CD4⁺T cells potently induce epithelial-mesenchymal-transition in premalignant and malignant pancreatic ductal epithelial cells–novel implications of CD4⁺T cells in pancreatic cancer development

Abstract

Chronic pancreatitis (CP) is a risk factor of pancreatic ductal adenocarcinoma (PDAC) and characterized by a pronounced desmoplastic reaction with CD4C T cells accounting for the majority of the stromal T cell infiltrate. Epithelial-mesenchymal-transition (EMT) is a critical process for metastasis by which epithelial/carcinoma cells become enabled to disseminate probably prior to tumor formation. To investigate whether CD4 C T cells induce EMT in human pancreatic ductal epithelial cells, premalignant H6c7 cells were mono-or co-cultured with human CD4¡ regulatory T cells (T-regs) or CD4 C CD25 ¡ T-effector cells (T-effs) being isolated by negative magnetic bead separation from blood of healthy donors. Particularly in the presence of activated T-effs, H6c7 cells acquired a spindle-shaped morphology, reduced E-cadherin expression, and elevated expression of the mesenchymal proteins vimentin, L1CAM, and ZEB-1. This was accompanied by an increased invasive behavior. Moreover, activated Teffs exerted similar effects in the PDAC cell line T3M4. Blocking of TNF-a and IL-6 being released at greater amounts into supernatants during co-cultures with activated T-effs attenuated the EMT-associated alterations in H6c7 cells. Supporting these findings, EMT-associated alterations (exemplified by reduced E-cadherin expression and enhanced expression of vimentin and L1CAM) were predominantly detected in ductal epithelium of CP tissues surrounded by a dense stroma enriched with CD4 C T cells. Overall this study points to a novel role of CD4 C T cells beyond their immune function in pancreatic tumorigenesis and underscores the view that EMT induction in pancreatic ductal epithelial cells represents an early event in PDAC development being essentially promoted by inflammatory processes.

The Crosstalk between Nrf2 and TGF-β1 in the Epithelial-Mesenchymal Transition of Pancreatic Duct Epithelial Cells

“…when originating from chronic inflammation. Besides the decreasing E-cadherin expression, vimentin and L1CAM expression slightly increased in these PanINs, as shown previously [ 63 ]. Intriguingly, the expression of these three markers was not concomitantly altered in the same PanIN.…”

NK-cell Editing Mediates Epithelial-to-Mesenchymal Transition via Phenotypic and Proteomic Changes in Melanoma Cell Lines

“…Recently, it has also been proposed that certain immune cells present in the tumor microenvironment (namely MDSCs, macrophages, neutrophils, and CD4 þ T cells) could even favor tumor progression by promoting epithelial-mesenchymal transition (EMT; refs. [14][15][16][17][18].…”

“…Various stimuli can favor tumor cell transition including TGFb and WNT signaling, alteration of receptor Tyr-kinase pathways, hypoxia, and, as mentioned above, the interaction with certain immune cell types (14)(15)(16)(17)(18)(19). To our knowledge, no information is available on a possible NK:tumor cell cross-talk in the context of the tumor cell phenotype switching, although the EMT could preferentially occur at the tumor borders, where NK cells have been more frequently localized (6,18).…”

Immunological Aspects of the Tumor Microenvironment and Epithelial-Mesenchymal Transition in Gastric Carcinogenesis

“…Furthermore, CD8+ lymphocytes stimulate the release of proinflammatory Il-17, promoting tumorigenesis and worsening the clinical outcome of GC [223]. Th1, Th2, Treg, and Th17 are all inducers of EMT and can be obtained due to the differentiation of naive CD4+ T helper cells [224]. A high Th1/Th2 ratio correlates with a better prognosis of GC incidents.…”