scholarly journals RNA m6A Demethylase ALKBH5 Protects Against Pancreatic Ductal Adenocarcinoma via Targeting Regulators of Iron Metabolism

2021 ◽  
Vol 9 ◽  
Author(s):  
Rui Huang ◽  
Lin Yang ◽  
Zhiwen Zhang ◽  
Xiaoding Liu ◽  
Yi Fei ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Cell Line ◽  
Iron Metabolism ◽  
Epithelial Mesenchymal Transition ◽  
Regulatory Protein ◽  
Pancreatic Cancer Cell Line ◽  
Ductal Adenocarcinoma ◽  
Stable Cell Line ◽  
Mesenchymal Transition

Although RNA m6A regulators have been implicated in the tumorigenesis of several different types of tumors, including pancreatic cancer, their clinical relevance and intrinsic regulatory mechanism remain elusive. This study analyzed eight m6A regulators (METTL3, METTL14, WTAP, FTO, ALKBH5, and YTHDF1-3) in pancreatic ductal adenocarcinoma (PDAC) and found that only RNA m6A demethylase ALKBH5 serves as an independent favorable prognostic marker for this tumor. To better understand the molecular mechanism underlying the protective effect conferred by ALKBH5 against pancreatic tumorigenesis, we performed a transcriptome-wide analysis of m6A methylation, gene expression, and alternative splicing (AS) using the MIA PaCa-2 stable cell line with ALKBH5 overexpression. We demonstrated that ALKBH5 overexpression induced a reduction in RNA m6A levels globally. Furthermore, mRNAs encoding ubiquitin ligase FBXL5, and mitochondrial iron importers SLC25A28 and SLC25A37, were identified as substrates of ALKBH5. Mechanistically, the RNA stabilities of FBXL5 and SLC25A28, and the AS of SLC25A37 were affected, which led to their upregulation in pancreatic cancer cell line. Particularly, we observed that downregulation of FBXL5 in tumor samples correlated with shorter survival time of patients. Owing to FBXL5-mediated degradation, ALKBH5 overexpression incurred a significant reduction in iron-regulatory protein IRP2 and the modulator of epithelial-mesenchymal transition (EMT) SNAI1. Notably, ALKBH5 overexpression led to a significant reduction in intracellular iron levels as well as cell migratory and invasive abilities, which could be rescued by knocking down FBXL5. Overall, our results reveal a previously uncharacterized mechanism of ALKBH5 in protecting against PDAC through modulating regulators of iron metabolism and underscore the multifaceted role of m6A in pancreatic cancer.

scholarly journals Tumor-derived exosomal long noncoding RNA LINC01133, regulated by Periostin, contributes to pancreatic ductal adenocarcinoma epithelial-mesenchymal transition through the Wnt/β-catenin pathway by silencing AXIN2

Oncogene ◽  
2021 ◽  
Vol 40 (17) ◽  
pp. 3164-3179
Author(s):  
Yang Liu ◽  
Tianchi Tang ◽  
Xiaosheng Yang ◽  
Peng Qin ◽  
Pusen Wang ◽  
...  
Keyword(s):  
Pancreatic Ductal Adenocarcinoma ◽  
Noncoding Rna ◽  
Pancreatic Tumor ◽  
Epithelial Mesenchymal Transition ◽  
Noncoding Rnas ◽  
Ductal Adenocarcinoma ◽  
Overall Survival Rate ◽  
Poor Overall Survival ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells

AbstractPancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies and rapidly progressive diseases. Exosomes and long noncoding RNAs (lncRNAs) are emerging as vital mediators in tumor cells and their microenvironment. However, the detailed roles and mechanisms of exosomal lncRNAs in PDAC progression remain unknown. Here, we aimed to clarify the clinical significance and mechanisms of exosomal lncRNA 01133 (LINC01133) in PDAC. We analyzed the expression of LINC01133 in PDAC and found that exosomal LINC01133 expression was high and positively correlated with higher TNM stage and poor overall survival rate of PDAC patients. Further research demonstrated that Periostin could increase exosome secretion and then enhance LINC01133 expression. In addition, Periostin increased p-EGFR, p-Erk, and c-myc expression, and c-myc could bind to the LINC01133 promoter region. These findings suggested that LINC01133 can be regulated by Periostin via EGFR pathway activity. We also observed that LINC01133 promoted the proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) of pancreatic cancer cells. We subsequently evaluated the effect of LINC01133 on the Wnt/β-catenin pathway and confirmed that LINC01133 can interact with Enhancer Of Zeste Homolog 2 (EZH2) and then promote H3K27 trimethylation. This can further silence AXIN2 and suppress GSK3 activity, ultimately activating β-catenin. Collectively, these data indicate that exosomal LINC01133 plays an important role in pancreatic tumor progression, and targeting LINC01133 may provide a potential treatment strategy for PDAC.

