A subgroup of pancreatic adenocarcinoma is sensitive to the 5-aza-dC DNA methyltransferase inhibitor

Innovative Experimental Ultrasound and US-Related Techniques Using the Murine Model in Pancreatic Ductal Adenocarcinoma: A Systematic Review

Pancreatic ductal adenocarcinoma (PDAC) is a cancer with one of the highest mortality rates in the world. Several studies have been conductedusing preclinical experiments in mice to find new therapeutic strategies. Experimental ultrasound, in expert hands, is a safe, multifaceted, and relatively not-expensive device that helps researchers in several ways. In this systematic review, we propose a summary of the applications of ultrasonography in a preclinical mouse model of PDAC. Eighty-eight studies met our inclusion criteria. The included studies could be divided into seven main topics: ultrasound in pancreatic cancer diagnosis and progression (n: 21); dynamic contrast-enhanced ultrasound (DCE-US) (n: 5); microbubble ultra-sound-mediated drug delivery; focused ultrasound (n: 23); sonodynamic therapy (SDT) (n: 7); harmonic motion elastography (HME) and shear wave elastography (SWE) (n: 6); ultrasound-guided procedures (n: 9). In six cases, the articles fit into two or more sections. In conclusion, ultrasound can be a really useful, eclectic, and ductile tool in different diagnostic areas, not only regarding diagnosis but also in therapy, pharmacological and interventional treatment, and follow-up. All these multiple possibilities of use certainly represent a good starting point for the effective and wide use of murine ultrasonography in the study and comprehensive evaluation of pancreatic cancer.

Combining the antianginal drug perhexiline with chemotherapy induces complete pancreatic cancer regression in vivo

Pancreatic ductal adenocarcinoma (PDAC) remains one of the human cancers with the poorest prognosis. Interestingly, we found that mitochondrial respiration in primary human PDAC cells depends mainly on the fatty acid oxidation (FAO) to meet basic energy requirements. Therefore, we treated PDAC cells with perhexiline, a well-recognized FAO inhibitor used in cardiac diseases. Some PDAC cells respond efficiently to perhexiline, which acts synergistically with chemotherapy (gemcitabine) in vitro and in two xenografts in vivo. Importantly, perhexiline in combination with gemcitabine induces complete tumor regression in one PDAC xenograft. Mechanistically, this co-treatment causes energy and oxidative stress promoting apoptosis but does not exert inhibition of FAO. Yet, our molecular analysis indicates that the carnitine palmitoyltransferase 1C (CPT1C) isoform is a key player in the response to perhexiline and that patients with high CPT1C expression have better prognosis. Our study reveals that repurposing perhexiline in combination with chemotherapy is a promising approach to treat PDAC.

Preclinical models derived from endoscopic ultrasound-guided tissue acquisition for individualized treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with poor outcomes. Although the management strategies have evolved in recent years, the PDAC 5-year survival rate remains at only 9%; it may become the second leading cause of cancer death in the USA by 2030. Only 15-20% of PDAC patients are eligible to undergo surgery; diagnostic biopsies and individualized treatment present a more significant challenge for the remaining group. Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has been widely used in the diagnosis of pancreatic masses. With the advancement of this sampling technique, adequate specimens can be obtained from all patients with PDAC in both early and late clinical stages. Recent data suggest that the specimens obtained from EUS-TA might be used to establish viable preclinical models, which conserve the genetic mutation and preserve the heterogeneity of the original tumors. Additionally, any drug sensitivity evident in the EUS-TA-derived preclinical models might predict the clinical response, thus guiding the prospective therapeutic selection. As we move toward the era of precision medicine, this review provides an update on the role of EUS-TA as a method for obtaining genetic material used in preclinical models that can assess and stratify individuals according to their individual cancer biology.

