Molecular Drivers of Pancreatic Cancer Pathogenesis: Looking Inward to Move Forward

Personalized nutrition after discharge for pancreatic surgery: A study protocol

Background: Pancreatic cancer has an increasing incidence and prevalence trend. Its prognosis is negatively affected by poor/altered nutritional status. Therefore, nutritional interventions play a critical/pivotal role at any stage. Despite being included in the prehabilitation items of Enhanced Recovery After Surgery (ERAS) protocols for pancreatic surgery, nutritional recommendations concerning early post-discharge period are lacking. Aim: To assess the acceptability and feasibility of a personalized and standardized food plan for patients following pancreatic surgery. A secondary aim is to determine if adherence to a personalized food plan is linked to improved postoperative outcomes. Methods: A prospective monocentric cohort study will be performed, including 180 patients undergoing pancreatic surgery. Body composition, nutritional, muscular, and hydro-electrolyte status will be assessed with bio-impedance analysis (BIA). Patients will receive a personalized nutritional plan after discharge for the following 45 days. Summary: Detailed nutritional indications have been formulated with broad consensus for the pre-operative (prehabilitation) and postoperative period. No previous study has specifically formulated or validated a nutritional intervention focused on the early post-discharge period. The results of this study might contribute to paving the way for future research and to broaden nutritional recommendations within the ERAS protocol.

Sorcin can trigger pancreatic cancer-associated new-onset diabetes through the secretion of inflammatory cytokines such as serpin E1 and CCL5

A rise in blood glucose is an early warning sign of underlying pancreatic cancer (PC) and may be an indicator of genetic events in PC progression. However, there is still a lack of mechanistic research on pancreatic cancer-associated new-onset diabetes (PCAND). In the present study, we identified a gene SRI, which possesses a SNP with the potential to distinguish PCAND and Type 2 diabetes mellitus (T2DM), by machine learning on the basis of the UK Biobank database. In vitro and in vivo, sorcin overexpression induced pancreatic β-cell dysfunction. Sorcin can form a positive feedback loop with STAT3 to increase the transcription of serpin E1 and CCL5, which may directly induce β-cell dysfunction. In 88 biopsies, the expression of sorcin was elevated in PC tissues, especially in PCAND samples. Furthermore, plasma serpin E1 levels are higher in peripheral blood samples from PCAND patients than in those from T2DM patients. In conclusion, sorcin may be the key driver in PCAND, and further study on the sorcin-STAT3-serpin E1/CCL5 signaling axis may help us better understand the pathogenesis of PCAND and identify potential biomarkers.

B7 homolog 3 in pancreatic cancer

Despite advances in cancer treatment, pancreatic cancer (PC) remains a disease with high mortality rates and poor survival outcomes. The B7 homolog 3 (B7-H3) checkpoint molecule is overexpressed among many malignant tumors, including PC, with low or absent expression in healthy tissues. By modulating various immunological and nonimmunological molecular mechanisms, B7-H3 may influence the progression of PC. However, the impact of B7-H3 on the survival of patients with PC remains a subject of debate. Still, most available scientific data recognize this molecule as a suppressive factor to antitumor immunity in PC. Furthermore, it has been demonstrated that B7-H3 stimulates the migration, invasion, and metastasis of PC cells, and enhances resistance to chemotherapy. In preclinical models of PC, B7-H3-targeting monoclonal antibodies have exerted profound antitumor effects by increasing natural killer cell-mediated antibody-dependent cellular cytotoxicity and delivering radioisotopes and cytotoxic drugs to the tumor site. Finally, PC treatment with B7-H3-targeting antibody-drug conjugates and chimeric antigen receptor T cells is being tested in clinical studies. This review provides a comprehensive analysis of all PC-related studies in the context of B7-H3 and points to deficiencies in the current data that should be overcome by future research.

Identification of novel curcumin derivatives against pancreatic cancer: a comprehensive approach integrating 3D-QSAR pharmacophore modeling, virtual screening, and molecular dynamics simulations

Pancreatic cancer, known as the "silent killer," poses a daunting challenge in cancer therapy. The dysregulation of the PI3Kα signaling pathway in pancreatic cancer has attracted considerable interest as a promising target for therapeutic intervention. In this regard, the use of curcumin derivatives as inhibitors of PI3Kα has emerged, providing a novel and promising avenue for developing effective treatments for this devastating disease. Computational approaches were employed to explore this potential and investigate 58 curcumin derivatives with cytotoxic activity against the Panc-1 cell line. Our approach involved ligand-based pharmacophore modeling and atom-based 3D-QSAR analysis. The resulting QSAR model derived from the best-fitted pharmacophore hypothesis (AAHRR_1) demonstrated remarkable performance with high correlation coefficients (R2) of 0.990 for the training set and 0.977 for the test set. The cross-validation coefficient (Q2) of 0.971 also validated the model's predictive power. Tropsha's recommended criteria, including the Y-randomization test, were employed to ensure its reliability. Furthermore, an enrichment study was conducted to evaluate the model's performance in identifying active compounds. AAHRR_1 was used to screen a curated PubChem database of curcumin-related compounds. Two molecules (CID156189304 and CID154728220) exhibited promising pharmacokinetic properties and higher docking scores than Alpelisib, warranting further investigation. Extensive molecular dynamics simulations provided crucial insights into the conformational dynamics within the binding site, validating their stability and behavior. These findings contribute to our understanding of the potential therapeutic effectiveness of these compounds as PI3Kα inhibitors in pancreatic cancer.Communicated by Ramaswamy H. Sarma.

The bioengineered and multifunctional nanoparticles in pancreatic cancer therapy: Bioresponisive nanostructures, phototherapy and targeted drug delivery

The multidisciplinary approaches in treatment of cancer appear to be essential in term of bringing benefits of several disciplines and their coordination in tumor elimination. Because of the biological and malignant features of cancer cells, they have ability of developing resistance to conventional therapies such as chemo- and radio-therapy. Pancreatic cancer (PC) is a malignant disease of gastrointestinal tract in which chemotherapy and radiotherapy are main tools in its treatment, and recently, nanocarriers have been emerged as promising structures in its therapy. The bioresponsive nanocarriers are able to respond to pH and redox, among others, in targeted delivery of cargo for specific treatment of PC. The loading drugs on the nanoparticles that can be synthetic or natural compounds, can help in more reduction in progression of PC through enhancing their intracellular accumulation in cancer cells. The encapsulation of genes in the nanoparticles can protect against degradation and promotes intracellular accumulation in tumor suppression. A new kind of therapy for cancer is phototherapy in which nanoparticles can stimulate both photothermal therapy and photodynamic therapy through hyperthermia and ROS overgeneration to trigger cell death in PC. Therefore, synergistic therapy of phototherapy with chemotherapy is performed in accelerating tumor suppression. One of the important functions of nanotechnology is selective targeting of PC cells in reducing side effects on normal cells. The nanostructures are capable of being surface functionalized with aptamers, proteins and antibodies to specifically target PC cells in suppressing their progression. Therefore, a specific therapy for PC is provided and future implications for diagnosis of PC is suggested.

