Pancreatic Cancer: Current Progress and Future Challenges

MicroRNAs as the critical regulators of epithelial mesenchymal transition in pancreatic tumor cells

Pancreatic cancer (PC), as one of the main endocrine and digestive systems malignancies has the highest cancer related mortality in the world. Lack of the evident clinical symptoms and appropriate diagnostic markers in the early stages of tumor progression are the main reasons of the high mortality rate among PC patients. Therefore, it is necessary to investigate the molecular pathways involved in the PC progression, in order to introduce novel early diagnostic methods. Epithelial mesenchymal transition (EMT) is a critical cellular process associated with pancreatic tumor cells invasion and distant metastasis. MicroRNAs (miRNAs) are also important regulators of EMT process. In the present review, we discussed the role of miRNAs in regulation of EMT process during PC progression. It has been reported that the miRNAs mainly regulate the EMT process in pancreatic tumor cells through the regulation of EMT-specific transcription factors and several signaling pathways such as WNT, NOTCH, TGF-β, JAK/STAT, and PI3K/AKT. Considering the high stability of miRNAs in body fluids and their role in regulation of EMT process, they can be introduced as the non-invasive diagnostic markers in the early stages of malignant pancreatic tumors. This review paves the way to introduce a non-invasive EMT based panel marker for the early tumor detection among PC patients.

Complementary and alternative medicine mention and recommendations in pancreatic cancer clinical practice guidelines: A systematic review and quality assessment

Background

Pancreatic cancer is the third leading cause of cancer death in the United States, which is attributed to limited treatment options. Complementary and alternative medicine (CAM) therapies have been proposed to provide benefits in treating pancreatic cancer. Despite its importance in treatment, clinicians are not generally well equipped to counsel their patients about CAM therapies. This review identified the quantity and assessed the quality of clinical practice guidelines (CPGs) providing CAM recommendations for the treatment and/or management of pancreatic cancer.

Methods

A systematic review was conducted to identify pancreatic cancer CPGs. MEDLINE, EMBASE and CINAHL were searched from 2011 to 2022. The Guidelines International Network (GIN) and the National Center for Complementary and Integrative Health (NCCIH) websites were also searched. Eligible CPGs published by non-profit agencies on treatment and/or management of pancreatic cancer for adults were assessed using the Appraisal of Guidelines, Research and Evaluation II (AGREE II) instrument.

Results

From 31 eligible search results, 7 CPGs mentioned CAM and 3 CPGs made CAM recommendations. The mean scaled domain percentages of the CPGs in this study (overall, CAM-specific) were as follows: scope and purpose (81.3%, 77.8%), stakeholder involvement (63.9%, 42.6%), rigor-of-development (51.0%, 40.3%), clarity-of-presentation (83.3%, 54.6%), applicability (42.3%, 30.5%), and editorial independence (58.3%, 58.3%).

Conclusions

Evaluation of the CPGs demonstrated that quality varied both within and between CPGs. CPGs that scored well could be used by patients and clinicians as the basis for discussion for the use of CAM therapies. Future research should identify other appropriate CAM therapies for further development of CPGs for pancreatic cancer.

Registration

The protocol was registered on PROSPERO (registration number: CRD42022334025).

Elucidating the molecular determinants in the process of gastrin C-terminal pentapeptide amide end activating cholecystokinin 2 receptor by Gaussian accelerated molecular dynamics simulations

Gastrin plays important role in stimulating the initiation and development of many gastrointestinal diseases through interacting with the cholecystokinin 2 receptor (CCK2R). The smallest bioactive unit of gastrin activating CCK2R is the C-terminal tetrapeptide capped with an indispensable amide end. Understanding the mechanism of this smallest bioactive unit interacting with CCK2R on a molecular basis could provide significant insights for designing CCK2R antagonists, which can be used to treat gastrin-related diseases. To this end, we performed extensive Gaussian accelerated molecular dynamics simulations to investigate the interaction between gastrin C-terminal pentapeptide capped with/without amide end and CCK2R. The amide cap influences the binding modes of the pentapeptide with CCK2R by weakening the electrostatic attractions between the C-terminus of the pentapeptide and basic residues near the extracellular domain in CCK2R. The C-terminus with the amide cap penetrates into the transmembrane domain of CCK2R while floating at the extracellular domain without the amide cap. Different binding modes induced different conformational dynamics of CCK2R. Residue pairs in CCK2R had stronger correlated motions when binding with the amidated pentapeptide. Key residues and interactions important for CCK2R binding with the amidated pentagastrin were also identified. Our results provide molecular insights into the determinants of the bioactive unit of gastrin activating CCK2R, which would be of great help for the design of CCK2R antagonists.

