rather than initiation. Additionally, we demonstrated that fibroblast-derived EREG requires ERK activation to induce proliferation of intestinal epithelial cells (IEC) and tumor development in vivo. To demonstrate the functional relevance of EREG-producing tumor-associated fibroblasts, we developed a novel system for adoptive transfer of these cells via mini-endoscopic local injection. It was found that transfer of EREG-producing, but not Ereg-deficient, fibroblasts from tumors significantly augmented growth of colitis-associated neoplasms in vivo. In conclusion, our data indicate that EREG and tumor-associated fibroblasts play a crucial role in controlling tumor growth in colitis-associated neoplasms.

Authors

Clemens Neufert, Christoph Becker, Özlem Türeci, Maximilian J. Waldner, Ingo Backert, Katharina Floh, Imke Atreya, Moritz Leppkes, Andre Jefremow, Michael Vieth, Regine Schneider-Stock, Patricia Klinger, Florian R. Greten, David W. Threadgill, Ugur Sahin, Markus F. Neurath

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Figure 10

EREG promotes the development of colitis-associated tumors via activation of ERK.

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EREG promotes the development of colitis-associated tumors via activatio...
(A) CMT93 cells were cultured with EREG (100 ng/ml) or PBS. Cell lysates were quantified for phospho-ERK1/2, total ERK1/2, and β-actin by Western blots. (B) IEC were cultured in the presence of PBS or EREG (100 ng/ml) and ERK inhibitors PD98059 (1 μg/ml) or U0126 (40 ng/ml), as indicated. Cell numbers were determined after 24 and 48 hours. The experiment was performed twice with similar results. *P < 0.05. (C) Freshly harvested tumors of sizes 3–4 were cut into pieces and equally distributed into tissue culture wells. Next, tumor tissue was cultured with EREG and ERK inhibitors (U0126, PD98059). After 60 minutes, tumors were lysed and quantified for phospho-ERK1/2, total ERK1/2, and β-actin by Western blotting. The experiment was repeated twice with similar results. (D–F) Colitis-associated tumors were induced in WT mice by AOM and 1 cycle of DSS. Apcmin/+ mice were screened at the age of 6 weeks for the presence of sporadic rectosigmoidal tumors. Endoscopically guided injections of PBS, EREG, or ERK inhibitor (U0126) were made into growing tumors 4 times in 10 days starting at day 30. The change of tumor load was monitored by endoscopy until day 45. Data are from 1 out of 3 experiments and represent mean values ± SD (n = 3–5 per group). *P < 0.05.