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With limited treatment options, cachexia remains a major challenge for patients with cancer. Characterizing the interplay between tumor cells and the immune microenvironment may help identify potential therapeutic targets for cancer cachexia. Herein, we investigate the critical role of macrophages in potentiating pancreatic cancer induced muscle wasting via promoting TWEAK (TNF-like weak inducer of apoptosis) secretion from the tumor. Specifically, depletion of macrophages reverses muscle degradation induced by tumor cells. Macrophages induce non-autonomous secretion of TWEAK through CCL5/TRAF6/NF-κB pathway. TWEAK promotes muscle atrophy by activating MuRF1 initiated muscle remodeling. Notably, tumor cells recruit and reprogram macrophages via the CCL2/CCR2 axis and disrupting the interplay between macrophages and tumor cells attenuates muscle wasting. Collectively, this study identifies a feedforward loop between pancreatic cancer cells and macrophages, underlying the non-autonomous activation of TWEAK secretion from tumor cells thereby providing promising therapeutic targets for pancreatic cancer cachexia., Competing Interests: Declaration of interests C.W. Houchen has ownership interest in COARE Holdings Inc., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Epidermal growth factor receptor (EGFR) is an essential target for cancer treatment. However, EGFR inhibitor erlotinib showed limited clinical benefit in pancreatic cancer therapy. Here, we showed the underlying mechanism of tumor microenvironment suppressing the sensitivity of EGFR inhibitor through the pancreatic stellate cell (PSC)., Methods: The expression of alpha-smooth muscle actin (α-SMA) and hypoxia marker in human pancreatic cancer tissues were detected by immunohistochemistry, and their correlation with overall survival was evaluated. Human immortalized PSC was constructed and used to investigate the potential effect on pancreatic cancer cell lines in hypoxia and normoxia. Luciferase reporter assay and Chromatin immunoprecipitation were performed to explore the potential mechanisms in vitro. The combined inhibition of EGFR and Met was evaluated in an orthotopic xenograft mouse model of pancreatic cancer., Findings: We found that high expression levels of α-SMA and hypoxia markers are associated with poor prognosis of pancreatic cancer patients. Mechanistically, we demonstrated that hypoxia induced the expression and secretion of HGF in PSC via transcription factor HIF-1α. PSC-derived HGF activates Met, the HGF receptor, suppressing the sensitivity of pancreatic cancer cells to EGFR inhibitor in a KRAS-independent manner by activating the PI3K-AKT pathway. Furthermore, we found that the combination of EGFR inhibitor and Met inhibitor significantly suppressed tumor growth in an orthotopic xenograft mouse model., Interpretation: Our study revealed a previously uncharacterized HIF1α-HGF-Met-PI3K-AKT signaling axis between PSC and cancer cells and indicated that EGFR inhibition plus Met inhibition might be a promising strategy for pancreatic cancer treatment., Funding: This study was supported by The National Natural Science Foundation of China., Competing Interests: Declaration of interests The authors declare that they have no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background & Aims: Rapid deconditioning, also called cachexia, and metabolic reprogramming are two hallmarks of pancreatic cancer. Acetyl-coenzyme A synthetase short-chain family member 2 (ACSS2) is an acetyl-enzyme A synthetase that contributes to lipid synthesis and epigenetic reprogramming. However, the role of ACSS2 on the nonselective macropinocytosis and cancer cachexia in pancreatic cancer remains elusive. In this study, we demonstrate that ACSS2 potentiates macropinocytosis and muscle wasting through metabolic reprogramming in pancreatic cancer., Methods: Clinical significance of ACSS2 was analyzed using samples from patients with pancreatic cancer. ACSS2-knockout cells were established using the clustered regularly interspaced short palindromic repeats-associated protein 9 system. Single-cell RNA sequencing data from genetically engineered mouse models was analyzed. The macropinocytotic index was evaluated by dextran uptake assay. Chromatin immunoprecipitation assay was performed to validate transcriptional activation. ACSS2-mediated tumor progression and muscle wasting were examined in orthotopic xenograft models., Results: Metabolic stress induced ACSS2 expression, which is associated with worse prognosis in pancreatic cancer. ACSS2 knockout significantly suppressed cell proliferation in 2-dimensional