Immunohistochemical analysis of a panel of cancer stem cell markers and potential therapeutic markers in pancreatic ductal adenocarcinoma.

PURPOSE: Pancreatic Ductal Adenocarcinoma (PDAC) is the most common type of pancreatic malignancies. It is known for its aggressive nature and high mortality rate. This calls for an urgent need of new prognostic and therapeutic markers that can be targeted for personalized treatment of the patient. METHODS: Among 142 patients diagnosed with pancreatic cancers at Aga Khan University Hospital, a total of 62 patients were selected based on their confirmed diagnosis of PDAC. Immunohistochemistry was performed on Formalin-Fixed Paraffin-Embedded (FFPE) sections using selected antibodies (CD44, CD133, L1CAM, HER2, PD-L1, EGFR, COX2 and cyclin D1). All the slides were scored independently by two pathologists as per the set criteria. RESULTS: Expression of all cancer stem cell markers was found to be significantly associated with one or more potential therapeutic markers. CD44 expression was significantly associated with HER2 (p = 0.032), COX2 (p = 0.005) and EGFR expression (p = 0.008). CD133 expression also showed significant association with HER2 (p = 0.036), COX2 (p = 0.004) and EGFR expression (p = 0.018). L1CAM expression was found to be associated with expression of COX2 (p = 0.017). None of the proteins markers showed association with overall survival of the patient. On the other hand, among the clinicopathological characteristics, histological differentiation (p = 0.047), lymphovascular invasion (p = 0.021) and perineural invasion (p = 0.014) were found to be significantly associated with patient's overall survival. CONCLUSION: Internationally, this is the first report that assesses the selected panel of cancer stem cell markers and potential therapeutic targets in a single study and evaluates its combined expression. The study clearly demonstrates association between expression of cancer stem cell markers and therapeutic targets hence paves a way for precision medicine for pancreatic cancer patients.

Deciphering the immunopeptidome in vivo reveals new tumour antigens.

Immunosurveillance of cancer requires the presentation of peptide antigens on major histocompatibility complex class I (MHC-I) molecules1-5. Current approaches to profiling of MHC-I-associated peptides, collectively known as the immunopeptidome, are limited to in vitro investigation or bulk tumour lysates, which limits our understanding of cancer-specific patterns of antigen presentation in vivo6. To overcome these limitations, we engineered an inducible affinity tag into the mouse MHC-I gene (H2-K1) and targeted this allele to the KrasLSL-G12D/+Trp53fl/fl mouse model (KP/KbStrep)7. This approach enabled us to precisely isolate MHC-I peptides from autochthonous pancreatic ductal adenocarcinoma and from lung adenocarcinoma (LUAD) in vivo. In addition, we profiled the LUAD immunopeptidome from the alveolar type 2 cell of origin up to late-stage disease. Differential peptide presentation in LUAD was not predictable by mRNA expression or translation efficiency and is probably driven by post-translational mechanisms. Vaccination with peptides presented by LUAD in vivo induced CD8+ T cell responses in naive mice and tumour-bearing mice. Many peptides specific to LUAD, including immunogenic peptides, exhibited minimal expression of the cognate mRNA, which prompts the reconsideration of antigen prediction pipelines that triage peptides according to transcript abundance8. Beyond cancer, the KbStrep allele is compatible with other Cre-driver lines to explore antigen presentation in vivo in the pursuit of understanding basic immunology, infectious disease and autoimmunity.

Role of Maspin, CK17 and Ki-67 Immunophenotyping in Diagnosing of Pancreatic Ductal Adenocarcinoma in Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology.

