Progress in the treatment of metastatic pancreatic cancer and the search for next opportunities

Successful immunotherapy with PD-1 Iinhibitor for advanced pancreatic cancer: report of two cases and review of literature

Pancreatic cancer is a highly malignant tumor, and most patients are diagnosed at an advanced stage. Unfortunately, due to the immunosuppressive tumor microenvironment of pancreatic cancer, the benefits of immunotherapy for patients with advanced pancreatic cancer are still unclear. Here, we present two cases of advanced pancreatic cancer being controlled by immunotherapy, with pathological diagnoses of ductal adenocarcinoma and acinar cell carcinoma, respectively. Next-generation sequencing (NGS) of both patients is high tumor mutation burden (tumor mutation burden-High) and microsatellite stable. The patient with pancreatic ductal adenocarcinoma was diagnosed as a locally advanced disease (stage III). She received irreversible electroporation, used the programmed death receptor-1 (PD-1) inhibitor (pembrolizumab) combined with chemotherapy (S-1), and then used only the PD-1 inhibitor as a maintenance treatment. As a result, the patient's lesion was significantly reduced, with a partial response time of up to 31 months. The patient with acinar cell carcinoma was diagnosed as a metastatic disease (stage IV), next-generation sequencing revealed mutations in SMAD4 and KMT2D, and two chemotherapy regimens were used unsuccessfully. Then, the combination of chemotherapy with PD-1 (tislelizumab) and vascular endothelial growth factor/vascular endothelial growth factor receptor (anlotinib) inhibitors were used, and the lesions of the patient were significantly reduced, and the progression-free survival after immunotherapy was 19 months. In advanced pancreatic cancer, a prognosis of this magnitude is rare. Our cases reveal the potential of immunotherapy as a cornerstone treatment in the management of advanced pancreatic cancer.

Homoharringtonine sensitizes pancreatic cancer to erlotinib by direct targeting and miRNA-130b-3p-mediated EphB4-JAK2-STAT3 axis

OBJECTIVES

Pancreatic cancer (PC) is a very lethal malignancy with a scarcity of treatment options. Although erlotinib- and gemcitabine-based treatments have been approved for PC, their effectiveness is limited. The present study is aimed at exploring the molecular and epigenetic mechanisms of anticancer activities of homoharringtonine (HHT) and its interaction with erlotinib to develop a potential therapeutic strategy for PC.

METHODS

The RT-qPCR, western blotting, immunofluorescence and expression-vectors and oligonucleotide transfection were employed to determine the expression characteristics of onco-factors. Anticancer activities were determined by MTT, colony forming, and flowcytometric analysis. Dual luciferase assay was conducted to confirm putative target of miR-130b-3p. In-vivo experiments were followed by immunohistochemical assay.

KEY FINDINGS

The EphB4/JAK2/STAT3 pathway drives the growth and proliferation of PC through induction of prosurvival factors and cell cycle mediators. HHT directly and epigenetically via miR-130b-3p targets EphB4, leading to downregulation of JAK2/STAT3 pathway. The inactivation of STAT3 results in diminution of antiapoptotic factors and cell cycle mediators. HHT also enhances the anticancer activity of erlotinib.

CONCLUSIONS

HHT demonstrates potential anticancer activities in PC by downregulating EphB4/JAK2/STAT3 signalling. HHT also produces synergistic effects with erlotinib.

Mitochondrial Metabolism in Pancreatic Ductal Adenocarcinoma: From Mechanism-Based Perspectives to Therapy

Pancreatic ductal adenocarcinoma (PDAC), the fourteenth most common malignancy, is a major contributor to cancer-related death with the utmost case fatality rate among all malignancies. Functional mitochondria, regardless of their complex ecosystem relative to normal cells, are essential in PDAC progression. Tumor cells' potential to produce ATP as energy, despite retaining the redox potential optimum, and allocating materials for biosynthetic activities that are crucial for cell growth, survival, and proliferation, are assisted by mitochondria. The polyclonal tumor cells with different metabolic profiles may add to carcinogenesis through inter-metabolic coupling. Cancer cells frequently possess alterations in the mitochondrial genome, although they do not hinder metabolism; alternatively, they change bioenergetics. This can further impart retrograde signaling, educate cell signaling, epigenetic modifications, chromatin structures, and transcription machinery, and ultimately satisfy cancer cellular and nuclear demands. To maximize the tumor microenvironment (TME), tumor cells remodel nearby stromal cells and extracellular matrix. These changes initiate polyclonality, which is crucial for growth, stress response, and metastasis. Here, we evaluate all the intrinsic and extrinsic pathways drawn by mitochondria in carcinogenesis, emphasizing the perspectives of mitochondrial metabolism in PDAC progression and treatment.

Efficacy and safety of immune checkpoint inhibitors in advanced pancreatic cancer: A real world study in Chinese cohort

Previous clinical studies had not shown expected results in advanced pancreatic cancer (APC) with single-agent checkpoint inhibitors. Until the present day, little is known about their performance in real-world settings. So, in this study, we investigate the ICIs' efficacy and safety in Chinese APC patients. Patients with APC who received ICIs between November 2018 to June 2021 were enrolled in this retrospective study. The efficacy end points included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR) and adverse events (AEs). This study included 104 patients and the median OS (mOS) and median PFS (mPFS) were 9.1 and 5.4 months, respectively. In the subgroup analyses, the mOS was longer for patients receiving combined radiotherapy than for those that didn't (13.8 vs 7.0 months, p < .001), whereas the mPFS was also longer, and the ORR and DCR were higher. Specifically, the mOS was longer for patients who had received a combination of chemotherapy than for those combined with targeted therapy (11.6 vs 5.6 months, p = .002), with the mPFS being also longer. ICIs as a first-line treatment could resulted to better survival. The mOS was longer for patients with a high TMB compared to those with low (19.3 vs 7.2 months, p = .004), whereas AEs were considered to be tolerable. The combination therapy of ICIs was proved to be safe and effective for treating APC, especially the combination of chemotherapy and radiotherapy, which would benefit from additional prospective studies.

Meta-analysis of gemcitabine plus nab-paclitaxel combined with targeted agents in the treatment of metastatic pancreatic cancer

BACKGROUND

Gemcitabine plus nab-paclitaxel (GA) is a commonly used first-line treatment regimen for metastatic pancreatic cancer, and many studies will add a novel targeted agent to this regimen for improving patient survival rate. However, the clinical effectiveness of GA is the most controversial issue.

AIM

To compare the efficacy and safety of GA regimen with a targeted agent and GA regimen.

METHODS

Up to 1 December 2021, the eligible randomized controlled trials (RCTs) relating to GA and GA with a targeted agent were searched on PubMed, EMBASE and Cochrane Library for eligible data. We screened out appropriate studies for overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and toxicity, which had been pooled and finally analyzed by using Stata version 15.1. In addition, we use Reference Citation Analysis (https://www.referencecitationanalysis.com/) to collect the latest related literature to improve the latest cutting-edge research results.

RESULTS

Seven RCTs involving 1544 patients (848 men and 696 women) were included. There were no significant differences between GA with a targeted agent and GA in PFS [hazard ratio (HR): 1.18 95% confidence interval (CI): 0.91-1.53], OS (HR: 1.12 95%CI: 0.99-1.27), and ORR (HR: 0.96 95%CI: 0.71-1.29). There was no notable difference in the two groups in grade 3/4 toxicity (fatigue, anemia, vomiting and neutropenia), whereas the incidence of grade 3/4 diarrhea considerably increased in GA with a targeted drug.

CONCLUSION

Adding a novel targeted agent to the GA regimen did not improve survival rate of patients with metastatic pancreatic cancer.

