PALB2 upregulation is associated with a poor prognosis in pancreatic ductal adenocarcinoma

During DNA repair, BRCA1 and BRCA2 interact with the tumor suppressor partner and localizer of BRCA2 (PALB2). PALB2 mutations are associated with an increased risk of breast and ovarian carcinoma, and upregulated PALB2 expression is associated with poor clinical outcomes. The present study investigated the role and prognostic value of PALB2 in pancreatic ductal adenocarcinoma (PDAC). PALB2 expression was inhibited using a small interfering RNA in PDAC cell lines, and the subsequent effects on cell proliferation and migration were investigated. Tissue microarrays from 157 patients undergoing a pancreaticoduodenectomy for PDAC were analyzed via immunohistochemistry, and PALB2 expression was compared with patient outcomes using Kaplan-Meier curves and the multivariate Cox regression model. PALB2-knockdown in PDAC cells had little effect on cell proliferation, but significantly decreased cell migration. Relatively high PALB2 expression was observed in PDAC tissues compared with in peritumoral tissues. Overall survival (OS) was negatively associated with PALB2 expression. TNM stage and PALB2 expression were identified as independent prognostic factors associated with OS via multivariate analysis. Overall, the present study demonstrated that PDAC cell migration was dependent on PALB2, which was further supported by the finding that elevated PALB2 expression in PDAC tissues was associated with poor survival in patients with PDAC. Therefore, PALB2 may serve as a novel prognostic marker in PDAC, which may aid with the development of therapeutic strategies for the disease.     

THBS2 as a prognostic biomarker for patients diagnosed with metastatic pancreatic ductal adenocarcinoma

Patients newly diagnosed with metastatic pancreatic ductal adenocarcinoma generally have poor survival, with heterogeneous rates of progression. Biomarkers that could predict progression and/or survival would help inform patients and providers as they make care decisions. In a previous retrospective study, we discovered that circulating thrombospondin-2 (THBS2) could, in combination with CA19-9, better distinguish patients with PDAC versus healthy controls. Here we evaluated whether THBS2 levels, previously not known to be prognostic, were associated with outcome in 68 patients at time of diagnosis of metastatic PDAC. Specifically, we interrogated the association of THBS2 level, alone or in combination with CA19-9, with progression by 90 days and/or survival to 180 days. The results indicate that elevated THBS2 levels alone, at the time of a metastatic PDAC diagnosis, can identify patients with a shorter time to death and thus help patients and providers when planning treatment.     

Arpin downregulation is associated with poor prognosis in pancreatic ductal adenocarcinoma

IntroductionArpin (Arp2/3 complex inhibitor), a novel protein found in 2013, plays a pivotal role in cell motility and migration. However, the prognostic value of Arpin in pancreatic ductal adenocarcinoma (PDAC) remains unknown.Materials and methodsWe analyzed the gene expression of ARPIN using the GEO dataset (GSE71989) and validated the results by immunohistochemistry (IHC) and Western blot in our clinical database. Tissue microarray specimens from 214 patients who underwent curative pancreatectomy for PDAC were used. The tumors that expressed high and low levels of Arpin were compared with patient outcome using Kaplan-Meier curves and the multivariate Cox proportional hazard regression model. IHC was then used in 43 paired primary tumor tissues and metastasis tissues to detect the expression of Arpin.ResultsArpin had low expression in the tumor tissue compared with the paracancerous tissue in PDAC. Patients with low intratumoral Arpin expression had worse overall survival (OS) and recurrence-free survival (RFS) than patients with high expression in the training set (p < 0.001, p < 0.001) and validation set (p < 0.001, p < 0.001). The multivariate analysis revealed that the 8th edition TNM stage and Arpin expression were independent prognostic factors associated with OS and RFS in the training and validation sets, respectively. Arpin had lower expression in the metastasis tissues than in the primary tumors of patients with PDAC (p = 0.048).ConclusionThe Arpin level is an independent prognostic factor that can be a potential predictor to aid in the management of PDAC.     

