Cell Lineage Infidelity in PDAC Progression and Therapy Resistance

Mucinous cystic neoplasms and simple mucinous cysts are two distinct precursors of pancreatic cancer: clinicopathological, genomic, and transcriptomic characterization

Mucinous cystic neoplasms (MCNs) of the pancreas are macroscopic precursors of pancreatic cancer. A similar cystic lesion but lacking the ovarian-type subepithelial stroma has been recently defined as a simple mucinous cyst (SMC); however, its nature remains unclear. This study aims to define the clinicopathological and molecular profiles of a cohort of MCNs and SMCs of the pancreas and their associated invasive carcinoma. Overall, 23 cases were identified, comprising 19 MCNs and 4 SMCs with co-occurring invasive carcinoma. A multiregional (two samples from each cystic lesion and one from the adenocarcinoma) DNA and RNA sequencing approach was used. The key findings can be summarized as follows: (1) Molecular association: In 22/23 cases (95.7%), the concomitant mucinous cyst and invasive carcinoma shared specific genomic alterations, establishing for the first time that SMC is a true precursor of pancreatic cancer. (2) Clinical behavior: carcinomas arising from SMC appeared to be more aggressive than those arising from MCN. (3) Mutational profile: both cyst types showed significant similarities to conventional pancreatic ductal adenocarcinoma (PDAC), with KRAS and TP53 the most commonly altered genes. (4) Intracystic heterogeneity: while most molecular alterations were present in both analyzed cystic areas, RNF43 showed the highest heterogeneity. (5) CDKN2A: its alterations were predominantly restricted to the invasive component, suggesting a role in driving the invasion in a subset of cases. CNKN2A may also serve as a potential biomarker for identifying high-risk cysts. (6) RNAseq: most cases showed a switch from the classical to the basal transcriptome subtype during the progression from cystic neoplasms to invasive cancers. These findings establish SMCs as new precursors of pancreatic cancer and provide critical insights into the tumorigenesis of MCNs, with potential immediate implications for tumor taxonomy and clinical management. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Multiplexed glycan immunofluorescence identification of pancreatic cancer cell subpopulations in both tumor and blood samples

Pancreatic ductal adenocarcinoma (PDAC) tumor heterogeneity impedes the development of biomarker assays for early disease detection. We hypothesized that PDAC cell subpopulations could be identified by aberrant glycan signatures in both tumor tissue and blood samples. We used multiplexed glycan immunofluorescence to distinguish between PDAC and noncancer cell subpopulations within tumor tissue, and we developed hybrid glycan sandwich assays to determine whether the aberrant glycan signatures could be detected in blood samples. We found that PDAC cells were identified by signatures of glycans detected by four glycan-binding proteins (VVL, CA19-9, sTRA, and GM2) and that there are three types of glycan-defined PDAC tumors: sTRA type, CA19-9 type, and intermixed. In patient-matched tumor and blood samples, the PDAC tumor type could be determined by the aberrant glycans in the blood. As a result, the combined assays of aberrant glycan signatures were more sensitive and specific than any individual assay. Our results demonstrate a methodology to detect and stratify PDAC.

Advancing pancreatic cancer research and therapeutics: the transformative role of organoid technology

Research on pancreatic cancer has transformed with the advent of organoid technology, providing a better platform that closely mimics cancer biology in vivo. This review highlights the critical advancements facilitated by pancreatic organoid models in understanding disease progression, evaluating therapeutic responses, and identifying biomarkers. These three-dimensional cultures enable the proper recapitulation of the cellular architecture and genetic makeup of the original tumors, providing insights into the complex molecular and cellular dynamics at various stages of pancreatic ductal adenocarcinoma (PDAC). We explore the applications of pancreatic organoids in dissecting the tumor microenvironment (TME); elucidating cancer progression, metastasis, and drug resistance mechanisms; and personalizing therapeutic strategies. By overcoming the limitations of traditional 2D cultures and animal models, the use of pancreatic organoids has significantly accelerated translational research, which is promising for improving diagnostic and therapeutic approaches in clinical settings, ultimately aiming to improve the outcomes of patients with pancreatic cancer.

