Selenite modulates phenotype-dependent epithelial-mesenchymal plasticity in pancreatic ductal adenocarcinoma: integrated in vitro analyses and patient-derived ex vivo tissue-slice cultures.
Pancreatic ductal adenocarcinoma (PDAC) is characterized by profound therapy resistance, desmoplasia, and phenotypic plasticity. While sodium selenite is a redox-active compound with reported tumor-selective cytotoxicity, its impact on epithelial-mesenchymal transition (EMT) states in PDAC remains insufficiently defined. We investigated whether selenite modulates EMT-associated phenotypes in a dose- and context-dependent manner using complementary in vitro and patient-derived ex vivo models and linked marker shifts to histological tumor regression in PDAC tissue slices.
Three PDAC cell lines spanning distinct baseline EMT states (PANC-1, HPAF-II, Capan-2) were profiled by quantitative immunofluorescence for a predefined epithelial (EpCAM, cytokeratin, E-cadherin) and mesenchymal-associated (AHNAK2, ITGAV, vimentin) protein panel, with or without TGF-β pretreatment. Ex vivo tissue slices from treatment-naïve, non-metastatic PDAC resections (n = 10) were cultured in a within-patient paired design (0 h, 24 h, 48 h controls; 5 or 15 µM selenite during the second 24 h). Histological tumor regression was scored by a blinded pancreatic pathologist (Evans; CAP), compartment-resolved marker expression was quantified by multiplex immunofluorescence, and paired RNA sequencing was performed in a subset of donors (n = 4).
In vitro, responses were phenotype-contingent: the epithelial-biased HPAF-II and Capan-2 lines showed partial epithelial reinforcement and a consistent reduction of mesenchymal markers (particularly ITGAV, vimentin), whereas the mesenchymal-biased PANC-1 exhibited limited modulation. TGF-β pretreatment attenuated epithelial-promoting effects while suppression of mesenchymal markers was retained in a cell line-dependent manner. In ex vivo slices, selenite induced a dose-dependent improvement in histological tumor regression and increased the tumor-compartment epithelial-mesenchymal ratio at 15 µM, driven mainly by epithelial-marker upregulation, while mesenchymal markers showed no uniform suppression. At 15 µM, transcriptomics revealed a compact treatment response characterized by downregulation of basement-membrane/ECM modules without broad reversal across EMT gene sets; EMT scoring indicated heterogeneous shifts at 5 µM and a more consistent epithelial-leaning shift at 15 µM in most donors.
Selenite was associated with reinforcement of epithelial features mainly in malignant PDAC compartments in a baseline-state-, dose-, and context-dependent manner, with higher-dose phenotypic shifts occurring alongside stronger histological tumor response in clinically proximal models.
Not applicable.
Three PDAC cell lines spanning distinct baseline EMT states (PANC-1, HPAF-II, Capan-2) were profiled by quantitative immunofluorescence for a predefined epithelial (EpCAM, cytokeratin, E-cadherin) and mesenchymal-associated (AHNAK2, ITGAV, vimentin) protein panel, with or without TGF-β pretreatment. Ex vivo tissue slices from treatment-naïve, non-metastatic PDAC resections (n = 10) were cultured in a within-patient paired design (0 h, 24 h, 48 h controls; 5 or 15 µM selenite during the second 24 h). Histological tumor regression was scored by a blinded pancreatic pathologist (Evans; CAP), compartment-resolved marker expression was quantified by multiplex immunofluorescence, and paired RNA sequencing was performed in a subset of donors (n = 4).
In vitro, responses were phenotype-contingent: the epithelial-biased HPAF-II and Capan-2 lines showed partial epithelial reinforcement and a consistent reduction of mesenchymal markers (particularly ITGAV, vimentin), whereas the mesenchymal-biased PANC-1 exhibited limited modulation. TGF-β pretreatment attenuated epithelial-promoting effects while suppression of mesenchymal markers was retained in a cell line-dependent manner. In ex vivo slices, selenite induced a dose-dependent improvement in histological tumor regression and increased the tumor-compartment epithelial-mesenchymal ratio at 15 µM, driven mainly by epithelial-marker upregulation, while mesenchymal markers showed no uniform suppression. At 15 µM, transcriptomics revealed a compact treatment response characterized by downregulation of basement-membrane/ECM modules without broad reversal across EMT gene sets; EMT scoring indicated heterogeneous shifts at 5 µM and a more consistent epithelial-leaning shift at 15 µM in most donors.
Selenite was associated with reinforcement of epithelial features mainly in malignant PDAC compartments in a baseline-state-, dose-, and context-dependent manner, with higher-dose phenotypic shifts occurring alongside stronger histological tumor response in clinically proximal models.
Not applicable.
Authors
Aricak Aricak, Shi Shi, Moro Moro, Ghaderi Ghaderi, Dillner Dillner, Fuxe Fuxe, Björnstedt Björnstedt, Szekerczés Szekerczés
View on Pubmed