Overexpression of rhophilin 2 promotes pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is the seventh leading cause of global cancer deaths. In recent years, targeted therapy has been used for pancreatic cancer; however, the drugs available for use in targeted therapy for pancreatic cancer are still very limited. Hence, identification of novel targeted molecules for PDAC is required. Rhophilin 2 (RHPN2) was proven to be a driver gene in glioblastoma. However, the function of RHPN2 in PDAC remains unknown. In the present study, the function of RHPN2 was investigated. The RHPN2 levels were overexpressed by pcDNA3.1-RHPN2 and downregulated by si-RHPN2. Cell proliferation was assessed using the MTT assay and apoptosis was assessed using flow cytometry. The results revealed that high RHPN2 levels in PDAC tissue were correlated with a low overall survival rate of patients with PDAC. Inhibition of RHPN2 reduced SW1990 and PANC1 proliferation and increased the rate of apoptosis. Network analysis demonstrated that centrosomal protein 78 expression was negatively correlated with RHPN2 expression. In conclusion, the present study demonstrated that RHPN2 may promote PDAC making it a potential candidate for targeted therapy.     

单羧酸转运蛋白1促进胰腺导管癌细胞浸润转移的机制研究

背景与目的：单羧酸转运蛋白1（monocarboxylate transporter 1，MCT1）是细胞转运乳酸、丙酮酸等代谢产物及能量物质的一种重要蛋白质，其在胰腺导管癌中的作用及机制鲜有研究报道。该研究旨在探讨MCT1在胰腺导管癌中的表达及临床病理学意义。方法：纳入78例胰腺导管癌患者的癌组织及癌旁正常组织，运用免疫组织化学技术检测MCT1在癌组织和癌旁正常组织中的表达水平并分析其临床病理学意义。在体外细胞系水平上，我们运用胰腺癌细胞系PANC-1和Capan-1，运用细胞克隆形成实验、细胞划痕和Transwell实验分析沉默MCT1后胰腺癌细胞增殖、迁移和浸润的改变。为明确MCT1的相关作用机制，我们通过生物信息学分析，预测miR-124-3p是MCT1的潜在调控微小RNA；为了进一步验证，我们运用双荧光素酶报告实验分析miR-124-3p对MCT1的调控效果；运用实时荧光定量聚合酶链反应（real-time fluorescence quantitative polymerase chain reaction，RTFQ-PCR）分别检测51对新鲜胰腺癌组织中MCT1和miR-124-3p的基因表达并分析两者的相关性。结果：MCT1的阳性表达主要位于细胞膜和细胞质。相比癌旁正常组织，MCT1在胰腺导管癌组织中显著高表达，其表达水平与胰腺导管癌的分化程度、临床分期、淋巴结转移和不良预后具有显著相关性。在体外细胞系水平上，沉默MCT1能够显著抑制胰腺癌细胞系PANC-1和Capan-1的增殖、迁移和浸润；miR-124-3p在胰腺癌组织中显著低表达，并且与MCT1 mRNA的表达具有显著负相关性，能够负调控MCT1的蛋白表达。结论：MCT1是胰腺导管腺癌的致癌基因，miR-124-3p能够负调控MCT1的表达。     

High expression of vascular endothelial growth factor is associated with liver metastasis and a poor prognosis for patients with ductal pancreatic adenocarcinoma

BACKGROUND: Vascular endothelial growth factor (VEGF), a recently identified growth factor with significant angiogenic properties, is a multifunctional angiogenic cytokine that is expressed in many tumors. High VEGF expression has been shown to correlate with the incidence of metastasis and poor prognosis in various cancers. In this study, the authors investigated VEGF expression and microvessel density (MVD) in ductal pancreatic adenocarcinoma and examined the correlations among VEGF expression, clinicopathologic factors, and clinical outcome. The authors especially focused on the correlation between VEGF expression and liver metastasis. METHODS: Paraffin embedded tumor specimens of 142 surgically resected pancreas carcinoma were immunohistochemically stained for VEGF and MVD. The correlations among VEGF expression and MVD, clinicopathologic factors, and clinical outcome were then statistically analyzed. RESULTS: One hundred thirty-two (93%) of 142 ductal pancreatic adenocarcinomas were positive for VEGF protein by immunohistochemistry. A significant correlation was observed between VEGF positivity and MVD (P < 0.0001). Multivariate logistic regression analysis indicated a significant association between high VEGF expression and liver metastasis (P = 0.010) but no other factors, such as age, tumor size, histologic type, lymph node metastasis, venous invasion, neural invasion, peritoneal metastasis, or local recurrence. Patients with tumors that showed moderate or high VEGF expression had significantly shorter survival than patients with low VEGF expression or none at all in their tumors (P < 0.05). CONCLUSIONS: These results indicate that VEGF expression is closely correlated with MVD and seems to be an important predictor for both liver metastasis and poor prognosis in ductal pancreatic adenocarcinoma.     