BACKGROUND AND STUDY AIM: One of the problems in diagnosing pancreatic ductal adenocarcinoma (PDAC) is differentiation between PDAC cells and benign pancreatic tissue cells in cytologic samples. This study aimed to evaluate the usefulness of Maspin, CK17 and Ki-67 immunocytochemistry (ICC) in differentiation between these two groups of cells. MATERIALS AND METHODS: This retrospective study was carried on 80 cases of PDAC and 25 cell blocks of benign pancreatic tissue cells as a control group for evaluation of Maspin, CK17 and Ki-67 ICC. PDAC cases were sampled by endoscopic ultrasound guided fine needle aspiration cytology (EUS-FNAC), while cell blocks of control group were aspirated from benign pancreatic tissues that were obtained from the pancreatic surgically resected specimens. Immunostaining patterns, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of each antibody as well as possible antibody combined panels of these markers in differentiation between the two groups were evaluated. RESULTS: Positive immunoreactivity for Maspin, CK17 and Ki-67 were 92.5%, 80% and 72.5% in PDAC cases, respectively. In contrast to PDAC cases, all the cell blocks of benign pancreatic tissue cells were negative for these markers. Regarding different panels, combined use of Maspin, CK17 and Ki-67 together as a triple test (at least one of them is positive) achieved the highest sensitivity of 98.8%, specificity of 100%, PPV of 100%, NPV of 96.2% and accuracy of 99% in the differentiation between PDAC and benign pancreatic tissue. CONCLUSION: Employing this short panel [Maspin, CK17 and Ki-67] is helpful for better differentiation between PDAC and benign pancreatic tissue.

Clinical Perspective on Proteomic and Glycomic Biomarkers for Diagnosis, Prognosis, and Prediction of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is known as a highly aggressive malignant disease. Prognosis for patients is notoriously poor, despite improvements in surgical techniques and new (neo)adjuvant chemotherapy regimens. Early detection of PDAC may increase the overall survival. It is furthermore foreseen that precision medicine will provide improved prognostic stratification and prediction of therapeutic response. In this review, omics-based discovery efforts are presented that aim for novel diagnostic and prognostic biomarkers of PDAC. For this purpose, we systematically evaluated the literature published between 1999 and 2020 with a focus on protein- and protein-glycosylation biomarkers in pancreatic cancer patients. Besides genomic and transcriptomic approaches, mass spectrometry (MS)-based proteomics and glycomics of blood- and tissue-derived samples from PDAC patients have yielded new candidates with biomarker potential. However, for reasons discussed in this review, the validation and clinical translation of these candidate markers has not been successful. Consequently, there has been a change of mindset from initial efforts to identify new unimarkers into the current hypothesis that a combination of biomarkers better suits a diagnostic or prognostic panel. With continuing development of current research methods and available techniques combined with careful study designs, new biomarkers could contribute to improved detection, prognosis, and prediction of pancreatic cancer.

MicroRNA-216a targets WT1 expression and regulates KRT7 transcription to mediate the progression of pancreatic cancer-A transcriptome analysis.

Gene expression profiling has been broadly performed in the field of cancer research. This study aims to explore the key gene regulatory network and focuses on the functions of microRNA (miR)-216a in pancreatic cancer (PC). PC datasets GSE15471, GSE16515, and GSE32676 were used to screen the differentially expressed genes (DEGs) in PC. A miRNA microarray analysis and gene oncology analysis suggested miR-216a as an important differentially expressed miRNA in PC. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that miR-216a and the DEGs are largely enriched on the phosphatidyl inositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway. miR-216a targeted Wilms Tumor 1 (WT1), while WT1 promoted transcription activity of keratin 7 (KRT7). Upregulation of miR-216a reduced proliferation and invasiveness of PC cells, while further upregulation of WT1 blocked the functions of miR-216a. Silencing of KRT7 diminished the oncogenic role of WT1. The in vitro results were reproduced in vivo. High expression of miR-216a while poor expression of WT1 indicated better prognosis of PC patients. The miR-216a/WT1/KRT7 axis influenced the activity of the PI3K/AKT pathway. To conclude, this study evidenced that miR-216a suppressed WT1 expression and blocked KRT7 transcription, which inactivated the PI3K/AKT signaling and reduced PC progression.

Expression of Calretinin, Marker of Mesothelial Differentiation, in Pancreatic Ductal Adenocarcinoma: A Potential Diagnostic Pitfall.

