scholarly journals Crosstalk between KRAS, SRC and YAP Signaling in Pancreatic Cancer: Interactions Leading to Aggressive Disease and Drug Resistance

Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5126
Author(s):  
Enrique Rozengurt ◽  
Guido Eibl

Pancreatic ductal adenocarcinoma (PDAC), the predominant form of pancreatic cancer, remains a devastating disease. The purpose of this review is to highlight recent literature on mechanistic and translational developments that advance our understanding of a complex crosstalk between KRAS, YAP and Src tyrosine kinase family (SFK) in PDAC development and maintenance. We discuss recent studies indicating the importance of RAS dimerization in signal transduction and new findings showing that the potent pro-oncogenic members of the SFK phosphorylate and inhibit RAS function. These surprising findings imply that RAS may not play a crucial role in maintaining certain subtypes of PDAC. In support of this interpretation, current evidence indicates that the survival of the basal-like subtype of PDAC is less dependent on RAS but relies, at least in part, on the activity of YAP/TAZ. Based on current evidence, we propose that SFK propels PDAC cells to a state of high metastasis, epithelial-mesenchymal transition (EMT) and reduced dependence on KRAS signaling, salient features of the aggressive basal-like/squamous subtype of PDAC. Strategies for PDAC treatment should consider the opposite effects of tyrosine phosphorylation on KRAS and SFK/YAP in the design of drug combinations that target these novel crosstalk mechanisms and overcome drug resistance.

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.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A1016-A1017
Author(s):  
Prateek Kulkarni ◽  
Reetobrata Basu ◽  
John J Kopchick

Abstract In 2020, the National Cancer Institute (NCI) estimates 57,600 new cases and 47,050 deaths in the US due to pancreatic ductal adenocarcinoma (PDAC). A dismal 10% five-year overall survival rate in PDAC is attributed to late diagnosis, limited treatment options, a remarkably high metastasis rate, and resistance of this cancer to available therapies. Therefore, a better understanding of the mechanisms of how PDAC tumors acquire drug resistance and spread to distal parts of the body are necessary for developing novel therapeutic approaches. Exosomes, microscopic vesicles released from most cells (both tumor and non-tumor) have been recently established to play a significant role in cell to cell communication. Exosomes modulate their target cell responses systematically depending on the nature of exosomal cargoes (nucleic acids, proteins, and lipids). PDAC derived exosomes have been implicated to promote metastasis via forming a pre-metastatic niche of cells as well as enhancing drug resistance. Growth hormone (GH) secreted primarily by the pituitary gland promotes metastasis and drug resistance as shown by plethora of studies. No study has directly assessed the effect of GH on exosomal cargoes in terms of promoting metastases and drug resistance. In this report, we show that GH modulates various pancreatic cancer cell exosomal cargoes which in turn potentially amplifies tumor invasion and metastases. Our data shows that GH treatment on human and mouse PDAC cells increases the exosomal protein levels of TGFβ - a critical inducer of epithelial-to-mesenchymal transition (EMT, a process leading to metastasis). In addition, GH treatment also increases extracellular matrix-degrading enzymes, MMP2 and 9, as well as multi-drug efflux pump ABCC1, ABCB1, and ABCG2 in PDAC cells. These results strongly implicate GH action in driving EMT and chemoresistance via exosomes in pancreatic cancer. Exosomes have a crucial impact especially in the areas of diagnostics and therapeutics. This report is the first to show that GH modulates the effects of exosomes secreted by pancreatic cancer cells. Acknowledgement: This work was supported in part by the State of Ohio’s Eminent Scholar Program that includes a gift from Milton and Lawrence Goll, by the AMVETS, and Ohio University’s Student Enhancement Award and Edison Biotechnology Institute.


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.


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.


2019 ◽  
Vol 37 (4_suppl) ◽  
pp. TPS473-TPS473 ◽  
Author(s):  
Muhammad Shaalan Beg ◽  
Andrew M. Lowy ◽  
Peter J. O'Dwyer ◽  
Gayle S. Jameson ◽  
Erkut Hasan Borazanci ◽  
...  

