Pancreatic cancer: a comprehensive review and update

A comparative analysis and survival analysis of open versus minimally invasive radical antegrade modular pancreatosplenectomy for pancreatic cancer: a systematic review and meta-analysis

Background

Pancreatic ductal adenocarcinoma (PDAC) is a major public health concern, ranking as the fourth leading cause of cancer-related mortality in the United States. Traditional surgical approaches often yield suboptimal outcomes, highlighting the need for innovative surgical strategies. Radical antegrade modular pancreatosplenectomy (RAMPS) has demonstrated improvements in surgical visualization and oncological outcomes. Recently, laparoscopic RAMPS (L-RAMPS) has been introduced as a minimally invasive alternative.

Objectives

This meta-analysis aims to compare the safety and efficacy of open RAMPS (O-RAMPS) versus L-RAMPS, focusing on operative outcomes, minimally invasive outcomes, intra-abdominal outcomes, overall postoperative outcomes, and oncologic outcomes.

Methods

A systematic review and meta-analysis were conducted following PRISMA guidelines. Eligible studies included prospective or retrospective cohort studies and randomized controlled trials comparing L-RAMPS with O-RAMPS. Data were extracted from EMBASE, PubMed, and the Cochrane Library databases through September 16, 2023. The ROBINS-I tool was used to assess the risk of bias. Statistical analyses included odds ratios (OR), risk differences (RD), mean differences (MD), and survival analyses.

Results

Eight studies involving 588 patients were included. O-RAMPS was associated with longer operative times (MD = 39.39 minutes, 95% CI = 22.93 to 55.84) and greater blood loss (MD = -231.84 mL, 95% CI = -312.00 to -151.69). No significant differences were observed in blood transfusion rates, pancreatic fistula rates, delayed gastric emptying, or length of hospital stay. L-RAMPS demonstrated a shorter time to oral feeding (MD = -0.79 days, 95% CI = -1.35 to -0.22). Survival analysis suggested a potentially improved long-term prognosis for L-RAMPS.

Conclusion

L-RAMPS offers advantages over O-RAMPS in terms of reduced blood loss, faster time to oral feeding, and potentially better long-term prognosis. Further research is warranted, particularly regarding the learning curve of L-RAMPS and its broader applicability.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42024498383.

TP53 gene status can promote sensitivity and resistance to chemotherapeutic drugs and small molecule signal transduction inhibitors

TP53 is normally a tumor suppressor. However, it is mutated in at least 50% of human cancers. Usually, we assume that mutation of the TP53 is associated with loss of sensitivity to various drugs as in most cases wild type (WT) TP53 activity is lost. This type of mutations is often dominant-negative (DN) mutations as they can interfere with the normal functions of WT-TP53 which acts as a tetramer. These mutations can result in altered gene expression patterns. There are some TP53 mutations which may lack some of the normal functions of TP53 but have additional functions; these types of mutations are called gain of function (GOF) mutations. There is another class of TP53 mutations, they are TP53 null mutations as the cells have deleted the TP53 gene (TP53-null). Although TP53 mutations were initially considered undruggable, other approaches have been developed to increase TP53 activity. One approach was to develop mouse double minute 2 homolog (MDM2) inhibitors as MDM2 suppresses TP53 activity. In addition, there have been mutant TP53 reactivators created, which will at least partially restore some of the critical growth suppressing effects of TP53. Some of these mutant TP53 reactivators have shown promise in clinical trial in certain types of cancer patients, especially myelodysplastic syndrome (MDS). In this review, we summarize the development of novel TP53 reactivators and MDM2 inhibitors. Both approaches are aimed at increasing or restoring TP53 activity. Attempts to increase TP53 activity in various TP53 mutant tumors could increase therapy of multiple deadly diseases.

Biological Characterization of One Oxadiazole Derivative (5(4-Hydroxyphenyl)-2-(N-Phenyl Amino)-1,3,4-Oxadiazole): In Vitro, In Silico, and Network Pharmacological Approaches

Oxadiazole compounds are of great interest because they have a range of biological activities ranging from antioxidants to anticancer agents. Against this background, we wanted to demonstrate the antioxidant, enzyme inhibitory, and anticancer effects of 5(4-hydroxyphenyl)-2-(N-phenylamino)-1,3,4-oxadiazole (Hppo). Antioxidant abilities were measured through free radical scavenging and reducing power tests. Enzyme inhibitory effects were studied by cholinesterases, tyrosinase, amylase, and glucosidase. The anticancer effect was tested on pancreatic cancer cell lines (PANC-1, CRL-169) and on HEK293 cell lines. The compound showed significant antioxidant activity (particularly in the CUPRAC (cupric acid-reducing antioxidant capacity) assay) and enzyme inhibitory properties (particularly glucosidase inhibition). In the anticancer test, the compound showed strong anticancer activity in pancreatic cancer with apoptotic signaling pathways. These results were confirmed by molecular modeling and bioinformatics tools. Thus, our findings can provide novel and versatile compounds for the development of multidirectional drugs in the pharmaceutical industry.

Incidence Rates and Time Trends of Pancreatic Cancer in the Golestan Province, Northeastern Iran, 2006-2019

BACKGROUND

Pancreatic cancer (PC) is one of the most malignant cancers with a poor prognosis. Despite advances in the diagnosis and management of PC, the survival rate remains low. In Iran, the incidence of PC is increasing, with mortality rates nearly doubling over the past 25 years. Therefore, this study was designed to assess the temporal variations and incidence of PC in Golestan province, as a prominent hub for gastrointestinal cancers in Iran.

METHODS

In this cross-sectional study, patient information was obtained from the Golestan Population-Based Cancer Registry (GPCR) from 2006 to 2019. We calculated age-standardized incidence rates (ASRs) using the World standard population and reported the rates per 100000 persons-year. To compare ASRs across sexes and residence areas, incidence rate ratios (IRR) were calculated using Poisson regression models. We calculated the estimated annual percentage changes (EAPC) to assess time trends in incidence rates of PC in Golestan during the study period.

RESULTS

Among a total of 560 PC new cases (mean age of 63.72 years), 46.61% were diagnosed through clinical or paraclinical methods. The crude incidence rate and ASR were 2.24 and 2.95 (95% CI: 2.70‒3.20) per 100000 persons-year, respectively. The ASR of PC was significantly higher in males (3.78; 95% CI: 3.37‒4.19) than females (2.17; 95% CI: 1.88‒2.46) (IRR=1.71; P<0.01). The ASR was higher in the urban (3.23; 95% CI: 2.88‒3.58) compared to the rural population (2.65; 95% CI: 2.30‒3.00) (IRR=1.23; P=0.02). The ASR of PC increased from 1.97 to 3.53 during 2006 to 2019 with an EAPC of 4.39 (95% CI: -3.56 to 12.75). The EAPCs were 4.85% and 4.37% in women and men, respectively.

CONCLUSION

Our study showed that the incidence of PC is increasing in the Golestan province. Also, the incidence rate was higher in men, elderly people, and the urban population.

Salicylaldehyde-derived piperazine-functionalized hydrazone ligand-based Pt(II) complexes: inhibition of EZH2-dependent tumorigenesis in pancreatic ductal adenocarcinoma, synergism with PARP inhibitors and enhanced apoptosis

Piperazine is an important functional unit of many clinically approved drugs, including chemotherapeutic agents. In the current study, methyl piperazine was incorporated and eight salicylaldehyde-derived piperazine-functionalized hydrazone ONN-donor ligands (L) and their Pt(II) complexes (L-PtCl) were prepared. The structures of all these ligands (L1-L8) and Pt(II) complexes (C1-C8) were determined using 1H and 13C NMR, UV-vis, FT-IR and HR-ESI MS analyses, whereas the structures of C1, C5, C6, C7 and C8 were determined in the solid state using single crystal X-ray diffraction analysis. Solution state stabilities of C3, C4, C5 and C6 were determined via time-dependent UV-vis spectroscopy. All these complexes (C1-C8) were studied for their anticancer effect in pancreatic ductal adenocarcinoma cells, including BxPC3, MIAPaCa-2 and PANC1 cells. C1-C8 displayed a potential cytotoxic effect in all these cancer cells, among which C5, C6 and C8 showed the strongest inhibitory effect in comparison with standard chemotherapeutic agents, including 5-fluorouracil (5-FU), cisplatin (CP), oxaliplatin and doxorubicin (DOX). C5, C6 and C8 suppressed the growth of pancreatic cancer cells in a dose-dependent manner. Moreover, C5, C6 and C8 inhibited clonogenic potential and invasion ability and induced apoptosis in PANC1 cells. Importantly, C5, C6 and C8 synergized the anticancer effect with PARP inhibitors, including olaparib, veliparib and niraparib, in pancreatic cancer cells, thus suggesting an important role of C5, C6 and C8 in induction of apoptosis in combination with PARP inhibitors. C5 combined with PARP inhibitors induced caspase3/7 activity and suppressed ATP production. Mechanistically, C5, C6 and C8 inhibited EZH2 protein expression to suppress EZH2-dependent tumorigenesis. Overall, these results highlighted the importance of these piperazine-functionalized Pt(II) complexes as potential anticancer agents to suppress pancreatic ductal adenocarcinoma tumorigenesis by targeting the EZH2-dependent pathway.