Mechanisms of Regulation of Cell Fate in Breast Development and Cancer

This chapter focuses on the mechanisms of regulation of cell fate in breast development, occurring mainly after birth, as well as in breast cancer. First, we will review how the microenvironment of the breast, as well as external cues, plays a crucial role in mammary gland cell specification and will describe how it has been shown to reprogram non-mammary cells into mammary epithelial cells. Then we will focus on the transcription factors and master regulators which have been established to be determinant for basal (BC) and luminal cell (LC) identity, and will describe the experiments of ectopic expression or loss of function of these transcription factors which demonstrated that they were crucial for cell fate. We will also discuss how master regulators are involved in the fate choice of LCs between estrogen receptor (ER)-positive cells and ER- cells, which will give rise to alveolar cells upon pregnancy and lactation. We will describe how oncogene expression induces reprogramming and change of fate of mammary epithelial cells before tumor appearance, which could be an essential step in tumorigenesis. Finally, we will describe the involvement of master regulators of mammary epithelial cells in breast cancer.

Exosome applications for the diagnosis and treatment of pancreatic ductal adenocarcinoma: An update (Review)

Pancreatic ductal adenocarcinoma (PDAC) is a malignant neoplasm that typically manifests with subtle clinical manifestations in its early stages and frequently eludes diagnosis until the advanced phases of the disease. The limited therapeutic options available for PDAC significantly contribute to its high mortality rate, highlighting the urgent need for novel biomarkers capable of effectively identifying early clinical manifestations and facilitating precise diagnosis. The pivotal role of cellular exosomes in both the pathogenesis and therapeutic interventions for PDAC has been underscored. Furthermore, researchers have acknowledged the potential of exosomes as targeted drug carriers against regulatory cells in treating PDAC. The present article aims to provide a comprehensive review encompassing recent advancements in utilizing exosomes for elucidating mechanisms underlying disease development, patterns of metastasis, diagnostic techniques and treatment strategies associated with PDAC.

Collagen signaling and matrix stiffness regulate multipotency in glandular epithelial stem cells in mice

Glandular epithelia, including mammary gland (MG) and prostate, are composed of luminal and basal cells. During embryonic development, glandular epithelia arise from multipotent stem cells (SCs) that are replaced after birth by unipotent basal and unipotent luminal SCs. Different conditions, such as basal cell transplantation, luminal cell ablation, and oncogene expression can reinduce adult basal SC (BaSCs) multipotency in different glandular epithelia. The mechanisms regulating the reactivation of multipotency are incompletely understood. Here, we have found that Collagen I expression is commonly upregulated in BaSCs across the different multipotent conditions. Increasing collagen concentration or stiffness of the extracellular matrix (ECM) promotes BaSC multipotency in MG and prostate organoids. Single cell RNA-seq of MG organoids in stiff conditions have uncovered the importance of β1 integrin/FAK/AP-1 axis in the regulation of BaSC multipotency. Altogether our study uncovers the key role of Collagen signaling and ECM stiffness in the regulation of multipotency in glandular epithelia.

Differential activity of MAPK signalling defines fibroblast subtypes in pancreatic cancer