Induction of Apoptosis in Human Pancreatic Cancer Stem Cells by the Endoplasmic Reticulum-Targeted Alkylphospholipid Analog Edelfosine and Potentiation by Autophagy Inhibition

Pancreatic cancer is one of the most lethal malignancies with a poor and gloomy prognosis and the highest mortality-to-incidence ratio. Pancreatic cancer remains an incurable malignancy, and current therapies are ineffective. We isolated cancer stem cells (CSCs) from the human PANC-1 pancreatic cancer cell line as CD44⁺CD24⁺EpCAM⁺ cells. These CSCs form pancreatic cancer spheres or spheroids and develop tumors in SCID mice after subcutaneous injection of as few as 100 cells per mouse. Here, we found that the alkylphospholipid analog edelfosine inhibited CSC pancreatic cancer spheroid formation and induced cell death, as assessed by an increase in the percentage of cells in the sub-G₀/G₁ region by means of flow cytometry, indicative of DNA breakdown and apoptosis. This correlated with an increase in caspase-3 activity and PARP breakdown, as a major substrate of caspase-3, following PANC-1 CSC treatment with edelfosine. The antitumor ether lipid edelfosine colocalized with the endoplasmic reticulum in both PANC-1 cells as well as PANC-1 CSCs by using a fluorescent edelfosine analog, and induced an endoplasmic reticulum stress response in both PANC-1 cells and PANC-1 CSCs, with a potent CHOP/GADD153 upregulation. Edelfosine elicited a strong autophagy response in both PANC-1 cells and PANC-1 CSCs, and preincubation of CSCs with autophagy inhibitors, chloroquine or bafilomycin A1, enhanced edelfosine-induced apoptosis. Primary cultures from pancreatic cancer patients were sensitive to edelfosine, as well as their respective isolated CSCs. Nontumorigenic pancreatic human cell line HPNE and normal human fibroblasts were largely spared. These data suggest that pancreatic CSCs isolated from established cell lines and pancreatic cancer patients are sensitive to edelfosine through its accumulation in the endoplasmic reticulum and induction of endoplasmic reticulum stress.

Epigenetic Blockade of Hippocampal SOD2 Via DNMT3b-Mediated DNA Methylation: Implications in Mild Traumatic Brain Injury-Induced Persistent Oxidative Damage

The recurrent events of mild trauma exacerbate the vulnerability for post-traumatic stress disorder; however, the underlying molecular mechanisms are scarcely known. The repeated mild traumatic brain injury (rMTBI) perturbs redox homeostasis which is primarily managed by superoxide dismutase 2 (SOD2). The current study investigates the role of DNA methylation in SOD2 gene regulation and its involvement in rMTBI-induced persistent neuropathology inflicted by weight drop injury paradigm. The oxidative damage, neurodegenerative indicators, and SOD2 function and its regulation in the hippocampus were analyzed after 48 h and 30 days of rMTBI. The temporal and episodic increase in ROS levels (oxidative stress) heightened 8-hydroxyguanosine levels indicating oxidative damage after rMTBI that was concomitant with decline in SOD2 function. In parallel, occupancy of DNMT3b at SOD2 promoter was higher post 30 days of the first episode of rMTBI causing hypermethylation at SOD2 promoter. This epigenetic silencing of SOD2 promoter was sustained after the second episode of rMTBI causing permanent blockade in SOD2 response. The resultant oxidative stress further culminated into the increasing number of degenerating neurons. The treatment with 5-azacytidine, a pan DNMT inhibitor, normalized DNA methylation levels and revived SOD2 function after the second episode of rMTBI. The release of blockade in SOD2 expression by DNMT inhibition also normalized the post-traumatic oxidative consequences and relieved the neurodegeneration and deficits in learning and memory as measured by novel object recognition test. In conclusion, DNMT3b-mediated DNA methylation plays a critical role in SOD2 gene regulation in the hippocampus, and the perturbations therein post rMTBI are detrimental to redox homeostasis manifesting into neurological consequences.