OBJECTIVE: Pancreatic ductal adenocarcinoma is one of the most common causes of "peritoneal carcinomatosis" and has an insidious growth pattern. Thus, it falls into the differential diagnosis of other peritoneal malignancies including malignant mesothelioma. Recently, we have encountered an undifferentiated pancreatic carcinoma presenting with peritoneal disease and exhibiting immunoreactivity to calretinin, mimicking mesothelioma. In this study, we explored the incidence of calretinin expression in pancreatic ductal adenocarcinoma. MATERIALS AND METHODS: Calretinin immunohistochemical staining was performed on the tissue microarrays (TMAs), which were created using three 0.6 mm diameter punches per tumor (n=113). Distribution and intensity of expression were evaluated. RESULTS: The TMAs contained 86 well/moderately differentiated and 27 poorly differentiated/undifferentiated carcinomas. Calretinin was positive in nine tumors (8%); six with diffuse and strong staining, three with focal and/or weak staining. The incidence of calretinin expression was 15% in poorly differentiated/undifferentiated carcinomas (vs. 6% in well/moderately differentiated carcinomas, p=0.03). CONCLUSIONS: Pancreatic ductal adenocarcinomas, especially when poorly differentiated/undifferentiated, may be diffusely and strongly positive for calretinin creating a potential diagnostic challenge with malignant mesothelioma. Therefore, caution should be exercised when using this marker to explore a diagnosis of malignant mesothelioma. Tumors expressing calretinin without other mesothelial markers should prompt a careful evaluation of the morphologic and immunohistochemical features to exclude other malignancies. If the diagnosis of pancreatic ductal adenocarcinoma is considered, ductal differentiation can be demonstrated by using additional immunohistochemical markers such as mucin-related glycoproteins (MUC1, MUC5AC) and/or oncoproteins (CEA, B72.3, CA125).

Prognostic significance and therapeutic potential of the immune checkpoint VISTA in pancreatic cancer.

OBJECTIVE: V-domain Ig suppressor of T cell activation (VISTA) is a novel immune checkpoint protein that belongs to the B7 family. The aim of this study was to investigate the prognostic significance and therapeutic potential of VISTA in patients with pancreatic cancer. METHODS: Using immunohistochemistry (IHC), we examined the expression of VISTA and demonstrated the associations between the VISTA and overall survival in 223 PDAC patients from 2 different unrelated retrospective cohorts. The multiplex immunofluorescence was performed to illuminate the relationship between VISTA expression and tumor-infiltrating immune cell subclusters of PDAC. We also verified the findings in The Cancer Genome Atlas (TCGA) dataset. The anti-tumor effect of anti-VISTA therapy was studied by the mouse model with liver metastases of PDAC. RESULTS: The VISTA protein was highly expressed in 25.6% of tumor cells (TCs), 38.1% of immune cells, and 26.0% of endothelial cells in 223 PDAC tumor tissues. VISTA expression in TCs was significantly associated with prolonged overall survival. Multiplex immunofluorescence analysis revealed that VISTA level was positively correlated with CD68+ macrophages, CD3+ T cells, and CD19+ B cells in PDAC. However, a higher expression level of VISTA was detected in tumor-infiltrating CD68+ macrophages than in CD3+ T and CD19+ B cells. Furthermore, anti-VISTA antibody treatment significantly reduced the number of metastatic nodules in livers of mouse models of PDAC with liver metastases. CONCLUSION: VISTA expressed in TCs is associated with a favorable prognosis in PDAC. Moreover, immunotherapy with anti-VISTA antibodies may potentially be an effective treatment strategy against PDAC.

Quantitative structural analysis of glycans expressed within tumors derived from pancreatic cancer patient-derived xenograft mouse models.

Pancreatic ductal adenocarcinoma (PDAC) is an intractable malignancy for which novel therapeutic targets are in high demand. To uncover glycans expressed within PDAC, we previously performed glycome profiling of PDAC cell lines using lectin microarray and found that the lectin rBC2LCN with specificity to a Fucα1-2Galß1-3 motif exhibited strong binding to a PDAC cell line (Capan-1) and to all tumor tissues derived from 69 pancreatic cancer patients. Nevertheless, no information was available as to whether glycans containing the Fucα1-2Galß1-3 motif are expressed within PDAC. Here we used HPLC combined with MALDI-TOFMS to perform a structural and quantitative glycome analysis targeting both N- and O-glycans derived from two types of patient-derived PDAC xenograft mouse models, PC3 (well-differentiated) and PC42 (poorly-differentiated). A higher percentage of highly branched and sialylated complex-type N-glycans was detected in PC42 relative to PC3. The percentage of core 1 O-glycans was higher in PC42 relative to PC3, whereas that of core 3 O-glycans was higher in PC3. Cancer-related glycan epitopes such as Lewis A and Lewis Y were detected in core 3 O-glycans of both PC3 and PC42. H-type3 containing the Fucα1-2Galß1-3 motif was detected in Core 2 O-glycans in both models, explaining the molecular mechanism of the binding of rBC2LCN to PDAC.