Recent Advancements in the Application of Circulating Tumor DNA as Biomarkers for Early Detection of Cancers

Early detection of cancer is vital for increasing patient survivability chances. The three major techniques used to diagnose cancers are instrumental examination, tissue biopsy, and tumor biomarker detection. Circulating tumor DNA (ctDNA) has gained much attention in recent years due to advantages over traditional technology, such as high sensitivity, high specificity, and noninvasive nature. Through the mechanism of apoptosis, necrosis, and circulating exosome release in tumor cells, ctDNA can spread throughout the circulatory system and carry modifications such as methylations, mutations, gene rearrangements, and microsatellite instability. Traditional gene-detection technology struggles to achieve real-time, low-cost, and portable ctDNA measurement, whereas electrochemical biosensors offer low cost, high specificity alongside sensitivity, and portability for the detection of ctDNA. Therefore, this review focuses on describing the recent advancements in ctDNA biomarkers for various cancer types and biosensor developments for real-time, noninvasive, and rapid ctDNA detection. Further in the review, ctDNA sensors are also discussed in regards to their selections of probes for receptors based on the electrode surface recognition elements.

Safety and Effectiveness of Perioperative Hyperthermic Intraperitoneal Chemotherapy with Gemcitabine in Patients with Resected Pancreatic Ductal Adenocarcinoma: Clinical Trial EudraCT 2016-004298-41

BACKGROUND

Despite the improvement in therapies, pancreatic cancer represents one of the most cancer-related deaths. In our hypothesis, we propose that Hyperthermic Intraperitoneal Chemotherapy with gemcitabine after pancreatic cytoreductive surgery could reduce tumor progression by reducing residual neoplastic volume and residual pancreatic cancer stem cells.

MATERIALS AND METHODS

A randomized trial involving 42 patients. All patients were diagnosed with pancreatic ductal adenocarcinoma. Group I: R0 resection. Group II. R0 resection and HIPEC with gemcitabine (120 mg/m2 for 30 min). Effectiveness was measured with analysis of overall survival, disease-free survival, distant recurrence, locoregional recurrence, and measuring of pancreatic cancer stem cells (EpCAM+CXCR4+CD133+).

RESULTS

From 2017 to 2023, 63 patients were recruited for our clinical trial; 21 patients were included in each group, and 21 were excluded. Locoregional recurrence, p-value: 0.022, was lower in the experimental group. There were no significant differences between the two groups in hospital mortality, perioperative complications, or hospital costs. We found a significant decrease in pancreatic cancer stem cells in patients in the experimental group after treatment, p -value of 0.018.

CONCLUSIONS

The use of HIPEC with gemcitabine after surgery in patients with resectable pancreatic ductal adenocarcinoma reduces locoregional recurrence and may be associated with a significant decrease in pancreatic cancer stem cells.

CENPN contributes to pancreatic carcinoma progression through the MDM2-mediated p53 signaling pathway

Introduction

We undertook an in-depth investigation of the data pertaining to pancreatic adenocarcinoma (PAAD) to identify potential targets for the development of precision therapies.

Material and methods

The construction of a protein-protein interaction (PPI) network was based on overlapping differentially expressed genes (DEGs) identified in the GSE16515, GSE32676, and GSE125158 datasets. A subsequent bioinformatic analysis was performed on the interconnected genes within the PPI network, leading to the identification of the central gene, CENPN. In vitro experimentation such as CCK8 and Transwell experiments was employed to elucidate the impact of CENPN expression patterns on PAAD cell proliferation, migration, and invasion. Furthermore, the investigation revealed through comprehensive enrichment analysis that the pivotal signaling pathway associated with CENPN is the p53 signaling pathway.

Results

Following a comprehensive bioinformatic analysis of 161 concordant differentially expressed genes (DEGs) across three microarray datasets, CENPN emerged as the central gene under investigation. Overexpression of CENPN in pancreatic adenocarcinoma (PAAD) was associated with unfavorable patient outcomes and heightened sensitivity to four PAAD therapies: gemcitabine, docetaxel, paclitaxel, and sunitinib. Reduced CENPN expression impeded PAAD cell proliferation, migration, and invasion; however, these effects were counteracted upon upregulation of CENPN expression. Additionally, CENPN interacted with MDM2, promoting PAAD progression by targeting the p53 signaling pathway.

Conclusions

The findings of our study substantiate that CENPN is associated with the pathogenesis of PAAD. Consequently, CENPN appears to be a promising candidate for targeted precision therapy in clinical applications.

Risk factors for early-onset pancreatic ductal adenocarcinoma: A systematic literature review

BACKGROUND

Emerging cancer trends suggest an increase in pancreatic cancer incidence in individuals younger than its typical age of onset, potentially reflecting changes in population exposures and lifestyles.

PATIENTS AND METHODS

We conducted a PRISMA-standard systematic literature review to identify non-heritable risk factors for early-onset pancreatic ductal adenocarcinoma (PDAC) (PROSPERO number: CRD42022299397). Systematic searches of MEDLINE and Embase bibliographic databases were performed (January 2022), and publications were screened against predetermined eligibility criteria; data were extracted using standardised data fields. The STROBE checklist was used to assess the completeness of reporting as a proxy for publication quality. Data were categorised by risk factor and analysed descriptively.

RESULTS

In total, 24 publications were included. All publications reported observational study data; thresholds for age group comparisons ranged between 40 and 65 years. Lifestyle factors investigated included smoking, alcohol consumption, obesity, physical inactivity, meat intake, socioeconomic status and geographical residence. Clinical factors investigated included pancreatitis, diabetes/insulin resistance, prior cancer and cancer stage at diagnosis, hepatitis B infection, metabolic syndrome and long-term proton pump inhibitor exposure. Publication STROBE scores were 6-21 (maximum, 22). Eight studies reported results adjusted for confounders. Potential non-heritable risk factors for early-onset PDAC that warrant further investigation included smoking, alcohol consumption, pancreatitis and hepatitis B infection.

CONCLUSION

Evidence for non-heritable risk factors for early-onset PDAC is heterogeneous, but four factors were identified that might aid the identification of at-risk individuals who may benefit from screening and risk reduction strategies.

The p53 reactivator PRIMA-1MET synergises with 5-fluorouracil to induce apoptosis in pancreatic cancer cells

Pancreatic cancer (PC) is one of the deadliest malignancies; p53 is mutated in approximately 75% of PC patients. Hence, the protein derived from mutant/wild-type TP53 may represent a therapeutic target. Interestingly, a p53 reactivator (PRIMA-1MET) showed promise in clinical trials of haematological malignancies; therefore, it warrants an in vitro evaluation in PC cell lines. To evaluate the antiproliferative effects of PRIMA-1MET, either alone or combined with the common chemotherapy 5-fluorouracil (5-FU), against mutated and wild-type p53 PC cell lines. This study involved p53-mutant (AsPC-1) and p53-wild type (Capan-2) PC cell lines. The cytotoxicity of PRIMA-1MET alone or in combination with 5-FU was evaluated by MTT assay. Synergism was assessed by calculating the combination index (CI) via CalcuSyn software. Fluorescence microscopy was used to analyse apoptosis following acridine orange/ethidium bromide (AO/EB) staining. Morphological changes were investigated with an inverted microscope. Quantitative reverse transcription PCR (RT‒qPCR) was used to measure gene expression. Both PC cell lines were sensitive to PRIMA-1MET monotherapy. Furthermore, PRIMA-1MET and 5-FU had a synergistic effect (CI < 1), reflected by significant enhancement of apoptosis and morphological changes in the combination vs. monotherapy treatments. Moreover, the RT‒qPCR results indicated increased expression of the NOXA and TP73 genes in combination-treated cells. Our data suggested that PRIMA-1MET, whether alone or combined with 5-FU, has an antiproliferative effect on PC cell lines regardless of p53 mutational status. The synergism of the combination was associated with significant apoptosis induction through p53-dependent and p53-independent pathways. Preclinical confirmation of these data in in vivo models is highly recommended.

Effects of CCN6 overexpression on the cell motility and activation of p38/bone morphogenetic protein signaling pathways in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancer types that is highly resistant to conventional treatments, such as chemotherapy and radiotherapy. As the demand for more effective therapeutics for PDAC treatment increases, various approaches have been studied to develop novel targets. The cellular communication network (CCN) family is a matricellular protein that modulates various cellular functions, including cell adhesion, proliferation, migration, and invasiveness. Despite this, little is known about the role of CCN6 in PDAC. The current study investigated the role of CCN6 in PDAC by generating CCN6-overexpressing PANC-1 cells (PANC-1-CCN6) by infecting lentivirus particles containing CCN6. PANC-1-CCN6 induces cell viability and tumorigenesis than PANC-1 cells with empty vector (control). The PANC-1-CCN6 formed more colonies, and the size of spheroids increased compared to the control. The upregulation of CCN6 enhances the expression of bone morphogenetic proteins (BMPs) genes and the upregulation of p38 mitogen-activated protein kinases (MAPKs). In PANC-1-CCN6 cells, the levels of N-cadherin, VEGF, and Snail expression were higher than the control, while E-cadherin expression was lower, which is associated with upregulation of epithelial-to-mesenchymal transition (EMT). Consistent with the changes in EMT-related proteins in PANC-1-CCN6, the migratory ability and invasiveness were enhanced in PANC-1-CCN6. Xenografted PANC-1-CCN6 in immunocompromised mice exhibited accelerated tumor growth than the control group. In immunohistochemistry (IHC), the PANC-1-CCN6 xenografted tumor showed an increased positive area of PCNA and Ki-67 than the control. These results suggest that CCN6 plays a tumorigenic role and induces the metastatic potential by the p38 MAPK and BMPs signaling pathways. Although the role of CCN6 has been introduced as an antitumor factor, there was evidence of CCN6 acting to cause tumorigenesis and invasion in PANC-1.