Cytotoxic Nitrobenzoyl Sesquiterpenoids from an Antarctica Sponge-Derived Aspergillus insulicola

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplastic diseases of the pancreas with fatal proliferation and metastasis and no medicine available for treatment. From an Antarctica sponge-derived fungus, Aspergillus insulicola HDN151418, four new nitrobenzoyl sesquiterpenoids, namely, insulicolides D-G (1-4), were isolated. Compounds 3 and 4 exhibited selective inhibition against human PDAC cell lines. Further studies indicated that compound 4 could significantly suppress cell proliferation to induce apoptosis and blocked migration and invasion of PDAC cells. Compound 4 could also avoid resistance and improved the therapeutic effect of the chemotherapy drug gemcitabine. A preliminary mechanism study showed that compound 4 can significantly inhibit the expression of EGFR and XIAP in PDAC cells. Altogether, 4 is a potential lead compound for anti-PDAC drug research.

Randomized phase II study of the Bruton tyrosine kinase inhibitor acalabrutinib, alone or with pembrolizumab in patients with advanced pancreatic cancer

Background

The immunosuppressive desmoplastic stroma of pancreatic cancer represents a major hurdle to developing an effective immune response. Preclinical studies in pancreatic cancer have demonstrated promising anti-tumor activity with Bruton tyrosine kinase (BTK) inhibition combined with programmed cell death receptor-1 (PD-1) blockade.

Methods

This was a phase II, multicenter, open-label, randomized (1:1) clinical trial evaluating the BTK inhibitor acalabrutinib, alone (monotherapy) or in combination with the anti-PD-1 antibody pembrolizumab (combination therapy). Eligible patients were adults with histologically confirmed metastatic or locally advanced unresectable pancreatic ductal adenocarcinoma with an Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≤1 who had received at least one prior systemic therapy. Oral acalabrutinib 100 mg twice daily was administered with or without intravenous pembrolizumab 200 mg on day 1 of each 3-week cycle. Peripheral blood was analyzed for changes in immune markers, and tumors from exceptional responders were molecularly analyzed.

Results

A total of 77 patients were enrolled (37 monotherapy; 40 combination therapy) with a median age of 64 years; 77% had an ECOG PS of 1. The median number of prior therapies was 3 (range 1–6). Grade 3–4 treatment-related adverse events were seen in 14.3% of patients in the monotherapy arm and 15.8% of those in the combination therapy arm. The overall response rate and disease control rate were 0% and 14.3% with monotherapy and 7.9% and 21.1% with combination therapy, respectively. Median progression-free survival was 1.4 months in both arms. Peripheral blood flow analysis demonstrated consistent reductions in granulocytic (CD15+) myeloid-derived suppressor cells (MDSCs) over time. Two exceptional responders were found to be microsatellite stable with low tumor mutation burden, low neoantigen load and no defects in the homologous DNA repair pathway.

Conclusions

The combination of acalabrutinib and pembrolizumab was well tolerated, but limited clinical activity was seen with either acalabrutinib monotherapy or combination therapy. Peripheral reductions in MDSCs were seen. Efforts to understand and target the pancreatic tumor microenvironment should continue.

Trial registration number

NCT02362048.

Therapeutic Approaches for Metastases from Colorectal Cancer and Pancreatic Ductal Carcinoma

Metastasis is the process of dissemination of a tumor, whereby cells from the primary site dislodge and find their way to other tissues where secondary tumors establish. Metastasis is the primary cause of death related to cancer. This process warrants changes in original tumoral cells and their microenvironment to establish a metastatic niche. Traditionally, cancer therapy has focused on metastasis prevention by systematic treatments or direct surgical re-sectioning. However, metastasis can still occur. More recently, new therapies direct their attention to targeting cancer stem cells. As they propose, these cells could be the orchestrators of the metastatic niche. In this review, we describe conventional and novel developments in cancer therapeutics for liver and lung metastasis. We further discuss the resistance mechanisms of targeted therapy, the advantages, and disadvantages of diverse treatment approaches, and future novel strategies to enhance cancer prognosis.

Exploiting oxidative phosphorylation to promote the stem and immunoevasive properties of pancreatic cancer stem cells

Pancreatic ductal adenocarcinoma (PDAC), the fourth leading cause of cancer death, has a 5-year survival rate of approximately 7-9%. The ineffectiveness of anti-PDAC therapies is believed to be due to the existence of a subpopulation of tumor cells known as cancer stem cells (CSCs), which are functionally plastic, and have exclusive tumorigenic, chemoresistant and metastatic capacities. Herein, we describe a 2D in vitro system for long-term enrichment of pancreatic CSCs that is amenable to biological and CSC-specific studies. By changing the carbon source from glucose to galactose in vitro, we force PDAC cells to utilize OXPHOS, resulting in enrichment of CSCs defined by increased CSC biomarker and pluripotency gene expression, greater tumorigenic potential, induced but reversible quiescence, increased OXPHOS activity, enhanced invasiveness, and upregulated immune evasion properties. This CSC enrichment method can facilitate the discovery of new CSC-specific hallmarks for future development into targets for PDAC-based therapies.

Conversion Therapy for Advanced Pancreatic Cancer: The Case Series and Literature Review

Background

Pancreatic cancer has a high incidence and mortality. Most patients are in an advanced stage at the time of initial diagnosis and cannot be cured by a single surgery. The ASCO clinical practice guideline emphasized the overall management and multidisciplinary comprehensive treatment which put forward the concept of conversion therapy. In this paper, the real-world observation and study were carried out to explore the conversion effect of chemotherapy in patients with advanced pancreatic cancer and their long-term survival.

Methods

The subjects of this study are advanced pancreatic cancer patients who visited the oncology department of Zhejiang Provincial People’s Hospital from 2015 to 2019. Collected and summarized the cases, and selected 5 representative patients for analysis, all of them received standard treatment (FOLFIRINOX, AS, AG, or GS). The progress, clinical evaluation, adverse reactions, and prognosis of these patients after conversion therapy were analyzed and discussed in conjunction with relevant literature.

Results

Five patients with advanced pancreatic cancer received conversion therapy with an average survival time of 29.8 months, two of them received surgical treatment, and postoperative evaluations were pathological complete response (pCR). The tolerance of chemotherapy was good in five patients, and no serious adverse reactions of grade 3 or 4 occurred.

Conclusion

Conversion therapy for patients with advanced pancreatic cancer strives for surgical opportunities of radical resection, prolongs survival and improves quality of life.

CONKO-006: A randomised double-blinded phase IIb-study of additive therapy with gemcitabine + sorafenib/placebo in patients with R1 resection of pancreatic cancer - Final results

BACKGROUND

CONKO-006 was designed for patients with pancreatic adenocarcinoma with postsurgical R1 residual status to evaluate the efficacy and safety of the combination of gemcitabine and sorafenib (GemSorafenib) compared with those of gemcitabine + placebo (GemP) for 12 cycles.

PATIENTS AND METHODS

This randomised, double-blind, placebo-controlled, multicenter study was planned to detect an improvement in recurrence-free survival (RFS) from 42% to 60% after 18 months. Secondary objectives were overall survival (OS), safety and duration of treatment.

RESULTS

122 patients were included between 02/2008 and 09/2013; 57 were randomised to GemSorafenib and 65 to GemP. Patient characteristics were wellbalanced (GemSorafenib/GemP) in terms of median age (63/63 years), tumour size (T3/T4: 97/97%), and nodal positivity (86/85%). Grade 3/4 toxicities comprised diarrhoea (GemSorafenib: 12%; GemP: 2%), elevated gamma-glutamyl transferase (GGT) (19%; 9%), fatigue (5%; 2%) and hypertension (5%; 2%), as well as neutropenia (18%; 25%) and thrombocytopenia (9%; 2%). By August 2017, 118 (97%) RFS event had occurred. There were no difference in RFS (median GemSorafenib: 8.5 versus GemP: 9.4 months; p = 0.730) nor OS (median GemSorafenib: 17.6 versus GemP: 17.5 months; p = 0.481). Landmark analyses suggest that patients who received more than six cycles of postoperative chemotherapy had significantly longer OS (p = 0.021).