Pancreatic Cancer: Updates in Pathogenesis and Therapies

Despite the progress in pancreatic cancer (PC) chemo/radiotherapies, immunotherapies, and novel targeted therapies and the improvement in its peri-operative management policies, it still has a dismal catastrophic prognosis due to delayed detection, early neural and vascular invasions, early micro-metastatic spread, tumour heterogeneities, drug resistance either intrinsic or acquired, unique desmoplastic stroma, and tumour microenvironment (TME). Understanding tumour pathogenesis at the detailed genetic/epigenetic/metabolic/molecular levels as well as studying the tumour risk factors and its known precancerous lesions aggressively is required for getting a more successful therapy for this challenging tumour. For a better outcome of this catastrophic tumour, it should be diagnosed early and treated through multidisciplinary teams of surgeons, gastroenterologists/interventional upper endoscopists, medical/radiation oncologists, diagnostic/intervention radiologists, and pathologists at high-volume centres. Moreover, surgical resection with a negative margin (R0) is the only cure for it. In this chapter; we discuss the recently updated knowledge of PC pathogenesis, risk factors, and precancerous lesions as well as its different management tools (i.e. surgery, chemo/radiotherapies, immunotherapies, novel targeted therapies, local ablative therapies, etc.).

Insulin receptor tyrosine kinase substrate (IRTKS) promotes the tumorigenesis of pancreatic cancer via PI3K/AKT signaling

Pancreatic cancer (PC) is a common type of tumor, which ranks for the seventh leading cause of cancer death worldwide. Insulin receptor tyrosine kinase substrate (IRTKS) plays an important regulatory role in cell proliferation, motility and survival. In this study, we explore the effect of IRTKS on the occurrence and development of PC. The expression and clinical features of IRTKS were predicted in database, PC cell lines and samples. IRTKS overexpressed and knocked down PC cell lines were established by lentivirus. CCK-8 assay, scratch migration assay and Transwell assay were used to analyze IRTKS oncogenic functions in cell lines. Bioinformatic enrichment analysis were conducted to explore the biological functions IRTKS involved in PC and Western Bolt assay was performed to reveal the downstream signaling molecules. It is detected that IRTKS is highly expressed in PC (P < 0.05), and overexpression of IRTKS predicted worse overall survival (OS, P = 0.018). The proliferation, migration and invasion ability were significantly enhanced in IRTKS overexpressed cells and inhibited in IRTKS knocked down cells (P < 0.05). Bioinformatic enrichment analysis based on GSE46583 dataset showed that IRTKS was significantly involved in PI3K/AKT pathway. Further investigation revealed that overexpression of IRTKS upregulated the ratio of p-PI3K/PI3K and p-AKT/AKT in vitro, while silencing of IRTKS presented opposite results, and PI3K inhibitor LY294002 treatment induced the phenotypic alteration of cell lines (P < 0.05). In conclusion, IRTKS plays an important role in PC tumorigenesis via PI3K/AKT pathway phosphorylated activation, and has a potential clinical application value in prognosis for PC.

Exosomics in oral cancer diagnosis, prognosis, and therapeutics - An emergent and imperative non-invasive natural nanoparticle-based approach

Exosomes- the natural nanoparticles belonging to heterogeneous vesicles are released via nearly all sorts of cells, including tumour cells, to oprate intercellular communication. Selective packaging of exosomes amid nucleic acids, phospholipids, and proteins makes them ideal for intercellular communications occurring among different cells. The existence of exosomes has been validated in various biofluids, including saliva. Being non-invasive and in direct contact with oral malignant cells, saliva establishes itself as a preeminent source of early cancer biomarkers. In context, the role and providence of both recipient and donor secreting cells are persuaded through exosomal cargo.Several studies have emphasized the influence of exosomal contents in different stages of cancer development, reconciling interactions between tumour cells and their surrounding niche. More explicitly, a transformation of exosomal contents such as nucleic acids, lipids, and proteins can endorse tumour progression and help ascertain a secluded pre-metastatic niche crammed with substances that errand cancer cell proliferation,angiogenesis, metastasis, and drug resistance. The blooming field of exosomes has directed the evolution of high-end isolation and characterization techniques along with the development of an entirely new field- exosomics that comprises complete analysis of exosomal cargo in various physiological conditions, including oral cancer. Researchers have discovered multiple pathways involved in exosome biogenesis to understand numerous events associated with cancer progression. Tissue-specific packaging of exosomes makes them a novel source of prognostic and diagnostic biomarkers and potential therapeutic targets. The extent of the current review confers the contemporary perception of the versatile task of exosomes, especially salivary exosomes, as potential biomarkers in the progression and diagnosis as well as therapeutics of oral cancers and their potential employment in clinical applications.

LRG1 in pancreatic cancer cells promotes inflammatory factor synthesis and the angiogenesis of HUVECs by activating VEGFR signaling

BACKGROUND

This study aimed to investigate the roles of leucine-rich alpha-2-glycoprotein 1 (LRG1) in regulating angiogenesis during pancreatic cancer (PC) pathogenesis.

METHODS

LRG1 expression in tissues was detected by qRT-PCR and immunohistochemistry. LRG1 in BxPC-3 and Capan-2 cells was knocked down or overexpressed. Cell viability and the migration and invasion abilities of cells were analyzed using the Cell Counting Kit-8 (CCK-8) assay and Transwell system, respectively. Interleukin-1 beta (IL-1β), IL-18, and vascular endothelial growth factor A (VEGFA) contents in cell culture were measured by ELISA, and the angiogenesis of HUVECs was assessed by the in vitro tube formation assay. In vitro LRG1 expression in BxPC-3 and Capan-2 cells was determined using immunofluorescence.

RESULTS

The results showed that LRG1 expression was significantly increased in pancreatic cancer tissues and cell lines. LRG1 knockdown inhibited the viability, migration, invasion, and IL-1β and IL-18 synthesis of BxPC-3 and Capan-2 cells. VEGFA synthesis in BxPC-3 and Capan-2 cells was also inhibited by LRG1 knockdown, which caused impaired tube formation of co-cultured HUVECs. LRG1 overexpression enhanced the viability, migration, and invasion of BxPC-3 and Capan-2 cells, also causing elevated tube formation of HUVECs and IL-1β and IL-18 synthesis in co-cultures of HUVECs and BxPC-3 or Capan-2 cells. Silencing of VEGF receptor (VEGFR) abrogated the enhanced tube formation and IL-1β and IL-18 synthesis in HUVECs co-cultured with BxPC-3 or Capan-2 cells overexpressing LRG1.

CONCLUSIONS

In conclusion, LRG1, which is highly expressed in pancreatic cancer cells, promotes inflammatory factor synthesis and the angiogenesis of HUVECs though activating the VEGFR signaling pathway.

Towards an updated view on the clinical management of pancreatic adenocarcinoma: Current and future perspectives

Pancreatic cancer has a dire prognosis and will represent the second leading cause of cancer death in the next 10 years. The multifactorial approach represents one of the main issues in controlling the extension of this neoplasm. In recent years, the characteristics of the tumor microenvironment, metastasis mechanisms and the relationship between immune system and neoplastic cells have been described, which has made it possible to understand the pathophysiology of pancreatic adenocarcinoma. Currently, there is a failure to provide an effective preventive method or early detection, so patients present with an advanced stage at the time of diagnosis. Despite numerous efforts, little progress has been made in clinical outcome and in improving survival in long term. Therefore, in the recent years, diverse diagnostic tests, treatments and possible approaches have been developed in the fields of radiotherapy, chemotherapy and surgery to find a combination of them that improves life expectancy in patients diagnosed with pancreatic cancer. At the moment, numerous clinical trials are being conducted to evaluate preventive diagnostic procedures such as serological markers or perfecting available imaging tests. On the other hand, implementation of immunotherapy is being studied in a neoplasm that has lagged in the application of this procedure since present possible treatments do not substantially improve quality of life. Therefore, the purpose of our study is to summarize the main progresses that have been made in the diagnosis, treatment and screening of this disease, explaining the limitations that have been observed and analyzing future prospects in the management of this illness.