Effects of chloroquine and hydroxychloroquine on the sensitivity of pancreatic cancer cells to targeted therapies

Approaches to improve pancreatic cancer therapy are essential as this disease has a very bleak outcome. Approximately 80% of pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). PDAC is a cancer which is difficult to effectively treat as it is often detected late in the disease process. Almost all PDACs (over 90%) have activating mutations in the GTPase gene KRAS. These mutations result in constitutive KRas activation and the mobilization of downstream pathways such as the Raf/MEK/ERK pathway. Small molecule inhibitors of key components of the KRas/Raf/MEK/ERK pathways as well as monoclonal antibodies (MoAbs) specific for upstream growth factor receptors such insulin like growth factor-1 receptor (IGF1-R) and epidermal growth factor receptors (EGFRs) have been developed and have been evaluated in clinical trials. An additional key regulatory gene frequently mutated (∼75%) in PDAC is the TP53 tumor suppressor gene which controls the transcription of multiple genes involved in cell cycle progression, apoptosis, metabolism, cancer progression and other growth regulatory processes. Small molecule mutant TP53 reactivators have been developed which alter the structure of mutant TP53 protein and restore some of its antiproliferative activities. Some mutant TP53 reactivators have been examined in clinical trials with patients with mutant TP53 genes. Inhibitors to the TP53 negative regulator Mouse Double Minute 2 (MDM2) have been developed and analyzed in clinical trials. Chloroquine and hydroxychloroquine are established anti-malarial and anti-inflammatory drugs that also prevent the induction of autophagy which can have effects on cancer survival. Chloroquine and hydroxychloroquine have also been examined in various clinical trials. Recent studies are suggesting effective treatment of PDAC patients may require chemotherapy as well as targeting multiple pathways and biochemical processes.

The Significance of FDG PET/CT-Derived Parameters in Determining Prognosis of Cases with Pancreatic Adenocarcinoma: A Prospective Study

Background and objectives: Pancreatic adenocarcinoma represents one of the common malignancies with a relatively poor prognosis. However, early detection of this type of cancer may prove to be curable. Recent advancements in the radiological techniques might represent a hope for the early diagnosis and prediction of prognosis of pancreatic adenocarcinoma. This study aimed to assess the prognostic value of the primary tumor volumetric parameters obtained from FDG PET/CT first stage for the overall survival (OS) and progression-free survival (PFS) of patients with pancreatic adenocarcinoma and to explore the possible correlation between serum matrix metalloproteinase-2 (MMP-2) and the patients’ characteristics. Methods: Fifty patients with pancreatic adenocarcinoma were subjected to FDG PET/CT scan. The SUVpeak, SUVmax, and the metabolic tumor volume (MTV) were determined, as well as the SUVmean of the liver. Moreover, serum levels of MMP-2 were assessed. Follow-up of the patients was carried out for sixty months with determination of PFS and OS. Results: Peak SUV ≥ 3.9 was significantly correlated with the primary pancreatic lesions’ mean total glycolytic activity of >92 g, and MTV and was directly correlated with mortality. There was a positive correlation between peak SUV ≥ 3.9 and 50% SUVmax threshold > 82. Moreover, there was significant correlation between the total glycolytic activity and the studied clinicopathologic factors, except the age and sex of the patients and ECOG performance status. In addition, FDG uptake and the tumor glycolytic activity were substantially linked with a shorter PFS. Similarly, a strong correlation was found between MTV and PFS. Serum MMP-2 levels showed a significant relationship with the performance status, tumor stage, SUVmax threshold, and the glycolytic activity. Conclusions: Peak SUV, main lesion SUVmax, serum MMP-2, and the tumor glycolytic activity are good predictors of PFS of patients with pancreatic adenocarcinoma.

Wild type and gain of function mutant TP53 can regulate the sensitivity of pancreatic cancer cells to chemotherapeutic drugs, EGFR/Ras/Raf/MEK, and PI3K/mTORC1/GSK-3 pathway inhibitors, nutraceuticals and alter metabolic properties

TP53 is a master regulator of many signaling and apoptotic pathways involved in: aging, cell cycle progression, gene regulation, growth, apoptosis, cellular senescence, DNA repair, drug resistance, malignant transformation, metastasis, and metabolism. Most pancreatic cancers are classified as pancreatic ductal adenocarcinomas (PDAC). The tumor suppressor gene TP53 is mutated frequently (50-75%) in PDAC. Different types of TP53 mutations have been observed including gain of function (GOF) point mutations and various deletions of the TP53 gene resulting in lack of the protein expression. Most PDACs have point mutations at the KRAS gene which result in constitutive activation of KRas and multiple downstream signaling pathways. It has been difficult to develop specific KRas inhibitors and/or methods that result in recovery of functional TP53 activity. To further elucidate the roles of TP53 in drug-resistance of pancreatic cancer cells, we introduced wild-type (WT) TP53 or a control vector into two different PDAC cell lines. Introduction of WT-TP53 increased the sensitivity of the cells to multiple chemotherapeutic drugs, signal transduction inhibitors, drugs and nutraceuticals and influenced key metabolic properties of the cells. Therefore, TP53 is a key molecule which is critical in drug sensitivity and metabolism of PDAC.

Effects of the Mutant TP53 Reactivator APR-246 on Therapeutic Sensitivity of Pancreatic Cancer Cells in the Presence and Absence of WT-TP53

The TP53 tumor suppressor is mutated in ~75% of pancreatic cancers. The mutant TP53 protein in pancreatic ductal adenocarcinomas (PDAC) promotes tumor growth and metastasis. Attempts have been made to develop molecules that restore at least some of the properties of wild-type (WT) TP53. APR-246 is one such molecule, and it is referred to as a mutant TP53 reactivator. To understand the potential of APR-246 to sensitize PDAC cells to chemotherapy, we introduced a vector encoding WT-TP53 into two PDAC cell lines, one lacking the expression of TP53 (PANC-28) and one with a gain-of-function (GOF) mutant TP53 (MIA-PaCa-2). APR-246 increased drug sensitivity in the cells containing either a WT or mutant TP53 protein with GOF activity, but not in cells that lacked TP53. The introduction of WT-T53 into PANC-28 cells increased their sensitivity to the TP53 reactivator, chemotherapeutic drugs, and signal transduction inhibitors. The addition of WT-TP53 to PDAC cells with GOF TP53 also increased their sensitivity to the drugs and therapeutics, indicating that APR-246 could function in cells with WT-TP53 and GOF TP53. These results highlight the importance of knowledge of the type of TP53 mutation that is present in cancer patients before the administration of drugs which function through the reactivation of TP53.

APR-246-The Mutant TP53 Reactivator-Increases the Effectiveness of Berberine and Modified Berberines to Inhibit the Proliferation of Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer. In ~75% of PDAC, the tumor suppressor TP53 gene is mutated. Novel approaches to treat cancer involve compounds called mutant TP53 reactivators. They interact with mutant TP53 proteins and restore some of their growth suppressive properties, but they may also interact with other proteins, e.g., TP63 and TP73. We examined the ability of the TP53 reactivator APR-246 to interact with eleven modified berberine compounds (NAX compounds) in the presence and absence of WT-TP53 in two PDAC cell lines: the MIA-PaCa-2, which has gain of function (GOF) TP53 mutations on both alleles, and PANC-28, which lacks expression of the WT TP53 protein. Our results indicate the TP53 reactivator-induced increase in therapeutic potential of many modified berberines.

Comparisons of Outcomes Between Adolescent and Young Adult with Older Patients After Radical Resection of Pancreatic Ductal Adenocarcinoma by Propensity Score Matching: A Single-Center Study

Purpose

Adolescent and young adult (AYA) pancreatic ductal adenocarcinoma (PDAC) occurs in patients below 40 years old. Whether AYA patients have worse outcomes compared with older patients is still controversial. The purpose of this study is to compare the outcomes of AYA patients and older patients after radical surgery for PDAC.

Methods

A single-center, retrospective, cohort study was conducted in patients who underwent radical surgery for PDAC in Xiangya Hospital Central South University from January 2007 to December 2019. The clinicopathological data and results of patients with PDAC were collected and analyzed retrospectively. They were divided into AYA group and older group based on age (<40, AYA group; ≥40, older group). Based on all the considered covariates except age, we estimated 1:2 case propensity score matching (PSM).

Results

A total of 1033 cases were enrolled, 46 cases (4.45%) in the AYA group. Both before and after PSM, the AYA patients have a higher preoperative CA19-9 than the older patients (P < 0.001) and (P < 0.001). Pathological results showed that AYA group had a higher microvascular invasion rate (P < 0.001 and P = 0.045) than older group. The median time of overall survival (OS) in AYA group and older group were 13 months (95% CI = 11.50-14.50) and 14 months (95% CI = 13.50-14.50), respectively. Additionally, AYA group have a worse 2-year OS rate than older group (8.70% vs 25.23%, P = 0.011 and 8.70% vs 25.00%, P = 0.023). According to the Log rank test, AYA group have a worse cumulative OS rate than older group (P = 0.002) and (P = 0.030), respectively.

Conclusion

PDAC might be more aggressive in AYA, and the cumulative OS after radical PDAC surgery in AYA patients is worse than that in older patients.

