Project description:<p>The involvement of membrane-bound solute carriers (SLCs) in neoplastic transdifferentiation processes is poorly defined. Here, we examined changes in the SLC landscape during epithelial-mesenchymal transition (EMT) of pancreatic cancer cells. We show that two SLCs from the organic anion/cation transporter family, SLC22A10 and SLC22A15, favor EMT via interferon (IFN) α and γ signaling activation of receptor tyrosine kinase-like orphan receptor 1 (ROR1) expression. In addition, SLC22A10 and SLC22A15 allow tumor cell accumulation of glutathione to support EMT via the IFNα/γ-ROR1 axis. Moreover, a pan-SLC22A inhibitor lesinurad reduces EMT-induced metastasis and gemcitabine chemoresistance to prolong survival in mouse models of pancreatic cancer, thus identifying new vulnerabilities for human PDAC.</p>
Project description:Epithelial plasticity – reversible modulation of a cell’s epithelial and mesenchymal features – is associated with cancer metastasis and chemoresistance. This process is classically driven by a small cohort of transcription factors, several of which have been reported to functionally interact with epigenetic modifiers at the promoters of key epithelial and mesenchymal genes. However, the extent to which epigenetic changes underlie epithelial plasticity at the genomic level remains largely unknown. Here we show that genome-wide regulation of a single histone mark, H3K36me2, is critical for establishing stable epithelial-mesenchymal states in various genetic, chemical, and cellular contexts. Through targeted CRISPR-Cas9 screening, we discovered two histone-modifying enzymes involved in the writing and erasing of H3K36me2 that act reciprocally to regulate epithelial-mesenchymal identity, tumor differentiation, and metastasis. Using genetic approaches to inhibit H3K36me2, we found that modulation of the mark itself is a conserved mechanism underlying the mesenchymal state. Although H3K36me2 is distributed broadly throughout the genome, it is associated with altered enhancer activity affecting a relatively small number of genes, including those associated with master epithelial-mesenchymal regulatory factors. Our results thus outline an epigenome-scale mechanism by which a specific histone modification regulates cellular plasticity in cancer.
Project description:Depletion of Zeb1 in a KPC-model for pancreatic cancer affected strongly the formation of precursor lesions, tumour grading, invasion and notably metastasis during PDAC progression. In this context, EMT is important for metastasis, but there is variability and specificity (and not redundancy) in the role and function of different EMT-inducing transcription factors.
Project description:Epithelial plasticity – reversible modulation of a cell’s epithelial and mesenchymal features – is associated with cancer metastasis and chemoresistance. This process is classically driven by a small cohort of transcription factors, several of which have been reported to functionally interact with epigenetic modifiers at the promoters of key epithelial and mesenchymal genes. However, the extent to which epigenetic changes underlie epithelial plasticity at the genomic level remains largely unknown. Here we show that genome-wide regulation of a single histone mark, H3K36me2, is critical for establishing stable epithelial-mesenchymal states in various genetic, chemical, and cellular contexts. Through targeted CRISPR-Cas9 screening, we discovered two histone-modifying enzymes involved in the writing and erasing of H3K36me2 that act reciprocally to regulate epithelial-mesenchymal identity, tumor differentiation, and metastasis. Using genetic approaches to inhibit H3K36me2, we found that modulation of the mark itself is a conserved mechanism underlying the mesenchymal state. Although H3K36me2 is distributed broadly throughout the genome, it is associated with altered enhancer activity affecting a relatively small number of genes, including those associated with master epithelial-mesenchymal regulatory factors. Our results thus outline an epigenome-scale mechanism by which a specific histone modification regulates cellular plasticity in cancer.
Project description:Epithelial plasticity – reversible modulation of a cell’s epithelial and mesenchymal features – is associated with cancer metastasis and chemoresistance. This process is classically driven by a small cohort of transcription factors, several of which have been reported to functionally interact with epigenetic modifiers at the promoters of key epithelial and mesenchymal genes. However, the extent to which epigenetic changes underlie epithelial plasticity at the genomic level remains largely unknown. Here we show that genome-wide regulation of a single histone mark, H3K36me2, is critical for establishing stable epithelial-mesenchymal states in various genetic, chemical, and cellular contexts. Through targeted CRISPR-Cas9 screening, we discovered two histone-modifying enzymes involved in the writing and erasing of H3K36me2 that act reciprocally to regulate epithelial-mesenchymal identity, tumor differentiation, and metastasis. Using genetic approaches to inhibit H3K36me2, we found that modulation of the mark itself is a conserved mechanism underlying the mesenchymal state. Although H3K36me2 is distributed broadly throughout the genome, it is associated with altered enhancer activity affecting a relatively small number of genes, including those associated with master epithelial-mesenchymal regulatory factors. Our results thus outline an epigenome-scale mechanism by which a specific histone modification regulates cellular plasticity in cancer.
Project description:The molecular mechanisms underlying exceptional radioresistance in pancreatic cancer remain elusive. In the present study, we established a stable radioresistant pancreatic cancer cell line MIA PaCa-2-R by exposing the parental MIA PaCa-2 cells to fractionated ionizing radiation (IR). Systematic proteomics and bioinformatics comparison of protein expression in MIA PaCa-2 and MIA PaCa-2-R cells revealed that several growth factor- and cytokine-mediated pathways, including the OSM/STAT3, PI3K/AKT and MAPK/ERK pathways, were activated in the radioresistant cells, leading to enhanced cell migration, invasion and epithelial-mesenchymal transition (EMT), and inhibition of apoptosis. We focused functional analysis on one of the most upregulated proteins in the radioresistant cells, CD73, which is a cell surface protein that is overexpressed in a variety types of cancer. Ectopic overexpression of CD73 in the parent cells resulted in radioresistance and conferred resistance to IR-induced apoptosis. Knockdown of CD73 resensitized the radioresistant cells to IR and IR-induced apoptosis. The effect of CD73 on radioresistance and apoptosis is independent of the enzymatic activity of CD73. Further studies suggest that CD73 confers acquired radioresistance in pancreatic cancer cells at least in part through inactivating proapoptotic protein BAD via phosphorylation of BAD at Ser-136. Furthermore, we found that knockdown of CD73 in the radioresistant cells alone reverted the gene expression and phenotype of the radioresistant cells from those of mesenchymal-like cells to the ones of epithelial cells, demonstrating that CD73 upregulation is required for maintaining EMT in the radioresistant cells. Our results support the notion that the enhanced growth factor/cytokine signaling that promotes epithelial-mesenchymal plasticity, and acquisition of cancer stem-like cell properties contributes to acquired radioresistance in the residual surviving cells after fractionated irradiation, and that CD73 is a novel downstream factor of those enhanced signaling and acts to confers acquired radioresistance and maintains EMT in the radioresistant pancreatic cancer cells.