ABSTRACT: Slug-dependent upregulation of L1CAM is responsible for the increased invasion potential of pancreatic cancer cells following long-term 5-FU-treatment
Project description:In pancreatic cancer the survival rate is low, as the available treatment options usually only extend survival and seldom produce a cure. Drug resistance and disease reoccurrence is the typical reason for death after cancer diagnosis. 5-Fluorouracil (5-FU) is the main chemostatic used in first line therapy. However the majority of the tumors become resistant to treatment. To investigate acquired 5-FU resistance in pancreatic adenocarcinoma, we established chemoresistant monoclonal cell lines from the Panc03.27 cell line by long-term exposure to 5-FU. In addition to increased expression of markers associated with multidrug resistance, the 5-FU resistant clones showed alterations typical of the process of epithelial-to-mesenchymal transition (EMT), including upregulation of mesenchymal markers and increased invasiveness. Microarray analysis revealed the L1CAM pathway as one of the most upregulated pathways in the chemoresistant clones, which was confirmed on RNA and protein levels. Expression of the adhesion molecule L1CAM is associated with a chemoresistant and migratory phenotype of pancreatic cancer. Using esiRNA targeting L1CAM, or by blocking the extracellular part of L1CAM with monoclonal antibodies, we discovered that the increased invasiveness observed in the chemoresistant cells depends on L1CAM. Using esiRNA targeting β-catenin and/or Slug, we discovered that L1CAM expression depends on Slug rather than β-catenin in the 5-FU resistant cells. We demonstrate a functional link between Slug and the expression level of L1CAM in pancreatic cancer cells having undergone EMT following long-term exposure to 5-FU. Our findings provide further insight into the molecular mechanisms leading to a chemoresistant and migratory phenotype in pancreatic cancer cells and indicate the importance of Slug-induced L1CAM in refractory pancreatic cancer. Examination of expression of 5-Fluorouracil (5-FU) Panc03.27 cell line resistant clone versus expression of 5-FU sensitive clones (NT) in 4 replicates per cell lines
Project description:In pancreatic cancer the survival rate is low, as the available treatment options usually only extend survival and seldom produce a cure. Drug resistance and disease reoccurrence is the typical reason for death after cancer diagnosis. 5-Fluorouracil (5-FU) is the main chemostatic used in first line therapy. However the majority of the tumors become resistant to treatment. To investigate acquired 5-FU resistance in pancreatic adenocarcinoma, we established chemoresistant monoclonal cell lines from the Panc03.27 cell line by long-term exposure to 5-FU. In addition to increased expression of markers associated with multidrug resistance, the 5-FU resistant clones showed alterations typical of the process of epithelial-to-mesenchymal transition (EMT), including upregulation of mesenchymal markers and increased invasiveness. Microarray analysis revealed the L1CAM pathway as one of the most upregulated pathways in the chemoresistant clones, which was confirmed on RNA and protein levels. Expression of the adhesion molecule L1CAM is associated with a chemoresistant and migratory phenotype of pancreatic cancer. Using esiRNA targeting L1CAM, or by blocking the extracellular part of L1CAM with monoclonal antibodies, we discovered that the increased invasiveness observed in the chemoresistant cells depends on L1CAM. Using esiRNA targeting β-catenin and/or Slug, we discovered that L1CAM expression depends on Slug rather than β-catenin in the 5-FU resistant cells. We demonstrate a functional link between Slug and the expression level of L1CAM in pancreatic cancer cells having undergone EMT following long-term exposure to 5-FU. Our findings provide further insight into the molecular mechanisms leading to a chemoresistant and migratory phenotype in pancreatic cancer cells and indicate the importance of Slug-induced L1CAM in refractory pancreatic cancer.