Effects of the MDM2 inhibitor Nutlin-3a on sensitivity of pancreatic cancer cells to berberine and modified berberines in the presence and absence of WT-TP53

Approaches to improve pancreatic cancer therapy are essential as this disease has a very bleak outcome. Approximately 80% of pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). A key regulatory gene frequently mutated (∼75%) in PDAC is the TP53 tumor suppressor gene which controls the transcription of multiple genes involved in cell cycle progression, apoptosis, cancer progression and other growth regulatory processes. The mouse double minute 2 homolog (MDM2) gene product is a nuclear-localized E3 ubiquitin ligase and negatively regulates the TP53 protein which results in its proteasomal degradation. Various MDM2 inhibitors have been isolated and examined in clinical trials, especially in patients with hematological malignancies. Nutlin-3a is one of the first MDM2 inhibitors isolated. Berberine (BBR) is a natural product found in many fruits and berries and used in traditional medicine for centuries. It has many biological effects, and some are anti-proliferative in nature. BBR may activate the expression of TP53 and inhibit cell cycle progression as well as other events important in cell growth. To understand more about the potential of compounds like BBR and chemical modified BBRs (NAX compounds) to sensitize PDAC cells to MDM2 inhibitors, we introduced either WT-TP53 or the pLXSN empty vector control into two PDAC cell lines, one lacking expression of TP53 (PANC-28) and one with gain-of-function mutant TP53 on both alleles (MIA-PaCa-2). Our results indicate that nutlin-3a was able to increase the sensitivity to BBR and certain NAX compounds. The effects of nutlin-3a were usually more substantial in those cells containing an introduced WT TP53 gene. These results highlight the importance of knowledge of the type of TP53 mutation that is present in cancer patients before the administration of drugs which function by stabilization of the TP53 protein.

Treatment patterns and survival in patients with early-onset pancreatic cancer

BACKGROUND

Pancreatic cancer is uncommon in patients younger than 50 years, although its incidence is increasing. This study characterizes treatment utilization for early-onset pancreatic cancer (EOPC) versus average-age-onset pancreatic cancer (AOPC) and identifies factors associated with failure to receive treatment.

METHODS

The National Cancer Data Base (NCDB) was queried for patients with EOPC (age < 50 years) or AOPC (age ≥ 50 years) from 2004 to 2016. Multinomial regression was used to compare utilization (single modality vs multimodal treatment with or without surgery vs no treatment) between EOPC and AOPC. Kaplan-Meier methods were used to estimate overall survival (OS).

RESULTS

Of 248,634 patients, 15,710 (6.3%) had EOPC. There were more male patients (56% vs 50%), non-White patients, and privately insured patients (61% vs 30%) with EOPC versus AOPC, without notable differences in clinical stage distribution. Patients with EOPC received more chemotherapy (38% vs 29%), surgery (9% vs 6.9%), chemoradiation (12% vs 9.2%), and multimodal treatment (21% vs 15%). The odds of receiving multimodal curative therapy were significantly higher for patients with EOPC versus patients with AOPC after adjustments for confounders (odds ratio, 3.89; 95% confidence interval [CI], 3.66-4.15; P < .001). Nineteen percent of patients with EOPC, in contrast to 39% of patients with AOPC, received no treatment. Patients with AOPC more frequently declined chemotherapy (15% vs 9.5%). One-year OS was higher for EOPC versus AOPC across each stage (0/I/II, 72% [95% CI, 71%-74%] vs 53% [95% CI, 53%-54%]; III, 48% [95% CI, 45%-50%] vs 38% [95% CI, 37%-38%]; IV, 25% [95% CI, 24%-26%] vs 15% [95% CI, 15%-15%]) and treated patients (0/I/II, 75% [95% CI, 74%-77%] vs 64% [95% CI, 63%-64%]; III, 51% [95% CI, 49%-54%] vs 47% [95% CI, 47%-48%]; IV, 29% [95% CI, 28%-31%] vs 23% [95% CI, 23%-24%]).

CONCLUSIONS

Patients with EOPC receive more oncologic therapy than patients with AOPC, although the intensity, type, and duration of chemotherapy are not available in the NCDB; however, 19% and 39%, respectively, receive no therapy. Underutilization may explain suboptimal oncologic outcomes. Efforts to improve access and treatment utilization in all age groups are warranted.

Effects of microRNA-103 on the Proliferation and Apoptosis of Pancreatic Cancer Cells via Targeting Phosphatase and Tensin Homolog Deleted on Chromosome Ten (PTEN) and Activating Phosphoinositide 3-Kinase/A Serine/Threonine Kinase (PI3K/Akt) Signaling Pathway

Objective: To investigate whether micro ribonucleic acid (miR)-103 affects pancreatic cancer (PaCa) cells via PTEN-activated PI3K/Akt signaling pathway. Methods: Differences in miR-103 expression in 35 pairs of PaCa tissues and cell lines (SW1990 and PATU8988S) were detected by RT-qPCR. miR-103 inhibitor was transfected into PaCa PATU8988S cell followed by analysis of proliferation and apoptosis of PaCa cells by MTT assay and flow cytometry, respectively. Results: MiR-103 exhibited a significantly high expression in PaCa tissues and cell lines (p < 0.05). Besides, the exogenous inhibition of miR-103 expression in PATU8988S cells significantly inhibited cell proliferation and migration but increased apoptosis activity (p < 0.05). According to the prediction of TargetScan biological database, miR-103 could bind PTEN 3′ untranslated region (3′UTR) and miR-103 was confirmed to suppress PTEN expression in a targeted way (p<0.05). Furthermore, down-regulation of PTEN activated PI3K/Akt signaling to affect the proliferation and apoptosis of PaCa cells (p < 0.05 or p <0.01). Conclusion: MiR-103 displays a significantly increased expression in PaCa cells and targets PTEN to activate PI3K/Akt signaling pathway, thus promoting malignant phenotype formation.

Safety of perioperative hyperthermic intraperitoneal chemotherapy with gemcitabine in patients with resected pancreatic adenocarcinoma: a pilot study of the clinical trial EudraCT 2016-004298-41

Background

Hyperthermic intraperitoneal chemotherapy (HIPEC) with gemcitabine, after cytoreductive surgery, may reduce the tumor progression of pancreatic cancer through the reduction of the neoplastic volume and the subpopulation of residual pancreatic cancer stem cells, improving the survival of patients with pancreatic cancer and decreasing the recurrence of the disease.

Methods

A pilot study is performed with the first ten patients in the experimental group. A randomized study (phase II-III clinical trial) that requires a population of 42 patients, with 21 patients in each group. All patients have a diagnosis of ductal adenocarcinoma of the pancreas, which will be surgically resected with curative intention. (I) Group I: after an R0 resection, patients receive individualized adjuvant treatments. (II) Group II: after an R0 resection, HIPEC is performed with gemcitabine (120 mg/m² for 30 min), and they also receive individualized adjuvant treatments. To analyze the safety of the procedure, the main variables measured were as follows: grades of complications by means of the Clavien-Dindo system: pancreas surgery complications (e.g., pancreatic fistula, perioperative hemorrhage, delayed gastric emptying, biliary fistula), operative mortality, and laboratory parameters to control system functions. Values were measured three times: preoperatively, twenty-four hours after surgery, and on the 7th postoperative day.

Results

From 2018 to 2019, 31 patients were recruited for our clinical trial. Fifteen patients were excluded because of intraoperative unresectability or a different intraoperative histologic diagnosis. Ten patients were included in the experimental group (resection plus HIPEC gemcitabine). The mean age was 65±7 years, and six patients were female (60%). We confirmed the histologic diagnosis of ductal pancreatic adenocarcinoma in all patients prior to HIPEC. Total pancreatectomy was performed in five patients. The surgical median time was 360 min, and the hospital stay was 11 days. Four patients showed complications classified as Clavien-Dindo type II and one showing type I. Six patients were classified as having stage III tumors. To date, no hospital mortality, locoregional recurrence, or differences between the two groups in terms of perioperative complications, biochemical and gasometric values, or Clavien-Dindo complication grades were observed.

Conclusions

Our clinical pilot study demonstrated a similar perioperative outcome that allows the trial until main objectives are achieved.

Prognostic significance and immune infiltration of microenvironment-related signatures in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is 1 of the highly fatal and most aggressive types of malignancies and accounts for the vast majority of Pancreatic Cancer. Numerous studies have reported that the tumor microenvironment (TME) was significantly correlated with the oncogenesis, progress, and prognosis of various malignancies. Therefore, mining of TME-related genes is reasonably important to improve the overall survival of patients with PDAC.The Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data algorithm was applied to identify differential expressed genes. Functional and pathway enrichment analyses, protein-protein interaction network construction and module analysis, overall survival analysis and tumor immune estimation resource database analysis were then performed on differential expressed genes.Data analysis indicated that higher immune scores were correlated with better overall survival (P = 0.033). Differential expression analysis obtained 90 intersection genes influencing both stromal and immune scores. Among these intersection genes, CA9, EBI3, SPOCK2, WDFY4, CD1D, and CCL22 were significantly correlated with overall survival in PDAC patients. Moreover, multivariate Cox analysis revealed that CA9, SPOCK2, and CD1D were the most significant prognostic genes, and were closely correlated with immune infiltration in TCGA cohort. Further analysis indicated that CD1D were significantly related with immune cell biomarkers for PDAC patients.In summary, our findings provide a more comprehensive insight into TME and show a list of prognostic immune associated genes in PDAC. However, further studies on these genes need to be performed to gain additional understanding of the association between TME and prognosis in PDAC.