scholarly journals Pancreatic Cancers with High Grade Tumor Budding Exhibit Hallmarks of Diminished Anti-Tumor Immunity

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1090
Author(s):  
Hassan Sadozai ◽  
Animesh Acharjee ◽  
Thomas Gruber ◽  
Beat Gloor ◽  
Eva Karamitopoulou
Keyword(s):  
Gene Expression ◽  
Pancreatic Cancer ◽  
Disease Progression ◽  
Immune Escape ◽  
Epithelial Mesenchymal Transition ◽  
Tumor Budding ◽  
Ductal Adenocarcinoma ◽  
Low Grade ◽  
High Grade ◽  
Mesenchymal Transition

Tumor budding is associated with epithelial-mesenchymal transition and diminished survival in a number of cancer types including pancreatic ductal adenocarcinoma (PDAC). In this study, we dissect the immune landscapes of patients with high grade versus low grade tumor budding to determine the features associated with immune escape and disease progression in pancreatic cancer. We performed immunohistochemistry-based quantification of tumor-infiltrating leukocytes and tumor bud assessment in a cohort of n = 111 PDAC patients in a tissue microarray (TMA) format. Patients were divided based on the ITBCC categories of tumor budding as Low Grade (LG: categories 1 and 2) and High Grade (HG: category 3). Tumor budding numbers and tumor budding grade demonstrated a significant association with diminished overall survival (OS). HG cases exhibit notably reduced densities of stromal (S) and intratumoral (IT) T cells. HG cases also display lower M1 macrophages (S) and increased M2 macrophages (IT). These findings were validated using gene expression data from TCGA. A published tumor budding gene signature demonstrated a significant association with diminished survival in PDAC patients in TCGA. Immune-related gene expression revealed an immunosuppressive TME in PDAC cases with high expression of the budding signature. Our findings highlight a number of immune features that permit an improved understanding of disease progression and EMT in pancreatic cancer.

scholarly journals BRM270 Inhibits the Proliferation of CD44 Positive Pancreatic Ductal Adenocarcinoma Cells via Downregulation of Sonic Hedgehog Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Do Luong Huynh ◽  
Hyebin Koh ◽  
Nisansala Chandimali ◽  
Jiao Jiao Zhang ◽  
Nameun Kim ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Sonic Hedgehog ◽  
Hedgehog Signaling ◽  
Ductal Adenocarcinoma ◽  
Cell Phenotype ◽  
Sonic Hedgehog Signaling ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells ◽  
Adenocarcinoma Cells

Pancreatic cancer has a poor survival rate as compared to other types of cancer. Surface marker CD44 plays important role in epithelial-mesenchymal transition and cancer stem cell phenotype. Therefore, targeting CD44 positive pancreatic cancer cells might enhance therapies effectiveness. Our previous studies indicated the antitumorigenesis effect of BRM270 in osteosarcoma, lung cancer, and glioblastoma; however there is no evidence on BRM270 impacts on pancreatic cancer growth. In this study, we investigated the effect of BRM270 on the isolated CD44 positive pancreatic ductal adenocarcinoma cells (CD44+PDAC). Results showed that CD44 positive cells undergo apoptosis induced by BRM270. Moreover, BRM270 also inhibits stemness and metastasis traits in CD44+PDAC via Sonic hedgehog signaling pathway and SALL4 expression.In vivostudy indicated that tumor growth derived from CD44+PDAC was suppressed as daily uptake by BRM270 5 mg/kg. These data suggest the alternative approach in antipancreatic tumorigenesis via herbal plants extract and selectively targeting CD44+PDAC cells in tumor.

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