Effects of 5-Aza-2'-deoxycytidine on hormone secretion and epigenetic regulation in sika deer ovarian granulosa cells

5-Aza-2'-deoxycytidine (5-Aza-dC), an inhibitor of DNA methyltransferases, is an effective treatment for various cancers and has improved the development rate of cloned embryos. Previous studies have reported the effect of 5-Aza-dC on fibroblasts; however, the mechanism whereby 5-Aza-dC affects sika deer granulosa cells and hormone secretion is presently unknown. Here, we showed that the cell cycle after treatment with different doses of 5-Aza-dC was significantly altered. The number of cells in the S phase was significantly increased in response to a concentration of 0.1 μM 5-Aza-dC. The rate of apoptosis was increased when cells were treated with 0.1 μM and 5 μM 5-Aza-dC. We showed that the protein level of H3K9me2 was significantly decreased in response to 5-Aza-dC. The activity levels of DNA methyltransferase were reduced by a moderate dose of 5-Aza-dC. Furthermore, the secretion of E₂ and P₄ was influenced by different doses of 5-Aza-dC. Our study suggested that 5-Aza-dC affected hormone secretion in sika deer granulosa cells through cell development and epigenetic regulation. The findings of this study lay the foundation for further epigenetic studies in sika deer.

Targeting Mitochondrial Complex I Overcomes Chemoresistance in High OXPHOS Pancreatic Cancer

Mitochondrial respiration (oxidative phosphorylation, OXPHOS) is an emerging target in currently refractory cancers such as pancreatic ductal adenocarcinoma (PDAC). However, the variability of energetic metabolic adaptations between PDAC patients has not been assessed in functional investigations. In this work, we demonstrate that OXPHOS rates are highly heterogeneous between patient tumors, and that high OXPHOS tumors are enriched in mitochondrial respiratory complex I at protein and mRNA levels. Therefore, we treated PDAC cells with phenformin (complex I inhibitor) in combination with standard chemotherapy (gemcitabine), showing that this treatment is synergistic specifically in high OXPHOS cells. Furthermore, phenformin cooperates with gemcitabine in high OXPHOS tumors in two orthotopic mouse models (xenografts and syngeneic allografts). In conclusion, this work proposes a strategy to identify PDAC patients likely to respond to the targeting of mitochondrial energetic metabolism in combination with chemotherapy, and that phenformin should be clinically tested in appropriate PDAC patient subpopulations.

DNMT1 as a therapeutic target in pancreatic cancer: mechanisms and clinical implications

BACKGROUND

Pancreatic cancer or pancreatic ductal adenocarcinoma (PDAC) is one of the most devastating cancer types with a 5-year survival rate of only 9%. PDAC is one of the leading causes of cancer-related deaths in both genders. Epigenetic alterations may lead to the suppression of tumor suppressor genes, and DNA methylation is a predominant epigenetic modification. DNA methyltransferase 1 (DNMT1) is required for maintaining patterns of DNA methylation during cellular replication. Accumulating evidence has implicated the oncogenic roles of DNMT1 in various malignancies including PDACs.

CONCLUSIONS

Herein, the expression profiles, oncogenic roles, regulators and inhibitors of DNMT1 in PDACs are presented and discussed. DNMT1 is overexpressed in PDAC cases compared with non-cancerous pancreatic ducts, and its expression gradually increases from pre-neoplastic lesions to PDACs. DNMT1 plays oncogenic roles in suppressing PDAC cell differentiation and in promoting their proliferation, migration and invasion, as well as in induction of the self-renewal capacity of PDAC cancer stem cells. These effects are achieved via promoter hypermethylation of tumor suppressor genes, including cyclin-dependent kinase inhibitors (e.g., p14, p15, p16, p21 and p27), suppressors of epithelial-mesenchymal transition (e.g., E-cadherin) and tumor suppressor miRNAs (e.g., miR-148a, miR-152 and miR-17-92 cluster). Pre-clinical investigations have shown the potency of novel non-nucleoside DNMT1 inhibitors against PDAC cells. Finally, phase I/II clinical trials of DNMT1 inhibitors (azacitidine, decitabine and guadecitabine) in PDAC patients are currently underway, where these inhibitors have the potential to sensitize PDACs to chemotherapy and immune checkpoint blockade therapy.

