biostudies-literatureGerlach KDFGInterdisciplinary Center for Clinical ResearchMedical Research CouncilGerman Research CouncilCollaborative Research CentersEmerging Fields Initiative and the Ludwig Demling Center1893-1910https://www.ebi.ac.uk/biostudies/studies/S-EPMC10197880biostudies-literatureUnknown16(12)<h4>Background and aims</h4>Colorectal cancer [CRC] is one of the most frequent malignancies, but the molecular mechanisms driving cancer growth are incompletely understood. We characterised the roles of the cytokine IL-9 and Th9 cells in regulating CRC development.<h4>Methods</h4>CRC patient samples and samples from AOM/DSS treated mice were analysed for expression of IL-9, CD3, and PU.1 by FACS analysis and immunohistochemistry. IL-9 citrine reporter mice, IL-9 knockout mice, and PU.1 and GATA3 CD4-Cre conditional knockout mice were studied in the AOM/DSS model. DNA minicircles or hyper-IL-6 were used for overexpression of cytokines in vivo. Effects of IL-6 and IL-9 were determined in organoid and T cell cultures. Claudin2/3 expression was studied by western blotting and bacterial translJournal of Crohn's & colitisPU.1-driven Th9 Cells Promote Colorectal Cancer in Experimental Colitis Models Through Il-6 Effects in Intestinal Epithelial Cells.PMC10197880CRC 1181/2-B02MC_U105178805GE3043/3-1 [434401404]WE4656/2-2Popp VAtreya RDregelies TNeurath MFGerlach KAl-Saifi RRosenbauer FGonzalez Acera MFichtner-Feigl SVieth MMcKenzie ANJWirtz SWeigmann BfalsePU.1-driven Th9 Cells Promote Colorectal Cancer in Experimental Colitis Models Through Il-6 Effects in Intestinal Epithelial Cells.<h4>Background and aims</h4>Colorectal cancer [CRC] is one of the most frequent malignancies, but the molecular mechanisms driving cancer growth are incompletely understood. We characterised the roles of the cytokine IL-9 and Th9 cells in regulating CRC development.<h4>Methods</h4>CRC patient samples and samples from AOM/DSS treated mice were analysed for expression of IL-9, CD3, and PU.1 by FACS analysis and immunohistochemistry. IL-9 citrine reporter mice, IL-9 knockout mice, and PU.1 and GATA3 CD4-Cre conditional knockout mice were studied in the AOM/DSS model. DNA minicircles or hyper-IL-6 were used for overexpression of cytokines in vivo. Effects of IL-6 and IL-9 were determined in organoid and T cell cultures. Claudin2/3 expression was studied by western blotting and bacterial transl2022-01-01T00:00:00Z2022 Dec2025-04-21T22:46:22.617Z2025-04-05T18:51:46.727ZS-EPMC101978803579380710.1093/ecco-jcc/jjac097