Role of epigenetics in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, associated with poor survival outcomes. Lack of early diagnosis, resistance to conventional therapeutic treatments (including immunotherapy) and recurrence are some of the major hurdles in PDAC and contribute to its poor survival rate. While the risk of genetic predisposition to cancers is widely acknowledged and understood, recent advances in whole-genome and next-generation sequencing techniques have led to the acknowledgment of the role played by epigenetics, especially in PDAC. Epigenetic changes are heritable genetic modifications that influence gene expression without altering the DNA sequence. Epigenetic mechanisms (e.g., DNA methylation, post-translational modification of histone complexes and ncRNA) that result in reversible changes in gene expression are increasingly understood to be responsible for tumor initiation, development and even escape from immune surveillance. Our review seeks to highlight the various components of the epigenetic machinery that are known to be implicated in PDAC initiation and development and the feasibility of targeting these components to identify novel pharmacological strategies that could potentially lead to breakthroughs in PDAC treatment.

Contrast-enhanced ultrasound of pancreatic melanoma: A case report and literature review

Melanoma is a malignant tumor that originates from melanocytes, most of which are of cutaneous origin. Most melanomas identified in the pancreas are metastatic, and primary pancreatic melanoma is extremely rare and has rarely been discussed. The correct preoperative diagnosis of pancreatic metastatic melanoma, especially primary melanoma, is challenging. Herein, we report a 43-year-old man who presented to our hospital due to unexplained left abdominal distension and pain. Abdominal ultrasound examination demonstrated multiple space-occupying lesions of the pancreas, and hypoechoic masses partially filled the splenic vein behind the pancreatic body. In the contrast-enhanced ultrasound (CEUS), all of these lesions showed iso-enhancement to slight hypo-enhancement in the arterial phase and hypo-enhancement in the venous phase. Masses in the splenic vein also showed hypo-enhancement. Imaging features suggested that the pancreatic lesions were malignant tumors. The tumor markers carcinoembryonic antigen, carbohydrate antigen 125 and carbohydrate antigen 19-9 were within normal limits. Based on clinical symptoms, imaging findings and incidence of pancreatic tumors, the patient’s clinical diagnosis was pancreatic carcinoma. Surgery was performed for the patient, while postoperative pathology confirmed malignant melanoma of the pancreas. Therefore, it is significant to identify the clinical and imaging manifestations of pancreatic melanoma in order to better manage the disease. Herein, we reported this case and reviewed the literature from 2000 to 2021 on the clinical and imaging features of 26 patients with pancreatic melanoma. It may improve clinicians’ awareness of the clinical and imaging performance of pancreatic melanoma, resulting in improved diagnosis, differential diagnosis, treatment, and outcomes.

Comprehensive Analysis of Expression, Prognostic Value, and Immune Infiltration for Ubiquitination-Related FBXOs in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most refractory human malignancies. F-box only proteins (FBXO) are the core components of SKP1-cullin 1-F-box E3 ubiquitin ligase, which have been reported to play crucial roles in tumor initiation and progression via ubiquitination-mediated proteasomal degradation. However, the clinical implications and biological functions of FBXOs in PDAC have not been fully clarified. Herein we perform a comprehensive analysis for the clinical values and functional roles of FBXOs in PDAC using different public databases. We found that FBXO1 (CCNF), FBXO20 (LMO7), FBXO22, FBXO28, FBXO32, and FBXO45 (designated six-FBXOs) were robustly upregulated in PDAC tissues, which predicted an adverse prognosis of PDAC patients. There was a significant correlation between the expression levels of six-FBXOs and the clinicopathological features in PDAC. The transcriptional levels of six-FBXOs were subjected to the influence of promoter methylation levels. There were more than 40% genetic alterations and mutations of six-FBXOs, which affected the clinical outcome of PDAC patients. Furthermore, the expression of six-FBXOs was associated with immune infiltrations and activated status, including B cells, CD8⁺ T cells, CD4⁺ T cells, NK cells, macrophages, and dendritic cells. The functional prediction revealed that the six-FBXOs were involved in ubiquitination-related pathways and other vital signaling pathways, such as p53, PI3K/Akt, and Hippo pathway. Therefore, six-FBXOs are the promising prognostic biomarkers or potential targets for PDAC diagnosis and treatment.

microRNA-21 Regulates Stemness in Pancreatic Ductal Adenocarcinoma Cells

Pancreatic ductal adenocarcinoma (PDAC) is the most common and aggressive type of pancreatic cancer (PCa) with a low survival rate. microRNAs (miRs) are endogenous, non-coding RNAs that moderate numerous biological processes. miRs have been associated with the chemoresistance and metastasis of PDAC and the presence of a subpopulation of highly plastic "stem"-like cells within the tumor, known as cancer stem cells (CSCs). In this study, we investigated the role of miR-21, which is highly expressed in Panc-1 and MiaPaCa-2 PDAC cells in association with CSCs. Following miR-21 knockouts (KO) from both MiaPaCa-2 and Panc-1 cell lines, reversed expressions of epithelial-mesenchymal transition (EMT) and CSCs markers were observed. The expression patterns of key CSC markers, including CD44, CD133, CX-C chemokine receptor type 4 (CXCR4), and aldehyde dehydrogenase-1 (ALDH1), were changed depending on miR-21 status. miR-21 (KO) suppressed cellular invasion of Panc-1 and MiaPaCa-2 cells, as well as the cellular proliferation of MiaPaCa-2 cells. Our data suggest that miR-21 is involved in the stemness of PDAC cells, may play roles in mesenchymal transition, and that miR-21 poses as a novel, functional biomarker for PDAC aggressiveness.