Highlights on the Role of KRAS Mutations in Reshaping the Microenvironment of Pancreatic Adenocarcinoma

The most frequent mutated oncogene family in the history of human cancer is the RAS gene family, including NRAS, HRAS, and, most importantly, KRAS. A hallmark of pancreatic cancer, recalcitrant cancer with a very low survival rate, is the prevalence of oncogenic mutations in the KRAS gene. Due to this fact, studying the function of KRAS and the impact of its mutations on the tumor microenvironment (TME) is a priority for understanding pancreatic cancer progression and designing novel therapeutic strategies for the treatment of the dismal disease. Despite some recent enlightening studies, there is still a wide gap in our knowledge regarding the impact of KRAS mutations on different components of the pancreatic TME. In this review, we will present an updated summary of mutant KRAS role in the initiation, progression, and modulation of the TME of pancreatic ductal adenocarcinoma (PDAC). This review will highlight the intriguing link between diabetes mellitus and PDAC, as well as vitamin D as an adjuvant effective therapy via TME modulation of PDAC. We will also discuss different ongoing clinical trials that use KRAS oncogene signaling network as therapeutic targets.

Cyclin Dependent Kinase-1 (CDK-1) Inhibition as a Novel Therapeutic Strategy against Pancreatic Ductal Adenocarcinoma (PDAC)

The role of CDK1 in PDAC onset and development is two-fold. Firstly, since CDK1 activity regulates the G2/M cell cycle checkpoint, overexpression of CDK1 can lead to progression into mitosis even in cells with DNA damage, a potentially tumorigenic process. Secondly, CDK1 overexpression leads to the stimulation of a range of proteins that induce stem cell properties, which can contribute to the development of cancer stem cells (CSCs). CSCs promote tumor-initiation and metastasis and play a crucial role in the development of PDAC. Targeting CDK1 showed promising results for PDAC treatment in different preclinical models, where CDK1 inhibition induced cell cycle arrest in the G2/M phase and led to induction of apoptosis. Next to this, PDAC CSCs are uniquely sensitive to CDK1 inhibition. In addition, targeting of CDK1 has shown potential for combination therapy with both ionizing radiation treatment and conventional chemotherapy, through sensitizing tumor cells and reducing resistance to these treatments. To conclude, CDK1 inhibition induces G2/M cell cycle arrest, stimulates apoptosis, and specifically targets CSCs, which makes it a promising treatment for PDAC. Screening of patients for CDK1 overexpression and further research into combination treatments is essential for optimizing this novel targeted therapy.

MicroRNAs as biomarkers and perspectives in the therapy of pancreatic cancer

Pancreatic cancer is considered as one of the most aggressive tumor types, representing over 45,750 mortality cases annually in the USA solely. The aggressive nature and late identification of pancreatic cancer, combined with the restrictions of existing chemotherapeutics, present the mandatory need for the advancement of novel treatment systems. Ongoing reports have shown an important role of microRNAs (miRNAs) in the initiation, migration, and metastasis of malignancies. Besides, abnormal transcriptional levels of miRNAs have regularly been related with etiopathogenesis of pancreatic malignancy, underlining the conceivable utilization of miRNAs in the management of pancreatic disease patients. In this review article, we give a concise outline of molecular pathways involved in etiopathogenesis of pancreatic cancer patients as well as miRNA implications in pancreatic cancer patients. Ensuing sections describe the involvement of miRNAs in the diagnosis, prognosis, and therapy of pancreatic cancer patients. The involvement of miRNAs in the chemoresistance of pancreatic cancers was also discussed. End area portrays the substance of survey with future headings.

Decoding Genes: Current Update on Radiogenomics of Select Abdominal Malignancies

Technologic advances in chromosomal analysis and DNA sequencing have enabled genome-wide analysis of cancer cells, yielding considerable data on the genetic basis of malignancies. Evolving knowledge of tumor genetics and oncologic pathways has led to a better understanding of histopathologic features, tumor classification, tumor biologic characteristics, and imaging findings and discovery of targeted therapeutic agents. Radiogenomics is a rapidly evolving field of imaging research aimed at correlating imaging features with gene mutations and gene expression patterns, and it may provide surrogate imaging biomarkers that may supplant genetic tests and be used to predict treatment response and prognosis and guide personalized treatment options. Multidetector CT, multiparametric MRI, and PET with use of multiple radiotracers are some of the imaging techniques commonly used to assess radiogenomic associations. Select abdominal malignancies demonstrate characteristic imaging features that correspond to gene mutations. Recent advances have enabled us to understand the genetics of steatotic and nonsteatotic hepatocellular adenomas, a plethora of morphologic-molecular subtypes of hepatic malignancies, a variety of clear cell and non-clear cell renal cell carcinomas, a myriad of hereditary and sporadic exocrine and neuroendocrine tumors of the pancreas, and the development of targeted therapeutic agents for gastrointestinal stromal tumors based on characteristic KIT gene mutations. Mutations associated with aggressive phenotypes of these malignancies can sometimes be predicted on the basis of their imaging characteristics. Radiologists should be familiar with the genetics and pathogenesis of common cancers that have associated imaging biomarkers, which can help them be integral members of the cancer management team and guide clinicians and pathologists. Online supplemental material is available for this article. ^©RSNA, 2020 See discussion on this article by Luna (pp 1627-1630).

Emerging Treatment Strategies in Pancreatic Cancer

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is one of the main causes of cancer death in well-developed countries. Therapeutic advances in PDAC to date have been modest. Recent progress to understand the molecular landscape of the disease has opened new treatment opportunities for a small subset of patients, frequently those with KRAS wild-type disease. Novel treatment strategies in PDAC include, among others, the use of nanotechnology and metabolic reprogramming. In addition, new strategies are being investigated, which are designed to overcome the resistance to checkpoint inhibitors, targeting DNA repair pathways including mismatch repair, increasing antigen presentation through the use of vaccines, targeting various signaling pathways, and reprogramming the tumor microenvironment. Here, we review the landscape of PDAC treatment strategies and some of these new agents.

Immunotherapeutic approach for advanced pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the USA and the seventh leading cause of cancer-related death worldwide. Most of the patients' presentation is in advanced stages and remains resistant to currently available standard therapies. An in-depth understanding of PDAC's pathogenesis has shown that immunotherapy could bring about a revolution in the treatment response. Immunotherapy in PDAC appears promising in preclinical studies but failed to show benefits in clinical studies. These novel agents' therapeutic failure can be attributed to multiple variables including the tumor microenvironment, early metastasis, tumor heterogeneity and resistance to therapy. There is a need to develop biomarkers for the patient's stratification and provide individualized treatment to improve treatment outcomes.