[Organoids from pancreatic ductal adenocarcinoma]

Pancreatic ductal adenocarcinoma (PDAC) is a rapidly evolving and most frequently fatal disease. Despite the enormous progress in understanding the mechanisms related to PDAC pathogenesis, the impact on patient management has not yet been possible. Pancreatic organoids can be generated from small amounts of tissue. One of the most promising applications of organoids is that they can serve as a platform for selecting the right drugs for each patient. This approach has the potential to identify individual therapeutic vulnerabilities by allowing the personalization of treatments. However, these analyzes require several weeks before obtaining enough organoids from the same individual, to carry out the tests with several drugs, and to analyze the results, which limits its use in current clinical practice for the patients with a PDAC, whose it must be remembered that half die within 6 months of diagnosis. To overcome this obstacle, we assessed the ability of transcriptomic molecular signatures to identify patients with a particular sensitivity profile to a given treatment. The approaches based on transcriptomic profiling have the enormous advantage of using very little biological material and thus significantly reducing the time to arrive at the selection of more effective drugs to each patient.

DNA methylation inhibitor attenuates polyglutamine-induced neurodegeneration by regulating Hes5

Spinal and bulbar muscular atrophy (SBMA) is a polyglutamine-mediated neuromuscular disease caused by a CAG repeat expansion in the androgen receptor (AR) gene. While transcriptional dysregulation is known to play a critical role in the pathogenesis of SBMA, the underlying molecular pathomechanisms remain unclear. DNA methylation is a fundamental epigenetic modification that silences the transcription of various genes that have a CpG-rich promoter. Here, we showed that DNA methyltransferase 1 (Dnmt1) is highly expressed in the spinal motor neurons of an SBMA mouse model and in patients with SBMA. Both genetic Dnmt1 depletion and treatment with RG108, a DNA methylation inhibitor, ameliorated the viability of SBMA model cells. Furthermore, a continuous intracerebroventricular injection of RG108 mitigated the phenotype of SBMA mice. DNA methylation array analysis identified hairy and enhancer of split 5 (Hes5) as having a CpG island with hyper-methylation in the promoter region, and the Hes5 expression was strongly silenced in SBMA. Moreover, Hes5 over-expression rescued the SBMA cells possibly by inducing Smad2 phosphorylation. Our findings suggest DNA hyper-methylation underlies the neurodegeneration in SBMA.

Pancreatic Cancer Heterogeneity Can Be Explained Beyond the Genome

Pancreatic ductal adenocarcinoma (PDAC) remains a major health problem because it induces almost systematic mortality. Carcinogenesis begins with genetic aberrations which trigger epigenetic modifications. While genetic mutations initiate tumorigenesis, they are unable to explain the vast heterogeneity observed among PDAC patients. Instead, epigenetic changes drive transcriptomic alterations that can regulate the malignant phenotype. The contribution of factors from the environment and tumor microenvironment defines different epigenetic landscapes that outline two clinical subtypes: basal, with the worst prognosis, and classical. The epigenetic nature of PDAC, as a reversible phenomenon, encouraged several studies to test epidrugs. However, these drugs lack specificity and although there are epigenetic patterns shared by all PDAC tumors, there are others that are specific to each subtype. Molecular characterization of the epigenetic mechanisms underlying PDAC heterogeneity could be an invaluable tool to predict personalized therapies, stratify patients and search for novel therapies with more specific phenotype-based targets. Novel therapeutic strategies using current anticancer compounds or existing drugs used in other pathologies, alone or in combination, could be used to kill tumor cells or convert aggressive tumors into a more benign phenotype.

Trefoil factor(s) and CA19.9: A promising panel for early detection of pancreatic cancer

Background

Trefoil factors (TFF1, TFF2, and TFF3) are small secretory molecules that recently have gained significant attention in multiple studies as an integral component of pancreatic cancer (PC) subtype-specific gene signature. Here, we comprehensively investigated the diagnostic potential of all the member of trefoil family, i.e., TFF1, TFF2, and TFF3 in combination with CA19.9 for detection of PC.