Knockdown of LRRN1 inhibits malignant phenotypes through the regulation of HIF-1α/Notch pathway in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most refractory and fatal human malignancies. Leucine-rich repeat neuronal protein-1 (LRRN1) plays a crucial role in the development of the nervous system. However, the clinical implications and biological functions of LRRN1 in PDAC remain unclear. We found that LRRN1 expression was upregulated in PDAC tissues compared with paracancerous tissues and normal pancreatic tissues through the different public databases, tissue microarray-based immunohistochemistry, and dimethylbenzanthracene-induced PDAC murine model. The expression level of LRRN1 was closely related to the overall survival and disease-free survival of PDAC patients. Cox multivariate analysis indicated that LRRN1 was an independent adverse prognostic factor. The small hairpin RNA (shRNA)-mediated LRRN1 knockdown remarkably restrained the proliferative, migratory, and invasive capacities, as well as promoted cell apoptosis and increased G0/G1 arrest in PDAC cells. The xenograft murine subcutaneous bearing model and metastasis model verified that silencing of LRRN1 effectively dampened tumor growth and metastasis in vivo. Specifically, LRRN1 exerted its biological functions through the HIF-1α/Notch signaling pathway, and LRRN1 knockdown could dampen Jagged 1-mediated Notch pathway activation. Therefore, LRRN1 could serve as the potential therapeutic or prognostic target for PDAC.

Systematic review and trial sequential analysis of high-intensity focused ultrasound combined with chemotherapy versus chemotherapy in the treatment of unresectable pancreatic ductal adenocarcinoma

PURPOSE

This study aimed to compare the survival benefits between high-intensity focused ultrasound (HIFU) combined with chemotherapy and chemotherapy alone in patients with unresectable pancreatic ductal adenocarcinoma (PDAC).

METHODS

All randomized clinical trials (RCTs) and observational studies were systematically searched through the databases of PubMed, EMBASE, CNKi and CQVIP up to December 2020. Case reports, case series and nonsystematic reviews were excluded. A meta-analysis was conducted to generate combined hazard ratios (HRs) with 95% confidence intervals (CI) for overall survival (OS).

RESULTS

Seven trials, containing a total of 992 patients, were included in this study. The meta-analysis showed that a combination of HIFU and chemotherapy increased overall survival compared with chemotherapy alone, with a pooled HR of 0.40 (95% confidence interval [CI], 0.28-0.58). The combined therapy group had a significant advantage in 1-year survival rate (OR: 0.35, 95% CI: 0.22-0.53, p = 0.00). The trial sequence analysis (TSA) showed that there were enough trials to control for random errors.

CONCLUSION

Our analysis suggests that HIFU combined with chemotherapy intravenously will prolong survival for unresectable PDAC patients. The TSA showed that the survival benefit of combined therapy was definitive and there was no need to expand the sample size for repetitive exploration.

JAK/STAT of all trades: Linking inflammation with cancer development, tumor progression, and therapy resistance

Inflammation is at the forefront of carcinogenesis, tumor progression, and resistance to therapy. The JAK/STAT signaling axis is a central pathway that mediates the cellular response to inflammation and contributes to carcinogenesis. The JAK/STAT pathway coordinates intercellular communication between tumor cells and their immune microenvironment, and JAK/STAT activation leads to the expression of a variety of proteins involved in cell proliferation, cell survival, stemness, self-renewal, evasion of immunosurveillance mechanisms, and overall tumor progression. Activation of JAK/STAT signaling also mediates resistance to radiation therapy or cytotoxic agents, and modulates tumor cell responses to molecularly targeted and immune modulating drugs. Despite extensive research focused on understanding its signaling mechanisms and downstream phenotypic and functional consequences in hematological disorders, the importance of JAK/STAT signaling in solid tumor initiation and progression has been underappreciated. We highlight the role of chronic inflammation in cancer, the epidemiological evidence for contribution of JAK/STAT to carcinogenesis, the current cancer prevention measures involving JAK/STAT inhibition, and the impact of JAK/STAT signaling activity on cancer development, progression, and treatment resistance. We also discuss recent therapeutic advances in targeting key factors within the JAK/STAT pathway with single agents, and the use of these agents in combination with other targeted therapies and immune checkpoint inhibitors.