KIF23 enhances cell proliferation in pancreatic ductal adenocarcinoma and is a potent therapeutic target

Background

In recent research, high expression of kinesin family member 23 (KIF23), one of the kinesin motor proteins involved in the regulation of cytokinesis, has been shown to be related to poor prognosis in glioma and paclitaxel-resistant gastric cancer, as a results of the enhancement of proliferation, migration, and invasion. In this study, we analyzed the role of KIF23 in the progression of pancreatic ductal adenocarcinoma.

Methods

A bioinformatic method was used to analyze the KIF23 mRNA level in pancreatic tumor tissues compared with normal pancreatic tissues and to analyze the connection between high KIF23 expression and prognosis. We examined the expression of KIF23 using immunohistochemistry and analyzed the connection between the expression of KIF23 and clinicopathological features in pancreatic ductal adenocarcinoma patients. In addition, a colony formation assay, MTT assay, and western blot assay were performed in vitro, along with a mouse xenograft model in vivo, to analyze the effect of KIF23 on proliferation. Further, the correlation between KIF23 and CDCA8 was analyzed by TCGA and immunohistochemical data.

Results

Bioinformatic results showed that KIF23 mRNA expression was higher in pancreatic tumor tissues than in normal pancreatic tissues and a poor prognosis has been linked to the high expression of KIF23. Immunohistochemistry revealed that KIF23 was highly expressed at the protein level and high expression of KIF23 correlated with adverse clinicopathological features. Our experimental results demonstrated that knockdown of KIF23 could inhibit the proliferation of pancreatic cells. Further, a positive correlation between KIF23 and CDCA8 expression existed, and KIF23 might promote pancreatic cancer proliferation by affecting CDCA8 expression.

Conclusions

Our data showed that high expression of KIF23 is associated with a poor prognosis, and KIF23 might be a potential therapeutic target for pancreatic ductal adenocarcinoma.

Complete Response of Synchronous Liver Metastasis in a Pancreatic Ductal Adenocarcinoma, When Surgery Could Represent a Therapeutic Option

Metastatic pancreatic ductal adenocarcinoma (PDAC) is characterized by poor prognosis and short survival. Today, the use of new polytherapeutic regimens increases clinical outcome of these patients opening new clinical scenario. A crucial issue related to the actual improvement achieved with these new regimens is represented by the occasional possibility to observe a radiological complete response of metastatic lesions in patients with synchronous primary tumor. What could be the best therapeutic management of these patients? Could surgery represent an indication? Herein, we reported a case of a patient with PDAC of the head with multiple liver metastases, who underwent first-line chemotherapy with mFOLFIRINOX. After 10 cycles, he achieved a complete radiological response of liver metastases and a partial response of pancreatic lesion. A duodenocephalopancreasectomy was performed. Due to liver a lung metastases after 8 months from surgery, a second-line therapy was started with a disease-free survival and overall survival of 8 months and 45 months, respectively. Improvement in the molecular characterization of PDAC could help in the selection of patients suitable for multimodal treatments. This trial is registered with NCT02892305 and NCT00855634.

Educational Case: Pancreatic Adenocarcinoma: Clinical Presentation, Pathogenesis, Diagnostic, and Therapeutic Modalities

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Acinar transformed ductal cells exhibit differential mucin expression in a tamoxifen-induced pancreatic ductal adenocarcinoma mouse model

Pancreatic cancer (PC) is acquired postnatally; to mimic this scenario, we developed an inducible KrasG12D; Ptf1a-CreER™ (iKC) mouse model, in which Kras is activated postnatally at week 16 upon tamoxifen (TAM) administration. Upon TAM treatment, iKC mice develop pancreatic intraepithelial neoplasia (PanIN) lesions and PC with metastasis at the fourth and fortieth weeks, respectively, and exhibited acinar-to-ductal metaplasia (ADM) and transdifferentiation. Kras activation upregulated the transcription factors Ncoa3, p-cJun and FoxM1, which in turn upregulated expression of transmembrane mucins (Muc1, Muc4 and Muc16) and secretory mucin (Muc5Ac). Interestingly, knockdown of KrasG12D in multiple PC cell lines resulted in downregulation of MUC1, MUC4, MUC5AC and MUC16. In addition, iKC mice exhibited ADM and transdifferentiation. Our results show that the iKC mouse more closely mimics human PC development and can be used to investigate pancreatic ductal adenocarcinoma (PDAC) biomarkers, early onset of PDAC, and ADM. The iKC model can also be used for preclinical strategies such as targeting mucin axis alone or in combination with neo-adjuvant, immunotherapeutic approaches and to monitor chemotherapy response.

Screening potential microRNAs associated with pancreatic cancer: Data mining based on RNA sequencing and microarrays

Pancreatic cancer is a malignant tumor of the digestive tract, rendering it difficult to make an accurate diagnosis. The 5 year survival rate for pancreatic cancer is <1%, and surgical resection rarely proves to be effective. Therefore, the identification of more effective methods for the early detection of pancreatic cancer is an urgent requirement. The present study aimed to explore key genes and microRNAs (miRNAs) associated with the pathogenesis of pancreatic cancer. Public databases were searched, and the data were integrated from The Cancer Genome Atlas and Gene Expression Omnibus databases, leading to the identification of 23 differentially expressed miRNAs (DE-miRNAs). A total of four of the DE-miRNAs were upregulated (hsa-miR-892b, hsa-miR-194-2, hsa-miR-200a and hsa-miR-194-1), whereas 19 downregulated DE-miRNAs (hsa-miR-424, hsa-miR-191, hsa-miR-484, hsa-miR-142, hsa-miR-15b, hsa-miR-450a-1, hsa-miR-423, hsa-miR-126, hsa-miR-505, hsa-miR-16-1, hsa-miR-342, hsa-miR-130a, hsa-miR-3613, hsa-miR-450a-2, hsa-miR-26b, hsa-miR-451, hsa-miR-19b-2, hsa-miR-106a and hsa-miR-503) were identified using the cut-off criteria of P<0.05 and |log 2FC|>1.0. Hsa-miR-3613-5p was identified as a prognostic DE-miRNA. The functional enrichment analyses demonstrated that the target genes of hsa-miR-3613-5p may be associated with the p53 signaling pathway. Survival analysis performed for genes in the p53 signaling pathway revealed that cyclin-dependent kinase 6 and ribonucleoside-diphosphate reductase subunit M2 may be the most likely to be associated with prognostic value. The integrated analysis performed in the current study demonstrated that hsa-miR-3613-5p may be used as a potential prognostic marker for pancreatic cancer.

The Diagnostic Accuracy of Mutant KRAS Detection from Pancreatic Secretions for the Diagnosis of Pancreatic Cancer: A Meta-Analysis

This meta-analysis aims to identify the diagnostic accuracy of mutations in the Kirsten Rat Sarcoma (KRAS) oncogene in the diagnosis of pancreatic ductal adenocarcinoma (PDAC). The survival of PDAC remains poor often due to the fact that disease is advanced at diagnosis. We analysed 22 studies, with a total of 2156 patients, to identify if the detection of KRAS mutations from pancreatic exocrine secretions yields sufficient specificity and sensitivity to detect patients with PDAC amongst healthy individuals. The majority of the studies were retrospective, samples were obtained endoscopically or surgically, and included comparator populations of patients with chronic pancreatitis and pre-malignant pancreatic lesions (PanIN) as well as healthy controls. We performed several analyses to identify the diagnostic accuracy for PDAC among these patient populations. Our results highlighted that the diagnostic accuracy of KRAS mutation for PDAC was of variable sensitivity and specificity when compared with PanINs and chronic pancreatitis, but had a higher specificity among healthy individuals. The sensitivity of this test must be improved to prevent missing early PDAC or PanINs. This could be achieved with rigorous prospective cohort studies, in which high-risk patients with normal cross-sectional imaging undergo surveillance following KRAS mutation testing.