TPS473 Background: The Axl pathway coordinately mediates immune evasion and drug resistance in pancreatic cancer. Systemic Axl inhibition can enhance the efficacy of cancer therapy by blocking tumor cell proliferation, survival and drug resistance associated with epithelial-mesenchymal transition (EMT), and targeting innate immune suppression in the tumor microenvironment. Bemcentinib (BGB324) is a first in class, selective oral inhibitor of Axl. Our group has shown that bemcentinib therapy, in combination with gemcitabine, improved survival in multiple preclinical models of pancreatic cancer. Methods: This is a multicenter, randomized, phase 1b/2 clinical trial of nab-paclitaxel/gemcitabine/cisplatin with or without bemcentinib. Patients with metastatic pancreatic cancer, good performance status and preserved liver, kidney and hematologic function are eligible. The treatment schedule is as follows: Bemcentinib 100 or 200 mg daily, nab-paclitaxel 125 mg/m2, gemcitabine 1000 mg/m2 and cisplatin 25 mg/m2 intravenously on D1, 8 every 21 days. 3 -12 patients will be recruited in part 1 following a modified 3+3 dose finding scheme. Part 2 of the study is a 1:1 randomized phase 2 design enrolling 62 patients. The primary objective is to determine complete response rate. Secondary end points are overall response rate, PFS and adverse events. A parallel biomarker study will accompany the trial analyzing blood and tissue samples to determine the effect of chemotherapy and bemcentinib on 1) Axl pathway activity in tumor tissue, 2) changes in immune landscape including upregulation of immune cytokines, and immune cell infiltration into the tumor, 3) apoptosis and decreased proliferation of tumor and 4) to identify predictive biomarkers of response. Clinical trial information: NCT03649321.


2020 ◽  
Vol 21 (12) ◽  
pp. 4473
Author(s):  
Mei Jen Hsieh ◽  
Tai-Jan Chiu ◽  
Yu Chun Lin ◽  
Ching-Chieh Weng ◽  
Yu-Ting Weng ◽  
...  

Pancreatic cancer (PC) is a highly lethal malignancy due to the cancer routinely being diagnosed late and having a limited response to chemotherapy. Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic malignant tumor, representing more than 85% of all pancreatic cancers. In the present study, we characterized the phenotypes of concomitant P53 and APC mutations in pancreatic neoplasms driven by the oncogene KRAS in genetically modified mice (GEMM). In this GEMM setting, APC haploinsufficiency coupled with P53 deletion and KRASG12D activation resulted in an earlier appearance of pancreatic intraepithelial neoplasia (PanIN) lesions and progressed rapidly to highly invasive and metastatic PDAC. Through a microarray analysis of murine PDAC cells derived from our APC-deficient PDAC model, we observed that APC loss leads to upregulated CD34 expression in PDAC. CD34 is a member of a family of single-pass transmembrane proteins and is selectively expressed in hematopoietic progenitor cells, vascular endothelial cells, interstitial precursor cells, and various interstitial tumor cells. However, the functional roles of CD34 in pancreatic cancer remain unclear. Thus, in this study, we explored the mechanisms regarding how CD34 promotes the deterioration of pancreatic malignancy. Our results demonstrated that the increased expression of CD34 induced by APC inactivation promotes the invasion and migration of PDAC cells, which may relate to PDAC metastasis in vivo. Collectively, our study provides first-line evidence to delineate the association between CD34 and the APC/Wnt pathway in PDAC, and reveals the potential roles of CD34 in PDAC progression.


Cancers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 6204
Author(s):  
Meena U. Rajagopal ◽  
Shivani Bansal ◽  
Prabhjit Kaur ◽  
Shreyans K. Jain ◽  
Tatiana Altadil ◽  
...  