Methods

Trefoil factors (TFFs) gene expression was analyzed in publicly available cancer genome datasets, followed by assessment of their expression in genetically engineered spontaneous mouse model (GEM) of PC (KrasG12D; Pdx1-Cre (KC)) and in human tissue microarray consisting of normal pancreas adjacent to tumor (NAT), precursor lesions (PanIN), and various pathological grades of PC by immunohistochemistry (IHC). Serum TFFs and CA19.9 levels were evaluated via ELISA in comprehensive sample set (n = 362) comprised of independent training and validation sets each containing benign controls (BC), chronic pancreatitis (CP), and various stages of PC. Univariate and multivariate logistic regression and receiver operating characteristic curves (ROC) were used to examine their diagnostic potential both alone and in combination with CA19.9.

Findings

The publicly available datasets and expression analysis revealed significant increased expression of TFF1, TFF2, and TFF3 in human PanINs and PC tissues. Assessment of KC mouse model also suggested upregulated expression of TFFs in PanIN lesions and early stage of PC. In serum analyses studies, TFF1 and TFF2 were significantly elevated in early stages of PC in comparison to benign and CP control group while significant elevation in TFF3 levels were observed in CP group with no further elevation in its level in early stage PC group. In receiver operating curve (ROC) analyses, combination of TFFs with CA19.9 emerged as promising panel for discriminating early stage of PC (EPC) from BC (AUC_{TFF1+TFF2+TFF3+CA19.9} = 0.93) as well as CP (AUC_{TFF1+TFF2+TFF3+CA19.9} = 0.93). Notably, at 90% specificity (desired for blood-based biomarker panel), TFFs combination improved CA19.9 sensitivity by 10% and 25% to differentiate EPC from BC and CP respectively. In an independent blinded validation set, the combination of TFFs and CA19.9 (AUC_{TFF1+TFF2+TFF3+CA19.9} = 0.82) also improved the overall efficacy of CA19.9 (AUC_CA19.9 = 0.66) to differentiate EPC from CP proving unique biomarker capabilities of TFFs to distinguish early stage of this deadly lethal disease.

Interpretation

In silico, tissue and serum analyses validated significantly increased level of all TFFs in precursor lesions and early stages of PC. The combination of TFFs enhanced sensitivity and specificity of CA19.9 to discriminate early stage of PC from benign control and chronic pancreatitis groups.

CDH13 promoter methylation regulates cisplatin resistance of non-small cell lung cancer cells

Reversing cisplatin resistance of lung cancer cell line A549/DDP through recovering cadherin 13 (CDH13) expression by demethylation was investigated in the current study. RT-PCR was used to measure CDH13 expression in lung cancer A549 and A549/DDP cells with or without 5-Aza-CdR intervention. Methylation-specific PCR was used to detect CDH13 methylation. MTT assay and flow cytometry were used to measure the effects of cisplatin on inhibiting cell proliferation, apoptosis, and the reversal of cisplatin resistance. The IC₅₀ value of cisplatin for A549 and A549/DDP cells was 3.278±0.532 and 28.341±1.435 µmol/l, respectively (P<0.05). The cisplatin-resistance index of A549/DDP cells was up to 8.65. After 2.5, 10, or 40 µmol/l 5-Aza-CdR treatment, the apoptotic rates of A549/DDP cells were 9.4±0.86, 18.1±1.42 and 42±2.01%, respectively, which were significantly different to those of the control group (P<0.05). Methylation-specific PCR detected both methylation (M) and unmethylation (U) bands at CDH13 promoter region before 5-Aza-CdR intervention while it only detected an unmethylation band after the treatment with a higher concentration of 5-Aza-CdR, which indicates the transformation to unmethylation state. When 10 µmol/l 5-Aza-CdR was added, the IC₅₀ of cisplatin to A549/DDP cells was 8.472±0.415 µmol/l, and cisplatin resistance was reversed by 3.35-fold. CDH13 methylation is related to the cisplatin resistance of A549/DDP cells. 5-Aza-CdR can inhibit CDH13 methylation and recover CDH13 expression. With the increase in 5-Aza-CdR concentration, the unmethylation state of CDH13 is enhanced, which can strengthen the function of cisplatin inhibiting proliferation and apoptosis in A549/DDP cells.