Non-coding RNAs in pancreatic ductal adenocarcinoma: New approaches for better diagnosis and therapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies with a 5-year survival rate less than 8%, which has remained unchanged over the last 50 years. Early detection is particularly difficult due to the lack of disease-specific symptoms and a reliable biomarker. Multimodality treatment including chemotherapy, radiotherapy (used sparingly) and surgery has become the standard of care for patients with PDAC. Carbohydrate antigen 19-9 (CA 19-9) is the most common diagnostic biomarker; however, it is not specific enough especially for asymptomatic patients. Non-coding RNAs are often deregulated in human malignancies and shown to be involved in cancer-related mechanisms such as cell growth, differentiation, and cell death. Several micro, long non-coding and circular RNAs have been reported to date which are involved in PDAC. Aim of this review is to discuss the roles and functions of non-coding RNAs in diagnosis and treatments of PDAC.

Efficacy of Chemotherapy Integrated With Traditional Korean Medicine in Patients With Metastatic Pancreatic Cancer: A Single-Center Retrospective Study

Background:

This retrospective study investigated the efficacy and safety of chemotherapy (CTX) integrated with Traditional Korean Medicine (TKM) in patients with metastatic pancreatic cancer, in a single Korean center.

Methods:

From January, 2014 to February, 2019, patients with metastatic pancreatic cancer who had received CTX were enrolled. Overall survival (OS), demographic characteristics, and adverse events were examined. Statistical analysis was utilized to evaluate the differences in characteristics and to compare the survival rates between the CTX group and CTX+TKM group. Kaplan-Meier curves were used to compare the differences in survival time. A Cox regression analysis was performed to determine the hazard ratio of the risk of mortality.

Results:

A total 37 participants were included and visited a TKM hospital 7.4 ± 8.3 months after being diagnosed with metastatic pancreatic cancer. The median age of the participants was 62 years; 26 patients (70.3%) had an Eastern Cooperative Oncology Group (ECOG) performance status between 0 and 2, and 23 patients (62.2 %) had first-line CTX failure. The median OS of all patients was 3.8 months (95% CI, 3.1-4.6). The CTX + TKM group showed longer survival (4.1 months; 95% CI, 2.4- .8) than the CTX group (2.4 months, 95% CI 0.2-4.6) but this was not statistically significant (P = .217). Chemotherapy with TKM treatment for more than 30 days (CTX + TKM ≥ 30) significantly prolonged median OS (9.1 months; 95% CI, 3.6-14.5; P = .025) compared to chemotherapy alone. Cox hazard ratio analysis revealed that CTX + TKM ≥ 30 and prior chemotherapy were significantly independent prognostic factors for OS. The main herbs in the TKM treatment were Rhus verniciflua Stokes and Astragalus. Severe adverse events with respect to TKM treatment were not reported.

Conclusions:

TKM treatment integrated with chemotherapy may prolong OS in patients with metastatic pancreatic cancer compared to chemotherapy treatment alone. More rigorous prospective clinical trials are needed to confirm this result.

A panel of 8 miRNAs as a novel diagnostic biomarker in pancreatic cancer

Pancreatic cancer (PC) is one of the major causes of cancer mortality in developed countries. Therefore, there is an urgent need to derive biomarkers for early diagnosis of PC patients at high risk.This study was designed to identify a panel of miRNAs that might serve as biomarkers for the early diagnosis of PC.The data containing both PC and control samples were extracted from the Gene Expression Omnibus (GEO) database. EdgeR was applied to identify the differentially expressed miRNAs and genes between PC patients and healthy controls. Then a miRNA-mRNA network was constructed based on the differentially expressed miRNAs and genes. The miRNAs-based biomarker for PC was finally constructed by random forest. Finally, AUC was used to evaluate the performance of miRNAs to classify PC and control samples.A total of 33 differentially expressed miRNAs, 753 differentially expressed genes, and 8 miRNAs (hsa-mir-139, hsa-mir-31, hsa-mir-196b, hsa-mir-221, hsa-mir-203b, hsa-mir-215, hsa-mir-144, and hsa-mir-4433b) that play important roles in PC were identified. The target genes of these miRNAs were found to be mainly enriched in negative regulation of acute inflammatory response cell-substrate responses, and o-glycan processing pathways. The constructed biomarkers based on these 8 miRNAs could distinguish samples coming from PC and healthy controls.We identified a panel of eight-miRNAs that would serve as early diagnostic biomarkers for PC patients.

LncRNA OIP5-AS1 promotes the malignancy of pancreatic ductal adenocarcinoma via regulating miR-429/FOXD1/ERK pathway

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), a subtype of pancreatic cancer, is a malignant tumor with unfavorable prognosis. Despite accumulating researches have made efforts on finding novel therapeutic methods for this disease, the underlying mechanism of long non-coding RNAs (lncRNAs) remains elusive. OIP5 antisense RNA 1 (OIP5-AS1) has been reported to play important role in the occurrence and development of multiple human cancers. This study was aimed at unveiling the regulatory role of OIP5-AS1 in PDAC.