Sensitivity of pancreatic cancer cells to chemotherapeutic drugs, signal transduction inhibitors and nutraceuticals can be regulated by WT-TP53

Pancreatic ductal adenocarcinoma (PDAC) is a highly metastatic malignancy. Approximately 85% of pancreatic cancers are classified as PDACs. The survival of PDAC patients is very poor and only 5-10% of patients survive 5 years after diagnosis. Mutations at the KRAS and TP53 gene are frequently observed in PDAC patients. The PANC-28 cell line lacks wild-type (WT) TP53. In the following study, we have investigated the effects of restoration of WT TP53 activity on the sensitivity of PANC-28 pancreatic cancer cells to various drugs which are used to treat PDAC patients as well as other cancer patients. In addition, we have examined the effects of signal transduction inhibitors which target critical pathways frequently deregulated in cancer. The effects of the anti-diabetes drug metformin and the anti-malarial drug chloroquine were also examined as these drugs may be repurposed to treat other diseases. Finally, the effects of certain nutraceuticals which are used to treat various ailments were also examined. Introduction of WT-TP53 activity in PANC-28 PDAC cells, can increase their sensitivity to various drugs. Attempts are being made clinically to increase TP53 activity in various cancer types which will often inhibit cell growth by multiple mechanisms.

Comparison of minimal invasive versus open radical antegrade modular pancreatosplenectomy (RAMPS) for pancreatic ductal adenocarcinoma: a single center retrospective study

INTRODUCTION

Radical antegrade modular pancreatosplenectomy (RAMPS) was proposed a decade ago with the aim to achieve higher R0 tangential margin and radical N1 lymph node resection for left-sided pancreatic adenocarcinoma (PDAC), which has been widely accepted worldwide at present. Laparoscopic RAMPS (Lap-RAMPS) has been attempted for PDAC during last several years, however, no outcomes evaluation by comparison between laparoscopic vs open RAMPS has been reported yet.

MATERIALS AND METHODS

From August, 2012 to March, 2018, patients undergoing open or lap-RAMPS for the diagnosis of left-sided PDAC were reviewed from a prospective database. Patients excluded if they were related with combined organs or vessels resection, systematic metastasis as well as conversion from open RAMPS to lap RAMPS. The surgical and oncologic outcomes were compared.

RESULTS

A total of 48 PDAC patients were enrolled (25 underwent lap-RAMPS and 23 underwent open-RAMPS). There were no significant differences in demographic or perioperative morbidity. In the lap-RAMPS group, R0 transection margin and retroperitoneal margin were both achieved in 23 of 25 patients (92%). In the open RAMPS group, R0 transection margin was achieved in 21 of 23 patients (91.3%), R0 retroperitoneal margin was 22 of 23 patients (95.65%). There were no differences in pathological examinations. The number of lymph node (LN) retrieved between lap-RAMPS and open- RAMPS group was not significant difference (15.84 vs 18.22; P = 0.268). Median disease-free survival (DFS) was analogous in two groups (18.11 m vs 20.00 m, P = 0.999). Median overall survival (OS) was 24.53 m in lap-RAMPS group and 28.73 m in the open-RAMPS group (P = 0.633).

CONCLUSIONS

Lap-RAMPS is technically feasible, and has comparable long-term oncological outcome with open-RMAPS.

GLUT-1 as a predictor of worse prognosis in pancreatic adenocarcinoma: immunohistochemistry study showing the correlation between expression and survival

BACKGROUND

Various parameters have been considered for predicting survival in pancreatic ductal adenocarcinoma. Information about western population is missing. The aim of this study is to assess the association between Glucose transporter type 1 (GLUT-1) expression and prognosis for patients with PDAC submitted for surgical resection in a European cohort.

METHODS

Retrospective analysis of PDAC specimens after pancreatoduodenectomy assessing GLUT-1 expression according to intensity (weak vs strong) and extension (low if < 80% cells were stained, high if > 80%) was performed. Statistical analysis was performed using the exact Fisher test, Student t test or the Mann-Whitney U test. Survival was analysed using the Kaplan-Meier method and compared with the Log-rank test. The differences were considered significant at a two-sided p value of < 0.05. All statistical analyses were performed using SPSS® 23.0 for Windows (SPSS Inc., Chicago, IL, USA).

RESULTS

Our study consisted of 39 patients of which 58.9% presented with weak and 41.1% with strong intensity. The median extension was 90%: 28.2% cases presented with a low extension and 71.8% with a high extension. No significant differences related to intensity were found. The high-extension group showed a higher percentage of T3 PDAC (92.9% vs 63.6%, p = 0.042) and LNR20 (35.7% vs 0%, p = 0.037) as well as shorter disease-free survival (17.58 vs 54.46 months; p = 0.048).

CONCLUSIONS

Our findings suggest that GLUT-1 could be related to higher aggressivity in PDAC and could be used as a prognostic marker, identifying patients with a worse response to current therapies who could benefit from more aggressive treatments.

Distinct Clinical Characteristics in Young-Onset Pancreatic Neuroendocrine Tumor

BACKGROUND

We aimed to study the effect of socioeconomic differences and molecular characteristics on survival in patients with young-onset pancreatic neuroendocrine tumors (YOPNET) and typical-onset PNET (TOPNET).

METHODS

We identified the patients with YOPNET (<50 years) and TOPNET (≥50 years) who underwent definitive surgery diagnosed between 2004 and 2016 using the National Cancer Database. We evaluated overall survival (OS) using the Kaplan-Meier and Cox regression methods before and after propensity score matching. A publicly available genomic dataset was used to compare mutation frequencies among the two groups.

RESULTS

A total of 6259 patients with PNET were included, of which 27% were YOPNET. Patients with YOPNET were more likely to be Black, Hispanic, female, and have private insurance versus patients with TOPNET (all p < 0.001). Patients with YOPNET had a lower comorbidity score, but higher stage and tumor size (all p < 0.001). YOPNET was associated with a greater improved OS than TOPNET before and after propensity score matching (p < 0.001). On multivariable analysis, this survival difference persisted for YOPNET as an independent prognostic factor (unmatched p = 0.008; matched p = 0.01). For genomic analysis, patients with YOPNET had a lower rate of multiple endocrine neoplasia type-1 (MEN-1) mutation than patients with TOPNET (26% vs. 56%, p < 0.001).

CONCLUSIONS

YOPNET represents a disease with distinct clinical features. Patients with YOPNET who underwent definitive surgery had better OS than patients with TOPNET despite having higher stage and tumor size. YOPNET also had lower rate of MEN-1 mutation.

Metabolic Profiling of Early and Late Recurrent Pancreatic Ductal Adenocarcinoma Using Patient-Derived Organoid Cultures

Pancreatic ductal adenocarcinoma (PDAC) is associated with high mortality and will become the second most common cause of cancer-associated mortality by 2030. The poor prognosis arises from a lack of sensitive biomarkers, limited therapeutic options, and the astonishingly high recurrence rate after surgery of 60-80%. The factors driving this recurrence, however, remain enigmatic. Therefore, we generated patient-derived organoids (PDOs) from early- and late-recurrent PDAC patients. Cellular identity of PDOs was confirmed by qPCR, ddPCR, and IHC analyses. This is the first study investigating the metabolism in PDOs of different, clinically significant PDAC entities by untargeted GC/MS profiling. Partial least square discriminant analysis unveiled global alterations between the two sample groups. We identified nine metabolites to be increased in early recurrent PDOs in comparison to late recurrent PDOs. More than four-times increased were fumarate, malate, glutamate, aspartate, and glutamine. Hence, α-keto acids were elevated in PDO-conditioned medium derived from early recurrent patients. We therefore speculate that an increased anaplerotic metabolism fuels the Krebs-cycle and a corresponding higher accessibility to energy fastens the recurrence in PDAC patients. Therein, a therapeutic intervention could delay PDAC recurrence and prolong survival of affected patients or could serve as biomarker to predict recurrence in the future.

Metabolic Adaptation during nab-Paclitaxel Resistance in Pancreatic Cancer Cell Lines

Pancreatic ductal adenocarcinoma (PDAC) correlates with high mortality and is about to become one of the major reasons for cancer-related mortality in the next decades. One reason for that high mortality is the limited availability of effective chemotherapy as well as the intrinsic or acquired resistance against it. Here, we report the impact of nab-paclitaxel on the cellular metabolome of PDAC cell lines. After establishment of nab-paclitaxel resistant cell lines, comparison of parental and resistant PDAC cell lines by metabolomics and biochemical assessments revealed altered metabolism, enhanced viability and reduced apoptosis. The results unveiled that acute nab-paclitaxel treatment affected primary metabolism to a minor extent. However, acquisition of resistance led to altered metabolites in both cell lines tested. Specifically, aspartic acid and carbamoyl-aspartic acid were differentially abundant, which might indicate an increased de novo pyrimidine synthesis. This pathway has already shown a similar behavior in other cancerous entities and thus might serve in the future as vulnerable target fighting resistance acquisition occurring in common malignancies.