Fibroblast heterogeneity is increasingly recognised across cancer conditions. Given their important contribution to disease progression, mapping fibroblasts' heterogeneity is critical to devise effective anti-cancer therapies. Cancer-associated fibroblasts (CAFs) represent the most abundant cell population in pancreatic ductal adenocarcinoma (PDAC). Whether CAF phenotypes are differently specified by PDAC cell lineages remains to be elucidated. Here, we reveal an important role for the MAPK signalling pathway in defining PDAC CAF phenotypes. We show that epithelial MAPK activity promotes the myofibroblastic differentiation of CAFs by sustaining the expression and secretion of TGF-β1. We integrate single-cell profiling of post-perturbation transcriptional responses from mouse models with cellular and spatial profiles of human tissues to define a MAPKhigh CAF (mapCAF) phenotype. We show that this phenotype associates with basal-like tumour cells and reduced frequency of CD8+ T cells. In addition to elevated MAPK activity, this mapCAF phenotype is characterized by TGF-β signalling, hypoxia responsive signatures, and immunoregulatory gene programs. Furthermore, the mapCAF signature is enriched in myofibroblastic CAFs from various cancer conditions and correlates with reduced response to immune checkpoint inhibition in melanoma. Altogether, our data expand our knowledge on CAF phenotype heterogeneity and reveal a potential strategy for targeting myofibroblastic CAFs in vivo.

Hydrogel models of pancreatic adenocarcinoma to study cell mechanosensing

Pancreatic adenocarcinoma (PDAC) is the predominant form of pancreatic cancer and one of the leading causes of cancer-related death worldwide, with an extremely poor prognosis after diagnosis. High mortality from PDAC arises partly due to late diagnosis resulting from a lack of early-stage biomarkers and due to chemotherapeutic drug resistance, which arises from a highly fibrotic stromal response known as desmoplasia. Desmoplasia alters tissue mechanics, which triggers changes in cell mechanosensing and leads to dysregulated transcriptional activity and disease phenotypes. Hydrogels are effective in vitro models to mimic mechanical changes in tissue mechanics during PDAC progression and to study the influence of these changes on mechanosensitive cell responses. Despite the complex biophysical changes that occur within the PDAC microenvironment, carefully designed hydrogels can very closely recapitulate these properties during PDAC progression. Hydrogels are relatively inexpensive, highly reproducible and can be designed in a humanised manner to increase their relevance for human PDAC studies. In vivo models have some limitations, including species-species differences, high variability, expense and legal/ethical considerations, which make hydrogel models a promising alternative. Here, we comprehensively review recent advancements in hydrogel bioengineering for developing our fundamental understanding of mechanobiology in PDAC, which is critical for informing advanced therapeutics.

Multiplexed Glycan Immunofluorescence Identification of Pancreatic Cancer Cell Subpopulations in Both Tumor and Blood Samples

Pancreatic ductal adenocarcinoma (PDAC) tumor heterogeneity impedes the development of biomarker assays suitable for early disease detection that would improve patient outcomes. The CA19-9 glycan is currently used as a standalone biomarker for PDAC. Furthermore, previous studies have shown that cancer cells may display aberrant membrane-associated glycans. We therefore hypothesized that PDAC cancer cell subpopulations could be distinguished by aberrant glycan signatures. We used multiplexed glycan immunofluorescence combined with pathologist annotation and automated image processing to distinguish between PDAC cancer cell subpopulations within tumor tissue. Using a training-set/test-set approach, we found that PDAC cancer cells may be identified by signatures comprising 4 aberrant glycans (VVL, CA19-9, sTRA, and GM2) and that there are three glycan-defined PDAC tumor types: sTRA type, CA19-9 type, and intermixed. To determine whether the aberrant glycan signatures could be detected in blood samples, we developed hybrid glycan sandwich assays for membrane-associated glycans. In both patient-matched tumor and blood samples, the proportion of aberrant glycans detected was consistent. Furthermore, our multiplexed glycan immunofluorescent approach proved to be more sensitive and more specific than CA19-9 alone. Our results provide proof of concept for a novel methodology to improve early PDAC detection and patient outcomes.

Genomic determinants of biological aggressiveness and poor prognosis of pancreatic cancers: KRAS and beyond

INTRODUCTION

A marked histomolecular heterogeneity characterizes pancreatic cancer. Thus, different tumor histologies with divergent genomic profiles exist within the same category.