Project description:Perineural invasion (PNI) is a pivotal prognostic factor in pancreatic cancer, associated with aggressive tumor behavior and adverse patient outcomes. Despite its recognized clinical impact, the molecular mechanisms underlying PNI are not well understood. In this study, we isolated perineural invasion-associated cancer-associated fibroblasts (pCAFs), which demonstrated a markedly enhanced capacity to promote neural invasion in pancreatic cancer compared to non-perineural invasion-associated CAFs (npCAFs). Utilizing single-cell, high-throughput sequencing, and metabolomics, we identified a significant upregulation of glycolysis in pCAFs, fostering a high-lactate tumor microenvironment conducive to cancer progression. pCAFs-derived lactate is absorbed by tumor cells, facilitating histone H3K18 lactylation. This epigenetic modification activates the transcription of neural invasion-associated genes such as L1CAM and SLIT1, thereby driving PNI in pancreatic cancer. Further exploration of metabolic reprogramming in pCAFs revealed enhanced acetylation of the glycolytic enzyme GAPDH, correlated with increased enzymatic activity and glycolytic flux. Targeting of GAPDH and lactylation modifications significantly inhibits neural invasion in a KPC mouse model. Clinical data suggested that high levels of H3K18 lactylation correlate with severe PNI and poorer patient prognosis. Our findings provide critical insights into the role of pCAFs in the PNI of pancreatic cancer, highlighting glycolytic reprogramming and lactate-driven histone modifications as potential therapeutic targets for PDAC.
Project description:Perineural invasion (PNI) is a pivotal prognostic factor in pancreatic cancer, associated with aggressive tumor behavior and adverse patient outcomes. Despite its recognized clinical impact, the molecular mechanisms underlying PNI are not well understood. In this study, we isolated perineural invasion-associated cancer-associated fibroblasts (pCAFs), which demonstrated a markedly enhanced capacity to promote neural invasion in pancreatic cancer compared to non-perineural invasion-associated CAFs (npCAFs). Utilizing single-cell, high-throughput sequencing, and metabolomics, we identified a significant upregulation of glycolysis in pCAFs, fostering a high-lactate tumor microenvironment conducive to cancer progression. pCAFs-derived lactate is absorbed by tumor cells, facilitating histone H3K18 lactylation. This epigenetic modification activates the transcription of neural invasion-associated genes such as L1CAM and SLIT1, thereby driving PNI in pancreatic cancer. Further exploration of metabolic reprogramming in pCAFs revealed enhanced acetylation of the glycolytic enzyme GAPDH, correlated with increased enzymatic activity and glycolytic flux. Targeting of GAPDH and lactylation modifications significantly inhibits neural invasion in a KPC mouse model. Clinical data suggested that high levels of H3K18 lactylation correlate with severe PNI and poorer patient prognosis. Our findings provide critical insights into the role of pCAFs in the PNI of pancreatic cancer, highlighting glycolytic reprogramming and lactate-driven histone modifications as potential therapeutic targets for PDAC.
Project description:Chronic inflammation facilitates tumor progression. We discovered that a subset of non-small cell lung cancer cells underwent a gradually progressing epithelial-to-mesenchymal (EMT) phenotype following a 21-day exposure to IL-1β, an abundant proinflammatory cytokine in the at-risk for lung cancer pulmonary and the lung tumor microenvironments. Pathway analysis of the gene expression profile and in vitro functional studies revealed that the EMT and EMT-associated phenotypes, including enhanced cell invasion, PD-L1 upregulation, and chemoresistance, were sustained in the absence of continuous IL-1β exposure. We referred to this phenomenon as EMT memory. Utilizing a doxycycline-controlled SLUG expression system, we found that high expression of the transcription factor SLUG was indispensable for the establishment of EMT memory. High SLUG expression in tumors of lung cancer patients was associated with poor survival. Chemical or genetic inhibition of SLUG upregulation prevented EMT following the acute IL-1β exposure but did not reverse EMT memory. Chromatin immunoprecipitation and methylation-specific PCR further revealed a SLUG-mediated temporal regulation of epigenetic modifications, including accumulation of H3K27, H3K9, and DNA methylation, in the CDH1 (E-cadherin) promoter following the chronic IL-1β exposure. Chemical inhibition of DNA methylation not only restored E-cadherin expression in EMT memory, but also primed cells for chemotherapy-induced apoptosis.