Frequency of K-ras mutations in pancreatic intraductal neoplasias associated with pancreatic ductal adenocarcinoma and chronic pancreatitis: a meta-analysis

Molecular analyses have demonstrated mutations in the K-ras gene at codon 12 in the majority of pancreatic ductal adenocarcinomas (PDACs). In order to determine whether the K-ras mutation rate increases parallel to the grade of dysplasia in duct lesions, we performed a meta-analysis of the studies published between 1988 and 2003 that provide information on K-ras mutations in hyperplastic and dysplastic duct lesions in the pancreas. The described duct lesions were reclassified according to the nomenclature for pancreatic intraepithelial neoplasia (PanIN), and the molecular methods for detecting K-ras were reviewed. In PanIN lesions from pancreata of patients with PDAC, there was a stepwise increase in K-ras mutations that correlated with the grade of dysplasia of the PanIN lesion. K-ras mutations were found in 36%, 44%, and 87% of PanIN-1a, 1b, and 2-3 lesions, respectively (trend statistic P <.001). Mutation-enriched polymerase chain reaction (PCR) resulted in higher rates of K-ras mutations in PanIN than plain PCR did. The incidence of K-ras mutations in PanIN lesions associated with chronic pancreatitis (CP) or normal pancreas was low (around 10%). In CP, K-ras mutations were only found after a disease duration of 3 years. The correlation of the incidence of K-ras mutations with the grade of dysplasia in PanIN and the occurrence of these mutations in CP with a duration of more than 3 years underlines the importance of this genetic change for the development of PDAC.     

Clinical challenges associated with utility of neoadjuvant treatment in patients with pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an increasingly common cancer with a persistently poor prognosis, and only approximately 20% of patients are clearly anatomically resectable at diagnosis. Historically, a paucity of effective therapy made it inappropriate to forego the traditional gold standard of upfront surgery in favour of neoadjuvant treatment; however, modern combination chemotherapy regimens have made neoadjuvant therapy increasingly viable. As its use has expanded, the rationale for neoadjuvant therapy has evolved from one of ‘downstaging' to one of early treatment of micro-metastases and selection of patients with favourable tumour biology for resection. Defining resectability in PDAC is problematic; multiple differing definitions exist. Multidisciplinary input, both in initial assessment of resectability and in supervision of multimodality therapy, is therefore advised. European and North American guidelines recommend the use of neoadjuvant chemotherapy in borderline resectable (BR)-PDAC. Similar regimens may be applied in locally advanced (LA)-PDAC with the aim of improving potential access to curative-intent resection, but appropriate patient selection is key due to significant rates of recurrence after excision of LA disease. Upfront surgery and adjuvant chemotherapy remain standard-of-care in clearly resectable PDAC, but multiple trials evaluating the use of neoadjuvant therapy in this and other localised settings are ongoing.     

FXYD3 is overexpressed in pancreatic ductal adenocarcinoma and influences pancreatic cancer cell growth