Selective phytochemicals targeting pancreatic stellate cells as new anti-fibrotic agents for chronic pancreatitis and pancreatic cancer

Activated pancreatic stellate cells (PSCs) have been widely accepted as a key precursor of excessive pancreatic fibrosis, which is a crucial hallmark of chronic pancreatitis (CP) and its formidable associated disease, pancreatic cancer (PC). Hence, anti-fibrotic therapy has been identified as a novel therapeutic strategy for treating CP and PC by targeting PSCs. Most of the anti-fibrotic agents have been limited to phase I/II clinical trials involving vitamin analogs, which are abundant in medicinal plants and have proved to be promising for clinical application. The use of phytomedicines, as new anti-fibrotic agents, has been applied to a variety of complementary and alternative approaches. The aim of this review was to present a focused update on the selective new potential anti-fibrotic agents, including curcumin, resveratrol, rhein, emodin, green tea catechin derivatives, metformin, eruberin A, and ellagic acid, in combating PSC in CP and PC models. It aimed to describe the mechanism(s) of the phytochemicals used, either alone or in combination, and the associated molecular targets. Most of them were tested in PC models with similar mechanism of actions, and curcumin was tested intensively. Future research may explore the issues of bioavailability, drug design, and nano-formulation, in order to achieve successful clinical outcomes with promising activity and tolerability.

Routine Chest Computed Tomography for Staging of Pancreatic Head Carcinoma

OBJECTIVES

The diagnostic value of routine chest computed tomography (CT) in addition to abdominal CT in workup for pancreatic head carcinoma is unclear. The aim of this study was to determine if routine chest CT revealed significant lesions that altered the management of patients with suspected pancreatic head carcinoma.

METHODS

All Dutch pancreatic cancer centers were surveyed on the use of chest CT in preoperative staging. In addition, a single-center retrospective cohort study was performed including all patients referred with suspected pancreatic head malignancy without chest CT between 2005 and 2016. The primary end point was the proportion of patients in which chest CT revealed clinically significant lesions, leading to a change in management.

RESULTS

In 7 of 18 Dutch pancreatic cancer centers (39%), a preoperative chest CT is not routinely performed. In the study cohort, 170 of 848 patients (20%) were referred without chest CT and underwent one by local protocol. Chest CT revealed new suspicious lesions in 17 patients (10%), of whom 6 had metastatic disease (3.5%).

CONCLUSIONS

Routine use of chest CT in diagnostic workup for pancreatic head carcinoma reveals clinically significant lesions in 10% of patients, being metastases in up to 4%.

Clinicopathologic Features and Outcomes of Early-Onset Pancreatic Adenocarcinoma in the United States

BACKGROUND

Limited research has been performed regarding pancreatic ductal adenocarcinoma (PDAC) diagnosed in early-onset patients. This study defined early-onset disease as cancer diagnosed before the age of 50 years and aimed to characterize the clinicopathologic factors associated with early- versus late-onset patients.

METHODS

The National Cancer Database was queried to identify early- and late-onset PDAC patients with cancer diagnosed from 2004 to 2013. Patient demographics, tumor characteristics, treatment regimens, and overall survival (OS) were compared between the groups.

RESULTS

The study enrolled 207,062 patients, including 12,137 early-onset patients (5.9%) and 194,925 late-onset patients (94.1%). The early-onset patients (stage 3 or 4 cancer) were more likely to present with a later stage of disease (62.1% vs. 55.2%; p < 0.001) and to be male (57.1% vs. 50.0%; p < 0.001) than those with late-onset PDAC. The early-onset patients also presented with a lower Charlson/Deyo comorbidity score (80.9% vs. 66.6% had a score of 0; p < 0.001) and received higher rates of treatment (22.8% vs. 40.1% received no treatment, p < 0.001) than the late-onset patients. Furthermore, early-onset PDAC was associated with improved OS among all the PDAC patients (9.2 vs. 6.0 months; p < 0.001) and among the surgically resected patients (27.3 vs. 24.3 months; p < 0.001). Early-onset PDAC also was found to be independently associated with improved OS after adjustment for other significant clinicopathologic factors.

CONCLUSIONS

Despite features suggestive of aggressive tumor biology at presentation, early-onset PDAC was independently associated with better OS than late-onset PDAC among all patients and among curatively resected stage-matched patients.

ARHGAP4 regulates the cell migration and invasion of pancreatic cancer by the HDAC2/β-catenin signaling pathway

β-catenin is a subunit of the cadherin protein complex and acts as an intracellular signal transducer in the Wnt signaling pathway that mediates multiple cellular processes, such as cell migration and invasion. HDAC2 (histone deacetylase 2), a deacetylase that maintains histone H3 in a deacetylated state in the promoter region of Wnt-targeted genes where β-catenin is bound, negatively regulating β-catenin activation. However, the regulation of HDAC2/β-catenin pathway remains unclear. Here, we report ARHGAP4 as a new regulator of the β-catenin pathway that regulates cell invasion and migration of pancreatic cancer as well as the downstream effector MMP2 and MMP9 expression in vitro. Mechanistically, ARHGAP4 interacts with and ubiquitinates HDAC2, which in turn inhibits β-catenin activation. Furthermore, treatment of CAY10683, an HDAC2 inhibitor, and XAV939, a Wnt/β-catenin pathway inhibitor, attenuated the effects of ARHGAP4 silencing on pancreatic cancer cells. Overall, our findings establish ARHGAP4 as a novel regulator of HDAC2/β-catenin pathway with a critical role in tumorigenesis.

Glycolysis promotes the progression of pancreatic cancer and reduces cancer cell sensitivity to gemcitabine

Previous studies have reported that increased glycolytic activity enhances chemotherapy resistance in some types of malignancies. However, whether glycolysis influences the curative effect of gemcitabine (GEM) on pancreatic cancer (PC) cells remains unclear. The aim of this study was to investigate the status of glycolysis in PC and its association with tolerance to GEM. Data from The Cancer Genome Atlas (TCGA) were used to analyze the correlation between glycolysis-related gene (GRG) expression and PC progression and prognosis. 2-Deoxy-D-glucose (2-DG) was applied to assess the effect of glycolysis inhibition on PC cell death and GEM tolerance. Expression of some GRGs, such as HK1, GAPDH, PKM2, and LDHA, was significantly associated with the prognosis of PC. Furthermore, HK1, PKLR, and LDHA expression correlated positively with PC progression. Further analysis revealed that cancer cell death was markedly enhanced following glycolysis inhibition and that the sensitivity of cancer cells to GEM was notably increased in the presence of 2-DG. Our findings indicate that abnormally increased glycolytic activity promotes the development of PC and enhances drug tolerance to GEM. 2-DG combined with GEM is a potential therapy for PC.

Identification of a 4-miRNA signature as a potential prognostic biomarker for pancreatic adenocarcinoma

An microRNA (miRNA) signature to predict the clinical outcome of pancreatic adenocarcinoma (PAAD) is still lacking. In the current study, we aimed at identifying and evaluating a prognostic miRNA signature for patients with PAAD. The miRNA expression profile and the clinical information regarding patients with PAAD were recruited from The Cancer Genome Atlas database. Differentially expressed miRNAs were identified between normal and tumor samples. By means of survival analysis, a 4-miRNA signature for predicting patients' with PAAD overall survival (OS) was constructed. Receiver operating characteristic (ROC) analysis was applied to determine the efficiency of survival prediction. Furthermore, the biological function of the predicted miRNAs was evaluated using a bioinformatics approach. Four (hsa-mir-126, hsa-mir-3613, hsa-mir-424, and hsa-mir-4772) out of 17 differentially expressed miRNAs were associated to the OS of patients with PAAD. Moreover, the area under the curve (AUC) of the constructed 4-miRNA signature associated to patients' with PAAD 2-year survival was 0.789. The multivariate Cox's proportional hazards regression model suggested that this 4-miRNA signature was an independent prognostic factor of other clinical parameters in patients with PAAD. Further pathway enrichment analyses revealed that the miRNAs in the 4-miRNA signature might regulate genes that affect focal adhesion, Wnt signaling pathway, and PI3K-Akt signaling pathway. Thus, these findings indicated that the 4-miRNA signature might be an effective independent prognostic biomarker in the prediction of PAAD patients' survival.

Combination Therapies and Drug Delivery Platforms in Combating Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC), the fourth leading cause of cancer-related death in the United States, is highly aggressive and resistant to both chemo- and radiotherapy. It remains one of the most difficult-to-treat cancers, not only due to its unique pathobiological features such as stroma-rich desmoplastic tumors surrounded by hypovascular and hypoperfused vessels limiting the transport of therapeutic agents, but also due to problematic early detection, which renders most treatment options largely ineffective, resulting in extensive metastasis. To elevate therapeutic effectiveness of treatments and overt their toxicity, significant enthusiasm was generated to exploit new strategies for combating PDAC. Combination therapy targeting different barriers to mitigate delivery issues and reduce tumor recurrence and metastasis has demonstrated optimal outcomes in patients' survival and quality of life, providing possible approaches to overcome therapeutic challenges. This paper aims to provide an overview of currently explored multimodal therapies using either conventional therapy or nanomedicines along with rationale, up-to-date progress, as well as the key challenges that must be overcome. Understanding the future directions of the field may assist in the successful development of novel treatment strategies for enhancing therapeutic efficacy in PDAC.

Novel potential biomarkers for pancreatic cancer - A systematic review

BACKGROUND

It is estimated that in developed countries the incidence rate of pancreatic cancer (PC) will continue to rise and by 2020 will be the second most fatal cancer. The mortality of PC patients closely parallels the incidence rate, as this malignancy remains asymptomatic until it reaches an advanced stage of disease. Thus, novel biochemical markers that improve the management of PC patients are necessary. The aim of the work that follows is to investigate whether selected inflammatory mediators might be used in the diagnosis of PC, with the aim of improving the prognosis for PC patients.

METHODS

We performed a thorough search for literature pertaining to our investigation via the MEDLINE/PubMed database.