and 3-dimensional models. Macropinocytosis-associated genes are upregulated in tumor tissues and are correlated with worse prognosis. ACSS2 knockout inhibited macropinocytosis. We identified Zrt- and Irt-like protein 4 (ZIP4) as a downstream target of ACSS2, and knockdown of ZIP4 reversed ACSS2-induced macropinocytosis. ACSS2 upregulated ZIP4 through ETV4-mediated transcriptional activation. ZIP4 induces macropinocytosis through cyclic adenosine monophosphate response element-binding protein-activated syndecan 1 (SDC1) and dynamin 2 (DNM2). Meanwhile, ZIP4 drives muscle wasting and cachexia via glycogen synthase kinase-β (GSK3β)-mediated secretion of tumor necrosis factor superfamily member 10 (TRAIL or TNFSF10). ACSS2 knockout attenuated muscle wasting and extended survival in orthotopic mouse models., Conclusions: ACSS2-mediated metabolic reprogramming activates the ZIP4 pathway, and promotes macropinocytosis via SDC1/DNM2 and drives muscle wasting through the GSK3β/TRAIL axis, which potentially provides additional nutrients for macropinocytosis in pancreatic cancer., (Copyright © 2022 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background & Aims: Pancreatic cancer has the highest prevalence of cancer-associated cachexia among all cancers. ZIP4 promotes pancreatic cancer progression by regulating oncogenic miR-373, and perturbation of circular RNAs (circRNAs) is associated with cancer aggressiveness. This study aimed to identify circRNAs involved in ZIP4/miR-373-driven cancer growth and cachexia and decipher the underlying mechanism., Methods: Differentially expressed circRNAs and potential targets of microRNA were identified through in silico analysis. The RNA interactions were determined by means of biotinylated microRNA pulldown, RNA immunoprecipitation, and luciferase reporter assays. The function of circRNA in ZIP4-miR-373 signaling axis were examined in human pancreatic cancer cells, 3-dimensional spheroids and organoids, mouse models, and clinical specimens. Mouse skeletal muscles were analyzed by means of histology., Results: We identified circANAPC7 as a sponge for miR-373, which inhibited tumor growth and muscle wasting in vitro and in vivo. Mechanistic studies showed that PHLPP2 is a downstream target of ZIP4/miR-373. CircANAPC7 functions through PHLPP2-mediated dephosphorylation of AKT, thus suppressing cancer cell proliferation by down-regulating cyclin D1 and inhibiting muscle wasting via decreasing the secretion of transforming growth factor-β through STAT5. We further demonstrated that PHLPP2 induced dephosphorylation of CREB, a zinc-dependent transcription factor activated by ZIP4, thereby forming a CREB-miR-373-PHLPP2 feed-forward loop to regulate tumor progression and cancer cachexia., Conclusion: This study identified circANAPC7 as a novel tumor suppressor, which functions through the CREB-miR-373-PHLPP2 axis, leading to AKT dephosphorylation, and cyclin D1 and transforming growth factor-β down-regulation to suppress tumor growth and muscle wasting in pancreatic cancer., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Methylthioadenosine phosphorylase (MTAP) is a key enzyme associated with the salvage of methionine and adenine that is deficient in 20% to 30% of pancreatic cancer. Our previous study revealed that MTAP deficiency indicates a poor prognosis for patients with pancreatic ductal adenocarcinoma (PDAC). In this study, bioinformatics analysis of The Cancer Genome Atlas (TCGA) data indicated that PDACs with MTAP deficiency display a signature of elevated glycolysis. Metabolomics studies showed that that MTAP deletion-mediated metabolic reprogramming enhanced glycolysis and de novo purine synthesis in pancreatic cancer cells. Western blot analysis revealed that MTAP knockout stabilized hypoxia-inducible factor 1α (HIF1α) protein via posttranslational phosphorylation. RIO kinase 1 (RIOK1), a downstream kinase upregulated in MTAP-deficient cells, interacted with and phosphorylated HIF1α to regulate its stability. In vitro experiments demonstrated that the glycolysis inhibitor 2-deoxy-d-glucose (2-DG) and the de novo purine synthesis inhibitor l-alanosine synergized to kill MTAP-deficient pancreatic cancer cells. Collectively, these results reveal that MTAP deficiency drives pancreatic cancer progression by inducing metabolic reprogramming, providing a novel target and therapeutic strategy for treating MTAP-deficient disease. SIGNIFICANCE: This study demonstrates that MTAP status impacts glucose and purine metabolism, thus identifying multiple novel treatment options against MTAP-deficient pancreatic cancer., (©2021 American Association for Cancer Research.)