A novel epigenetic modulating agent sensitizes pancreatic cells to a chemotherapy agent

Pancreatic ductal adenocarcinoma (PDAC) is expected to be the second leading cause of cancer mortality by 2030. PDAC remains resistant to the majority of systemic chemotherapies. In this paper, we explore if epigenetic sensitization can improve chemotherapy response in PDAC. Multiple PDAC cell lines were tested with serial concentrations of the epigenetic modulators 5-azacitidine (Aza) and guadecitabine (SGI-110). Guadecitabine was effective at inhibiting the expression of DNA Methyltransferase 1 (DNMT1) and in decreasing cell viability at nanomolar concentrations. We also report that guadecitabine has increased efficacy following a delay period or as we reference, a ‘rest period’. Sensitization with guadecitabine improved response to the chemotherapeutic agent–Irinotecan- as measured by decreased cell viability and accompanied by an increase in caspase activity. Additional studies are needed to understand the mechanism of action.

Pathological and Molecular Aspects to Improve Endoscopic Ultrasonography-Guided Fine-Needle Aspiration From Solid Pancreatic Lesions

Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been applied to pancreatic lesions since the 1990s, and its use is now widespread. Improvements in endoscopic devices and sampling techniques have resulted in excellent diagnostic ability for solid pancreatic lesions. However, clinical improvements alone are not responsible for it; pathological aspects have also played important roles. Rapid on-site evaluation minimizes endoscopic procedures, although its value at improving the diagnostic ratio is still debated. Diagnostic efficacy differs by sample preparations (direct smear, cytospin, liquid-based cytology, cell block, and biopsy) and by staining methods (Papanicoloau, Diff-Quik, hematoxylin-eosin, and Giemsa). Several immunocytochemistry protocols aid in diagnosing epithelial components with cytological atypia and in differentiating various tumor types. One cytopathology diagnostic system is telecytology, which uses transmitted digital images and enables real-time diagnosis of EUS-FNA samples by expert cytologists at remote locations. However, EUS-FNA samples are useful for more than just diagnoses, as molecular analysis of these samples allows the identification of prognostic markers, such as genetic alterations in K-ras and EGFR. Expression of drug-metabolizing enzymes, human equilibrative nucleoside transporter 1, correlates with the response to gemcitabine-based chemotherapy. These pathology efforts have enhanced the diagnostic efficacy of EUS-FNA, thereby leading to better outcomes for patients with pancreatic diseases.

Inhibition of DNA methyltransferase 1 increases nuclear receptor subfamily 4 group A member 1 expression and decreases blood glucose in type 2 diabetes

Our previous genome-wide association studies showed that DNA methyltransferase 1 (DNMT1) is associated with increased susceptibility to type 2 diabetes (T2D) in Han Chinese individuals. Here, we aimed to further evaluate the role of DNMT1 in T2D. We performed a genome-wide DNA methylation array and found that the nuclear receptor subfamily 4 group A member 1 (NR4A1) promoter was hypermethylated in patients with T2D and in a mouse model of T2D. Moreover, DNA hypermethylation of the NR4A1 promoter reduced NR4A1 mRNA expression. Transient transfection of human NR4A1 into RIN-m5F and 293T cells caused DNMT1 inhibition and induced insulin receptor activation. NR4A1knockdown by shRNA resulted in overexpression of DNMT1 and inhibition of insulin receptor, suggesting that the NR4A1 gene is involved in the epigenetics pathway. Furthermore, T2D model mice treated with the DNMT1 inhibitor aurintricarboxylic acid (ATA) showed reduced activation of DNMT1 in pancreatic β cells; this effect reversed the changes in NR4A1 expression and decreased blood glucose in T2D model mice. Thus, our results showed for the first time that DNMT1 caused NR4A1 DNA hypermethylation and blocked insulin signaling in patients with T2D. Importantly, ATA therapy may be useful for decreasing blood glucose levels by reversing NR4A1-dependent insulin signaling. These findings improve our understanding of the crucial roles of these regulatory elements in human T2D.