Comprehensive Analysis of Expression, Clinicopathological Association and Potential Prognostic Significance of RABs in Pancreatic Cancer

RAB proteins (RABs) represent the largest subfamily of Ras-like small GTPases that regulate a wide variety of endosomal membrane transport pathways. Their aberrant expression has been demonstrated in various malignancies and implicated in pathogenesis. Using The Cancer Genome Atlas (TCGA) database, we analyzed the differential expression and clinicopathological association of RAB genes in pancreatic ductal adenocarcinoma (PDAC). Of the 62 RAB genes analyzed, five (RAB3A, RAB26, RAB25, RAB21, and RAB22A) exhibited statistically significant upregulation, while five (RAB6B, RAB8B, RABL2A, RABL2B, and RAB32) were downregulated in PDAC as compared to the normal pancreas. Racially disparate expression was also reported for RAB3A, RAB25, and RAB26. However, no clear trend of altered expression was observed with increasing stage and grade, age, and gender of the patients. PDAC from occasional drinkers had significantly higher expression of RAB21 compared to daily or weekly drinkers, whereas RAB25 expression was significantly higher in social drinkers, compared to occasional ones. The expression of RABL2A was significantly reduced in PDAC from diabetic patients, whereas RAB26 was significantly lower in pancreatitis patients. More importantly, a significant association of high expression of RAB21, RAB22A, and RAB25, and low expression of RAB6B, RABL2A, and RABL2B was observed with poorer survival of PC patients. Together, our study suggests potential diagnostic and prognostic significance of RABs in PDAC, warranting further investigations to define their functional and mechanistic significance.

The lipogenic LXR-SREBF1 signaling pathway controls cancer cell DNA repair and apoptosis and is a vulnerable point of malignant tumors for cancer therapy

Cancer cells are defective in DNA repair, so they experience increased DNA strand breaks, genome instability, gene mutagenesis, and tumorigenicity; however, multiple classic DNA repair genes and pathways are strongly activated in malignant tumor cells to compensate for the DNA repair deficiency and gain an apoptosis resistance. The mechanisms underlying this phenomenon in cancer are unclear. We speculate that a key DNA repair gene or signaling pathway in cancer has not yet been recognized. Here, we show that the lipogenic liver X receptor (LXR)-sterol response element binding factor-1 (SREBF1) axis controls the transcription of a key DNA repair gene polynucleotide kinase/phosphatase (PNKP), thereby governing cancer cell DNA repair and apoptosis. Notably, the PNKP levels were significantly reduced in 95% of human pancreatic cancer (PC) patients, particularly deep reduction for sixfold in all of the advanced-stage PC cases. PNKP is also deficient in three other types of cancer that we examined. In addition, the expression of LXRs and SREBF1 was significantly reduced in the tumor tissues from human PC patients compared with the adjacent normal tissues. The newly identified LXR-SREBF1-PNKP signaling pathway is deficient in PC, and the defect in the pathway contributes to the DNA repair deficiency in the cancer. Strikingly, further diminution of the vulnerable LXR-SREBF1-PNKP signaling pathway using a small molecule triptonide, a new LXR antagonist identified in this investigation, at a concentration of 8 nM robustly activated tumor-suppressor p53 and readily elevated cancer cell DNA strand breaks over an apoptotic threshold, and selectively induced PC cell apoptosis, resulting in almost complete elimination of tumors in xenograft mice without obvious complications. Our findings provide new insight into DNA repair and apoptosis in cancer, and offer a new platform for developing novel anticancer therapeutics.

Polymer nanoparticle-assisted chemotherapy of pancreatic cancer

Pancreatic cancer is a lethal disease characterized by highly dense stroma fibrosis. Only 15-20% of patients with pancreatic cancer have resectable tumors, and only around 20% of them survive to 5 years. Traditional cancer treatments have little effect on their prognosis, and successful surgical resection combined with effective perioperative therapy is the main method for maximizing long-term survival. For this reason, chemotherapy is an adjunct treatment for resectable cancer and is the main therapy for incurable pancreatic cancer, including metastatic pancreatic adenocarcinoma. However, there are various side effects of chemotherapeutic medicine and low drug penetration because the complex tumor microenvironment limits the application of chemotherapy. As a novel strategy, polymer nanoparticles make it possible to target the tumor microenvironment, release cytotoxic agents through various responsive reactions, and thus overcome the treatment barrier. As drug carriers, polymer nanoparticles show marked advantages, such as increased drug delivery and efficiency, controlled drug release, decreased side effects, prolonged half-life, and evasion of immunogenic blockade. In this review, we discuss the factors that cause chemotherapy obstacles in pancreatic cancer, and introduce the application of polymer nanoparticles to treat pancreatic cancer.

Pancreatic Cancer and Its Microenvironment-Recent Advances and Current Controversies

Pancreatic ductal adenocarcinoma (PDAC) causes annually well over 400,000 deaths world-wide and remains one of the major unresolved health problems. This exocrine pancreatic cancer originates from the mutated epithelial cells: acinar and ductal cells. However, the epithelia-derived cancer component forms only a relatively small fraction of the tumor mass. The majority of the tumor consists of acellular fibrous stroma and diverse populations of the non-neoplastic cancer-associated cells. Importantly, the tumor microenvironment is maintained by dynamic cell-cell and cell-matrix interactions. In this article, we aim to review the most common drivers of PDAC. Then we summarize the current knowledge on PDAC microenvironment, particularly in relation to pancreatic cancer therapy. The focus is placed on the acellular stroma as well as cell populations that inhabit the matrix. We also describe the altered metabolism of PDAC and characterize cellular signaling in this cancer.

Co-targeting of CXCR4 and hedgehog pathways disrupts tumor-stromal crosstalk and improves chemotherapeutic efficacy in pancreatic cancer

Pancreatic cancer (PC) remains a therapeutic challenge because of its intrinsic and extrinsic chemoresistance mechanisms. Here, we report that C-X-C motif chemokine receptor 4 (CXCR4) and hedgehog pathways cooperate in PC chemoresistance via bidirectional tumor-stromal crosstalk. We show that when PC cells are co-cultured with pancreatic stellate cells (PSCs) they are significantly more resistant to gemcitabine toxicity than those grown in monoculture. We also demonstrate that this co-culture-induced chemoresistance is abrogated by inhibition of the CXCR4 and hedgehog pathways. Similarly, the co-culture-induced altered expression of genes in PC cells associated with gemcitabine metabolism, antioxidant defense, and cancer stemness is also reversed upon CXCR4 and hedgehog inhibition. We have confirmed the functional impact of these genetic alterations by measuring gemcitabine metabolites, reactive oxygen species production, and sphere formation in vehicle- or gemcitabine-treated monocultures and co-cultured PC cells. Treatment of orthotopic pancreatic tumor-bearing mice with gemcitabine alone or in combination with a CXCR4 antagonist (AMD3100) or hedgehog inhibitor (GDC-0449) displays reduced tumor growth. Notably, we show that the triple combination treatment is the most effective, resulting in nearly complete suppression of tumor growth. Immunohistochemical analysis of Ki67 and cleaved caspase-3 confirm these findings from in vivo imaging and tumor measurements. Our findings provide preclinical and mechanistic evidence that a combination of gemcitabine treatment with targeted inhibition of both the CXCR4 and hedgehog pathways improves outcomes in a PC mouse model.