METHODS

RT-qPCR analysis revealed the OIP5-AS1 expression in PDAC tissues and adjacent normal ones. Kaplan-Meier method was applied to analyze the overall survival of patients with high or low level of OIP5-AS1. Gain- or loss-of function assays were performed to assess the effects of OIP5-AS1 knockdown on cell functions, including proliferation, migration and EMT process. Mechanism experiments, such as luciferase reporter and RNA pull-down assays proved the interaction between OIP5-AS1 and miR-429 as well as that between miR-429 and FOXD1.

RESULTS

OIP5-AS1 was up-regulated in PDAC tissues and cell lines, and high level of OIP5-AS1 indicated poor prognosis in PDAC patients. OIP5-AS1 knockdown hindered cell proliferation, migration and epithelial-mesenchymal transition (EMT) process, while overexpression of OIP5-AS1 caused the opposite results. OIP5-AS1 activated ERK pathway through up-regulating forkhead box D1 (FOXD1) expression by sponging miR-429. Furthermore, OIP5-AS1 facilitated cell growth in vivo.

CONCLUSION

OIP5-AS1 exerted oncogenic function in PDAC cells through targeting miR-429/FOXD1/ERK pathway.

Apoptosis induction and proliferation inhibition by silibinin encapsulated in nanoparticles in MIA PaCa-2 cancer cells and deregulation of some miRNAs

OBJECTIVES

Silibinin, as an herbal compound, has anti-cancer activity. Because of low solubility of silibinin in water and body fluids, it was encapsulated in polymersome nanoparticles and its effects were evaluated on pancreatic cancer cells and cancer stem cells.

MATERIALS AND METHODS

MIA PaCa-2 pancreatic cancer cells were treated with different doses of silibinin encapsulated in polymersome nanoparticles (SPNs). Stemness of MIA PaCa-2 cells was evaluated by hanging drop technique and CD133, CD24, and CD44 staining. The effects of SPNs on cell cycle, apoptosis and the expression of several genes and miRNAs were investigated.

RESULTS

IC50 of SPNs was determined to be 40 µg/ml after 24 hr. Our analysis showed that >98% of MIA PaCa-2 cells expressed three stem cell markers. FACS analysis showed a decrease in these markers in SPNs-treated cells. PI/AnnexinV staining revealed that 40 µg/ml and 50 µg/ml of SPNs increased apoptosis up to ~40% and >80% of treated cells, respectively. Upregulation of miR-34a, miR-126, and miR-let7b and downregulation of miR-155, miR-222 and miR-21 was observed in SPNs-treated cells. In addition, downregulation of some genes involved in proliferation or migration such as AKT3, MASPINE, and SERPINEA12, and upregulation of apoptotic genes were observed in treated cells.

CONCLUSION

Our results suggested that SPNs induced apoptosis and inhibited migration and proliferation in pancreatic cells and cancer stem cells through suppression of some onco-miRs and induction of some tumor suppressive miRs, as well as their targets.

Oxytocin and oxytocin receptor alterations, decreased survival, and increased chemoresistance in patients with pancreatic cancer

BACKGROUND

Oxytocin (OXT) and its receptor (OXTR) is associated with cancer. The present study was to investigate the correlation between the genetic expression alterations of OXT and OXTR and the outcomes in patients with pancreatic cancer (PC).

METHODS

Information regarding OXT and OXTR genetic alterations and changes in gene expression were retrieved from the Cancer Genome Atlas (TCGA) databases and analyzed using the cBioPortal online tool. We assessed the correlation of overall survival and disease/progression-free months to either OXT or OXTR genetic alterations and changes in gene expression using Kaplan-Meier and Cox regression analyses. Quantitative PCR (qPCR) was conducted to assess the mRNA expression levels of OXT and OXTR in human PC cell lines.

RESULTS

Five percent of PC cases showed mRNA upregulation in the OXT gene. These PC cases also showed genetic alterations and changes in gene expression of OXTR. The median months of survival and disease-free survival were lower for PC cases with genetic alterations and changes in gene expression in the OXT and OXTR genes as compared to those without such alterations. qPCR data showed that OXT and OXTR mRNA expression were 1-fold and 10-fold higher, respectively in PANC-1 cell lines as compared to L3.6pl cell lines in direct negative correlation with responsiveness to gemcitabine.

CONCLUSIONS

These data suggest that OXT and OXTR may potentially be important in PC progression, chemoresistance, and patient survival, and potentially could have prognostic and therapeutic implications in a subset of PC patients.