AREAS COVERED

Using data from PubMed, SCOPUS, and Embase (last search date: 04/04/2024), this expert-based, narrative review presents and discusses the essential molecular determinants of biological aggressiveness and poor prognosis in pancreatic cancer. First, KRAS mutation still represents one of the most critical difficulties in treating pancreatic cancers. In this district, it is mutated in > 90% of malignant tumors. Notably, actionable alterations for molecular-based therapies are typically lacking in KRAS-mutated pancreatic cancer. Furthermore, transcriptome-based studies clarified that the squamous phenotype is characterized by poorer prognosis and response to standard chemotherapy. We also discuss molecular biomarkers related to dismal prognosis in specific subsets of pancreatic cancer, such as SMAD4 in signet-ring cell carcinoma and TP53 in invasive cancers derived from intraductal tubulopapillary neoplasms.

EXPERT OPINION

The identification of the subgroups of pancreatic cancer with particularly unfavorable prognoses is a critical step for addressing specific research efforts. In addition to implementing and strengthening current precision oncology strategies, the decisive step for improving the survival of patients affected by pancreatic cancer must pass through targeting the KRAS gene.

Novel roles of PIWI proteins and PIWI-interacting RNAs in human health and diseases

Non-coding RNA has aroused great research interest recently, they play a wide range of biological functions, such as regulating cell cycle, cell proliferation, and intracellular substance metabolism. Piwi-interacting RNAs (piRNAs) are emerging small non-coding RNAs that are 24-31 nucleotides in length. Previous studies on piRNAs were mainly limited to evaluating the binding to the PIWI protein family to play the biological role. However, recent studies have shed more lights on piRNA functions; aberrant piRNAs play unique roles in many human diseases, including diverse lethal cancers. Therefore, understanding the mechanism of piRNAs expression and the specific functional roles of piRNAs in human diseases is crucial for developing its clinical applications. Presently, research on piRNAs mainly focuses on their cancer-specific functions but lacks investigation of their expressions and epigenetic modifications. This review discusses piRNA's biogenesis and functional roles and the recent progress of functions of piRNA/PIWI protein complexes in human diseases. Video Abstract.

Disruption of lineage integrity as a precursor to breast tumor initiation

Increase in lineage infidelity and/or imbalance is frequently observed around the earliest stage of breast tumor initiation. In response to disruption of homeostasis, differentiated cells can partially lose their identity and gain cellular plasticity, a process involving epigenome landscape remodeling. This increase of cellular plasticity may promote the malignant transformation of breast tumors and fuel their heterogeneity. Here, we review recent studies that have yield insights into important regulators of lineage integrity and mechanisms that trigger mammary epithelial lineage derail, and evaluate their impacts on breast tumor development.

Deoxyribonucleic acid methylation driven aberrations in pancreatic cancer-related pathways

Pancreatic cancer (PanCa) presents a catastrophic disease with poor overall survival at advanced stages, with immediate requirement of new and effective treatment options. Besides genetic mutations, epigenetic dysregulation of signaling pathway-associated enriched genes are considered as novel therapeutic target. Mechanisms beneath the deoxyribonucleic acid methylation and its utility in developing of epi-drugs in PanCa are under trails. Combinations of epigenetic medicines with conventional cytotoxic treatments or targeted therapy are promising options to improving the dismal response and survival rate of PanCa patients. Recent studies have identified potentially valid pathways that support the prediction that future PanCa clinical trials will include vigorous testing of epigenomic therapies. Epigenetics thus promises to generate a significant amount of new knowledge of biological and medical importance. Our review could identify various components of epigenetic mechanisms known to be involved in the initiation and development of pancreatic ductal adenocarcinoma and related precancerous lesions, and novel pharmacological strategies that target these components could potentially lead to breakthroughs. We aim to highlight the possibilities that exist and the potential therapeutic interventions.

