scholarly journals Wnt/β-Catenin Signaling: The Culprit in Pancreatic Carcinogenesis and Therapeutic Resistance

2019 ◽  
Vol 20 (17) ◽  
pp. 4242 ◽  
Author(s):  
Monish Ram Makena ◽  
Himavanth Gatla ◽  
Dattesh Verlekar ◽  
Sahithi Sukhavasi ◽  
Manoj K. Pandey ◽  
...  

Pancreatic ductal adenocarcinoma (PDAC) is responsible for 7.3% of all cancer deaths. Even though there is a steady increase in patient survival for most cancers over the decades, the patient survival rate for pancreatic cancer remains low with current therapeutic strategies. The Wnt/β-catenin pathway controls the maintenance of somatic stem cells in many tissues and organs and is implicated in pancreatic carcinogenesis by regulating cell cycle progression, apoptosis, epithelial-mesenchymal transition (EMT), angiogenesis, stemness, tumor immune microenvironment, etc. Further, dysregulated Wnt has been shown to cause drug resistance in pancreatic cancer. Although different Wnt antagonists are effective in pancreatic patients, limitations remain that must be overcome to increase the survival benefits associated with this emerging therapy. In this review, we have summarized the role of Wnt signaling in pancreatic cancer and suggested future directions to enhance the survival of pancreatic cancer patients.

2020 ◽  
Vol 21 (13) ◽  
pp. 4646
Author(s):  
Eui Joo Kim ◽  
Yoon Jae Kim ◽  
Hye In Lee ◽  
Seok-Hoo Jeong ◽  
Hyo Jung Nam ◽  
...  

Chemoresistance is a leading cause of morbidity and mortality in patients with pancreatic cancer and remains an obstacle to successful treatment. The antioxidant transcription factor nuclear factor (erythroid-derived 2)-related factor 2 (NRF2), which plays important roles in tumor angiogenesis and invasiveness, is upregulated in pancreatic ductal adenocarcinoma (PDAC), where it correlates with poor survival. Here, we investigated the role of NRF2 in two 5-Fluourouracil-resistant (5-FUR) PDAC cell lines: BxPC-3 and CFPAC-1. Levels of NRF2 and antioxidants, such as heme oxygenase 1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), and superoxide dismutase 2 (SOD2), were higher in the chemoresistant cells than in their chemosensitive counterparts. Expression of epithelial mesenchymal transition (EMT) markers, stemness markers, including Nanog, Oct4, and CD133, and that of the drug transporter ATP binding cassette, subfamily G, member A2 (ABCG2) was also upregulated in 5-FUR PDAC cells. NRF2 knockdown reversed 5-FU resistance of PDAC cells via suppression of ABCG2 and HO-1. In summary, these data indicate that NRF2 is a potential target for resensitizing 5-FUR PDAC cells to 5-FU to improve treatment outcomes in patients with pancreatic cancer.


Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1090
Author(s):  
Hassan Sadozai ◽  
Animesh Acharjee ◽  
Thomas Gruber ◽  
Beat Gloor ◽  
Eva Karamitopoulou

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.


2019 ◽  
Author(s):  
Mark Kalisz ◽  
Edgar Bernardo ◽  
Anthony Beucher ◽  
Miguel Angel Maestro ◽  
Natalia del Pozo ◽  
...  

AbstractDefects in transcriptional regulators of pancreatic exocrine differentiation have been implicated in pancreatic tumorigenesis, but the molecular mechanisms are poorly understood. The locus encoding the transcription factor HNF1A harbors susceptibility variants for pancreatic ductal adenocarcinoma (PDAC), while KDM6A, encoding the histone demethylase UTX, carries somatic mutations in PDAC. Here, we show that pancreas-specific Hnf1a null mutations phenocopy Utx deficient mutations, and both synergize with KrasG12D to cause PDAC with sarcomatoid features. We combine genetic, epigenomic and biochemical studies to show that HNF1A recruits UTX to genomic binding sites in pancreatic acinar cells. This remodels the acinar enhancer landscape, activates a differentiation program, and indirectly suppresses oncogenic and epithelial-mesenchymal transition genes. Finally, we identify a subset of non-classical PDAC samples that exhibit the HNF1A/UTX-deficient molecular phenotype. These findings provide direct genetic evidence that HNF1A-deficiency promotes PDAC. They also connect the tumor suppressive role of UTX deficiency with a cell-specific molecular mechanism that underlies PDAC subtype definition.


2020 ◽  
Vol 7 ◽  
Author(s):  
Yong Zeng ◽  
Min Zou ◽  
Yan Liu ◽  
Keting Que ◽  
Yunbing Wang ◽  
...  