CONCLUSION

CONKO-006 is the first randomised clinical trial to include exclusively patients with PDAC with postsurgical R1 status thus far. Sorafenib added to gemcitabine did neither improve RFS nor OS. However, postoperative treatment exceeding six months seemed to prolong survival and should be further investigated in these high-risk patients.

CLINICAL TRIAL INFORMATION

German Tumor Study Registry (Deutsches Krebsstudienregister), DRKS00000242.

ISG15 and ISGylation is required for pancreatic cancer stem cell mitophagy and metabolic plasticity

Pancreatic cancer stem cells (PaCSCs) drive pancreatic cancer tumorigenesis, chemoresistance and metastasis. While eliminating this subpopulation of cells would theoretically result in tumor eradication, PaCSCs are extremely plastic and can successfully adapt to targeted therapies. In this study, we demonstrate that PaCSCs increase expression of interferon-stimulated gene 15 (ISG15) and protein ISGylation, which are essential for maintaining their metabolic plasticity. CRISPR-mediated ISG15 genomic editing reduces overall ISGylation, impairing PaCSCs self-renewal and their in vivo tumorigenic capacity. At the molecular level, ISG15 loss results in decreased mitochondrial ISGylation concomitant with increased accumulation of dysfunctional mitochondria, reduced oxidative phosphorylation (OXPHOS) and impaired mitophagy. Importantly, disruption in mitochondrial metabolism affects PaCSC metabolic plasticity, making them susceptible to prolonged inhibition with metformin in vivo. Thus, ISGylation is critical for optimal and efficient OXPHOS by ensuring the recycling of dysfunctional mitochondria, and when absent, a dysregulation in mitophagy occurs that negatively impacts PaCSC stemness.

The ubiquitin-like modifier ISG15 exerts post-translational protein regulation through ISGylation. Here, the authors show that ISGylation is necessary for pancreatic cancer stem cell self-renewal and tumourigenesis by supporting the recycling of non-functional mitochondria.

DRP1 upregulation promotes pancreatic cancer growth and metastasis through increased aerobic glycolysis

BACKGROUND

Mitochondrial shape is dynamically changed by fusion and fission processes in cells, and dysfunction of this process has become one of the emerging hallmarks of cancer. However, the expression patterns and biological effects of mitochondrial fission and fusion proteins in pancreatic cancer (PC) are still unclear.

METHODS

The expressions of mitochondrial fission and fusion proteins were first evaluated by quantitative reverse transcription polymerase chain reaction and western blot analysis in both PC cell lines and tissue samples. In addition, the biologic functions of the differentially expressed proteins in PC cell growth and metastasis both in vitro and in vivo and their potential underlying mechanisms were systematically explored.

RESULTS

We first found that DRP1 was substantially upregulated in PC cell lines and tissue samples mainly due to the downregulation of miR-29a, which contributed to the poor survival of PC patients. DRP1 promoted the growth and metastasis of PC cells both in vitro and in vivo by inducing G1-S cell cycle transition and matrix metalloproteinase 2 secretion. Mechanistic investigations revealed that increased DRP1 upregulation-mediated mitochondrial fission and subsequently enhanced aerobic glycolysis were involved in the promotion of growth and metastasis by DRP1 in PC cells.

CONCLUSIONS

Our findings demonstrate that mitochondrial fusion protein DRP1 plays a critical oncogenic role in PC cells by enhancing aerobic glycolysis, which could serve as a novel therapeutic target for PC treatment.

Development of Patient-Derived Preclinical Platform for Metastatic Pancreatic Cancer: PDOX and a Subsequent Organoid Model System Using Percutaneous Biopsy Samples

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal malignant tumor and more than 50% patients are diagnosed at metastatic stage. The preclinical model systems that reflect the genetic heterogeneity of metastatic tumors are urgently needed to guide optimal treatment. This study describes the development of patient-derived preclinical platform using very small sized-percutaneous liver gun biopsy (PLB) of metastatic pancreatic cancer, based on patient-derived xenograft (PDX)-mediated tissue amplification and subsequent organoid generation. To increase the success rate and shorten the tumor growth period, patient-derived orthotopic xenograft (PDOX) model was developed to directly implant threadlike PLB samples into the pancreas. The engraftment success rate of PDOX samples from 35 patients with metastatic PDAC was 47%, with these samples showing the potential to metastasize to distant organs, as in patients. The PDOX models retained the genetic alterations and histopathological features of the primary tumors. Tumor organoids were subsequently generated from first passage cancer cells isolated from F1 tumor tissue of PDOX that preserve the epithelial cancer characteristics and KRAS mutations of primary tumors. The response to gemcitabine of PDOX-derived organoids correlated with clinical outcomes in corresponding patients as well as PDOX models in vivo, suggesting that this PDOX-organoid system reflects clinical conditions. Collectively, these findings indicate that the proposed PDOX-organoid platform using PLB samples assessed both in vitro and in vivo could predict drug response under conditions closer to those found in actual patients, as well as enhancing understanding of the complexity of metastatic PDAC.

MST1R kinase accelerates pancreatic cancer progression via effects on both epithelial cells and macrophages

The MST1R (RON) kinase is overexpressed in >80% of human pancreatic cancers, but its role in pancreatic carcinogenesis is unknown. In this study, we examined the relevance of Mst1r kinase to Kras driven pancreatic carcinogenesis using genetically engineered mouse models. In the setting of mutant Kras, Mst1r overexpression increased acinar-ductal metaplasia (ADM), accelerated progression of pancreatic intraepithelial neoplasia (PanIN), and resulted in the accumulation of (mannose receptor C type 1) MRC1+, (arginase 1) Arg+ macrophages in the tumor microenvironment. Conversely, absence of a functional Mst1r kinase slowed PanIN initiation, resulted in smaller tumors, prolonged survival and a reduced tumor associated macrophage content. Mst1r expression was associated with increased production of its ligand Mst1, and in orthotopic models, suppression of Mst1 expression resulted in reduced tumor size, changes in macrophage polarization and enhanced T cell infiltration. This study demonstrates the functional significance of Mst1r during pancreatic cancer initiation and progression. Further, it provides proof of concept that targeting Mst1r can modulate pancreatic cancer growth and the microenvironment. This study provides further rationale for targeting Mst1r as a therapeutic strategy.

P21 activated kinase 2 promotes pancreatic cancer growth and metastasis

Pancreatic cancer has an overall 5-year survival rate of only 9%, due to its rapid metastasis and poor prognosis. To combat this disease, novel therapeutic targets and biomarkers are required. In this study, immunohistochemistry was used to detect the expression of P21 activated kinase 2 (PAK2) protein in the tissues of cancer and the paired adjacent normal tissues. The association between PAK2 and the clinicopathologic features of patients with pancreatic cancer was subsequently analyzed. The results indicated that PAK2 was overexpressed in the cancer tissues, which indicated high pTNM stage, poor tumor grade, lymph node metastasis and vascular invasion. In addition, the results demonstrated evidence of a close association between PAK2 expression and poor prognosis of patients with pancreatic cancer. The results also suggested that PAK2 may promote pancreatic cancer cell proliferation and migration in vitro through clone formation, MTT, wound healing and Transwell assays. The present study further identified that PAK2 could stimulate pancreatic cancer growth and metastasis in mice. Decreased expression of proliferation marker protein Ki-67 and proliferating cell nuclear antigen in response to PAK2 knockdown further verified the role of PAK2 in promoting cell proliferation by western blot analysis. In addition, the expression levels of matrix metallopeptidase (MMP) 2 and MMP9 were decreased in PANC1 and BxPC3 cell lines transfected with PAK2-short hairpin RNA as indicated in western blot analysis, suggesting a function of PAK2 in promoting cell invasion. Collectively, these findings revealed a critical role for PAK2 in the development of pancreatic cancer and may have important implications for the management of this disease.