Project description:Drug-tolerant persister (DTP) cells remain following chemotherapy and can cause cancer relapse. However, it is unclear when acquired resistance to chemotherapy emerges. Here, we compared the gene expression profiles of gastric cancer patient-derived cells (GC PDCs) and their respective xenograft tumors with different sensitivities to 5-fluorouracil (5-FU) by using immunodeficient female BALB/c-nu mice. RNA sequencing analysis of 5-FU-treated PDCs demonstrated that DNA replication/cell cycle-related genes were transiently induced in the earlier phase of DTP cell emergence, while extracellular matrix (ECM)-related genes were sustainably upregulated during long-term cell survival in 5-FU-resistant residual tumors. NicheNet analysis, which uncovers cell-cell signal interactions, indicated the transforming growth factor-β (TGF-β) pathway as the upstream regulator in response to 5-FU treatment. This induced ECM-related gene expression in the 5-FU-resistant tumor model. In the 5-FU-resistant residual tumors, there was a marked upregulation of cancer cell-derived TGF-β1 expression and increased phosphorylation of SMAD3, a downstream regulator of the TGF-β receptor. By contrast, these responses were not observed in a 5-FU-sensitive tumor model. We further found that TGF-β-related upregulation of ECM genes was preferentially observed in non-responders to chemotherapy with 5-FU and/or oxaliplatin among 22 patient-derived xenograft tumors. These observations suggest that chemotherapy-induced activation of the TGF-β1/SMAD3/ECM-related gene axis is a potential biomarker for the emergence of drug resistance in GCs.
Project description:L1 cell adhesion molecule (L1CAM) is overexpressed in various solid tumors, and its overexpression is linked to increased invasion, metastasis, angiogenesis, cancer stemness, and therapy resistance. However, the mechanisms of L1CAM-mediated carcinogenesis and radioresistance, particularly in high-grade serous ovarian carcinoma (HGSOC), the most common and lethal type of ovarian cancer, remain insufficiently understood. Anti-L1CAM radioimmunotherapy (RIT) using the radioisotopes Terbium-161 (Tb-161) and Lutetium-177 (Lu-177) has shown that Tb-161 is more cytotoxic than Lu-177, due to its distinct radioactive properties. Moreover, we identified a population of L1CAM+/CD133+ cells as cancer stem cells (CSCs) in ovarian cancer and demonstrated L1CAM's association with radioresistance. Understanding L1CAM-regulated downstream signaling and cellular responses to anti-L1CAM RIT with Tb-161, compared to Lu-177, is now critical. To address this, we established CRISPR-Cas9-mediated L1CAM knock-out (ΔL1CAM) in human ovarian cancer cells (OVCAR8) alongside a control cell line with a knockout of the nonessential gene AAVS1 (ΔAAVS1). In this study, quantitative phosphoproteomics, coupled with matching proteomics, revealed (i) L1CAM-dependent signaling pathways and biological processes by comparing ΔL1CAM with wild-type cells, and (ii) cellular responses to anti-L1CAM RIT with Tb-161 and Lu-177 in L1CAM-expressing ovarian cancer cells.
Project description:Tumor cells rely on glutamine to fulfill their metabolic demands and sustain proliferation. The elevated consumption of glutamine can lead to intratumoral nutrient depletion, causing metabolic stress that has the potential to impact tumor progression. Here, we show that nutrient stress caused by glutamine deprivation leads to the induction of epithelial-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC) cells. Mechanistically, we demonstrate that glutamine deficiency regulates EMT through the upregulation of the EMT master regulator Slug, a process that is dependent on both MEK/ERK signaling and ATF4. We find that Slug is required in PDAC cells for glutamine deprivation-induced EMT, cell motility and nutrient stress survival. Importantly, we decipher that Slug is associated with nutrient stress in PDAC tumors and is required for metastasis. These results delineate a novel role for Slug in the nutrient stress response and provide insight into how nutrient depletion might influence PDAC progression.
Project description:Tumor cells rely on glutamine to fulfill their metabolic demands and sustain proliferation. The elevated consumption of glutamine can lead to intratumoral nutrient depletion, causing metabolic stress that has the potential to impact tumor progression. Here, we show that nutrient stress caused by glutamine deprivation leads to the induction of epithelial-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC) cells. Mechanistically, we demonstrate that glutamine deficiency regulates EMT through the upregulation of the EMT master regulator Slug, a process that is dependent on both MEK/ERK signaling and ATF4. We find that Slug is required in PDAC cells for glutamine deprivation-induced EMT, cell motility and nutrient stress survival. Importantly, we decipher that Slug is associated with nutrient stress in PDAC tumors and is required for metastasis. These results delineate a novel role for Slug in the nutrient stress response and provide insight into how nutrient depletion might influence PDAC progression.