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy wherein a majority of patients present metastatic disease at diagnosis. Although the role of epithelial to mesenchymal transition (EMT), mediated by transforming growth factor beta (TGFβ), in imparting an aggressive phenotype to PDAC is well documented, the underlying biochemical pathway perturbations driving this behaviour have not been elucidated. We used high-resolution mass spectrometry (HRMS) based molecular phenotyping approach in order to delineate metabolic changes concomitant to TGFβ-induced EMT in pancreatic cancer cells. Strikingly, we observed robust changes in amino acid and energy metabolism that may contribute to tumor invasion and metastasis. Somewhat unexpectedly, TGFβ treatment resulted in an increase in intracellular levels of retinoic acid (RA) that in turn resulted in increased levels of extracellular matrix (ECM) proteins including fibronectin (FN) and collagen (COL1). These findings were further validated in plasma samples obtained from patients with resectable pancreatic cancer. Taken together, these observations provide novel insights into small molecule dysregulation that triggers a molecular cascade resulting in increased EMT-like changes in pancreatic cancer cells, a paradigm that can be potentially targeted for better clinical outcomes.


2020 ◽  
Vol 20 (12) ◽  
pp. 1153-1165 ◽  
Author(s):  
Jie Zhang ◽  
Mengna Wu ◽  
Yuqing Xu ◽  
Qianqian Song ◽  
Wenjie Zheng

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Chemoresistance remains the major factor for limited efficacy of the HCC treatment. Thus, exploring the mechanisms underlying drug resistance is of great importance. Secretory clusterin (sCLU), a stressactivated and ATP-independent molecular chaperone, is up-regulated in numerous tumors and correlated with malignant phenotypes. For HCC, the implication of sCLU was previously addressed in tumor growth, metastasis, as well as early diagnosis and poor prognosis. Notably, accumulating studies have emphasized its vital role in drug resistance of HCC. Depletion of sCLU synergistically could enhance the sensitivity of HCC cells to a variety of chemotherapy agents. Herein, we summarized the potential mechanisms accounting for the sCLU-induced chemoresistance, including promoting apoptosis evasion, facilitating epithelial-mesenchymal transition (EMT), maintaining the viability of cancer stem cell (CSC), enhancing drug efflux capacity, and regulating autophagic activities. The current evidence suggest that targeting sCLU might be a promising approach in overcoming chemoresistance of HCC.


2019 ◽  
Vol 121 (9) ◽  
pp. 786-795 ◽  
Author(s):  
Qi Chen ◽  
Jianxin Wang ◽  
Qi Zhang ◽  
Jingying Zhang ◽  
Yu Lou ◽  
...  

Abstract Background The progression and metastasis of pancreatic ductal adenocarcinoma (PDAC) is highly dependent on the tumour microenvironment. Most tumour-associated macrophages (TAMs) are M2 phenotype macrophages, which normally show anti-inflammatory functions in numerous disorders. Previously, we found that alternatively activated macrophages showed pro-inflammatory characteristics upon stimulation with hepatoma cell-derived debris; however, the molecular mechanism was unclear. Methods In vitro and in vivo experiments were employed to investigate the molecular mechanism. Using pancreatic cancer cell lines, mouse models and human tissues, we obtained a general picture of tumour cell-derived debris promoting metastasis of pancreatic cancer by inducing inflammation via TAMs. Results We showed that M2 macrophage-derived inflammation also exists in PDAC. Debris from PDAC cells induced potent IL-1β release by M2 macrophages via TLR4/TRIF/NF-κB signalling, and this effect was further boosted by IgG that was also derived from PDAC cells. Increased IL-1β promoted epithelial–mesenchymal transition and consequent metastasis of PDAC cells. A selective COX-2 inhibitor, celecoxib, enhanced the anti-tumoural efficacy of gemcitabine. Conclusions These data revealed a pro-inflammatory mechanism in PDAC, which indicated that IL-1β and COX-2 could be therapeutic targets of an anti-inflammatory strategy to treat PDAC.


Sign in / Sign up

Export Citation Format

Share Document