ERO1α promotes hypoxic tumor progression and is associated with poor prognosis in pancreatic cancer

Pancreatic cancer is a leading cause of mortality worldwide due to the difficulty of detecting early-stage disease and our poor understanding of the mediators that drive progression of hypoxic solid tumors. We therefore used a heavy isotope 'pulse/trace' proteomic approach to determine how hypoxia (Hx) alters pancreatic tumor expression of proteins that confer treatment resistance, promote metastasis, and suppress host immunity. Using this method, we identified that hypoxia stress stimulates pancreatic cancer cells to rapidly translate proteins that enhance metastasis (NOTCH2, NCS1, CD151, NUSAP1), treatment resistance (ABCB6), immune suppression (NFIL3, WDR4), angiogenesis (ANGPT4, ERO1α, FOS), alter cell metabolic activity (HK2, ENO2), and mediate growth-promoting cytokine responses (CLK3, ANGPTL4). Database mining confirmed that elevated gene expression of these hypoxia-induced mediators is significantly associated with poor patient survival in various stages of pancreatic cancer. Among these proteins, the oxidoreductase enzyme ERO1α was highly sensitive to induction by hypoxia stress across a range of different pancreatic cancer cell lines and was associated with particularly poor prognosis in human patients. Consistent with these data, genetic deletion of ERO1α substantially reduced growth rates and colony formation by pancreatic cancer cells when assessed in a series of functional assays in vitro. Accordingly, when transferred into a mouse xenograft model, ERO1α-deficient tumor cells exhibited severe growth restriction and negligible disease progression in vivo. Together, these data indicate that ERO1α is potential prognostic biomarker and novel drug target for pancreatic cancer therapy.

Tumor-Derived Extracellular Vesicles as a Novel Source of Protein Biomarkers for Cancer Diagnosis and Monitoring

"Liquid biopsies" have received attention as a complementary tool for traditional tissue biopsies that may enhance the spectrum of analysis for tumor-derived factors. One such factor gaining prominence in the liquid biopsy field is extracellular vesicles (EVs), membrane-bound nanovesicles which are secreted by cells into biofluids such as blood, urine, and saliva. EVs are released in both physiological and pathological conditions and can transport a variety of molecules, including proteins, metabolites, RNA, microRNAs, and DNA, to distant sites throughout the body. As such, they are emerging as a promising source of tumor biomarkers for the noninvasive diagnosis, prognosis, and monitoring of cancer patients. In particular, the wealth of tumor-related information that can be gleaned from the EV proteomic cargo has become apparent through mass spectrometric analysis, which has provided new benchmarks for clinically focused biomarker research. In this review, the current achievements in the use of MS for identifying potential EV-derived protein biomarkers of cancer are explored, and the techniques and challenges involved in this pursuit are summarized.

High expression of RAB38 promotes malignant progression of pancreatic cancer

Ras-Related Protein Rab-38 (RAB38), which belongs to the RAB family, is involved in the biogenesis of lysosome-related organelles and defense against certain microbial infections. However, the clinical significance and potential function of RAB38 in pancreatic adenocarcinoma remain unclear. In the present study, an immunohistochemical assay was performed to analyze the expression of RAB38 in pancreatic adenocarcinoma tumor specimens from 82 patients, and the clinicopathological characteristics and survival rate of these patients were further examined. To validate the role of RAB38 in tumors, the effect of RAB38 on tumor cell proliferation, migration and invasion was assessed by establishing RAB38 knockdown cell lines. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to examine the expression levels of proteins associated with the cancer cell behavior. In addition, the inhibitory effect of RAB38 silencing on pancreatic cancer was examined in mice. The immunohistochemistry results revealed that RAB38 was upregulated and positively correlated with the grade of progression in pancreatic adenocarcinoma patients. Further investigation indicated that RAB38 downregulation significantly suppressed the proliferation, migration and invasive capacity of pancreatic cancer cells, as well as decreased the expression levels of Ki67, proliferating cell nuclear antigen, and matrix metalloproteinases 2 and 9. RAB38 silencing also inhibited the development of pancreatic cancer in vivo. Taken together, a high level of RAB38 was significantly associated with the malignant phenotypes of pancreatic cancer, suggesting that RAB38 may serve as a novel biomarker and a potential therapeutic target for pancreatic cancer.

Dysregulation of key microRNAs in pancreatic cancer development

Pancreatic cancer (PC) is mentioned as one of the fourth major cause of cancer-related deaths and also is considered as one of the most malignancies worldwide. Sadly, widely metastasis is frequently observed at the time of PC detection and there are, thereby, almost poor prognosis and ineffective treatment in PC patients. microRNAs (miRNAs), a group of short non-coding RNAs, regulate various cellular and developmental mechanisms, such as cell growth, proliferation, apoptosis, differentiation and angiogenesis. Also, they have essential roles even on the progression of different human and animal diseases. In recent years, extensive studies confirmed the important role of miRNAs in various steps of PC developments, including; tumor initiation, invasion and metastasis, which can use valuably for cancer detection, prognosis and therapy. Therefore, the present study reviewed the new recent investigations in miRNAs involvement in the biology of PC associated with their clinical implications.