The expression and localization of FXYD domain containing ion transport regulator 3 (FXYD3), a transmembrane protein that acts as a chloride channel or chloride channel regulator, was analyzed in pancreatic tissues derived from donors and patients suffering from chronic pancreatitis (CP) or pancreatic ductal adenocarcinoma (PDAC) as well as in pancreatic cancer cells using QRT-PCR, laser-capture microdissection and microarray analysis, in situ hybridization and immunohistochemistry. FXYD3 antisense expressing T3M4 pancreatic cancer cells were generated and compared to control cells using anchorage-dependent and independent growth assays, and xenotransplantation into nude mice. FXYD3 mRNA levels were 3.4-fold increased in PDAC tissues compared to donor specimens (p = 0.006), and 3.9-fold increased in microdissected cancer cells compared to normal pancreatic ductal cells (p = 0.02). FXYD3 was localized in the tubular complexes and PanIN lesions of both CP and PDAC, as well as in pancreatic cancer cells. Downregulation of FXYD3 by stable antisense transfection increased significantly the doubling time of T3M4 pancreatic cancer cells from 44 +/- 2 hr to 55 +/- 12 hr (p = 0.02). Nude mice transplanted with antisense transfected cells displayed a significant increase in tumor doubling time from 3.3 days +/- 1.0 to 4.3 days +/- 0.43 (p = 0.058). Anchorage-independent growth and sensitivity to 5-fluorouracil, gemcitabine and cisplatin as well as to MgCl(2) were not dependent on the level of FXYD3 expression. In conclusion, overexpression of FXYD3 in pancreatic cancer may contribute to the proliferative activity of this malignancy.     

High beta integrin expression is differentially associated with worsened pancreatic ductal adenocarcinoma outcomes

Outcomes in pancreatic ductal adenocarcinoma (PDAC) are known to be worse in tumors with high integrin β1 expression, but targeted monotherapy against this integrin has not been effective. Seven other beta integrins are expressed in mammalian biology and they are known to have overlapping and compensatory signaling in biological systems. However, their roles in PDAC are poorly understood and have not been systematically compared to integrin β1 biology. In this study, we analyzed the clinical outcomes against beta integrin 1-8 (ITGB1-8) expression in PDAC samples from two large independent cohorts, The Cancer Genome Atlas (TCGA) and {"type":"entrez-geo","attrs":{"text":"GSE21501","term_id":"21501"}}GSE21501. Biological function and tumor microenvironment composition were studied using Gene Set Enrichment Analysis and xCell. Expression of all eight beta integrins is significantly increased in PDACs relative to normal pancreatic tissues (all P<0.001). ITGB1, 2, 5, and 6 have similarly enriched gene patterns related to transforming growth factor (TGF)-β, epithelial mesenchymal transition, inflammation, stemness, and angiogenesis pathways. Homologous recombination defects and neoantigens are increased in high-ITGB4, 5, and 6 tumors, with decreased overall survival in high-ITGB1, 5, and 6 tumors compared to low expression tumors (hazard ratios 1.5-2.0). High-ITGB1, 2, and 5 tumors have increased fibroblast infiltration (all P<0.01) while endothelial cells are increased in high-ITGB2 and 3 tumors (all P<0.05). Overall, beta integrin expression does not correlate to immune cell populations in PDACs. Therefore, while all beta integrins are overexpressed in PDACs, they exert differential effects on PDAC biology. ITGB2, 5, and 6 have a similar profile to ITGB1, suggesting that future research in PDAC integrin therapy needs to consider the complementary signaling profiles mediated by these integrins.     

Preoperative neutrophil-to-lymphocyte ratio as a prognosticator in early stage pancreatic ductal adenocarcinoma

Background

The neutrophil-to-lymphocyte ratio (NLR), which reflects the cancer-induced systemic inflammation response, has been proposed as a risk factor for poor long-term prognosis in cancer. We investigated the prognostic role of the NLR and the relationship between the NLR and TNM stage in pancreatic ductal adenocarcinoma (PDAC) patients following curative resection.

Diagnosis and staging of pancreatic ductal adenocarcinoma

The management of pancreatic ductal adenocarcinoma (PDAC) is a major public health concern worldwide. Currently, most PDAC patients are diagnosed in advanced stages. The signs and symptoms of the disease, except for jaundice, are non-specific. Thus, the current challenge is to identify earlier those individuals for whom specific screening tools and specific treatments would be beneficial. On the basis of the recommendations of the group of experts of multiple medical specialties of the GALLgo Project, the patients with PDAC should be managed by a multidisciplinary team to assess the personal and family history, the best diagnostic and staging procedures and consider all important aspects for treatment decisions. In this article, the group of experts proposes strategies to shorten the diagnosis times in PDAC patients.     