Promoter-Level Transcriptome Identifies Stemness Associated With Relatively High Proliferation in Pancreatic Cancer Cells

Both pancreatic intraepithelial neoplasia (PanIN), a frequent precursor of pancreatic cancer, and intraductal papillary mucinous neoplasm (IPMN), a less common precursor, undergo several phases of molecular conversions and finally develop into highly malignant solid tumors with negative effects on the quality of life. We approached this long-standing issue by examining the following PanIN/IPMN cell lines derived from mouse models of pancreatic cancer: Ptf1a-Cre; KrasG12D; p53f/+ and Ptf1a-Cre; KrasG12D; and Brg1f/f pancreatic ductal adenocarcinomas (PDAs). The mRNA from these cells was subjected to a cap analysis of gene expression (CAGE) to map the transcription starting sites and quantify the expression of promoters across the genome. Two RNA samples extracted from three individual subcutaneous tumors generated by the transplantation of PanIN or IPMN cancer cell lines were used to generate libraries and Illumina Seq, with four RNA samples in total, to depict discrete transcriptional network between IPMN and PanIN. Moreover, in IPMN cells, the transcriptome tended to be enriched for suppressive and inhibitory biological processes. In contrast, the transcriptome of PanIN cells exhibited properties of stemness. Notably, the proliferation capacity of the latter cells in culture was only minimally constrained by well-known chemotherapy drugs such as GSK690693 and gemcitabine. The various transcriptional factor network systems detected in PanIN and IPMN cells reflect the distinct molecular profiles of these cell types. Further, we hope that these findings will enhance our mechanistic understanding of the characteristic molecular alterations underlying pancreatic cancer precursors. These data may provide a promising direction for therapeutic research.

Hereditary and Sporadic Pancreatic Ductal Adenocarcinoma: Current Update on Genetics and Imaging

Pancreatic ductal adenocarcinoma (PDAC) is a genetically heterogeneous, biologically aggressive malignancy with a uniformly poor prognosis. While most pancreatic cancers arise sporadically, a small subset of PDACs develop in patients with hereditary and familial predisposition. Detailed studies of the rare hereditary syndromes have led to identification of specific genetic abnormalities that contribute to malignancy. For example, germline mutations involving BRCA1, BRCA2, PRSS1, and mismatch repair genes predispose patients to PDAC. While patients with Lynch syndrome develop a rare "medullary" variant of adenocarcinoma, intraductal papillary mucinous tumors are observed in patients with McCune-Albright syndrome. It is now well established that PDACs originate via a multistep progression from microscopic and macroscopic precursors due to cumulative genetic abnormalities. Improved knowledge of tumor genetics and oncologic pathways has contributed to a better understanding of tumor biology with attendant implications on diagnosis, management, and prognosis. In this article, the genetic landscape of PDAC and its precursors will be described, the hereditary syndromes that predispose to PDAC will be reviewed, and the current role of imaging in screening and staging assessment, as well as the potential role of molecular tumor-targeted imaging for evaluation of patients with PDAC and its precursors, will be discussed. Keywords: Abdomen/GI, Genetic Defects, Oncology, Pancreas Supplemental material is available for this article. © RSNA, 2020.

MicroRNAs in Pancreatic Cancer: biomarkers, prognostic, and therapeutic modulators

A severe lack of early diagnosis coupled with resistance to most available therapeutic options renders pancreatic cancer as a major clinical concern. The limited efficacy of current treatments necessitates the development of novel therapeutic strategies that are based on an understanding of the molecular mechanisms involved in pancreatic cancer progression. MicroRNAs (miRNAs) are non-coding small RNAs that regulate the expression of multiple proteins in the post-translation process and thus have promise as biomarkers, prognostic agents, and as advanced pancreatic therapies. Profiling of deregulated miRNAs in pancreatic cancer can correlate to diagnosis, indicate optimal treatment and predict response to therapy. Furthermore, understanding the main effector genes in pancreatic cancer along with downstream pathways can identify possible miRNAs as therapeutic candidates. Additionally, obstacles to the translation of miRNAs into the clinic are also considered. Distinct miRNA expression profiles can correlate to stages of malignant pancreatic disease, and hold potential as biomarkers, prognostic markers and clinical targets. However, a limited understanding and validation of the specific role of such miRNAs stunts clinical application. Target prediction using algorithms provides a wide range of possible targets, but these miRNAs still require validation through pre-clinical studies to determine the knock-on genetic effects.

Carboxypeptidase E-∆N Promotes Proliferation and Invasion of Pancreatic Cancer Cells via Upregulation of CXCR2 Gene Expression

Pancreatic cancer is one of the leading causes of cancer-related mortality worldwide. The molecular basis for the pathogenesis of this disease remains elusive. In this study, we have investigated the role of wild-type Carboxypeptidase E (CPE-WT) and a 40 kDa N-terminal truncated isoform, CPE-ΔN in promoting proliferation and invasion of Panc-1 cells, a pancreatic cancer cell line. Both CPE-WT and CPE-ΔN were expressed in Panc-1 and BXPC-3 pancreatic cancer cells. Immunocytochemical studies revealed that in CPE transfected Panc-1 cells, CPE-ΔN was found primarily in the nucleus, whereas CPE-WT was present exclusively in the cytoplasm as puncta, characteristic of secretory vesicles. Endogenous CPE-WT was secreted into the media. Overexpression of CPE-ΔN in Panc-1 cells resulted in enhancement of proliferation and invasion of these cells, as determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell proliferation assay and Matrigel invasion assay, respectively. In contrast, the expression of CPE-WT protein at comparable levels to CPE-ΔN in Panc-1 cells resulted in promotion of proliferation but not invasion. Importantly, there was an upregulation of the expression of CXCR2 mRNA and protein in Panc-1 cells overexpressing CPE-ΔN, and these cells exhibited significant increase in proliferation in a CXCR2-dependent manner. Thus, CPE-ΔN may play an important role in promoting pancreatic cancer growth and malignancy through upregulating the expression of the metastasis-related gene, CXCR2.

The Mutational Landscape of Pancreatic and Liver Cancers, as Represented by Circulating Tumor DNA

The mutational landscapes of pancreatic and liver cancers share many common genetic alterations which drive cancer progression. However, these mutations do not occur in all cases of these diseases, and this tumoral heterogeneity impedes diagnosis, prognosis, and therapeutic development. One minimally invasive method for the evaluation of tumor mutations is the analysis of circulating tumor DNA (ctDNA), released through apoptosis, necrosis, and active secretion by tumor cells into various body fluids. By observing mutations in those genes which promote transformation by controlling the cell cycle and oncogenic signaling pathways, a representation of the mutational profile of the tumor is revealed. The analysis of ctDNA is a promising technique for investigating these two gastrointestinal cancers, as many studies have reported on the accuracy of ctDNA assessment for diagnosis and prognosis using a variety of techniques.