Interferon-Induced Protein With Multiple Tetratricopeptide Repeats 3 Is Associated With Response to Chemotherapy and Recurrence but Not With Survival.

OBJECTIVES: The interferon-induced protein with multiple tetratricopeptide repeats 3 (IFIT3) seems to be associated with the prognosis in pancreatic cancer. Here we clarify whether the heterogeneity of IFIT3 expression affects previous IFIT3 analysis. METHODS: This retrospective study analyzes pancreatic cancer tissue samples retrieved by surgery from 2 independent patient cohorts. Patients underwent either primary surgery (n = 72) or received neoadjuvant chemotherapy (n = 12). Immunohistochemistry assessed IFIT3 expression and its heterogeneity. Complementarily, we analyzed publicly available transcriptomic data (n = 903). RESULTS: Of the primarily resected tumors, 16.4% were heterogeneous. Patients with IFIT3-negative tumors did not survive longer compared with patients with IFIT3-positive tumors. An analysis of publicly available data confirmed this result. Patients developing lung metastases had the best prognosis (4.8 years) with significantly lower IFIT3 expression compared with liver metastasis (P = 0.0117). Patients receiving neoadjuvant therapy who are IFIT3 negative had a longer disease-free survival (1.2 vs 0.3 years, P = 0.0081). CONCLUSIONS: Low IFIT3 expression is not associated with longer survival. Divergent results from tissue microarray analyses could be explained with tumor heterogeneity. As a single biomarker, IFIT3 is not suitable for predicting disease prognosis. Recurrence of lung metastases and response to neoadjuvant chemotherapy are associated with low IFIT3 expression.

Cancer cell line-specific protein profiles in extracellular vesicles identified by proteomics.

Extracellular vesicles (EVs), are important for intercellular communication in both physiological and pathological processes. To explore the potential of cancer derived EVs as disease biomarkers for diagnosis, monitoring, and treatment decision, it is necessary to thoroughly characterize their biomolecular content. The aim of the study was to characterize and compare the protein content of EVs derived from three different cancer cell lines in search of a specific molecular signature, with emphasis on proteins related to the carcinogenic process. Oral squamous cell carcinoma (OSCC), pancreatic ductal adenocarcinoma (PDAC) and melanoma brain metastasis cell lines were cultured in CELLine AD1000 flasks. EVs were isolated by ultrafiltration and size-exclusion chromatography and characterized. Next, the isolated EVs underwent liquid chromatography-mass spectrometry (LC-MS) analysis for protein identification. Functional enrichment analysis was performed for a more general overview of the biological processes involved. More than 600 different proteins were identified in EVs from each particular cell line. Here, 14%, 10%, and 24% of the identified proteins were unique in OSCC, PDAC, and melanoma vesicles, respectively. A specific protein profile was discovered for each cell line, e.g., EGFR in OSCC, Muc5AC in PDAC, and FN1 in melanoma vesicles. Nevertheless, 25% of all the identified proteins were common to all cell lines. Functional enrichment analysis linked the proteins in each data set to biological processes such as "biological adhesion", "cell motility", and "cellular component biogenesis". EV proteomics discovered cancer-specific protein profiles, with proteins involved in processes promoting tumor progression. In addition, the biological processes associated to the melanoma-derived EVs were distinct from the ones linked to the EVs isolated from OSCC and PDAC. The malignancy specific biomolecular cues in EVs may have potential applications as diagnostic biomarkers and in therapy.

Protein Signatures and Tissue Diagnosis of Pancreatic Cancer.

