DDB2 represses epithelial-to-mesenchymal transition and sensitizes pancreatic ductal adenocarcinoma cells to chemotherapy

Abstract

IntroductionDamage specific DNA binding protein 2 (DDB2) is an UV-indiced DNA damage recognition factor and regulator of cancer development and progression. DDB2 has dual roles in several cancers, either as an oncogene or as a tumor suppressor gene, depending on cancer localization. Here, we investigated the unresolved role of DDB2 in pancreatic ductal adenocarcinoma (PDAC). MethodsThe expression level of DDB2 in pancreatic cancer tissues and its correlation with patient survival were evaluated using publicly available data. Two PDAC cell models with CRISPR-modified DDB2 expression were developed: DDB2 was repressed in DDB2-high T3M4 cells (T3M4 DDB2-low) while DDB2 was overexpressed in DDB2-low Capan-2 cells (Capan-2 DDB2-high). Immunofluorescence and qPCR assays were used to investigate epithelial-to-mesenchymal transition (EMT) in these models. Migration and invasion properties of the cells were also determined using wound healing and transwell assays. Sensitivity to 5-fluorouracil (5-FU), oxaliplatin, irinotecan and gemcitabine were finally investigated by crystal violet assays.ResultsDDB2 expression level was reduced in PDAC tissues compared to normal ones and DDB2-low levels were correlated to shorter disease-free survival in PDAC patients. DDB2 overexpression increased expression of E-cadherin epithelial marker, and decreased levels of N-cadherin mesenchymal marker. Conversely, we observed opposite effects in DDB2 repression and enhanced transcription of SNAIL, ZEB1, and TWIST EMT transcription factors (EMT-TFs). Study of migration and invasion revealed that these properties were negatively correlated with DDB2 expression in both cell models. DDB2 overexpression sensitized cells to 5-fluorouracil, oxaliplatin and gemcitabine.ConclusionOur study highlights the potential tumor suppressive effects of DDB2 on PDAC progression. DDB2 could thus represent a promising therapeutic target or biomarker for defining prognosis and predicting chemotherapy response in patients with PDAC.

Enhanced Complement Expression in the Tumor Microenvironment Following Neoadjuvant Therapy: Implications for Immunomodulation and Survival in Pancreatic Ductal Adenocarcinoma

“…Among them, the most significantly upregulated DEG was DDB2 (p=0.00077), which encodes DNA damage-binding protein 2, a nuclear protein crucial for DNA repair and genomic stability. Additionally, DDB2 has been shown to suppress epithelial-to-mesenchymal transition (EMT) and enhance sensitivity to chemotherapy in PDAC 39 . Conversely, in the TME of NAT-treated PDAC, most DEGs are associated with complement signaling and regulation of innate and adaptive immune function.…”

CRISPR/Cas9-mediated knock-in of BRCA1/2 mutations restores response to olaparib in pancreatic cancer cell lines

“…We optimized our transfection protocol, which involved determining the optimal incubation times and reagent concentrations, with MCF7 cells, possibly leading to the higher FA observed compared to PDAC cell lines. Aside to the transfection capacity of each cell line, the epithelial phenotype and the well-differentiated status of Capan-2 cells 36 might explain the difficulty encountered for the transfection of these cells 37 . Furthermore, the difference between T3M4 and Capan-2 cells may be attributed to the HDR activity being restricted to the late S and G2 phases of cell cycle.…”

Enhanced Complement Expression in the Tumor Microenvironment Following Neoadjuvant Therapy: Implications for Immunomodulation and Survival in Pancreatic Ductal Adenocarcinoma

“…Among them, the most significantly upregulated DEG was DDB2 (p=0.00077), which encodes DNA damage-binding protein 2, a nuclear protein crucial for DNA repair and genomic stability. Additionally, DDB2 has been shown to suppress epithelial-to-mesenchymal transition (EMT) and enhance sensitivity to chemotherapy in PDAC(42) 2 . Conversely, in the TME of NAT-treated PDAC, most DEGs are associated with complement signaling and regulation of innate and adaptive immune function.…”