Expression Profiling of Circulating Tumor Cells in Pancreatic Ductal Adenocarcinoma Patients: Biomarkers Predicting Overall Survival

The interest in liquid biopsy is growing because it could represent a non-invasive prognostic or predictive tool for clinical outcome in patients with pancreatic ductal adenocarcinoma (PDAC), an aggressive and lethal disease. In this pilot study, circulating tumor cells (CTCs), CD16 positive atypical CTCs, and CTC clusters were captured and characterized in the blood of patients with PDAC before and after palliative first line chemotherapy by ScreenCell device, immunohistochemistry, and confocal microscopy analysis. Gene profiles were performed by digital droplet PCR in isolated CTCs, five primary PDAC tissues, and three different batches of RNA from normal human pancreatic tissue. Welsh's t-test, Kaplan-Meier survival, and Univariate Cox regression analyses have been performed. Statistical analysis revealed that the presence of high CTC number in blood is a prognostic factor for poor overall survival and progression free survival in advanced PDAC patients, before and after first line chemotherapy. Furthermore, untreated PDAC patients with CTCs, characterized by high ALCAM, POU5F1B, and SMO mRNAs expression, have shorter progression free survival and overall survival compared with patients expressing the same biomarkers at low levels. Finally, high SHH mRNA levels are negatively associated to progression free survival, whereas high vimentin mRNA levels are correlated with the most favorable prognosis. By hierarchical clustering and correlation index analysis, two cluster gene signatures were identified in CTCs: the first, with high expression of VEGFA, NOTCH1, EPCAM, IHH, is the signature of PDAC patients before chemotherapy, whereas the second, with an enrichment in the expression of CD44, ALCAM, and POU5F1B stemness and pluripotency genes, is reported after palliative chemotherapy. Overall our data support the clinic value of the identification of CTC's specific biomarkers to improve the prognosis and the therapy in advanced PDAC patients.

Hypoxia alters the release and size distribution of extracellular vesicles in pancreatic cancer cells to support their adaptive survival

Pancreatic tumors are highly desmoplastic and poorly-vascularized, and therefore must develop adaptive mechanisms to sustain their survival under hypoxic condition. Extracellular vesicles (EV) play vital roles in pancreatic tumor pathobiology by facilitating intercellular communication. Here we studied the effect of hypoxia on the release of EVs and examined their role in adaptive survival of pancreatic cancer (PC) cells. Hypoxia promoted the release of EV in PC cell lines, MiaPaCa and AsPC1, wherein former exhibited a far greater induction. Moreover, a time-dependent, measurable and significant increase was recorded for small EV (SEV) in both the cell lines with only minimal induction observed for medium (MEV) and large EVs (LEV). Similarly, noticeable changes in size distribution of SEV were also recorded with a shift toward smaller average size under extreme hypoxia. Thrombospondin (apoptotic bodies marker) was exclusively detected on LEVs, while Arf6 (microvesicles marker) was mostly present on MEV with some expression in LEV as well. However, CD9 and CD63 (exosome markers) were expressed in both SEV and MEVs with a decreased expression recorded under hypoxia. Among all subfractions, SEV was the most bioactive in promoting the survival of hypoxic PC cells and hypoxia-inducible factor-1α stabilization was involved in heightened EV release under hypoxia and for their potency to promote hypoxic cell survival. Altogether, our findings provide a novel mechanism for the adaptive hypoxic survival of PC cells and should serve as the basis for future investigations on broader functional implications of EV.

LINC00346 promotes pancreatic cancer progression through the CTCF-mediated Myc transcription

Although multiple factors are known to contribute to pancreatic ductal adenocarcinoma (PDAC) progression, the role of long non-coding RNAs (lncRNAs) in PDAC remains largely unknown. In this study, we present data that long intergenic non-coding RNA 346 (LINC00346) functions as a promoting factor for PDAC development. We first show that LINC00346 is highly expressed in pancreatic tumor specimens as compared to normal pancreatic tissue based on interrogation of The Cancer Genome Atlas (TCGA) pancreatic adenocarcinoma dataset. Of significance, this upregulation of LINC00346 is associated with overall survival (OS) and disease-free survival (DFS), respectively. We further show that knockout (KO) of LINC00346 impairs pancreatic cancer cell proliferation, tumorigenesis, migration, and invasion ability. Importantly, these phenotypes can be restored by LINC00346 re-expression in KO cells (i.e., rescue experiment). RNA precipitation assays combined with mass spectrometry analysis indicate that LINC00346 interacts with CCCTC-binding factor (CTCF), a known transcriptional repressor of c-Myc. This interaction between LINC00346 and CTCF prevents the binding of CTCF to c-Myc promoter, relieving the CTCF-mediated repression of c-Myc. Thus, LINC00346 functions as a positive transcriptional regulator of c-Myc. Together, these results suggest that LINC00346 contributes to PDAC pathogenesis by activating c-Myc, and as such, LINC00346 may serve as a potential biomarker and therapeutic target for PDAC.

Pancreatic cancer in young adults: changes, challenges, and solutions

Despite improvements in multidisciplinary treatments, survival of pancreatic cancer (PC) patients remains dismal. Studies dealing with early onset pancreatic cancer (EOPC) patients are scarce. In this review, we discuss differences between EOPC and late-onset pancreatic cancer based on findings in original papers and reviews with a focus on morphology, genetics, clinical outcomes and therapy. In conclusion, families with a positive history of PC and patients with BRCA 1 or 2 mutations should be monitored. Patients with EOPC usually present with better overall fitness compared to the average PC population, however often with even more aggressive cancer behaviour. Therefore, potent state-of-the-art multi-modal systemic therapies should be applied whenever possible. Large-scale registries and randomized clinical trials dealing with EOPC in regard to distinct biology and outcome are warranted.

Novel Survivin Inhibitor for Suppressing Pancreatic Cancer Cells Growth via Downregulating Sp1 and Sp3 Transcription Factors

BACKGROUND/AIMS

Targeting survivin, an anti-apoptotic protein and mitotic regulator, is considered as an effective therapeutic option for pancreatic cancer (PaCa). Tolfenamic acid (TA) showed anti-cancer activity in pre-clinical studies. A recent discovery demonstrated a copper(II) complex of TA (Cu-TA) can result in higher activity. In this study, the ability of Cu-TA to inhibit survivin and its transcription factors, Specificity protein (Sp) 1 and 3 in PaCa cell lines and tumor growth in mouse xenograft model were evaluated.

METHODS

Cell growth inhibition was measured in MIA PaCa-2 and Panc1 cells for 2 days using CellTiter-Glo kit. Sp1, Sp3 and survivin expression (by Western blot and qPCR), apoptotic cells and cell cycle phase distribution (by flow cytometry) were evaluated. A pilot study was performed using athymic nude mice [treated with vehicle/Cu-TA (25 or 50 mg/kg) 3 times/week for 4 weeks.