Tumor-associated macrophage-secreted 14-3-3ζ signals via AXL to promote pancreatic cancer chemoresistance

Pancreatic ductal adenocarcinoma (PDAC) is an inherently chemoresistant tumor. Chemotherapy leads to apoptosis of cancer cells, and in previous studies we have shown that tumor-associated macrophage (TAM) infiltration increases following chemotherapy in PDAC. Since one of the main functions of macrophages is to eliminate apoptotic cells, we hypothesized that TAMs phagocytose chemotherapy-induced apoptotic cells and secrete factors, which favor PDAC chemoresistance. To test this hypothesis, primary human PDAC cultures were treated with conditioned media (CM) from monocyte-derived macrophage cultures incubated with apoptotic PDAC cells (MØ^ApopCM). MØ^ApopCM pretreatment rendered naïve PDAC cells resistant to Gemcitabine- or Abraxane-induced apoptosis. Proteomic analysis of MØ^ApopCM identified YWHAZ/14-3-3 protein zeta/delta (14-3-3ζ), a major regulator of apoptotic cellular pathways, as a potential mediator of chemoresistance, which was subsequently validated in patient transcriptional datasets, serum samples from PDAC patients and using recombinant 14-3-3ζ and inhibitors thereof. Moreover, in mice bearing orthotopic PDAC tumors, the antitumor potential of Gemcitabine was significantly enhanced by elimination of TAMs using clodronate liposomes or by pharmacological inhibition of the Axl receptor tyrosine kinase, a 14-3-3ζ interacting partner. These data highlight a unique regulatory mechanism by which chemotherapy-induced apoptosis acts as a switch to initiate a protumor/antiapoptotic mechanism in PDAC via 14-3-3ζ/Axl signaling, leading to phosphorylation of Akt and activation of cellular prosurvival mechanisms. The data presented therefore challenge the idea that apoptosis of tumor cells is therapeutically beneficial, at least when immune sensor cells, such as macrophages, are present.

HIFU is safe, effective, and feasible in pancreatic cancer patients: a monocentric retrospective study among 523 patients

Purpose

This study aimed to evaluate the clinical value of high-intensity focused ultrasound (HIFU) combined with gemcitabine (GEM) in treating unresectable pancreatic ductal adenocarcinoma (PDAC).

Patients and methods

A total of 523 unresectable PDAC patients were recruited from December 30, 2007 to January 30, 2015 at Fudan University Shanghai Cancer Center. Among them, 347 received HIFU combined with GEM (with regional intra-arterial chemotherapy [RIAC] or with systemic chemotherapy) and the remaining patients received GEM only. Postoperative complications were observed, and overall survival was recorded.

Results

The median overall survival of patients who received HIFU combined with GEM vs GEM alone was 7.4 vs 6.0 months (P=0.002); the 6-month, 10-month, 1-year, and 2-year survival rates for patients in these two groups were 66.3% vs 47.5% (P<0.0001), 31.12% vs 15.9% (P<0.0001), 21.32% vs 13.64% (P=0.033), and 2.89% vs 2.27% (P=0.78), respectively. In the combined therapy group, the most obvious survival benefits were obtained among patients who received HIFU plus RIAC and systemic chemotherapy (used in the intervals between RIAC treatments). There were no severe complications in patients undergoing HIFU treatment.

Conclusion

We demonstrated the survival benefit of HIFU among PDAC patients treated with GEM. The benefit was most obvious in PDAC patients treated with HIFU plus RIAC and systemic chemotherapy.

Coexpression of UCA1 and ITGA2 in pancreatic cancer cells target the expression of miR-107 through focal adhesion pathway

OBJECTIVES

Abnormal expressions of microRNAs (miRNAs) are demonstrated in pancreatic cancer (PaC), but a major part of the mechanism remains elusive. This study mainly aimed to structure a coexpressed network of long noncoding RNA (lncRNA) and messenger RNA (mRNA) in PaC, as well as to explore their direct targets.

METHODS

LncRNA and mRNA microarrays were used to determine the expression profiles in PaC cells. Analysis of Kyoto Encyclopedia of Genes and Genomes pathway was performed to identify pathways associated with differentially expressed mRNAs. Coexpression profiles were identified by constructing differentially expressed lncRNA-mRNA regulatory network and further validated by quantitative real-time polymerase chain reaction assay and western blot assay. The bioinformatics computational method was applied to predict the biological target of lncRNA and mRNA, which was identified by luciferase reporter assay. Migration/invasion ability and apoptosis rate of cells were assessed by transwell assay and flow cytometry assay.

RESULTS

It was identified that the level of urothelial cancer associated 1 (UCA1) was increased in PaC cells, and the inhibition of UCA1 suppressed migration and invasion ability of the cancer cells. The luciferase reporter assay recognized that miR-107 was targeted by UCA1, and integrin subunit α 2 (ITGA2) was further targeted by miR-107. This confirmed the prediction of lncRNA-miRNA-mRNA regulation mechanism. In the regulatory pathways, UCA1 and ITGA2 promoted PaC progression via focal adhesion pathway related proteins such as ITGA3, SRC protooncogene/nonreceptor tyrosine kinase, protein tyrosine kinase 2, and AKT serine/threonine kinase 1.

CONCLUSION

The study revealed a regulatory network of UCA1-miR-107-ITGA2 and validated UCA1 and ITGA2 as potential prognostic factors for PaC.

EUS-guided irreversible electroporation using endoscopic needle-electrode in porcine pancreas

BACKGROUND

Endoscopic irreversible electroporation (IRE) can be performed using a flexible, thin, needle-shaped electrode for an endoscopic ultrasound (EUS)-guided procedure. This study aimed to evaluate the feasibility and efficacy of performing EUS-guided IRE with endoscopic needle-electrode in porcine pancreas.

METHODS

Experimental endoscopic IRE on the pancreas were performed by EUS-guided approach in three pigs and compared with surgical approach in three pigs. The animals were killed after 24 h and their pancreases collected.

RESULTS

IRE ablation using endoscopic needle-electrode was successful technically in EUS-guided approaches for the pancreas. Immediately following IRE, the ablated pancreatic tissue showed no gross change except focal hemorrhage. H&E staining presented a well-demarcated ablation site measuring 1.0-1.5 cm in diameter in the pancreas. TUNEL immunohistochemistry showed diffuse cell death along the puncture site 24 h after IRE. No complication was observed in pigs after endoscopic IRE ablation.

CONCLUSION

EUS-guided IRE ablation was feasible and effective for pancreas using the newly developed device.

A PET Imaging Strategy for Interrogating Target Engagement and Oncogene Status in Pancreatic Cancer

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is one of the most deadly cancers, with a 5-year survival rate of less than 10%. Physicians often rely on biopsy or CT to guide treatment decisions, but these techniques fail to reliably measure the actions of therapeutic agents in PDAC. KRAS mutations are present in >90% of PDAC and are connected to many signaling pathways through its oncogenic cascade, including extracellular regulated kinase (ERK) and MYC. A key downstream event of MYC is transferrin receptor (TfR), which has been identified as a biomarker for cancer therapeutics and imaging.

EXPERIMENTAL DESIGN

In this study, we aimed to test whether zirconium-89 transferrin ([⁸⁹Zr]Zr-Tf) could measure changes in MYC depending on KRAS status of PDAC, and assess target engagement of anti-MYC and anti-ERK-targeted therapies.

RESULTS

Mice bearing iKras*p53* tumors showed significantly higher (P < 0.05) uptake of [⁸⁹Zr]Zr-Tf in mice withdrawn from inducible oncogenic KRAS. A therapy study with JQ1 showed a statistically significant decrease (P < 0.05) of [⁸⁹Zr]Zr-Tf uptake in drug versus vehicle-treated mice bearing Capan-2 and Suit-2 xenografts. IHC analysis of resected PDAC tumors reflects the data observed via PET imaging and radiotracer biodistribution.