Background: Pancreatic cancer is characterized by extensive metastasis. Epithelial-mesenchymal transition (EMT) plasticity plays a critical role in tumor progression and metastasis by maintaining the transition between EMT and mesenchymal-epithelial transition states. Our aim is to understand the molecular events regulating metastasis and EMT plasticity in pancreatic cancer., Methods: The interactions between a cancer-promoting zinc transporter ZIP4, a zinc-dependent EMT transcriptional factor ZEB1, a coactivator YAP1, and integrin α3 (ITGA3) were examined in human pancreatic cancer cells, clinical specimens, spontaneous mouse models (KPC and KPCZ) and orthotopic xenografts, and 3-dimensional spheroid and organoid models. Correlations between ZIP4, miR-373, and its downstream targets were assessed by RNA in situ hybridization and immunohistochemical staining. The transcriptional regulation of ZEB1, YAP1, and ITGA3 by ZIP4 was determined by chromatin immunoprecipitation, co-immunoprecipitation, and luciferase reporter assays., Results: The Hippo pathway effector YAP1 is a potent transcriptional coactivator and forms a complex with ZEB1 to activate ITGA3 transcription through the YAP1/transcriptional enhanced associate domain (TEAD) binding sites in human pancreatic cancer cells and KPC-derived mouse cells. ZIP4 upregulated YAP1 expression via activation of miR-373 and inhibition of the YAP1 repressor large tumor suppressor 2 kinase (LATS2). Furthermore, upregulation of ZIP4 promoted EMT plasticity, cell adhesion, spheroid formation, and organogenesis both in human pancreatic cancer cells, 3-dimensional spheroid model, xenograft model, and spontaneous mouse models (KPC and KPCZ) through ZEB1/YAP1-ITGA3 signaling axis., Conclusion: We demonstrated that ZIP4 activates ZEB1 and YAP1 through distinct mechanisms. The ZIP4-miR-373-LATS2-ZEB1/YAP1-ITGA3 signaling axis has a significant impact on pancreatic cancer metastasis and EMT plasticity., (Copyright © 2021 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: N6-methyladenosine (m6A) is the most abundant mRNA modification. Whether m6A regulators can determine tumor aggressiveness and risk of immune evasion in pancreatic ductal adenocarcinoma (PDAC) remains unknown., Methods: An integrated model named "m6Ascore" is constructed based on RNA-seq data of m6A regulators in PDAC. Association of m6Ascore and overall survival is validated across several different datasets. Overlaps of m6Ascore and established molecular classifications of PDAC is examined. Immune infiltration, enriched pathways, somatic copy number alterations (SCNAs), mutation profiles and response to immune checkpoint inhibitors are compared between m6Ascore-high and m6Ascore-low tumors., Findings: m6Ascore is associated with dismal overall survival and increased tumor recurrence in PDAC as well as several other solid tumors including colorectal cancer and breast cancer. Basal-like (Squamous) PDAC has higher m6Ascore than that in the classical PDAC. Mechanism study showed m6Ascore-high tumors are characterized with reduced immune infiltration and T cells exhaustion. Meanwhile, m6Ascore is associated with genes regulating cachexia and chemoresistance in PDAC. Furthermore, distinct SCNAs patterns and mutation profiles of KRAS and TP53 are present in m6Ascore-high tumors, indicating immune evasion. m6Ascore-low tumors have higher response rates to immune checkpoint inhibitors (ICIs)., Interpretation: These findings indicate m6Ascore can predict aggressiveness and immune evasion in pancreatic cancer. This model has implications for pancreatic cancer prognosis and treatment response to ICIs., Funding: This work was supported in part by National Institutes of Health (NIH) grants to M. Li (R01 CA186338, R01 CA203108, R01 CA247234 and the William and Ella Owens Medical Research Foundation) and NIH/National Cancer Institute Q39 award P30CA225520 to Stephenson Cancer Center., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Pancreatic tumors undergo rapid growth and progression, become resistant to chemotherapy, and recur after surgery. We studied the functions of the solute carrier family 39 member 4 (SLC39A4, also called ZIP4), which regulates concentrations of intracellular zinc and is increased in pancreatic cancer cells, in cell lines and mice., Methods: We obtained 93 pancreatic cancer specimens (tumor and adjacent nontumor tissues) from patients who underwent surgery and gemcitabine chemotherapy and analyzed them by immunohistochemistry. ZIP4 and/or ITGA3 or ITGB1 were overexpressed or knocked down with short hairpin RNAs in AsPC-1 and MIA PaCa-2 pancreatic cancer cells lines, and in pancreatic cells from KPC and KPC-ZEB1-knockout mice, and pancreatic spheroids were established; cells and spheroids were analyzed by immunoblots, reverse transcription polymerase chain reaction, and liquid chromatography tandem mass spectrometry. We studied transcriptional regulation of ZEB1, ITGA3, ITGB1, JNK, and ENT1 by ZIP4 using chromatin precipitation and luciferase reporter assays. Nude mice were given injections of genetically manipulated AsPC-1 and MIA PaCa-2 cells, and growth of xenograft tumors and metastases was measured., Results: In pancreatic cancer specimens from patients, increased levels of ZIP4 were associated with shorter survival times. MIA PaCa-2 cells that overexpressed ZIP4 had increased resistance to gemcitabine, 5-fluorouracil, and cisplatin, whereas AsPC-1 