A mouse model for pain and neuroplastic changes associated with pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) continues to be one of the deadliest human malignancies and is associated with excruciating pain, which is a serious complication and severely impacts the quality of life in patients. In human patients, poor survival prognosis is linked to remarkable remodeling of intrapancreatic nerves, which, in turn, is correlated to increased pain intensity. Understanding mechanisms underlying pain associated with PDAC has been hampered by the lack of animal models which replicate all germane aspects of the disease and importantly, enable analyses of pain associated with PDAC. In this study, we describe an immunocompetent orthotopic mouse model of PDAC involving intrapancreatic growth of K8484 mouse PDAC cells, which reliably exhibits a large number of key characteristics of human PDAC, including its unique histopathology and neuroplastic changes. We observed that tumor-bearing mice demonstrated significant abdominal mechanical hypersensitivity to von Frey stimuli as well as on-going pain in the conditioned place preference paradigm. Moreover, a myriad of other behavioral tests revealed that indicators of overall well-being were significantly reduced in tumor-bearing mice as compared to sham mice. Morphological and immunohistochemical analyses revealed structural remodeling in several different types of sensory and autonomic nerve fibers. Finally, perineural invasion of tumor cells, a cardinal manifestation in human PDAC, was also observed in our orthotopic mouse model. Thus, we describe a validated tumor model for quantitatively testing hypersensitivity and pain in PDAC, which lays a crucial basis for interrogating tumor-nerve interactions and the molecular and cellular mechanisms underlying pain in PDAC.

Glypican-1-antibody-conjugated Gd-Au nanoclusters for FI/MRI dual-modal targeted detection of pancreatic cancer

Introduction

Pancreatic cancer (PC) has a poor prognosis with high mortality, due to the lack of effective early diagnostic and prognostic tools.

Materials and methods

In order to target and diagnose PC, we developed a dual-modal imaging probe using Glypican-1 (GPC-1) antibody conjugated with Gd–Au nanoclusters (NCs; Gd-Au-NC-GPC-1). GPC-1 is a type of cell surface heparan sulfate proteoglycan, which is often highly expressed in PC. The probe was successfully prepared with a hydrodynamic diameter ranging from 13.5 to 24.4 nm.

Results

Spectral characteristics showed absorption at 280 nm and prominent emission at 650 nm. Confocal microscopic imaging showed effective detection of GPC-1 highly expressed PC cells by Gd-Au-NC-GPC-1, which was consistent with flow cytometry results. In vitro relaxivity characterization demonstrated that the r1 value of the probe was 17.722 s⁻¹ mM⁻¹ Gd, which was almost 4 times higher compared with that of Gd-diethylenetriaminepentacetate (DTPA; r1 value =4.6 s⁻¹ mM⁻¹ Gd). Gd-Au-NC-GPC-1 exhibited similar magnetic resonance (MR) signals when compared to Gd-DTPA even at lower Gd concentrations. Much higher MR signals were registered in PC cells (COLO-357) compared with normal cells (293T). Furthermore, Gd-Au-NC-GPC-1 could effectively detect PC cells in vivo by dual-modal fluorescence imaging/magnetic resonance imaging (FI/MRI) at 30 minutes postinjection. In addition, Gd-Au-NC-GPC-1 did not show significant biotoxicity to normal cells at tested concentrations both in vitro and in vivo.

Conclusion

Gd-Au-NC-GPC-1 has demonstrated to be a promising dual-modal FI/MRI contrast agent for targeted diagnosis of PC.

Long non-coding RNA SNHG15 inhibits P15 and KLF2 expression to promote pancreatic cancer proliferation through EZH2-mediated H3K27me3

Long non-coding RNA (lncRNA) is emerging as an critical regulator in multiple cancers, including pancreatic cancer (PC). Recently, lncRNA SNHG15 was found to be up-regulated in gastric cancer and hepatocellular carcinoma, exerting oncogenic effects. Nevertheless, the biological function and regulatory mechanism of SNHG15 remain unclear in pancreatic cancer (PC). In this study, we reported that SNHG15 expression was also upregulated in PC tissues, and its overexpression was remarkably associated with tumor size, tumor node metastasis (TNM) stage and lymph node metastasis in patients with PC. SNHG15 knockdown inhibited proliferative capacities and suppressed apoptotic rate of PC cells in vitro, and impaired in-vivo tumorigenicity. Additionally, RNA immunoprecipitation (RIP) assays showed that SNHG15 epigenetically repressed the P15 and Kruppel-like factor 2 (KLF2) expression via binding to enhancer of zeste homolog 2 (EZH2), and chromatin immunoprecipitation assays (CHIP) assays demonstrated that EZH2 was capable of binding to promoter regions of P15 and KLF2 to induce histone H3 lysine 27 trimethylation (H3K27me3). Furthermore, rescue experiments indicated that SNHG15 oncogenic function partially involved P15 and KLF2 repression. Consistently, an inverse correlation between the expression of SNHG15 and traget genes were found in PC tissues. Our results reported that SNHG15 could act as an oncogene in PC, revealing its potential value as a biomarker for early detection and individualized therapy.