CONCLUSIONS

Our study demonstrates that [⁸⁹Zr]Zr-Tf is a valuable tool to noninvasively assess oncogene status and target engagement of small-molecule inhibitors downstream of oncogenic KRAS, allowing a quantitative assessment of drug delivery.

Discovery and Characterization of Dual Inhibitors of MDM2 and NFAT1 for Pancreatic Cancer Therapy

Overexpression and activation of the murine double minute 2 (MDM2) or nuclear factor of activated T cells 1 (NFAT1) oncoproteins frequently occur in pancreatic cancer. Most MDM2 inhibitors under development target MDM2-p53 binding and have little or no effect on cancers without functional p53, including pancreatic cancer. Some available compounds indirectly inhibit NFAT1 activity by interfering with calcineurin activity, but there are currently no specific inhibitors against NFAT1. Here we performed a high-throughput virtual and cell-based screening to yield a lead compound (MA242) that can directly bind both MDM2 and NFAT1 with high affinity, induce their protein degradation, and inhibit NFAT1-mediated transcription of MDM2 As a result of this binding, MA242 decreased cell proliferation and induced apoptosis in pancreatic cancer cell lines regardless of p53 status. MA242 alone or in combination with gemcitabine inhibited pancreatic tumor growth and metastasis without any host toxicity. Our data indicate that targeting both MDM2 and NFAT1 represents a novel and effective strategy to treat pancreatic cancer.Significance: These findings suggest that pharmacological inhibition of both MDM2 and NFAT1 is a promising strategy for the treatment of pancreatic cancer, even in tumors lacking functional p53. Cancer Res; 78(19); 5656-67. ©2018 AACR.

Oncological and genetic factors impacting PDX model construction with NSG mice in pancreatic cancer

A patient-derived xenograft (PDX) approach, which relies on direct transplantation of tumor specimens into an immunocompromised animal, is a commonly used method for investigating tumor therapy predictions in vivo. This study evaluated influencing factors, including clinical, oncological, and genetic variables, for a pancreatic PDX model in mice. Tumor specimens were obtained from 121 patients with pancreatic ductal adenocarcinoma who underwent surgical resection at the Changhai Pancreatic Surgery Medical Center (Shanghai, China) between April 2016 and February 2017. Pancreatic cancer (PC) samples <3 mm³ were subcutaneously implanted into the NOD/Shi-scid/IL-2Rγnull (NSG) mice. Once the xenograft reached 300-500 mm³ or reached 180 d after cell inoculation, the tumor was excised. Part of the tumor was subsequently transplanted to next-generation mice, and another part was analyzed by using immunohistochemistry. Among the 121 patients with PC, tumor xenograft was successfully generated in 86 patients (71.1%). Primary tumor >3.5 cm in size was independently associated with xenograft formation rate. In addition, several enriched mutated genes within the VEGF pathway and higher microvessel density were found in the positive group (with xenograft) compared with the negative group (without xenograft). We concluded that tumor size and mutated VEGF pathway in PC are important factors affecting PDX model construction with NSG mice.-Guo, S., Gao, S., Liu, R., Shen, J., Shi, X., Bai, S., Wang, H., Zheng, K., Shao, Z., Liang, C., Peng, S., Jin, G. Oncological and genetic factors impacting PDX model construction with NSG mice in pancreatic cancer.

Aqueous extracts of Paeonia suffruticosa modulates mitochondrial proteostasis by reactive oxygen species-induced endoplasmic reticulum stress in pancreatic cancer cells

BACKGROUND

Pancreatic cancer (PC) remains the leading cause of cancer mortality, with limited therapeutic targets, and alterations in endoplasmic reticulum (ER)-related proteostasis may be a potential target for therapy. The root bark of Paeonia suffruticosa has been shown to inhibit cancer growth and metastasis, although its impact on PC is unknown.

PURPOSE

To ascertain the anti-cancer effects of P. suffruticosa on oncogenic functions of PC and determine the detailed molecular mechanisms.

STUDY DESIGN

Efficacy assessment of extracts, in vitro using PC cells as a model system and in vivo in mouse xenograft tumors.

METHODS

P. suffruticosa aqueous extracts (PS) were prepared and assessed using liquid chromatography-tandem mass spectrometry. Cell viability, proteins, and cell components were measured using MTT assay, western blotting, and immunofluorescence. Cell apoptosis, cell cycle, and migration were assessed using colorimetric assays, fluorescence activated cell sorting, and transwell migration. Reactive oxygen species (ROS) were evaluated with a commercial 2'-7'-dichlorofluorescin diacetate kit. For the xenograft model, AsPC1 cells were inoculated subcutaneously into immunocompromised mice and PS (oral) was administered over 3 weeks with or without gemcitabine (GEM, intraperitoneal), a first-line advanced/metastatic PC therapy.

RESULTS

PS stimulated ER stress and affected mitochondrial membrane potential to increase autophagosome numbers and block their degradation, followed by autophagy induction and finally cell apoptosis. Additionally, PS-mediated proteostasis impairment resulted in altered dynamics of the actin cytoskeleton, cell motility impairment, and cell cycle progression inhibition. Conversely, a ROS scavenger partially reversed PS-mediated degradation of peptidyl-prolyl cis-trans isomerase B (PPIB), an ER protein important for protein folding, suggesting that ROS generation by PS may be the upstream of PS-triggering of mitophagy and final cell apoptosis. Nevertheless, oral administration of PS, alone or in combination with GEM, delayed tumor growth in a xenograft model without affecting body weight.

CONCLUSION

These findings indicate that PS may constitute a potential new alternative or complementary medicine for PC.

Change in plasma lactate concentration during arctigenin administration in a phase I clinical trial in patients with gemcitabine-refractory pancreatic cancer

Arctigenin is evaluated for antitumor efficacy in patients with pancreatic cancer. It has an inhibitory activity on mitochondrial complex I.Therefore, plasma lactate level of patients after arctigenin administration was evaluated for biomarker of clinical response and/or adverse effect. Plasma lactate level in 15 patients enrolled in a Phase I clinical trial of GBS-01 rich in arctigenin was analyzed by colorimetric assay. Statistical analyses for association of plasma lactate and clinical responses, pharmacokinetics of arctigenin, and background factors of each patient by multivariate and univariate analyses.In about half of the patients, transient increase of lactate was observed. Correlation between plasma lactate level and pharmacokinetic parameters of arctigenin and its glucuronide conjugate, and clinical outcome was not detected. Regarding to the determinant of lactate level, only slight association with liver function test was detected. Plasma lactate level is primary determined by reutilization rather than production for antitumor effect and dose not serve as a biomarker. Arctigenin, inhibition of mitochondrial complex I, plasma lactate concentration, phase I clinical trial of GBS-01, Cori cycle.

Targeting ERK enhances the cytotoxic effect of the novel PI3K and mTOR dual inhibitor VS-5584 in preclinical models of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease in urgent need of newer therapeutic modalities. Majority of patients with PDAC have mutations in KRAS, which unfortunately remains an ineffectual target. Our strategy here is to target KRAS downstream effectors PI3K and mTOR. In this study, we investigated the antitumor efficacy of the novel PI3K and mTOR dual inhibitor VS-5584 in PDAC. Our data shows that PI3K/mTOR dual inhibition causes ERK activation in all tested PDAC cell lines. Although the MEK inhibitor GSK1120212 could abrogate VS-5584-induced ERK activation, it did not substantially enhance cell death in all the cell lines tested. However, combination with ERK inhibitor SCH772984 not only mitigated VS-5584-induced ERK activation but also enhanced VS-5584-induced cell death. In a xenograft model of PDAC, we observed 28% and 44% tumor inhibition for individual treatment with VS-5584 and SCH772984, respectively, while the combined treatment showed superior tumor inhibition (80%) compared to vehicle control treatment. Our findings support the clinical development of VS-5584 and ERK inhibitor combination for PDAC treatment.