Tumor Microenvironment Role in Pancreatic Cancer Stem Cells

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a majority of patients presenting with unresectable or metastatic disease, resulting in a poor 5-year survival rate. This, in turn, is due to a highly complex tumor microenvironment and the presence of cancer stem cells, both of which induce therapy resistance and tumor relapse. Therefore, understanding and targeting the tumor microenvironment and cancer stem cells may be key strategies for designing effective PDAC therapies. In the present review, we summarized recent advances in the role of tumor microenvironment in pancreatic neoplastic progression.

Blockage of retinoic acid signaling via RARγ suppressed the proliferation of pancreatic cancer cells by arresting the cell cycle progression of the G1-S phase

BACKGROUND

Our study and several studies have reported that in some cancers, including pancreatic ductal adenocarcinoma (PDAC), the expression of squamous lineage markers, such as esophagus-tissue-specific genes, correlated with a poor prognosis. However, the mechanism by which the acquisition of squamous lineage phenotypes leads to a poor prognosis remains unclear. We previously reported that retinoic acid signaling via retinoic acid receptor γ (RARγ signaling) determines the differentiation lineage into the esophageal squamous epithelium. These findings hypothesized that the activation of RARγ signaling contributed to acquiring squamous lineage phenotypes and malignant behavior in PDAC.

METHODS

This study utilized public databases and immunostaining of surgical specimens to examine RARγ expression in PDAC. We evaluated the function of RARγ signaling by inhibitors and siRNA knockdown using a PDAC cell line and patient-derived PDAC organoids. The mechanism of the tumor-suppressive effects by blocking RARγ signaling was examined by a cell cycle analysis, apoptosis assays, RNA sequencing and Western blotting.

RESULTS

RARγ expression in pancreatic intraepithelial neoplasia (PanIN) and PDAC was higher than that in the normal pancreatic duct. Its expression correlated with a poor patient prognosis in PDAC. In PDAC cell lines, blockade of RARγ signaling suppressed cell proliferation by inducing cell cycle arrest in the G1 phase without causing apoptosis. We demonstrated that blocking RARγ signaling upregulated p21 and p27 and downregulated many cell cycle genes, including cyclin-dependent kinase 2 (CDK2), CDK4 and CDK6. Furthermore, using patient-derived PDAC organoids, we confirmed the tumor-suppressive effect of RARγ inhibition and indicated the synergistic effects of RARγ inhibition with gemcitabine.

CONCLUSIONS

This study clarified the function of RARγ signaling in PDAC progression and demonstrated the tumor-suppressive effect of selective blockade of RARγ signaling against PDAC. These results suggest that RARγ signaling might be a new therapeutic target for PDAC.

Epigenetic plasticity cooperates with cell-cell interactions to direct pancreatic tumorigenesis

The response to tumor-initiating inflammatory and genetic insults can vary among morphologically indistinguishable cells, suggesting as yet uncharacterized roles for epigenetic plasticity during early neoplasia. To investigate the origins and impact of such plasticity, we performed single-cell analyses on normal, inflamed, premalignant, and malignant tissues in autochthonous models of pancreatic cancer. We reproducibly identified heterogeneous cell states that are primed for diverse, late-emerging neoplastic fates and linked these to chromatin remodeling at cell-cell communication loci. Using an inference approach, we revealed signaling gene modules and tissue-level cross-talk, including a neoplasia-driving feedback loop between discrete epithelial and immune cell populations that was functionally validated in mice. Our results uncover a neoplasia-specific tissue-remodeling program that may be exploited for pancreatic cancer interception.

Phenotypic and genotypic infidelity in B-lineage neoplasms, including transdifferentiation following targeted therapy: Report from the 2021 SH/EAHP Workshop

OBJECTIVES

Session 2 of the 2021 Society for Hematopathology and European Association for Haematopathology Workshop collected examples of lineage infidelity and transdifferentiation in B-lineage neoplasms, including after targeted therapy.

METHODS

Twenty cases were submitted. Whole-exome sequencing and genome-wide RNA expression analysis were available on a limited subsample.