Cadherin-1 and cadherin-3 cooperation determines the aggressiveness of pancreatic ductal adenocarcinoma

Background:

Pancreatic ductal adenocarcinoma (PDAC) is characterised by an extensive tissue invasion and an early formation of metastasis. Alterations in the expression of cadherins have been reported in PDAC. Yet, how these changes contribute to tumour progression is poorly understood. Here, we investigated the relationship between cadherins expression and PDAC development.

Methods:

Cadherins expression was assessed by immunostaining in both human and murine tissue specimens. We have generated pancreatic cancer cell lines expressing both cadherin-1 and cadherin-3 or only one of these cadherins. Functional implications of such genetic alterations were analysed both in vitro and in vivo.

Results:

Cadherin-3 is detected early at the plasma membrane during progression of pancreatic intraepithelial neoplasia 1 (PanIN-1) to PDAC. Despite tumoural cells turn on cadherin-3, a significant amount of cadherin-1 remains expressed at the cell surface during tumourigenesis. We found that cadherin-3 regulates tumour growth, while cadherin-1 drives type I collagen organisation in the tumour. In vitro assays showed that cadherins differentially participate to PDAC aggressiveness. Cadherin-3 regulates cell migration, whereas cadherin-1 takes part in the invadopodia activity.

Conclusions:

Our results show differential, but complementary, roles for cadherins during PDAC carcinogenesis and illustrate how their expression conditions the PDAC aggressiveness.

Speeding towards individualized treatment for pancreatic cancer by taking an alternative road

Accumulation of genetic mutations drives the development of pancreatic ductal adenocarcinoma (PDAC). Contrary to what it is expected, however, genetic analyses, no matter how precise or detailed, do not allow the identification of patient groups with different clinical outcomes or the selection of specific treatments. In fact, clinical outcome and sensitivity to treatments are associated with a given phenotype and are therefore associated at a transcriptomic level. In practical terms, therefore, the most appropriate readout for phenotypically stratifying PDACs should be transcriptomic and not genetic analysis. Recently data indicate that studying the expression of a selected gene set could inform selection of the most appropriate treatment for patients, moving towards an individualized medicine approach for this dismal disease. We are optimizing this approach by developing a platform based on obtaining organoids directly from surgical as well as endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsies of tumors, which serve as a source of RNA, allowing determination of the transcription level of some informative genes. We are convinced that in the near future, the treatment of cancers will be preceded by an extensive molecular characterization of cancer cells in order to select the most appropriate treatments.

Future role of endoscopic ultrasound in personalized management of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is aggressive and lethal with the majority of cases presenting with advanced unresectable disease due to delayed diagnosis. Despite improvement in surgery, chemotherapies, and intensive care medicine, the outcome of PDAC remains poor, which may relate to the tumor biology. Recent data suggest that PDAC is a "systemic cancer" with complex molecular or genomics derangement with marked heterogeneity. The ability to characterize the PDAC better by detailed evaluation of tissue biomarkers or genomics allows for improved prediction of prognosis and stratification of treatment, a concept known as "personalized cancer therapy." Using tissue from resected PDAC specimens has several weaknesses and is only possible in 20% of patients with PDAC. Endoscopic ultrasound (EUS)-guided biopsy overcomes these weaknesses, and with recent advancements in needle technology, tissue can be obtained for personalized cancer therapy for all patients with PDAC. This review aims to outline our current understanding of the molecular biology of PDAC specifically focusing on how EUS-guided biopsy may play a fundamental role in tissue acquisition, allowing for assessment and stratify therapy according to the individual cancer biology as we move toward the era of precision medicine.