Staging of pancreatic ductal adenocarcinoma with spiral CT and MRI

Detection of pancreatic adenocarcinoma is crucial for accurate staging both with spiral CT and dynamic MRI; consequently an accurate technique is required and so-called pancreatic phase is recognized as the best one for tumor conspicuity. For vascular involvement optimal results have been achieved in assessing unresectability; vein involvement seems more difficult to be defined as it is sustained by a different spread compared to arterial involvement. Grading of vessel circumference contact represents the best tool in "venous" staging, but shape deformation and collateral veins dilation are also important signs. Lymph node staging is less accurate, lacking in specificity, but spiral CT demonstrated better results if compared with dynamic MRI. Assessment of liver metastases has been improved by the advent of spiral CT and dynamic contrast enhanced MRI, while peritoneal staging seems to be unaffected. In conclusion, both spiral CT and dynamic contrast enhanced MRI are accurate in pancreatic adenocarcinoma staging, mainly for vessels and liver involvement; no definite differences have been established, because only a few studies have compared them both with state-of-art techniques. Therefore standardized multicentric trials are desirable. Up to now, the choice of which technique to employ should be based on local expertise; moreover, the aggressive approach of surgical equipes should be kept in mind.     

Stromal galectin-1 expression is associated with long-term survival in resectable pancreatic ductal adenocarcinoma

The overall 5 year survival rate for pancreatic ductal adenocarcinoma (i.e., PDAC) is a dismal 5%, although patients that have undergone surgical resection have a somewhat better survival rate of up to 20%. Very long-term survivors of PDAC (defined as patients with ≥ 10 year survival following apparently curative resection), on the other hand, are considerably less frequent. The molecular characteristics of very long-term survivors (VLTS) are poorly understood, but might provide novel insights into prognostication for this disease. In this study, a panel of five VLTS and stage-matched short-term survivors (STS, defined as disease-specific mortality within 14 months of resection) were identified, and quantitative proteomics was applied to comparatively profile tumor tissues from both cohorts. Differentially expressed proteins were identified in cancers from VLTS vs. STS patients. Specifically, the expression of galectin-1 was 2-fold lower in VLTS compared with STS tumors. Validation studies were performed by immunohistochemistry (IHC) in two additional cohorts of resected PDAC, including: 1) an independent cohort of VLTS and 2) a panel of sporadic PDAC with a considerable range of overall survival following surgery. Immunolabeling analysis confirmed that significantly lower expression of stromal galectin-1 was associated with VLTS (p = 0.02) and also correlated with longer survival in sporadic, surgically-treated PDAC cases (hazard ratio = 4.9, p = 0.002). The results from this study provide new insights to better understand the role of galectin-1 in PDAC survival, and might be useful for rendering prognostic information, and developing more effective therapeutic strategies aimed at improving survival.     

Carcinoembryonic antigen as a specific glycoprotein ligand of rBC2LCN lectin on pancreatic ductal adenocarcinoma cells

The rBC2LCN lectin, known as a stem cell marker probe that binds to an H type 3 fucosylated trisaccharide motif, was recently revealed to also bind to pancreatic ductal adenocarcinoma (PDAC) cells. A lectin-drug conjugate was generated by fusing rBC2LCN with a cytocidal toxin, and it showed a strong anticancer effect in in vitro and in vivo PDAC models. However, it is unclear which molecules are carrier proteins of rBC2LCN on PDAC cells. In this study, we identified a rBC2LCN-positive glycoprotein expressed in PDAC. Tumor lysates of PDAC patient-derived xenografts (PDXs) were coprecipitated with rBC2LCN lectin and analyzed by liquid chromatography–mass spectrometry. A total of 343 proteins were initially identified. We used a web-based database to select five glycoproteins and independently evaluated their expression in PDAC by immunohistochemistry (IHC). Among them, we focused on carcinoembryonic antigen 5 (CEA) as the most cancer-specific carrier protein in PDAC, as it showed the most prominent difference in expression rate between PDAC cells (74%) and normal pancreatic duct cells (0%, P > .0001). rBC2LCN lectin and CEA colocalization in PDAC samples was confirmed by double-staining analysis. Furthermore, rBC2LCN-precipitated fractions were blotted with an anti-CEA polyclonal antibody (pAb), and CEA pAb–precipitated fractions were blotted with rBC2LCN lectin. The results demonstrate that CEA is in fact a ligand of rBC2LCN lectin.