cells with ZIP4 knockdown had increased sensitivity to these drugs. In mice, xenograft tumors grown from AsPC-1 cells with ZIP4 knockdown were smaller and more sensitive to gemcitabine. ZIP4 overexpression significantly reduced accumulation of gemcitabine in pancreatic cancer cells, increased growth of xenograft tumors in mice, and increased expression of the integrin subunits ITGA3 and ITGB1; expression levels of ITGA3 and ITGB1 were reduced in cells with ZIP4 knockdown. Pancreatic cancer cells with ITGA3 or ITGB1 knockdown had reduced proliferation and formed smaller tumors in mice, despite overexpression of ZIP4; spheroids established from these cells had increased sensitivity to gemcitabine. We found ZIP4 to activate STAT3 to induce expression of ZEB1, which induced expression of ITGA3 and ITGB1 in KPC cells. Increased ITGA3 and ITGB1 expression and subsequent integrin α3β1 signaling, via c-Jun-N-terminal kinase (JNK), inhibited expression of the gemcitabine transporter ENT1, which reduced gemcitabine uptake by pancreatic cancer cells. ZEB1-knockdown cells had increased sensitivity to gemcitabine., Conclusions: In studies of pancreatic cancer cell lines and mice, we found that ZIP4 increases expression of the transcription factor ZEB1, which activates expression of ITGA3 and ITGB1. The subsequent increase in integrin α3β1 signaling, via JNK, inhibits expression of the gemcitabine transporter ENT1, so that cells take up smaller amounts of the drug. Activation of this pathway might help mediate resistance of pancreatic tumors to chemotherapeutic agents., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Purpose: As a main rate-limiting subunit of the 2-oxoglutarate dehydrogenase multienzyme complex, oxoglutarate dehydrogenase like (OGDHL) is involved in the tricarboxylic acid cycle, and frequently downregulated in human carcinoma and suppresses tumor growth. However, little is known about the role of OGDHL in human cancer, especially pancreatic cancer. Our goal is to study the underlying mechanism and define a novel signaling pathway controlled by OGDHL modulating pancreatic cancer progression., Experimental Design: The expression and functional analysis of OGDHL, miR-214, and TWIST1 in human pancreatic cancer tissues, cell lines, and xenograft tumor model were investigated. The correlations between OGDHL and those markers were analyzed., Results: OGDHL was downregulated in human pancreatic cancer and predicted poor prognosis. OGDHL overexpression inhibited migration and invasion of pancreatic cancer cells and suppressed pancreatic cancer tumor growth. OGDHL was shown to be negatively regulated by miR-214. TWIST1 upregulation induced miR-214 expression in pancreatic cancer. OGDHL suppressed TWIST1 expression through promoting ubiquitin-mediated proteasomal degradation of HIF1α and regulating AKT pathways. A combination of OGDHL downregulation and TWIST1 and miR-214 overexpression predicted worse prognosis in patients with pancreatic cancer., Conclusions: We demonstrated the prognostic value of OGDHL, miR-214, and TWIST1 in pancreatic cancer, and elucidated a novel pathway in OGDHL-regulated inhibition of pancreatic cancer tumorigenesis and metastasis. These findings may lead to new targeted therapy for pancreatic cancer through regulating OGDHL, miR-214, and TWIST1., (©2019 American Association for Cancer Research.)

Background & Aims: Cachexia, which includes muscle wasting, is a frequent complication of pancreatic cancer. There are no therapies that reduce cachexia and increase patient survival, so it is important to learn more about its mechanisms. The zinc transporter ZIP4 promotes growth and metastasis of pancreatic tumors. We investigated its effects on muscle catabolism via extracellular vesicle (EV)-mediated stimulation of mitogen-activated protein kinase 14 (p38 MAPK)., Methods: We studied nude mice with orthotopic tumors grown from human pancreatic cancer cell lines (AsPC-1 and BxPC-3); tumors were removed 8 days after cell injection and analyzed by histology. Mouse survival was analyzed by Kaplan-Meier curves. ZIP4 was knocked down in AsPC-1 and BxPC-3 cells with small hairpin RNAs; cells with empty vectors were used as controls. Muscle tissues were collected from mice and analyzed by histology and immunohistochemistry. Conditioned media from cell lines and 3-dimensional spheroid/organoid cultures of cancer cells were applied to C2C12 myotubes. The myotubes and the media were analyzed by immunoblots, enzyme-linked immunosorbent assays, and immunofluorescence microscopy. EVs were isolated from conditioned media and analyzed by immunoblots., Results: Mice with orthotopic tumors grown from pancreatic cancer cells with knockdown of ZIP4 survived longer and lost less body weight and muscle mass than mice with control tumors. Conditioned media from cancer cells activated p38 MAPK, induced expression of F-box protein 32 and UBR2 in C2C12 myotubes, and also led to loss of myofibrillar protein myosin heavy chain and myotube thinning. Knockdown of ZIP4 in cancer cells reduced these effects. ZIP4 knockdown also reduced pancreatic cancer cell release of heat shock protein (HSP) 70 and HSP90, which are associated with EVs, by decreasing CREB-regulated expression of RAB27B., Conclusions: ZIP4 promotes growth of orthotopic pancreatic tumors in mice and loss of muscle mass by activating CREB-regulated expression of RAB27B, required for release of EVs from pancreatic cancer