RESULTS

A diagnosis of B-cell acute lymphoblastic leukemia (B-ALL) was rendered on at least 1 biopsy from 13 patients. There was 1 case of acute myeloid leukemia (AML); the remaining 6 cases were mature B-cell neoplasms. Targeted therapy was administered in 7 cases of B-ALL and 4 cases of mature B-cell neoplasms. Six cases of B-ALL underwent lineage switch to AML or mixed-phenotype acute leukemia at relapse, 5 of which had rearranged KMT2A. Changes in maturational state without lineage switch were observed in 2 cases. Examples of de novo aberrant T-cell antigen expression (n = 2) were seen among the mature B-cell lymphoma cohort, and their presence correlated with alterations in tumor cell gene expression patterns.

CONCLUSIONS

This cohort of cases enabled us to illustrate, discuss, and review current concepts of lineage switch and aberrant antigen expression in a variety of B-cell neoplasms and draw attention to the role targeted therapies may have in predisposing neoplasms to transdifferentiation as well as other, less expected changes in maturational status.

Integrative characterization of intraductal tubulopapillary neoplasm (ITPN) of the pancreas and associated invasive adenocarcinoma

Pancreatic intraductal tubulopapillary neoplasm (ITPN) is a recently recognized intraductal neoplasm. This study aimed to clarify the clinicopathologic and molecular features of this entity, based on a multi-institutional cohort of 16 pancreatic ITPNs and associated adenocarcinomas. The genomic profiles were analyzed using histology-driven multi-regional sequencing to provide insight on tumor heterogeneity and evolution. Furthermore, an exploratory transcriptomic characterization was performed on eight invasive adenocarcinomas. The clinicopathologic parameters and molecular alterations were further analyzed based on survival indices. The main findings were as follows: 1) the concomitant adenocarcinomas, present in 75% of cases, were always molecularly associated with the intraductal components. These data definitively establish ITPN as origin of invasive pancreatic adenocarcinoma; 2) alterations restricted to infiltrative components included mutations in chromatin remodeling genes ARID2, ASXL1, and PBRM1, and ERBB2-P3H4 fusion; 3) pancreatic ITPN can arise in the context of genetic syndromes, such as BRCA-germline and Peutz-Jeghers syndrome; 4) mutational profile: mutations in the classical PDAC drivers are present, but less frequently, in pancreatic ITPN; 5) novel genomic alterations were observed, including amplification of the Cyclin and NOTCH family genes and ERBB2, fusions involving RET and ERBB2, and RB1 disruptive variation; 6) chromosomal alterations: the most common was 1q gain (75% of cases); 7) by transcriptome analysis, ITPN-associated adenocarcinomas clustered into three subtypes that correlate with the activation of signaling mechanism pathways and tumor microenvironment, displaying squamous features in their majority; and 8) TP53 mutational status is a marker for adverse prognosis. ITPNs are precursor lesions of pancreatic cancer with a high malignant transformation risk. A personalized approach for patients with ITPN should recognize that such neoplasms could arise in the context of genetic syndromes. BRCA alterations, ERBB2 and RET fusions, and ERBB2 amplification are novel targets in precision oncology. The TP53 mutation status can be used as a prognostic biomarker.

Challenges in precision medicine in pancreatic cancer: A focus in cancer stem cells and microbiota

Pancreatic cancer adenocarcinoma (PDAC) is a lethal disease, with the lowest 5-years survival rate of all cancers due to late diagnosis. Despite the advance and success of precision oncology in gastrointestinal cancers, the frequency of molecular-informed therapy decisions in PDAC is currently neglectable. The reasons for this dismal situation are mainly the absence of effective early diagnostic biomarkers and therapy resistance. PDAC cancer stem cells (PDAC-SC), which are regarded as essential for tumor initiation, relapse and drug resistance, are highly dependent on their niche i.e. microanatomical structures of the tumor microenvironment. There is an altered microbiome in PDAC patients embedded within the highly desmoplastic tumor microenvironment, which is known to determine therapeutic responses and affecting survival in PDAC patients. We consider that understanding the communication network that exists between the microbiome and the PDAC-SC niche by co-culture of patient-derived organoids (PDOs) with TME microbiota would recapitulate the complexity of PDAC paving the way towards a precision oncology treatment-response prediction.