The role of extracellular vesicles in mediating progression, metastasis and potential treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. As vectors for intercellular information exchange, the potential role of extracellular vesicles (EVs) in HCC formation, progression and therapy has been widely investigated. In this review, we explore the current status of the researches in this field. Altogether there is undeniable evidence that EVs play a crucial role in HCC development, metastasis. Moreover, EVs have shown great potential as drug delivery systems (DDSs) for the treatment of HCC. Exosomal miRNAs derived from HCC cells can enhance transformed cell growth in recipient cells by modulating the expression of transforming growth factor-β activated kinase-1(TAK1) and downstream signaling molecules. Furthermore, vacuolar protein sortin 4 homolog A(VPS4A) and insulin-like growth factor(IGF)-1 regulate exosome-mediated miRNAs transfer. Immune cells- derived EVs containing integrin αMβ2 or CD147 may facilitate HCC metastasis. In addition, EVs-mediated shuttle of long non-coding RNAs (lncRNAs), specifically linc- VLDLR and linc-ROR promote chemoresistance of malignant cells. Heat shock proteins (HSPs)-harboring exosomes derived from HCC tumor cells increase the antitumor effect of natural killer (NK) cells, thus enhancing HCC immunotherapy. Indeed, inhibition of HCC tumor growth has been associated with tumor cell-derived exosomes (TEX)-pulsed dentritic cells (DCs). Exosomes are also essential in liver metastasis during colorectal carcinoma (CRC) and pancreatic ductal adenocarcinomas (PDAC). Therefore, as nucleic acid and drug delivery vehicles, EVs show a tremendous potential for effective treatment against HCC.

Strategies for Increasing Pancreatic Tumor Immunogenicity

Immunotherapy has changed the standard of care for multiple deadly cancers, including lung, head and neck, gastric, and some colorectal cancers. However, single-agent immunotherapy has had little effect in pancreatic ductal adenocarcinoma (PDAC). Increasing evidence suggests that the PDAC microenvironment is comprised of an intricate network of signals between immune cells, PDAC cells, and stroma, resulting in an immunosuppressive environment resistant to single-agent immunotherapies. In this review, we discuss differences between immunotherapy-sensitive cancers and PDAC, the complex interactions between PDAC stroma and suppressive tumor-infiltrating cells that facilitate PDAC development and progression, the immunologic targets within these complex networks that are druggable, and data supporting combination drug approaches that modulate multiple PDAC signals, which should lead to improved clinical outcomes. Clin Cancer Res; 23(7); 1656-69. ©2017 AACRSee all articles in this CCR Focus section, "Pancreatic Cancer: Challenge and Inspiration."

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

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

Plasma microRNA panels to diagnose pancreatic cancer: Results from a multicenter study

Biomarkers for the early diagnosis of pancreatic cancer (PC) are urgent needed. Plasma microRNAs (miRNAs) might be used as biomarkers for the diagnosis of cancer. We analyzed 361 plasma samples from 6 surgical centers in China and performed machine learning approach. We gain insight of the association between the aberrant plasma miRNA expression and pancreatic disease. 671 microRNAs were screened in the discovery phase and 33 microRNAs in the training phase and 13 microRNAs in the validation phase. After the discovery phase and training phase, 2 diagnostic panels were constructed comprising 3 microRNAs in panel I (miR-486-5p, miR-126-3p, miR-106b-3p) and 6 microRNAs in panel II (miR-486-5p, miR-126-3p, miR-106b-3p, miR-938, miR-26b-3p, miR-1285). Panel I and panel II had high accuracy for distinguishing pancreatic cancer from chronic pancreatitis (CP) with area under the curve (AUC) values of 0.891 (Standard Error (SE): 0.097) and 0.889 (SE: 0.097) respectively, in the validation phase. Additionally, we demonstrated that the diagnostic value of the panels in discriminating PC from CP were comparable to that of carbohydrate antigen 19–9 (CA 19–9) 0.775 (SE: 0.053) (P = 0.1 for both). This study identified 2 diagnostic panels based on microRNA expression in plasma with the potential to distinguish PC from CP. These patterns might be developed as biomarkers for pancreatic cancer.

Antibody-based targeting of alternatively spliced tissue factor: a new approach to impede the primary growth and spread of pancreatic ductal adenocarcinoma

Alternatively spliced Tissue Factor (asTF) is a secreted form of Tissue Factor (TF), the trigger of blood coagulation whose expression levels are heightened in several forms of solid cancer, including pancreatic ductal adenocarcinoma (PDAC). asTF binds to β1 integrins on PDAC cells, whereby it promotes tumor growth, metastatic spread, and monocyte recruitment to the stroma. In this study, we determined if targeting asTF in PDAC would significantly impact tumor progression. We here report that a novel inhibitory anti-asTF monoclonal antibody curtails experimental PDAC progression. Moreover, we show that tumor-derived asTF is able to promote PDAC primary growth and spread during early as well as later stages of the disease. This raises the likelihood that asTF may comprise a viable target in early- and late-stage PDAC. In addition, we show that TF expressed by host cells plays a significant role in PDAC spread. Together, our data demonstrate that targeting asTF in PDAC is a novel strategy to stem PDAC progression and spread.

CONKO-005: Adjuvant Chemotherapy With Gemcitabine Plus Erlotinib Versus Gemcitabine Alone in Patients After R0 Resection of Pancreatic Cancer: A Multicenter Randomized Phase III Trial

Purpose Gemcitabine is standard of care in the adjuvant treatment of resectable pancreatic ductal adenocarcinoma (PDAC). The epidermal growth factor receptor tyrosine kinase inhibitor erlotinib in combination with gemcitabine has shown efficacy in the treatment of advanced PDAC and was considered to improve survival in patients with primarily resectable PDAC after R0 resection. Patients and Methods In an open-label, multicenter trial, patients were randomly assigned to one of two study arms: gemcitabine 1,000 mg/m² days 1, 8, 15, every 4 weeks plus erlotinib 100 mg once per day (GemErlo) or gemcitabine (Gem) alone for six cycles. The primary end point of the study was to improve disease-free survival (DFS) from 14 to 18 months by adding erlotinib to gemcitabine. Results In all, 436 patients were randomly assigned at 57 study centers between April 2008 and July 2013. A total of 361 instances (83%) of disease recurrence were observed after a median follow-up of 54 months. Median treatment duration was 22 weeks in both arms. There was no difference in median DFS (GemErlo 11.4 months; Gem 11.4 months) or median overall survival (GemErlo 24.5 months; Gem 26.5 months). There was a trend toward long-term survival in favor of GemErlo (estimated survival after 1, 2, and 5 years for GemErlo was 77%, 53%, and 25% v 79%, 54%, and 20% for Gem, respectively). The occurrence or the grade of rash was not associated with a better survival in the GemErlo arm. Conclusion To the best of our knowledge, CONKO-005 is the first study to investigate the combination of chemotherapy and a targeted therapy in the adjuvant treatment of PDAC. GemErlo for 24 weeks did not improve DFS or overall survival over Gem.