RESULTS

It has been proved that certain inflammatory mediators might be involved in tumor progression, such as growth, proliferation, migration and angiogenesis of tumor cells. In the present review, we summarized and referred to a number of original papers concerning the clinical significance of selected cytokines and specific inflammatory proteins such as C-reactive protein, as well as of various matrix metalloproteinases and their tissue inhibitors, as potential biomarkers for PC in comparison to well-established tumor markers for this malignancy.

CONCLUSION

Presented proteins might be potential biomarkers in the diagnosis and progression of PC.

The Impact of Epidemiological Factors and Treatment Interventions on Survival in Patients With Signet Ring Cell Carcinoma of the Pancreas

OBJECTIVES

Primary pancreatic signet ring cell carcinoma (SRCC) is a rare histologic variant of pancreatic carcinoma. A population-based analysis of pancreatic SRCC was performed to determine the predictive effects of epidemiological factors and treatment interventions on overall survival (OS) and disease-specific survival (DSS).

MATERIALS AND METHODS

The Surveillance, Epidemiology, and End Results registry was searched for pancreatic SRCC cases diagnosed between January 1, 1973 and December 31, 2013. Statistical analysis was performed using the Fisher exact test, χ(2) analysis, Kaplan-Meier method, log-rank test, and Cox proportional hazards regression.

RESULTS

The mean age among 497 patients was 66.6 years (SD, 11.9). Most patients were white (82.7%) and male (54.5%). The 1-, 2-, and 5-year OS rates were 17%, 9%, and 4%, respectively, while the corresponding 1-, 2-, and 5-year rates for DSS were 18%, 10%, and 5%, respectively. On univariable analysis; age, site, grade, stage, and treatment were predictive of OS and DSS (P<0.05). On multivariable analysis; radiation improved OS and DSS (adjusted hazard ratio [aHR], 0.592 and 0.589, respectively), pancreatectomy improved OS and DSS (aHR, 0.360 and 0.355, respectively), and combination therapy improved OS and DSS (aHR, 0.295 and 0.286, respectively). Age, site, and stage were also independent predictors of OS and DSS. Subgroup analysis demonstrated treatment to be an independent predictor of OS and DSS in localized/regional disease, in distant disease, and in patients diagnosed between 2000 and 2013.

CONCLUSIONS

Age, site, stage, and treatment independently predict OS and DSS in pancreatic SRCC.

Effects of the MDM-2 inhibitor Nutlin-3a on PDAC cells containing and lacking WT-TP53 on sensitivity to chemotherapy, signal transduction inhibitors and nutraceuticals

Mutations at the TP53 gene are readily detected (approximately 50-75%) in pancreatic ductal adenocarcinoma (PDAC) patients. TP53 was previously thought to be a difficult target as it is often mutated, deleted or inactivated on both chromosomes in certain cancers. In the following study, the effects of restoration of wild-type (WT) TP53 activity on the sensitivities of MIA-PaCa-2 pancreatic cancer cells to the MDM2 inhibitor nutlin-3a in combination with chemotherapy, targeted therapy, as well as, nutraceuticals were examined. Upon introduction of the WT-TP53 gene into MIA-PaCa-2 cells, which contain a TP53 gain of function (GOF) mutation, the sensitivity to the MDM2 inhibitor increased. However, effects of nutlin-3a were also observed in MIA-PaCa-2 cells lacking WT-TP53, as upon co-treatment with nutlin-3a, the sensitivity to certain inhibitors, chemotherapeutic drugs and nutraceuticals increased. Interestingly, co-treatment with nutlin-3a and certain chemotherapeutic drug such as irinotecan and oxaliplatin resulted in antagonistic effects in cells both lacking and containing WT-TP53 activity. These studies indicate the sensitizing abilities that WT-TP53 activity can have in PDAC cells which normally lack WT-TP53, as well as, the effects that the MDM2 inhibitor nutlin-3a can have in both cells containing and lacking WT-TP53 to various therapeutic agents.

Concurrent chemoradiotherapy using proton beams for unresectable locally advanced pancreatic cancer

BACKGROUND AND PURPOSE

We investigated clinical outcomes of proton beam concurrent chemoradiotherapy (CCRT) for unresectable, locally advanced pancreatic cancer (LAPC) patients.

MATERIALS AND METHODS

Records from 42 unresectable LAPC patients (21 male and 21 female, 39-83 years old) with IIB/III clinical staging of 1/41 treated by proton beam CCRT were retrospectively reviewed. Twelve patients received a conventional 50 Gray equivalents (GyE) in 25 fractions protocol and 30 others received a higher dose protocol of 54.0-67.5 GyE in 25-33 fractions. Gemcitabine or S-1 (Tegafur, Gimeracil and Oteracil) was used concurrently. Toxicity, overall survival (OS) and local control (LC) were examined.

RESULTS

Acute adverse events of grades 1, 2, 3 and 4 were found in 4, 15, 17 and 2 patients, respectively. All grade 3 and 4 events were hematologic. Late adverse events of grades 1 and 2 were found in 3 and 2 patients, respectively. No late adverse effects of grade 3 or higher were observed. The 1-year/2-year OS rates from the start of CCRT were 77.8/50.8% with median survival time (MST) of 25.6 months. The 1-year/2-year LC rate from CCRT start was 83.3/78.9% with a median time to local recurrence of more than 36 months. Total irradiation dose was the only significant factor in univariate analyses of OS and LC (p = 0.015 and 0.023, respectively).

CONCLUSION

Proton beam CCRT lengthened survival periods compared to previous photon CCRT data and higher dose irradiation prolonged LC and OS for unresectable LAPC patients. Proton beam therapy is therefore safe and effective in these cases.

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

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

MSC-Delivered Soluble TRAIL and Paclitaxel as Novel Combinatory Treatment for Pancreatic Adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer death in western countries with more than 100,000 new cases per year in Europe and a mortality rate higher than 90%. In this scenario, advanced therapies based on gene therapies are emerging, thanks to a better understanding of tumour architecture and cancer cell alterations. We have demonstrated the efficacy of an innovative approach for pancreatic cancer based on mesenchymal stromal cells (MSC) genetically engineered to produce TNF-related Apoptosis Inducing Ligand (TRAIL). Here we investigated the combination of this MSC-based approach with the administration of a paclitaxel (PTX)-based chemotherapy to improve the potential of the treatment, also accounting for a possible resistance onset.

Methods: Starting from the BXPC3 cell line, we generated and profiled a TRAIL-resistant model of pancreatic cancer, testing the impact of the combined treatment in vitro with specific cytotoxicity and metabolic assays. We then challenged the rationale in a subcutaneous mouse model of pancreatic cancer, assessing its effect on tumour size accounting stromal and parenchymal organization.

Results: PTX was able to restore pancreatic cancer sensitivity to MSC-delivered TRAIL by reverting its pro-survival gene expression profile. The two compounds cooperate both in vitro and in vivo and the combined treatment resulted in an improved cytotoxicity on tumour cells.

Conclusion: In summary, this study uncovers the potential of a combinatory approach between MSC-delivered TRAIL and PTX, supporting the combination of cell-based products and conventional chemotherapeutics as a tool to improve the efficacy of the treatments, also addressing possible mechanisms of resistance.

Cancer information needs according to cancer type: A content analysis of data from Japan's largest cancer information website

The provision of information about cancer is an important aspect of cancer care. Cancer information provided online is expected to meet the needs of information seekers. Whether information needs vary according to tumor site is largely unknown. We aimed to examine similarities and differences in informational needs by cancer type. Data were collected using a questionnaire administered on Japan's largest cancer information website, “Ganjoho service”. A total of 2782 free descriptive responses in the period from April 2012 to December 2017 were analyzed using text-mining software. We identified the top 10 informational need contents, in order of appearance frequency, for eight tumor sites: gastric, colorectal, esophageal, lung, pancreatic, breast, cervical, and prostate cancer. Frequent information needs common to all tumor sites included symptoms, disease stages, treatments, chance of cure, recovery, metastasis, and recurrence. A need for information about diet, pain, side effects of treatments, complementary and alternative medicine was frequent for some tumor sites. Tumor site-specific information should include the following, according to cancer type: information of scirrhous carcinoma for gastric cancer; unusual feces for colorectal cancer; lung X-ray images for lung cancer; early detection for pancreatic cancer; adenocarcinoma, sexual activity, pregnancy, and childbirth for cervical cancer; breast conservation or reconstruction and triple negative cancer for breast cancer; test values and diagnosis and urinary problems for prostate cancer; and hormone therapy for breast and prostate cancer. Cancer information provided online should meet these frequent informational needs, considering similarities and differences of the information required according to tumor site.

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We examined similarities and differences in cancer information needs by tumor site.

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Common needs are symptoms, stages, treatment, cure, recovery, metastasis, recurrence.

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Site-specific needs include diet, pain, side effects, early detection, test values.

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Cancer information should be provided to meet frequent needs, by tumor site.

Transcriptome-wide association study identifies multiple genes and pathways associated with pancreatic cancer

AIM

To identify novel candidate genes for pancreatic cancer.

METHODS

We performed a transcriptome-wide association study (TWAS) analysis of pancreatic cancer (PC). GWAS summary data were driven from the published studies of PC, totally involving 558 542 SNPs in 1896 individuals with pancreatic cancer and 1939 healthy controls. FUSION software was applied to the PC GWAS summary data for tissue-related TWAS analysis, including whole blood, peripheral blood, adipose, and pancreas. The functional relevance of identified genes with PC was further validated by Oncomine, STRING, and CluePedia tool.

