Expression of POU2F3 Transcription Factor Control Inflammation, Immunological Recruitment and Metastasis of Pancreatic Cancer in Mice

Abstract

TUFT cells have been described as strong modulators of inflammatory cells in several tissues including pancreas. TUFT cells, also known as DCLK1⁺ cells, are dependent of the transcriptional factor POU2F3. Several works report DCLK1⁺ cells in early stages of PDAC development suggesting an important role of TUFT cells in PDAC development. Therefore, we developed a mice model (PDX1-Cre;Kras^G12D;Ink4a^fl/fl), known as PKI model, deficient or not of POU2F3. In this animal model, deficiency of POU2F3 results in the absence of TUFT cells in PDAC as expected. Although, tumor development and growth are not significantly influenced, the development of liver metastasis was almost completely inhibited in POU2F3-deficient mice. Surprisingly, the absence of metastasis was associated with a higher expression of epithelial-to-mesenchymal transition markers, but to a lower inflammatory microenvironment suggesting that inflammation influences metastasis production more than epithelial-to-mesenchymal transition in this animal model. We can conclude that POU2F3 could be a new therapeutic target for control PDAC progression.

Keywords: PDAC; POU2F3; TUFT cells; epithelial-to-mesenchymal transition; metastasis.

Figure 1

POU2F3 is not essential for pancreatic carcinogenesis but it is critical for liver metastasis. (A) Kaplan Meier survival curve of PKI;POU2F3^+/+ and PKI;POU2F3^−/− mice (left panel) and the tumor weight at the sacrifice time (right panel). (B) Immuno-staining of POU2F3 and DCLK1 in the pancreas from PKI;POU2F3^+/+ and PKI;POU2F3^−/− mice. (C) Hematoxylin and Eosin staining of the pancreas and liver from PKI;POU2F3^+/+ and PKI;POU2F3^−/− mice. Values denote the metastasis per liver. Scale set as 100 µm.

Figure 2

PDAC from PKI;POU2F3^−/− mice is more differentiated. (A) Immuno-staining of Cdh1 in pancreas from PKI;POU2F3^+/+ and PKI;POU2F3^−/− mice. Values denote positive cells per field. (B) mRNA expression in pancreas from PKI;POU2F3^+/+ and PKI;POU2F3 mice. Scale set as 100 µm.

Figure 3

PDAC from PKI;POU2F3^−/− mice express less level of inflammatory markers and overexpress anti-apototic markers. mRNA expression in pancreas from PKI;POU2F3^+/+ and PKI;POU2F3 mice.

Figure 4

Immunological infiltration in PDAC. Immuno-staining of sections from pancreatic tumors. Values denote positive cells per field. Scale set as 100 µm.

Figure 5

Immunophenotyping of cells from spleen and peritoneal cavity is similar in both genotypes. Cell sorting by flow cytometry of spleen cells (A) and from peritoneal cavity (B) from PKI;POU2F3^+/+ and PKI;POU2F3^−/− mice.