RESULTS

The IC50 value for Cu-TA was about half than TA.Both agents repressed the protein expression of Sp1/Sp3/survivin, Cu-TA was more effective than TA. Especially effect on survivin inhibition was 5.2 (MIA PaCa-2) or 6.4 (Panc1) fold higher and mRNA expression of only survivin was decreased. Apoptotic cells increased with Cu-TA treatment in both cell lines, while Panc1 showed both effect on apoptosis and cell cycle (G2/M) arrest. Cu-TA decreased the tumor growth in mouse xenografts (25 mg/kg: 48%; 50 mg/kg: 68%). Additionally, there was no change observed in mice body weights, indicating no overt toxicity was occurring.

CONCLUSION

These results show that Cu-TA can serve as an effective survivin inhibitor for inhibiting PaCa cell growth.

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

AIM

To identify novel candidate genes for pancreatic cancer.

METHODS

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

RESULTS

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

CONCLUSION

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

Hydroxyeicosatetraenoic acids in patients with pancreatic cancer: a preliminary report

Previous experimental reports have demonstrated that lipoxygenase (LOX) derivatives of arachidonic acid (AA), such as hydroxyeicosatetraenoic acids (HETEs), may be of significance in the pathogenesis of pancreatic cancer. However, these observations have not been confirmed in clinical studies. In the current study, we comprehensively evaluated the systemic levels of selected LOX-derived HETEs such as 5-, 12- and 15-HETE in patients with pancreatic adenocarcinoma (n=36), chronic pancreatitis (n=39), and in healthy individuals (n=35). Compared to healthy individuals, patients with pancreatic adenocarcinoma showed 3-8-fold higher levels of 5-, 12- and 15-HETE (at least P<0.003). Similar results were observed in patients with chronic pancreatitis, who had elevated concentrations of all examined HETE acids compared to healthy volunteers (in all cases at least P<0.03). Interestingly, the levels of the examined HETEs were not significantly associated with the TNM stage of pancreatic cancer in our patients. Finally, analyses of receiver operating characteristic curves demonstrated that all HETEs examined had relatively low area under the curve values for discriminating pancreatic adenocarcinoma from non-cancerous conditions (0.49-0.61; P>0.05 in each case). Our study provides first preliminary clinical evidence for the significance of the examined HETEs in the clinical pathogenesis of pancreatic cancer and other pancreatic diseases in humans. Moreover, our data demonstrate that the HETEs examined here do not show sufficient clinical potential to be used as independent (bio)markers for differentiating pancreatic adenocarcinoma from other non-cancerous conditions in humans.

LncRNA co-expression network analysis reveals novel biomarkers for pancreatic cancer

High mortality and low survival rates for pancreatic ductal adenocarcinoma (PDAC) mainly result from the delay in diagnosis and treatment. Therefore, there is an urgent need to identify early PDAC biomarkers and new therapeutic targets. In this study, we applied a commonly used systems biology approach, the weighted gene co-expression network analysis (WGCNA), on lncRNA expression data. Eleven lncRNAs, namely A2M-AS1, DLEU2, LINC01133, LINC00675, MIR155HG, SLC25A25-AS1, LINC01857, LOC642852 (LINC00205), ITGB2-AS1, TSPOAP1-AS1 and PSMB8-AS1 have been identified and validated on an independent PDAC expression dataset. Furthermore, we characterized them by functional and pathway enrichment analysis and identified which lncRNAs showed differential expression, differential promoter methylation levels and copy number alterations between normal and PDAC samples. Finally, we also performed a survival analysis and identified A2M-AS1, LINC01133, LINC00205 and TSPOAP1-AS1 as prognostic biomarkers for PDAC. Interestingly, although only a few cancer-associated lncRNAs have been functionally characterized, LINC00675 and LINC01133 lncRNAs have already been demonstrated to be involved in PDAC development and progression. Therefore, our results provide new potential diagnostic/prognostic biomarkers and therapeutic targets for PDAC that deserve to be further investigated. Moreover, these lncRNAs may improve the understanding about molecular pathogenesis of PDAC.

Genetics of Pancreatic Neoplasms and Role of Screening

There is a wide spectrum of pancreatic neoplasms with characteristic genetic abnormalities, tumor pathways, and histopathology that primarily determine tumor biology, treatment response, and prognosis. Although most pancreatic tumors are sporadic, 10% of neoplasms occur in the setting of distinct hereditary syndromes. Detailed studies of these rare syndromes have allowed researchers to identify a myriad of specific genetic signatures of pancreatic tumors. A better understanding of tumor genomics may have significant clinical implications in the diagnosis and management of patients with pancreatic tumors. Evolving knowledge has paved the way to screening paradigms and protocols in individuals at higher risk of developing pancreatic tumors.

ETV4 Facilitates Cell-Cycle Progression in Pancreatic Cells through Transcriptional Regulation of Cyclin D1

The ETS family transcription factor ETV4 is aberrantly expressed in a variety of human tumors and plays an important role in carcinogenesis through upregulation of relevant target gene expression. Here, it is demonstrated that ETV4 is overexpressed in pancreatic cancer tissues as compared with the normal pancreas, and is associated with enhanced growth and rapid cell-cycle progression of pancreatic cancer cells. ETV4 expression was silenced through stable expression of a specific short hairpin RNA (shRNA) in two pancreatic cancer cell lines (ASPC1 and Colo357), while it was ectopically expressed in BXPC3 cells. Silencing of ETV4 in ASPC1 and Colo357 cells reduced the growth by 55.3% and 38.9%, respectively, while forced expression of ETV4 in BXPC3 cells increased the growth by 46.8% in comparison with respective control cells. Furthermore, ETV4-induced cell growth was facilitated by rapid transition of cells from G₁- to S-phase of the cell cycle. Mechanistic studies revealed that ETV4 directly regulates the expression of Cyclin D1 CCND1, a protein crucial for cell-cycle progression from G₁- to S-phase. These effects on the growth and cell cycle were reversed by the forced expression of Cyclin D1 in ETV4-silenced pancreatic cancer cells. Altogether, these data provide the first experimental evidence for a functional role of ETV4 in pancreatic cancer growth and cell-cycle progression.Implications: The functional and mechanistic data presented here regarding ETV4 in pancreatic cancer growth and cell-cycle progression suggest that ETV4 could serve as a potential biomarker and novel target for pancreatic cancer therapy. Mol Cancer Res; 16(2); 187-96. ©2017 AACR.

Inflammasomes and Cancer: The Dynamic Role of the Inflammasome in Tumor Development

Chronic Inflammation in tumor microenvironments is not only associated with various stages of tumor development, but also has significant impacts on tumor immunity and immunotherapy. Inflammasome are an important innate immune pathway critical for the production of active IL-1β and interleukin 18, as well as the induction of pyroptosis. Although extensive studies have demonstrated that inflammasomes play a vital role in infectious and autoimmune diseases, their role in tumor progression remains elusive. Multiple studies using a colitis-associated colon cancer model show that inflammasome components provide protection against the development of colon cancer. However, very recent studies demonstrate that inflammasomes promote tumor progression in skin and breast cancer. These results indicate that inflammasomes can promote and suppress tumor development depending on types of tumors, specific inflammasomes involved, and downstream effector molecules. The complicated role of inflammasomes raises new opportunities and challenges to manipulate inflammasome pathways in the treatment of cancer.