RESULTS

Transcriptome-wide association study analysis identified 19 genes significantly associated with PC, such as LRP5L (P value = 5.21 × 10^-5 ), SOX4 (P value = 3.2 × 10^-4 ), and EGLN3 (P value = 6.2 × 10^-3 ). KEGG pathway enrichment analysis detected several PC-associated pathways, such as One carbon pool by folate (P value = 1.60 × 10^-16 ), Cell cycle (P value = 1.27 × 10^-7 ), TGF-beta signaling pathway (P value = 4.64 × 10^-6 ). Further comparing the 19 genes with previously identified overexpressed genes in PC patients found one overlapped gene SOX4.

CONCLUSION

We identified some novel candidate genes and pathways associated with PC. Our results provide novel clues for the genetic mechanism studies of pancreatic cancer.

Long-Term Survivors of Pancreatic Cancer: A California Population-Based Study

OBJECTIVES

Pancreatic cancer continues to carry a poor prognosis with survival rates that have had minimal improvement over the past 4 decades. We report a population-based, comprehensive analysis of long-term survivors of pancreatic adenocarcinoma diagnosed in the diverse population of California.

METHODS

Data from the California Cancer Registry were used to evaluate long-term survival. A total of 70,442 patients diagnosed with pancreatic adenocarcinoma between 1988 and 2009 were identified. Logistic regression was used to identify factors associated with achieving 5-year survival.

RESULTS

The overall 5-year survival was 2.5%, with minimal incremental improvements throughout the 3 decades. Age, stage, degree of differentiation, and surgical resection were associated with 5-year survival. Furthermore, younger age and receiving care at a National Cancer Institute-designated cancer center were similarly correlated with 5-year survival regardless of surgical intervention. In addition, we identified stage, differentiation, and adjuvant chemotherapy as significant factors for long-term survival in surgically resected patients. In the unresectable patients, Asian/Pacific islanders and Hispanics were significantly more likely to reach the 5-year milestone than non-Hispanic whites.

CONCLUSIONS

Although pancreatic cancer mortality remains high, our study highlights baseline characteristics, treatment, biological factors, and ethnicity that are associated with long-term survival. These findings may serve as a springboard for further investigation.

Label-Free Biosensing Method for the Detection of a Pancreatic Cancer Biomarker Based on Dielectrophoresis Spectroscopy

We show that negative dielectrophoresis (DEP) spectroscopy is an effective transduction mechanism of a biosensor for the diagnosis and prognosis of pancreatic cancer using the biomarker CA 19-9. A substantial change in the negative DEP force applied to functionalized polystyrene microspheres (PM) was observed with respect to both the concentration level of the pancreatic cancer biomarker CA 19-9 and the frequency of the electric field produced by a pearl shaped interdigitated gold micro-electrode. The velocity of repulsion of a set of PM functionalized to a monoclonal antibody to CA 19-9 was calculated for several concentration cutoff levels of CA 19-9, including 0 U/mL and 37 U/mL, at the frequency range from 0.5 to 2 MHz. The velocity of repulsion of the PM from the electrode was determined using a side illumination and an automated software using a real-time image processing technique that captures the Mie scattering from the PM. Since negative DEP spectroscopy is an effective transduction mechanism for the detection of the cutoff levels of CA 19-9, it has the potential to be used in the early stage diagnosis and in the prognosis of pancreatic cancer.

Introduction of WT-TP53 into pancreatic cancer cells alters sensitivity to chemotherapeutic drugs, targeted therapeutics and nutraceuticals

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive, highly metastatic malignancy and accounts for 85% of pancreatic cancers. PDAC patients have poor prognosis with a five-year survival of only 5-10%. Mutations at the TP53 gene are readily detected in pancreatic tumors isolated from PDAC patients. We have investigated the effects of restoration of wild-type (WT) TP53 activity on the sensitivity of pancreatic cancer cells to: chemotherapy, targeted therapy, as well as, nutraceuticals. Upon introduction of the WT-TP53 gene into the MIA-PaCa-2 pancreatic cancer cell line, the sensitivity to drugs used to treat pancreatic cancer cells such as: gemcitabine, fluorouracil (5FU), cisplatin, irinotecan, oxaliplatin, and paclitaxel increased significantly. Likewise, the sensitivity to drugs used to treat other cancers such as: doxorubicin, mitoxantrone, and 4 hydroxy tamoxifen (4HT) also increased upon introduction of WT-TP53 into MIA-PaCa-2 cells. Furthermore, the sensitivity to certain inhibitors which target: PI3K/mTORC1, PDK1, SRC, GSK-3, and biochemical processes such as proteasomal degradation and the nutraceutical berberine as increased upon introduction of WT-TP53. Furthermore, in some cases, cells with WT-TP53 were more sensitive to the combination of drugs and suboptimal doses of the MDM2 inhibitor nutlin-3a. However, TP53-independent effects of nutlin-3a were observed upon treatment with either a proteasomal or a PI3K/mTOR inhibitor. These studies indicate the sensitizing effects that WT-TP53 can have in PDAC cells which normally lack WT-TP53 to various therapeutic agents and suggest approaches to improve PDAC therapy.

Comparison of Quality of Life before and after pancreaticoduodenectomy: a prospective study

Background

Pancreatic cancer is an aggressive malignancy, and surgical resection is the only therapeutic option with pancreaticoduodenectomy being considered the standard of care. It is essential to take into account the patients’ Quality of Life after the resection, in order to make more informed decisions about treatment options.

Objective

The aim of the study was to determine perceived Quality of Life levels among patients who undergo pancreaticoduodenectomy, in a period of six months after surgery.

Methods

This prospective study was conducted on all patients (n=40) who underwent pancreaticoduodenectomy in Attikon University General Hospital in Athens, Greece, from January 2013 to June 2015. The Quality of Life was assessed by use of EORTC QLQ-C30 and EORTC QOL-PAN26 questionnaires at four phases: First, after admission at the hospital preoperatively, and then one month, three months, and six months postoperatively. Repeated measurements analysis of variance (ANOVA) was used in order to evaluate changes in Quality of Life measures during the follow-up (postoperative) period. Data analysis was conducted using SPSS version 19. A p-value of less than or equal to 0.05 was set as the level of significance.

Results

The study revealed a mixed image. Except for the nausea and vomiting scale, where indeed a symptom increase is initially reported and then gradually decreases below preoperative levels by 6 months, scoring in many symptom scales worsens postoperatively. From first to fourth assessment, fatigue (Mean from 23.61 to 38.72, p=0.005) and financial difficulties scoring (Mean from 5.98 to 42.42, p<0.001) consistently worsen. Functionality scales scoring also tends to get worse between first and fourth assessment, with statistically significant changes for physical (p<0.001), role (p<0.001) and social functioning (p<0.001). However, a slight improvement can be noted in many scales from third to fourth assessment, as in diarrhea (Mean from 32.38 to 29.29), pancreatic pain (Mean from 17.71 to 2.34), global health status (Mean from 50.48 to 52.53) and social functioning (Mean from 43.81 to 48.48) scales.

Conclusions

Quality of Life levels among patients who undergo pancreaticoduodenectomy are getting worse following surgery. However, the longitudinal study of these changes may improve patients’ postoperative life by formulating evidence-based interventions concerning symptoms treatment and psychological and social support.

Downregulated miR-98-5p promotes PDAC proliferation and metastasis by reversely regulating MAP4K4

BACKGROUND

The aberrant expression of microRNAs (miRNAs) has emerged as important hallmarks of cancer. However, the molecular mechanisms underlying the differences of miRNA expression remain unclear. Many studies have reported that miR-98-5p plays vital functions in the development and progression of multiple cancers. However, its role in pancreatic ductal adenocarcinoma (PDAC) remains unknown.

METHODS

The expression of miR-98-5p and its specific target gene were determined in human PDAC specimens and cell lines by miRNA qRT-PCR, qRT-PCR and western blot. The effects of miR-98-5p depletion or ectopic expression on PDAC proliferation, migration and invasion were evaluated in vitro using CCK-8 proliferation assays, colony formation assays, wound healing assays and transwell assays. Furthermore, the in vivo effects were investigated using the mouse subcutaneous xenotransplantation and pancreatic tail xenotransplantation models. Luciferase reporter assays were employed to identify interactions between miR-98-5p and its specific target gene.

RESULTS

MiR-98-5p expression was significantly lower in cancerous tissues and associated with tumor size, TNM stage, lymph node metastasis and survival. Notably, a series of gain- and loss-of-function assays elucidated that miR-98-5p suppressed PDAC cell proliferation, migration and invasion both in vitro and in vivo. Luciferase reporter assays, western blot and qRT-PCR revealed MAP4K4 to be a direct target of miR-98-5p. The effects of ectopic miR-98-5p were rescued by MAP4K4 overexpression. In contrast, the effects of miR-98-5p depletion were impaired by MAP4K4 knockdown. Furthermore, miR-98-5p suppressed the MAPK/ERK signaling pathway through downregulation of MAP4K4. In addition, the expression level of miR-98-5p was negatively correlated with MAP4K4 expression in PDAC tissues and cell lines.

CONCLUSIONS

These results suggest that downregulation of miR-98-5p promotes tumor development by downregulation of MAP4K4 and inhibition of the downstream MAPK/ERK signaling, thus, highlighting the potential of miR-98-5p as a therapeutic target for PDAC.