cells. These EVs activate p38 MAPK and induce expression of F-box protein 32 and UBR2 in myotubes, leading to loss of myofibrillar myosin heavy chain and myotube thinning. Strategies to disrupt these pathways might be developed to reduce pancreatic cancer progression and accompanying cachexia., (Copyright © 2019 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Kras is a decisive oncogene in pancreatic ductal adenocarcinoma (PDAC). PIN1 is a key effector involved in the Kras/ERK axis, synergistically mediating various cellular events. However, the underlying mechanism by which PIN1 promotes the development of PDAC remains unclear. Here we sought to elucidate the effect of PIN1 on redox homeostasis in Kras-driven PDAC. PIN1 was prevalently upregulated in PDAC and predicted the prognosis of the disease, especially Kras-mutant PDAC. Downregulation of PIN1 inhibited PDAC cell growth and promoted apoptosis, partially due to mitochondrial dysfunction. Silencing of PIN1 damaged basal mitochondrial function by significantly increasing intracellular ROS. Furthermore, PIN1 maintained redox balance via synergistic activation of c-Myc and NRF2 to upregulate expression of antioxidant response element driven genes in PDAC cells. This study elucidates a new mechanism by which Kras/ERK/NRF2 promotes tumor growth and identifies PIN1 as a decisive target in therapeutic strategies aimed at disturbing the redox balance in pancreatic cancer. SIGNIFICANCE: This study suggests that antioxidation protects Kras-mutant pancreatic cancer cells from oxidative injury, which may contribute to development of a targeted therapeutic strategy for Kras-driven PDAC by impairing redox homeostasis., (©2018 American Association for Cancer Research.)

Purpose: To develop a synergistic combination therapy for advanced pancreatic cancer, using local phototherapy and immunotherapy, and to determine the efficacy and mechanism of the novel combination therapy using a highly metastatic pancreatic tumor model in mice. Experimental Design: Mice bearing Panc02-H7 pancreatic tumors (both subcutaneous and orthotopic) were treated with noninvasive or interventional photothermal therapy, followed by local application of an immunoadjuvant. Tumor growth and animal survival were assessed. Immune cell populations within spleen and tumors were evaluated by FACS and IHC, and cytokine levels were determined by ELISA. Results: Up to 75% of mice bearing subcutaneous tumors treated with combination therapy had complete tumor regression. Local photothermal therapy exposed/released damage-associated molecular patterns, which initiated an immunogenic tumor cell death, resulting in infiltration of antigen-presenting cells and Th1 immunity. Concomitant application of immunoadjuvant amplified Th1 immunity, especially the tumor-specific cytotoxic T lymphocyte response, with increased quantity and quality of T cells. Combination therapy also induced tumor-specific immune memory, as demonstrated by resistance to tumor rechallenge and production of memory T cells. For the treatment of orthotopic tumor, the combination therapy significantly reduced the primary tumors and metastases, and prolonged the animal survival time. Conclusions: This study indicated that combination of local phototherapy and immunotherapy induced a systemic immunity against established tumors and metastases in an aggressive, preclinical pancreatic tumor model, leading to a potential clinical method for patients with advanced pancreatic cancer. Clin Cancer Res; 24(21); 5335-46. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Purpose: ZIP4 is overexpressed in human pancreatic cancer and promotes tumor growth. However, little is known about the role of ZIP4 in advanced stages of this dismal neoplasm. Our goal is to study the underlying mechanism and define a novel signaling pathway controlled by ZIP4-modulating pancreatic tumor metastasis. Experimental Design: The expression of ZIP4, ZO-1, claudin-1, and ZEB1 in human pancreatic cancer tissues, genetically engineered mouse model, xenograft tumor model, and pancreatic cancer cell lines were examined, and the correlations between ZIP4 and those markers were also analyzed. Functional analysis of ZO-1, claudin-1, and ZEB1 was investigated in pancreatic cancer cell lines and orthotopic xenografts. Results: Genetic inactivation of ZIP4 inhibited migration and invasion in pancreatic cancer and increased the expression of ZO-1 and claudin-1. Conversely, overexpression of ZIP4 promoted migration and invasion and increased the expression of ZEB1 and downregulation of the aforementioned epithelial genes. ZIP4 downregulation of ZO-1 and claudin-1 requires the transcriptional repressor ZEB1. Further analysis demonstrated that ZIP4-mediated repression of ZO-1 and claudin-1 leads to upregulation of their targets FAK and Paxillin. Silencing of ZIP4 caused reduced phosphorylation of FAK and Paxillin, which was rescued by simultaneous blocking of ZO-1 or claudin-1. Clinically, we demonstrated that ZIP4 positively correlates with the levels of ZEB1 and inversely associates with the expression of ZO-1 and claudin-1. Conclusions: These findings suggest a novel pathway activated by ZIP4-controlling pancreatic cancer invasiveness and metastasis, which could serve as a new therapeutic target for this devastating disease. Clin Cancer Res; 24(13); 3186-96. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Metabolic bone disorders are associated with several types of human cancers. Pancreatic cancer patients usually suffer from severe nutrition deficiency, muscle wasting, and loss of bone mass. We have previously found that silencing of a zinc transporter ZIP4 prolongs the survival and reduces the severity of the cachexia in vivo. However, the role of ZIP4 in the pancreatic cancer related bone loss remains unknown. In this study we investigated the effect of ZIP4 knockdown on the bone structure, composition and mechanical properties of femurs in an orthotopic xenograft mouse model. Our data showed that silencing of ZIP4 resulted in increased bone tissue mineral density, decreased bone crystallinity and restoration of bone strength through the RANK/RANKL pathway. The results further support the impact of ZIP4 on the progression of pancreatic cancer, and suggest its potential significance as a therapeutic target for treating patients with such devastating disease and cancer related disorders.

Pancreatic cancer has the worst five-year survival rate of all malignancies due to its aggressive progression and resistance to therapy. Current therapies are limited to gemcitabine-based chemotherapeutics, surgery, and radiation. The current trend toward "personalized genomic medicine" has the potential to improve the treatment options for pancreatic cancer. Gene identification and genetic alterations like single nucleotide polymorphisms and mutations will allow physicians to predict the efficacy and toxicity of drugs, which could help diagnose pancreatic cancer, guide neoadjuvant or adjuvant treatment, and evaluate patients' prognosis. This article reviews the multifaceted roles of genomics and pharmacogenomics in pancreatic cancer., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Pancreatectomy is associated with significant morbidity and unpredictable outcome, with few diagnostic tools to determine, which patients gain the most benefit from this treatment, especially before the operation. This study aimed to define a preoperative signature panel of serum markers to indicate response to pancreatectomy for pancreatic cancer. Over 1000 patients with pancreatic cancer treated at two independent high-volume institutions were included in this study and were divided into three groups, including resected, locally advanced and metastatic. Eight serum tumor markers most commonly used in gastrointestinal cancers were analyzed for patient outcome. Preoperative CA19-9 independently indicated surgical response in pancreatic cancer. Patients with CA19-9 ≥1000 U/mL generally had a poor surgical benefit. However, a subset of these patients still achieved a survival advantage when CA19-9 levels decreased postoperatively. CEA and CA125 in the presence of CA19-9 ≥1000 U/mL could independently predict the non-decrease of CA19-9 postoperatively. The combination of the three markers was useful for predicting a worse surgical outcome with a median survival of 5.1 months vs. 23.0 months (p < 0.001) for the training cohort and 7.0 months vs. 18.2 months (p < 0.001) for the validation cohort and also suggested a higher prevalence of early distant metastasis after surgery. Resected patients with this proposed signature showed no survival advantage over patients in the locally advanced group who did not receive pancreatectomy. Therefore, a preoperative serum signature of CEA(+)/CA125(+)/CA19-9 ≥1000 U/mL is associated with poor surgical outcome and can be used to select appropriate patients with pancreatic cancer for pancreatectomy., (© 2014 UICC.)

Background: Tumor cells exhibit abnormal actin remodeling profiles, which involve the altered expressions of several important actin-binding proteins. Profilin1 (Pfn1), originally identified as an actin-associated protein, has been linked to several human malignancies. Our recent studies suggested that Pfn1 facilitates apoptosis in pancreatic cancer cells. Here, we investigated the exact role of Profilin1 (Pfn1) in pancreatic adenocarcinoma (PDAC) and the underlying mechanisms., Methods: Pfn1 protein expression in PDAC specimens was analyzed by immunohistochemistry using a tissue microarray (TMA) containing PDAC tumor tissue and corresponding normal tissue samples from 72 patients. The effect of Pfn1 expression on cancer proliferation was assessed in cells by up- and down-regulation of Pfn1 in vitro and in vivo. Immunoprecipitation and mass spectrometry were used to identify the Pfn1-associated proteins and potential pathways., Results: Pfn1 was downregulated in clinical pancreatic adenocarcinoma specimens compared with the surrounding benign tissues. Univariate survival analysis of the PDAC cohorts showed that low expression of Pfn1 was significantly correlated with shortened patient survival (mean 14.2 months versus 20.9 months, P < 0.05). Restoration of Pfn1 in pancreatic cancer cells with low endogenous Pfn1 expression resulted in a nontumorigenic phenotype, suggesting that Pfn1 may be a negative regulator of pancreatic cancer progression. Overexpression of Pfn1 in vivo decreased the tumor volume in orthotopic xenograft nude mice models. Pfn1 upregulated the expression of SIRT3, leading to HIF1α destabilization. This data revealed that aberrant Pfn1 expression contributes to pancreatic cancer progression., Conclusions: Our data suggest that Pfn1 is a tumor suppressor in pancreatic cancer that acts via a novel mechanism of regulating the SIRT3-HIF1α axis, independently of its cytoskeleton-related activity.