Effects of arginine-glycine-aspartic acid peptide-conjugated quantum dots-induced photodynamic therapy on pancreatic carcinoma in vivo

Quantum dots (QDs) conjugated with integrin antagonist arginine-glycine-aspartic acid (RGD) peptides (QDs-RGD) are novel nanomaterials with a unique optical property: a high molar extinction coefficient. Previously, we have shown that QDs-RGD demonstrate a photodynamic therapy (PDT) effect as new photosensitizers for the pancreatic cancer cell line SW1990 in vitro. Here, we investigate the application of QDs-RGD in mice bearing pancreatic tumors using PDT. To ensure that more photosensitizers accumulated in tumors, QDs-RGD were injected intratumorally. After selection of an adequate dosage for injection from analyses of biodistribution images captured by an IVIS system, PDT was initiated. Three groups were created according to different PDT procedures. In group 1, mice were injected with QDs-RGD intratumorally, and an optical fiber connected to a laser light was inserted directly into the tumor. Irradiation was sustained for 20 min with a laser light (630 nm) at 100 mW/cm2. In group 2, the laser optical fiber was placed around, and not inserted into, tumors. In group 3, PDT was conducted as in group 1 but without injection of QDs-RGD. After 28 days of observation, tumors on the back of mice in group 1 grew slowly (V/V0 =3.24±0.70) compared with the control groups, whose tumors grew quickly, and the mean V/V0 reached 6.08±0.50 (group 2) and 7.25±0.82 (group 3). Histology of tumor tissues showed more necrotic tissues, more inflammatory cells, and less vascular tissue in the PDT group than those in the control groups. These results suggest that QDs-RGD-mediated PDT, with illumination using an optical fiber inserted directly into the tumor, can inhibit the growth of SW1990 tumors with high efficiency in nude mice.

Natural Products as Adjunctive Treatment for Pancreatic Cancer: Recent Trends and Advancements

Pancreatic cancer is a type of common malignant tumors with high occurrence in the world. Most patients presented in clinic had pancreatic cancer at advanced stages. Furthermore, chemotherapy or radiotherapy had very limited success in treating pancreatic cancer. Complementary and alternative medicines, such as natural products/herbal medicines, represent exciting adjunctive therapies. In this review, we summarize the recent advances of using natural products/herbal medicines, such as Chinese herbal medicine, in combination with conventional chemotherapeutic agents to treat pancreatic cancer in preclinical and clinical trials.

The Expression and Prognostic Roles of MCMs in Pancreatic Cancer

OBJECTIVES

Minichromosome maintenance (MCM) proteins play important roles in DNA replication by interacting with other factors which participate in the regulation of DNA synthesis. Abnormal over-expression of MCMs was observed in numerous malignancies, such as colorectal cancer. However, the expression of MCMs in pancreatic cancer (PC) was less investigated so far. This study was designed to analyze the expression and prognostic roles of MCM1-10 in PC based on the data provided by The Cancer Genome Atlas (TCGA).

METHODS

Pearson χ2 test was applied to evaluate the association of MCMs expression with clinicopathologic indicators, and biomarkers for tumor biological behaviors. Kaplan-Meier plots and log-rank tests were used to assess survival analysis, and univariate and multivariate Cox proportional hazard regression models were used to recognize independent prognostic factors.

RESULTS

MCM1-10 were generally expressed in PC samples. The levels of some molecules were markedly correlated with that of biomarkers for S phase, proliferation, gemcitabine resistance. And part of these molecules over-expression was significantly associated with indicators of disease progression, such as depth of tumor invasion and lymph node metastasis. Furthermore, MCM2, 4, 6, 8, and 10 over-expression was remarkably associated with shorter disease free survival time, and MCM2, 4,8, and 10 over-expression was associated with shorter overall survival time. Further multivariate analysis suggested that MCM8 was an independent prognostic factor for PC.

CONCLUSION

MCMs abnormal over-expression was significantly associated with PC progression and prognosis. These molecules could be regarded as prognostic and therapeutic biomarkers for PC. The roles of MCMs may be vitally important and the underlying mechanisms need to be furtherinvestigated.

Long non-coding RNA IRAIN suppresses apoptosis and promotes proliferation by binding to LSD1 and EZH2 in pancreatic cancer

Long non-coding RNA (lncRNA) modulates gene expression, while lncRNA dysregulation is associated with human cancer. Furthermore, while recent studies have shown that lncRNA IRAIN plays an important role in other malignancies, the role of IRAIN in pancreatic cancer (PC) progression remains unclear. In this study, we found that upregulation of lncRNA IRAIN was significantly correlated with tumor size, TNM stage, and lymph node metastasis in a cohort of 37 PC patients. In vitro experiments showed that knockdown of IRAIN by small interfering RNA (siRNA) significantly induced cell apoptosis and inhibited cell proliferation in both BxPC-3 and PANC-1 cells. Further mechanism study showed that, by binding to histone demethylase lysine-specific demethylase 1 (LSD1), an enhancer of zeste homolog 2 (EZH2), IRAIN reduced PC tumor cell apoptosis and induced growth arrest by silencing the expression of Kruppel-like factor 2 (KLF2) and P15. Moreover, IRAIN expression was inversely correlated with that of KLF2 and P15 in PC tissues. To our knowledge, this is the first report elucidating the role and mechanism of IRAIN in PC progression.