RNF26 Promotes Pancreatic Cancer Proliferation by Enhancing RBM38 Degradation

OBJECTIVES

RING finger protein 26 (RNF26) plays an essential role in determining malignant tumor growth, whereas the role of which in pancreatic cancer (PC) has not been reported. This study aimed to investigate the role of RNF26 in PC cells.

METHODS

The Gene Expression Profiling Interactive Analysis was applied to study the role of RNF26 in malignant tumors. The in vitro or in vivo cell proliferation assays were used to investigate the role of RNF26 on the PC. The protein-protein interaction network analysis was used to search the binding partner of RNF26. The Western blot was used to reveal whether RNF26 promoted RNA binding motif protein-38 (RBM38) degradation in PC cells.

RESULTS

The Gene Expression Profiling Interactive Analysis tool showed that RNF26 was overexpressed in PC. Repressing RNF26 expression decreased PC cells growth, but overexpression of RNF26 increased PC proliferation. Furthermore, we demonstrated RNF26 degraded RBM38 to promote PC cell proliferation.

CONCLUSIONS

RNF26 was abnormally increased in PC, and upregulated RNF26 was correlated with a poor prognosis. RNF26 enhanced PC proliferation by inducing RBM38 degradation. We identified a novel RNF26-RBM28 axis involved in the progression of PC.

Sesquiterpene Lactones as Promising Candidates for Cancer Therapy: Focus on Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease which confers to patients a poor prognosis at short term. PDAC is the fourth leading cause of death among cancers in the Western world. The rate of new cases of pancreatic cancer (incidence) is 10 per 100,000 but present a 5-year survival of less than 10%, highlighting the poor prognosis of this pathology. Furthermore, 90% of advanced PDAC tumor present KRAS mutations impacting in several oncogenic signaling pathways, many of them associated with cell proliferation and tumor progression. Different combinations of chemotherapeutic agents have been tested over the years without an improvement of significance in its treatment. PDAC remains as one the more challenging biomedical topics thus far. The lack of a proper early diagnosis, the notable mortality statistics and the poor outcome with the available therapies urge the entire scientific community to find novel approaches against PDAC with real improvements in patients' survival and life quality. Natural compounds have played an important role in the process of discovery and development of new drugs. Among them, terpenoids, such as sesquiterpene lactones, stand out due to their biological activities and pharmacological potential as antitumor agents. In this review, we will describe the sesquiterpene lactones with in vitro and in vivo activity against pancreatic tumor cells. We will also discuss the mechanism of action of the compounds as well as the signaling pathways associated with their activity.

Emerging Role of Epigenetic Alterations as Biomarkers and Novel Targets for Treatments in Pancreatic Ductal Adenocarcinoma

Simple Summary

Epigenetic alterations cause changes in gene expression without affecting the DNA sequence and are found to affect several molecular pathways in pancreatic tumors. Such changes are reversible, making them potential drug targets. Furthermore, epigenetic alterations occur early in the disease course and may thus be explored for early detection. Hence, a deeper understanding of epigenetics in pancreatic cancer may lead to improved diagnostics, treatments, and prognostication.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with limited treatment options. Emerging evidence shows that epigenetic alterations are present in PDAC. The changes are potentially reversible and therefore promising therapeutic targets. Epigenetic aberrations also influence the tumor microenvironment with the potential to modulate and possibly enhance immune-based treatments. Epigenetic marks can also serve as diagnostic screening tools, as epigenetic changes occur at early stages of the disease. Further, epigenetics can be used in prognostication. The field is evolving, and this review seeks to provide an updated overview of the emerging role of epigenetics in the diagnosis, treatment, and prognostication of PDAC.