Carboxyl terminus of heat shock protein 70-interacting protein (CHIP) is an E3 ubiquitin ligase that is involved in protein quality control and mediates several tumor-related proteins in many cancers, but the function of CHIP in pancreatic cancer is not known. Here we show that CHIP interacts and ubiquitinates epidermal growth factor receptor (EGFR) for proteasome-mediated degradation in pancreatic cancer cells, thereby inhibiting the activation of EGFR downstream pathway. CHIP suppressed cell proliferation, anchor-independent growth, invasion and migration, as well as enhanced apoptosis induced by erlotinib in vitro and in vivo. The expression of CHIP was decreased in pancreatic cancer tissues or sera. Low CHIP expression in tumor tissues was correlated with tumor differentiation and shorter overall survival. These observations indicate that CHIP serves as a novel tumor suppressor by down-regulating EGFR pathway in pancreatic cancer cells, decreased expression of CHIP was associated with poor prognosis in pancreatic cancer.

Emerging evidence implicates the zinc importer ZIP4 as a critical factor that enhances pancreatic cancer proliferation; however, the role of ZIP4 in promoting pancreatic cancer progression by regulating apoptosis requires elucidation. To determine the effect of ZIP4 on apoptosis, we used cell lines where ZIP4 levels were upregulated or silenced in combination with Chelex 100 treatment to deplete intracellular zinc. Pancreatic cancer xenografts derived from those cells were also included. TUNEL and flow cytometry analysis were used to measure apoptosis and western blotting was used to analyze protein expression for PARP and multiple caspases. Cell cycle profiles were examined by flow cytometry. Zinc depletion by Chelex induced more apoptosis of pancreatic cancer cells in comparison to normal medium, where almost no apoptosis was observed. ZIP4 stably overexpressed MIA PaCa-2 (MIA-ZIP4) cells were more resistant to zinc depletion-induced apoptosis compared with vector control. Conversely, AsPC-1 (AsPC-shZIP4) cells with stable knockdown of ZIP4 were more sensitive to zinc deficiency than control. Resistance to apoptosis mediated by ZIP4 was accomplished by the caspase pathway. In vivo data also confirmed that ZIP4 overexpressed xenografts showed less apoptosis than controls. Cell cycle profiles indicate that silencing of ZIP4 leads to decreased cell population in S phase and G 0/G 1 arrest. These results described a previously uncharacterized role of ZIP4 in apoptosis resistance and elucidated a novel pathway through which ZIP4 regulates pancreatic cancer growth. This research provides additional evidence for ZIP4 and related signaling cascade as a molecular target for therapeutic intervention in pancreatic cancer.

Changes in the intracellular levels of the essential micronutrient zinc have been implicated in multiple diseases including pancreatic cancer; however, the molecular mechanism is poorly understood. Here, we report a novel mechanism where increased zinc mediated by the zinc importer ZIP4 transcriptionally induces miR-373 in pancreatic cancer to promote tumour growth. Reporter, expression and chromatin immunoprecipitation assays demonstrate that ZIP4 activates the zinc-dependent transcription factor CREB and requires this transcription factor to increase miR-373 expression through the regulation of its promoter. miR-373 induction is necessary for efficient ZIP4-dependent enhancement of cell proliferation, invasion, and tumour growth. Further analysis of miR-373 in vivo oncogenic function reveals that it is mediated through its negative regulation of TP53INP1, LATS2 and CD44. These results define a novel ZIP4-CREB-miR-373 signalling axis promoting pancreatic cancer growth, providing mechanistic insights explaining in part how a zinc transporter functions in cancer cells and may have broader implications as inappropriate regulation of intracellular zinc levels plays an important role in many other diseases., (© 2013 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.)