Systemic Chemotherapy in Advanced Pancreatic Cancer

Pancreatic cancer remains one of the most lethal cancers. These patients often have multiple symptoms, and integrated supportive care is critical in helping them remain well for as long as possible. Fluorouracil-based chemotherapy is known to improve overall survival (OS) by approximately 3 months, compared to the best supportive care alone. A 1997 study comparing gemcitabine and fluorouracil treatment of advanced pancreatic cancer patients showed an improvement in OS of 1 month in patients receiving gemcitabine. Over the next 10 years, multiple randomized studies compared single-agent gemcitabine with combination chemotherapy and showed no effective survival improvement. However, the addition of erlotinib, an epidermal growth factor receptor (EGFR) inhibitor, was associated with a significant improvement in OS of approximately 2 weeks. However, adoption of this regimen has not been widespread because of its limited effect and added toxicity. Two clinical trials have recently prolonged OS in advanced pancreatic cancer patients by almost 1 year. The first compared FOLFIRINOX with gemcitabine alone, and was associated with a significant improvement in median survival. The second compared gemcitabine and nab-paclitaxel with gemcitabine alone, and was associated with improvements in OS. At present, these regimens are considered standard treatment for patients with good performance statuses.

Never let it go: Stopping key mechanisms underlying metastasis to fight pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive neoplasm, predicted to become the second leading cause of cancer-related deaths before 2030. This dismal trend is mainly due to lack of effective treatments against its metastatic behavior. Therefore, a better understanding of the key mechanisms underlying metastasis should provide new opportunities for therapeutic purposes. Genomic analyses revealed that aberrations that fuel PDAC tumorigenesis and progression, such as SMAD4 loss, are also implicated in metastasis. Recently, microRNAs have been shown to play a regulatory role in the metastatic behavior of many tumors, including PDAC. In particular, miR-10 and miR-21 have appeared as master regulators of the metastatic program, while members of the miR-200 family are involved in the epithelial-to-mesenchymal switch, favoring cell migration and invasiveness. Several studies have also found a close relationship between cancer stem cells (CSCs) and biological features of metastasis, and the CSC markers ALDH1, ABCG2 and c-Met are expressed at high levels in metastatic PDAC cells. Emerging evidence reveals that exosomes are involved in the modulation of the tumor microenvironment and can initiate PDAC pre-metastatic niche formation in the liver and lungs. In this review, we provide an overview of the role of all these pivotal factors in the metastatic behavior of PDAC, and discuss their potential exploitation in the clinic to improve current therapeutics and identify new drug targets.

Economic evaluation for the US of nab-paclitaxel plus gemcitabine versus FOLFIRINOX versus gemcitabine in the treatment of metastatic pancreas cancer

BACKGROUND

Nab-paclitaxel plus gemcitabine (NAB-P + GEM) and FOLFIRINOX have shown superior efficacy over gemcitabine (GEM) in the treatment of metastatic pancreatic ductal adenocarcinoma (mPDA). Although the incremental clinical benefits are modest, both treatments represent significant advances in the treatment of a high-mortality cancer. In this independent economic evaluation for the US, the aim was to estimate the comparative cost-utility and cost-effectiveness of these three regimens from the payer perspective.

METHODS

In the absence of a direct treatment comparison in a single clinical trial, the Bucher indirect comparison method was used to estimate the comparative efficacy of each regimen. A Markov model evaluated life years (LY) and quality-adjusted life years (QALY) gained with NAB-P + GEM and FOLFIRINOX over GEM, expressed as incremental cost-effectiveness (ICER) and cost-utility ratios (ICUR). All costs and outcomes were discounted at 3%/year. The impact of parameter uncertainty on the model was assessed by probabilistic sensitivity analyses.

RESULTS

NAB-P + GEM was associated with differentials of +0.180 LY and +0.127 QALY gained over GEM at an incremental total cost of $25,965; yielding an ICER of $144,096/LY and ICUR of $204,369/QALY gained. FOLFIRINOX was associated with differentials of +0.368 LY and +0.249 QALY gained over GEM at an incremental total cost of $93,045; yielding an ICER of $253,162/LY and ICUR of $372,813/QALY gained. In indirect comparison, the overall survival hazard ratio (OS HR) for NAB-P + GEM vs FOLFIRINOX was 0.79 (95%CI = 0.59-1.05), indicating no superiority in OS of either regimen. FOLFIRINOX had an ICER of $358,067/LY and an ICUR of $547,480/QALY gained over NAB-P + GEM. Tornado diagrams identified variation in the OS HR, but no other parameters, to impact the NAB-P + GEM and FOLFIRINOX ICURs.

CONCLUSIONS

In the absence of a statistically significant difference in OS between NAB-P + GEM and FOLFIRINOX, this US analysis indicates that the greater economic benefit in terms of cost-savings and incremental cost-effectiveness and cost-utility ratios favors NAB-P + GEM over FOLFIRINOX.

HNRNPA2B1 regulates the epithelial-mesenchymal transition in pancreatic cancer cells through the ERK/snail signalling pathway

Background

Heterogeneous nuclear ribonucleoprotein A2B1 (HNRNPA2B1) is closely related to tumour occurrence and development, oncogene expression, apoptosis inhibition and invasion and metastasis capacities. However, its function in the epithelial–mesenchymal transition (EMT) of pancreatic cancer is not fully understood.

Methods

By comparing various wild-type pancreatic cancer cell lines, we determined which have a higher expression level of HNRNPA2B1 accompanied by the higher expression of N-cadherin and vimentin and lower expression of E-cadherin. Therefore, to elucidate the role of HNRNPA2B1 in EMT, we generated models of HNRNPA2B1 knockdown and overexpression in different types of pancreatic cancer cell lines (MIA Paca-2, PANC-1 and Patu-8988) and examined changes in expression of EMT-related factors, including CDH1, CDH2, vimentin and snail.

Results

The results show that HNRNPA2B1 promotes EMT development by down-regulating E-cadherin and up-regulating N-cadherin and vimentin, and also stimulates the invasion capacity and inhibits viability in human pancreatic cancer cell lines, the similar results in vivo experiments. Moreover, we found that HNRNPA2B1 likely regulates EMT progression in pancreatic carcinoma via the ERK/snail signalling pathway.

Conclusions

The results of this work suggest that HNRNPA2B1 inhibition has potential antitumour effects, which warrants in-depth investigation.

Current management and future directions in metastatic pancreatic adenocarcinoma

Of the anticipated 50,000 individuals expected to be diagnosed with pancreatic cancer in 2016, the majority will have metastatic disease. Given the noncurative nature of advanced pancreatic adenocarcinoma, treatment is aimed at inducing disease regression, controlling symptom, and extending life. The last 5 years have been marked by advances in the treatment of metastatic pancreatic cancer, specifically the approval by the US Food and Drug Administration of 2 combination chemotherapy regimens and the widespread use of a third, which have reproducibly been shown to improve survival. Ongoing studies are building on these regimens along with targeted and immunotherapeutic agents. This article will review the current treatment standards and emerging targets for metastatic pancreatic cancer. Cancer 2016;122:3765-3775. © 2016 American Cancer Society.

Preoperative evaluation of pancreatic ductal adenocarcinoma with synchronous liver metastasis: Diagnosis and assessment of unresectability

AIM

To identify predictors for synchronous liver metastasis from resectable pancreatic ductal adenocarcinoma (PDAC) and assess unresectability of synchronous liver metastasis.

METHODS

Retrospective records of PDAC patients with synchronous liver metastasis who underwent simultaneous resections of primary PDAC and synchronous liver metastasis, or palliative surgical bypass, were collected from 2007 to 2015. A series of pre-operative clinical parameters, including tumor markers and inflammation-based indices, were analyzed by logistic regression to figure out predictive factors and assess unresectability of synchronous liver metastasis. Cox regression was used to identify prognostic factors in liver-metastasized PDAC patients after surgery, with intention to validate their conformance to the indications of simultaneous resections and palliative surgical bypass. Survival of patients from different groups were analyzed by the Kaplan-Meier method. Intra- and post-operative courses were compared, including complications. PDAC patients with no distant metastases who underwent curative resection served as the control group.