Keratin 17 (K17), a member of type I acidic epithelial keratin family, has been reported to be upregulated in many malignant tumors and to be involved in promoting the development of tumors. However, the precise role of K17 in progression of pancreatic cancer is still unknown. In this study, we found that K17 expression was highly expressed in pancreatic cancer tissues and cell lines and that upregulated expression was associated with the pathological grade and poor prognosis. K17 expression served as an independent predictor of pancreatic cancer survival. Meanwhile, we showed that knocking down K17 induced pancreatic cancer cell proliferation, colony formation and tumor growth in xenografts in mice. However, K17 upregulation inhibited pancreatic cancer cell proliferation and colony formation. Further mechanistic study revealed that K17 knockdown promoted cell cycle progression by upregulating CyclinD1 expression and repressed cell apoptosis. However, K17 upregulation suppressed cell cycle progression by decreasing CyclinD1 expression, and induced apoptosis by increasing the levels of cleaved Caspase3. In addition, K17 knockdown promoted pancreatic cancer cell migration and invasion, but K17 upregulation suppressed cell migration and invasion. Moreover, knocking down K17 promoted epithelial-mesenchymal transition (EMT) in pancreatic cancer cell by inhibiting E-cadherin expression and inducing Vimentin expression, and the effects of K17 upregulation were opposite to that of K17downregulation. Taken together, our findings suggest that K17 functions as a potential tumor suppressor, even though it is upregulated in pancreatic cancer.


Author(s):  
Rui Huang ◽  
Lin Yang ◽  
Zhiwen Zhang ◽  
Xiaoding Liu ◽  
Yi Fei ◽  
...  

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.


2021 ◽  
Author(s):  
Nina Xue ◽  
Tingting Du ◽  
Fangfang Lai ◽  
Jing Jin ◽  
Ming Ji ◽  
...  

Abstract Extracellular heat shock protein 90α (HSP90α) has been reported to promote cancer cell invasion and migration. However, whether pancreatic cancer (PC) cells expressed membrane-bound or secreted HSP90α and its underlying mechanism for PC progression were still unclear. Our study pointed out that highly invasive Capan2 cells has a higher level of secreted HSP90α, rather than membrane HSP90α, compared with those of less invasive PL45 cells. The conditioned medium of Capan2 cells or recombinant HSP90α protein was able to stimulate the migration and invasion of PL45 or capan2 cells, which could be prevented by a neutralizing anti-HSP90α antibody. Furthermore, secreted HSP90α promoted elements of epithelial-mesenchymal transition (EMT) in PL45 cells, including increases in vimentin and snail expressions, decreases in E-cadherin expression and changes in cell shape towards a mesenchymal phenotype, but these phenomena were reversed by anti-HSP90α antibody in Capan2 cells. In addition, high levels of low-density lipoprotein receptor-related protein 1 (LRP1) mRNA were associated with worsened patient survival in pancreatic adenocarcinoma. LRP1 as a receptor of eHSP90α for its stimulatory role of PC cells EMT and metastasis by activating AKT signaling. Down-regulation of LRP1 could promote chemosensitivity to gemcitabine and doxorubicin, but not to topotecan and paclitaxel in Capan2 cells. Therefore, our study reveals a critical role of secreted HSP90α on EMT events and suggests blocking secreted HSP90α underlies an aspect of metastasis and chemoresistance.


Cancers ◽  
2018 ◽  
Vol 10 (2) ◽  
pp. 33 ◽  
Author(s):  
Sandra Valle ◽  
Laura Martin-Hijano ◽  
Sonia Alcalá ◽  
Marta Alonso-Nocelo ◽  
Bruno Sainz Jr.

Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer, is the 4th most frequent cause of cancer-related death worldwide, primarily due to the inherent chemoresistant nature and metastatic capacity of this tumor. The latter is believed to be mainly due to the existence of a subpopulation of highly plastic “stem”-like cells within the tumor, known as cancer stem cells (CSCs), which have been shown to have unique metabolic, autophagic, invasive, and chemoresistance properties that allow them to continuously self-renew and escape chemo-therapeutic elimination. As such, current treatments for the majority of PDAC patients are not effective and do not significantly impact overall patient survival (<7 months) as they do not affect the pancreatic CSC (PaCSC) population. In this context, it is important to highlight the need to better understand the characteristics of the PaCSC population in order to develop new therapies to target these cells. In this review, we will provide the latest updates and knowledge on the inherent characteristics of PaCSCs, particularly their unique biological properties including chemoresistance, epithelial to mesenchymal transition, plasticity, metabolism and autophagy.


Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4541
Author(s):  
Miltiadis Tsesmelis ◽  
Kanishka Tiwary ◽  
Katja Steiger ◽  
Nadine Sperb ◽  
Melanie Gerstenlauer ◽  
...  

Pancreatic ductal adenocarcinoma (PDAC) remains a largely incurable cancer type. Its high mortality is attributed to the lack of efficient biomarkers for early detection combined with its high metastatic properties. The aim of our study was to investigate the role of NF-κB signaling in the development and metastasis of PDAC. We used the well-established KPC mouse model, and, through genetic manipulation, we deleted NF-κB essential modulator (NEMO) in the pancreata of KPC mice. Interestingly, NEMO deletion altered the differentiation status of the primary tumor but did not significantly affect its development. However, in the absence of NEMO, the median survival of the mice was prolonged by 13.5 days (16%). In addition, examination of the liver demonstrated that, whereas KPC mice occasionally developed liver macro-metastasis, NEMO deletion completely abrogated this outcome. Further analysis of the tumor revealed that the expression of epithelial–mesenchymal transition (EMT) transcription factors was diminished in the absence of NEMO. Conclusively, our study provides evidence that NF-κB is dispensable for the progression of high-grade PanINs towards PDAC. In contrast, NF-κB signaling is essential for the development of metastasis by regulating the gene expression program of EMT.


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