Pancreatic cancer is the fourth leading cause of cancer deaths and is characterized by dismal prognosis. Xenograft and genetically engineered mouse (GEM) models have recapitulated critical elements of human pancreatic cancer, providing useful tools to probe the underlying cause of cancer etiology. In this review, we provide a brief description of the common genetic lesions that occur during the development of pancreatic cancer. Next, we describe the strengths and weaknesses of these two models and highlight key discoveries each has made. Although the relative merits of GEM and xenograft pancreatic cancer mouse models are subject to debate, both systems have and will continue to yield essential insights in understanding pancreatic cancer etiology. This information is critical for the development of new methods to screen, treat, and prevent pancreatic cancer., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Pancreatic cancers are typically resistant to chemo and radiation therapy and are predisposed to distant metastases. Circulating tumor cells (CTCs) are tumor cells disseminated from primary and metastatic sites and can be isolated from peripheral blood. CTC may overcome the limitation of the current available tumor markers, CA19-9. As a surrogate for 'real-time biopsy', CTCs allow recurrent assessment of a tumor's biological activity. We review the current methodologies for CTC extraction and characterization including antibody-based immunological assays, PCR-based assays, and novel technologies based on the physical or biological characteristics of CTCs. CTCs also provide an accessible link to the existence of epithelial to mesenchymal transition, tumor stem cell markers, and ongoing clonal mutations and epigenetic changes in the tumor. We also explore the potential of using CTC profiling in diagnosis, selection of neoadjuvant and adjuvant therapy, detection of recurrent disease, examination of pharmacodynamic biomarkers, as well as in gene therapy and immunotherapy for pancreatic cancer. Ongoing CTC characterization not only has the potential to represent all cells shed from primary pancreatic tumor and each metastatic site, but also allows dynamic sampling at multiple time points during the clinical course to identify the subpopulations of CTCs and the specific molecules driving metastasis and chemo resistance. We predict that CTC genotyping and phenotyping will play an increasing role in personalized therapy and in identification of novel therapeutic targets as well as monitoring the course and status of the disease., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Pancreatic cancer is the fourth leading cause of cancer related deaths in North America. The poor survival statistics are due to the fact that there are no reliable tests for early diagnosis and no effective therapies once metastasis has occurred. Surgical resection is the only curative treatment for pancreatic cancer; however, only less than 15% of the patients are eligible for surgery at diagnosis. New therapies are urgently needed for this malignant disease. And combinational therapy including surgery, chemotherapy and molecular targeted therapy may further improve the efficacy of individual therapies. However, a reliable mouse model which mimics the human disease and can be used for testing the surgical treatment and surgery-based combinational therapy is not available. In this study, we have established a mouse model for curative surgical resection of pancreatic cancer. Human pancreatic cancer cells were used to create orthotopic xenografts in nude mice, distal pancreatectomy was performed using imaging-guided technology to remove the pancreatic tumors, and sham surgery was performed in the control group. All mice survived the operation and no complication was observed. Surgical resection at early stage improved the survival rate and quality of life of the mice compared with the sham surgery and surgical resection at the late stage. If combined with other therapies such as chemotherapy and molecular targeted therapy, it could further improve the outcome of pancreatic cancer. This mouse model is a useful tool to study the surgical therapy and the tumor recurrence of pancreatic cancer, and could potentially impact the therapeutic choices for this deadly disease., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Pancreatic cancer is an aggressive solid tumour characterized by its local invasion, early metastasis and resistance to standard chemotherapy or radiation therapy. Tumour initiating cells (TICs) are not only capable of self-renewal and differentiation, but also play an important role in multi-drug resistance, and thus become a popular topic in cancer research especially in pancreatic cancer. In this review, we summarize the current progress of TICs in tumourigenesis, various newly identified surface markers of pancreatic TICs, and the signalling pathways such as epithelial-mesenchymal transition, sonic hedgehog and Notch that regulate TICs. We also discuss the role which microRNA plays in TICs as well as its application in TIC-targeted therapy along with other approaches., (© 2012 The Authors Journal of Cellular and Molecular Medicine © 2012 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.)

Introduction: Pancreatic cancer has the worst survival rate of all cancers. The current standard care for metastatic pancreatic cancer is gemcitabine, however, the success of this treatment is poor and overall survival has not improved for decades. Drug resistance (both intrinsic and acquired) is thought to be a major reason for the limited benefit of most pancreatic cancer therapies., Areas Covered: Previous studies have indicated various mechanisms of drug resistance in pancreatic cancer, including changes in individual genes or signaling pathways, the influence of the tumor microenvironment, and the presence of highly resistant stem cells. This review summarizes recent advances in the mechanisms of drug resistance in pancreatic cancer and potential strategies to overcome this., Expert Opinion: Increasing drug delivery efficiency and decreasing drug resistance is the current aim in pancreatic cancer treatment, and will also benefit the treatment of other cancers. Understanding the molecular and cellular basis of drug resistance in pancreatic cancer will lead to the development of novel therapeutic strategies with the potential to sensitize pancreatic cancer to chemotherapy, and to increase the efficacy of current treatments in a wide variety of human cancers.