RESULTS

CA125 > 38 U/mL (OR = 12.397, 95%CI: 5.468-28.105, P < 0.001) and diabetes mellitus (OR = 3.343, 95%CI: 1.539-7.262, P = 0.002) independently predicted synchronous liver metastasis from resectable PDAC. CA125 > 62 U/mL (OR = 5.181, 95%CI: 1.612-16.665, P = 0.006) and age > 62 years (OR = 3.921, 95%CI: 1.217-12.632, P = 0.022) correlated with unresectability of synchronous liver metastasis, both of which also indicated a worse long-term outcome of liver-metastasized PDAC patients after surgery. After the simultaneous resections, patients with post-operatively elevated serum CA125 levels had shorter survival than those with post-operatively reduced serum CA125 levels (7.7 mo vs 16.3 mo, P = 0.013). The survival of liver-metastasized PDAC patients who underwent the simultaneous resections was similar to that of non-metastasized PDAC patients who underwent curative pancreatectomy alone (7.0 mo vs 16.9 mo, P < 0.001), with no higher rates of either pancreatic fistula (P = 0.072) or other complications (P = 0.230) and no greater impacts on length of hospital stay (P = 0.602) or post-operative diabetic control (P = 0.479).

CONCLUSION

The criterion set up by CA125 levels could facilitate careful diagnosis of synchronous liver metastases from PDAC, and prudent selection of appropriate patients for the simultaneous resections.

ESE3 Inhibits Pancreatic Cancer Metastasis by Upregulating E-Cadherin

The ETS family transcription factor ESE3 is a crucial element in differentiation and development programs for many epithelial tissues. Here we report its role as a tumor suppressor in pancreatic cancer. We observed drastically lower ESE3 expression in pancreatic ductal adenocarcinomas (PDAC) compared with adjacent normal pancreatic tissue. Reduced expression of ESE3 in PDAC correlated closely with an increase in lymph node metastasis and vessel invasion and a decrease in relapse-free and overall survival in patients. In functional experiments, downregulating the expression of ESE3 promoted PDAC cell motility and invasiveness along with metastasis in an orthotopic mouse model. Mechanistic studies in PDAC cell lines, the orthotopic mouse model, and human PDAC specimens demonstrated that ESE3 inhibited PDAC metastasis by directly upregulating E-cadherin expression at the level of its transcription. Collectively, our results establish ESE3 as a negative regulator of PDAC progression and metastasis by enforcing E-cadherin upregulation. Cancer Res; 77(4); 874-85. ©2016 AACR.

Generation and molecular characterization of pancreatic cancer patient-derived xenografts reveals their heterologous nature

Pancreatic ductal adenocarcinoma (PDAC) is the most challenging type of cancer to treat, with a 5-year survival rate of <10%. Furthermore, because of the large portion of the inoperable cases, it is difficult to obtain specimens to study the biology of the tumors. Therefore, a patient-derived xenograft (PDX) model is an attractive option for preserving and expanding these tumors for translational research. Here we report the generation and characterization of 20 PDX models of PDAC. The success rate of the initial graft was 74% and most tumors were re-transplantable. Histological analysis of the PDXs and primary tumors revealed a conserved expression pattern of p53 and SMAD4; an exome single nucleotide polymorphism (SNP) array and Comprehensive Cancer Panel showed that PDXs retained over 94% of cancer-associated variants. In addition, Polyphen2 and the Sorting Intolerant from Tolerant (SIFT) prediction identified 623 variants among the functional SNPs, highlighting the heterologous nature of pancreatic PDXs; an analysis of 409 tumor suppressor genes and oncogenes in Comprehensive Cancer Panel revealed heterologous cancer gene mutation profiles for each PDX-primary tumor pair. Altogether, we expect these PDX models are a promising platform for screening novel therapeutic agents and diagnostic markers for the detection and eradication of PDAC.

Current evidence for cancer stem cells in gastrointestinal tumors and future research perspectives

Cancer stem cells (CSCs) are a very heterogeneous subpopulation of "stem-like" cancer cells that have been identified in many cancers, including leukemias and solid tumors. It is believed that CSCs drive tumor growth, malignant behavior and are responsible for the initiation of metastatic spread. In addition, CSCs have been implicated in chemotherapy and radiotherapy resistance. Current evidence supports the theory that CSCs share at least two main features of normal stem cells: self-renewal and differentiation, properties that contribute to tumor survival even in the presence of aggressive chemotherapy; however, the mechanism(s) governing the unique biology of CSCs remain unclear. In the field of gastrointestinal cancer, where we face very low survival rates across different tumor types, unraveling the role of CSCs in gastrointestinal tumors should improve our knowledge of cancer biology and chemoresistance, ultimately benefiting patient survival. Towards this end, much effort is being invested in the characterization of CSCs as a means of overcoming drug resistance and controlling metastatic spread. In this review we will cover the concept of CSCs, the current evidence for CSCs in gastrointestinal tumors and future research directions.

The ever-changing landscape of pancreatic cancer stem cells

Over the past decade, the cancer stem cell (CSC) concept in solid tumors has gained enormous momentum as an attractive model to explain tumor heterogeneity. The model proposes that tumors contain a subpopulation of rare cancer cells with stem-like properties that maintain the hierarchy of the tumor and drive tumor initiation, progression, metastasis, and chemoresistance. The identification and subsequent isolation of CSCs in pancreatic ductal adenocarcinoma (PDAC) in 2007 provided enormous insight into this extremely metastatic and chemoresistant tumor and renewed hope for developing more specific therapies against this disease. Unfortunately, we have made only marginal advances in applying the knowledge learned to the development of new and more effective treatments for pancreatic cancer. The latter has been partly due to the lack of adequate in vitro and in vivo systems compounded by the use of markers that do not reproducibly nor exclusively select for an enriched CSC population. Thus, attempts to define a pancreatic CSC-specific genetic, epigenetic or proteomic signature has been challenging. Fortunately recent advances in the CSC field have overcome many of these challenges and have opened up new opportunities for developing therapies that target the CSC population. In this review, we discuss these current advances, specifically new methods for the identification and isolation of pancreatic CSCs, new insights into the metabolic profile of CSCs at the level of mitochondrial respiration, and the utility of genetically engineered mouse models as surrogate systems to both study CSC biology and evaluate CSC-specific targeted therapies in vivo.

Nanomedicine developments in the treatment of metastatic pancreatic cancer: focus on nanoliposomal irinotecan

Nanoliposomal irinotecan (nal-IRI) was originally developed using an efficient and high-loading capacity system to encapsulate irinotecan within a liposomal carrier, producing a therapeutic agent with improved biodistribution and pharmacokinetic characteristics compared to free drug. Specifically, administration of nal-IRI results in prolonged exposure of SN-38, the active metabolite of irinotecan, within tumors, while at the same time offering the advantage of less systemic toxicity than traditional irinotecan. These favorable properties of nal-IRI, confirmed in a variety of tumor xenograft models, led to its clinical evaluation in a number of disease indications for which camptothecins have proven activity, including in colorectal, gastric, and pancreatic cancers. The culmination of these clinical trials was the NAPOLI-1 (Nanoliposomal irinotecan with fluorouracil and folinic acid in metastatic pancreatic cancer after previous gemcitabine-based therapy) trial, an international Phase III study evaluating nal-IRI both alone and in combination with 5-fluorouracil and leucovorin in patients with metastatic pancreatic adenocarcinoma following progression on gemcitabine-based chemotherapy. Positive results from NAPOLI-1 led to approval of nal-IRI (with 5-fluorouracil/leucovorin) in October 2015 by the US Food and Drug Administration specifically for the treatment of metastatic pancreatic cancer in the second-line setting and beyond, a clinical context in which there had previously been no accepted standard of care. As such, nal-IRI represents an important landmark in cancer drug development, and potentially ushers in a new era where a greater number of patients with advanced pancreatic cancer can be sequenced through multiple lines of therapy translating into meaningful improvements in survival.