BACKGROUND: Endoscopic ultrasound-guided fine-needle aspiration fails to diagnose up to 25% of patients with pancreatic ductal adenocarcinoma (PDAC). Proteomics can help to overcome this clinical dilemma. We hypothesized that soluble protein signatures can differentiate PDAC from benign tissues. STUDY DESIGN: Tissues were obtained from resected surgical specimens, lysed, and homogenates collected for analysis with a 41-protein multiplex assay. Analyte concentrations were normalized to total protein. Statistical analysis was performed to evaluate for differences in PDAC vs benign tissue. RESULTS: Tissues were obtained from 159 patients, 82 patients with PDAC naïve to therapy and 77 with benign pancreatic pathology. Fourteen analytes had a receiver operating characteristic curve area of >0.75 for predicting PDAC vs benign tissue. A recursive partitioning model using only 2 analytes, interleukin 1 receptor antagonist and transforming growth factor-α, provided an accuracy, sensitivity, and specificity of 91.2%, 90.2%, and 92.2%, respectively. A penalized logistic regression model found 12 analytes that provide diagnostic value to a protein signature. The mean area under the receiver operating characteristic after 50 tenfold cross-validations was 0.951. Accuracy, sensitivity, and specificity of this model were 91.2%, 87.8%, and 94.8%, respectively. Applying the scenario of 80% disease prevalence in patients undergoing endoscopic ultrasound with fine-needle aspiration for a pancreatic head mass, positive predictive value is 98.5% (95% CI 93.0% to 99.7%) and negative predictive value is 66.0% (95% CI 54.9% to 75.6%). CONCLUSIONS: Protein signatures from pancreatic specimens can differentiate PDAC from benign tissue. Additional work to validate these findings in a unique sample set is warranted.

Three-dimensional visualization of cleared human pancreas cancer reveals that sustained epithelial-to-mesenchymal transition is not required for venous invasion.

Venous invasion is three times more common in pancreatic cancer than it is in other major cancers of the gastrointestinal tract, and venous invasion may explain why pancreatic cancer is so deadly. To characterize the patterns of venous invasion in pancreatic cancer, 52 thick slabs (up to 5 mm) of tissue were harvested from 52 surgically resected human ductal adenocarcinomas, cleared with a modified iDISCO method, and labeled with fluorescent-conjugated antibodies to cytokeratin 19, desmin, CD31, p53 and/or e-cadherin. Labeled three-dimensional (3D) pancreas cancer tissues were visualized with confocal laser scanning or light sheet microscopy. Multiple foci of venous and even arterial invasion were visualized. Venous invasion was detected more often in 3D (88%, 30/34 cases) than in conventional 2D slide evaluation (75%, 25/34 cases, P < 0.001). 3D visualization revealed pancreatic cancer cells crossing the walls of veins at multiple points, often at points where preexisting capillary structures bridge the blood vessels. The neoplastic cells often retained a ductal morphology (cohesive cells forming tubes) as they progressed from a stromal to intravenous location. Although immunolabeling with antibodies to e-cadherin revealed focal loss of expression at the leading edges of the cancers, the neoplastic cells within veins expressed e-cadherin and formed well-oriented glands. We conclude that venous invasion is almost universal in pancreatic cancer, suggesting that even surgically resectable PDAC has access to the venous spaces and thus the ability to disseminate widely. Furthermore, we observe that sustained epithelial-mesenchymal transition is not required for venous invasion in pancreatic cancer.

SPARC expression in desmoplastic and non desmoplastic pancreatic carcinoma and cholangiocarcinoma.

BACKGROUND: The pancreatobiliary carcinomas are characterized by presence of desmoplastic stroma. Overexpression of secreted protein acid and rich in cysteine (SPARC), a matrix producing agent has been documented in pancreatic ductal adenocarcinomas, with survival benefits. This study was targeted to see if SPARC expression in pancreatobiliary carcinomas is responsible for stromal desmoplasia and its prognostic significance. METHODS: In this retrospective study 48 cases of pancreatic cancer and 27 cases of cholangiocarcinoma were analyzed. The expression pattern of SPARC and vascular endothelial growth factor (VEGF) (angiogenic factors) was evaluated by immunohistochemistry on formalin fixed paraffin embedded tissues. Immunoreactivity was scored semi quantitatively based on stain intensity and stain distribution. SPARC expression was correlated with tumor histology, stromal desmoplasia, VEGF expression, various histological parameters and overall survival in patients. Real time polymerase chain reaction was performed in few cases to validate the immunohistochemistry expression pattern. RESULTS: SPARC expression was high in peritumoral stroma in pancreatic carcinoma than in pancreatic controls; however, SPARC expression pattern was not grossly different in desmoplastic and non-desmoplastic pancreatobiliary carcinomas and in cholangiocarcinomas. No definite correlation was noted between SPARC expression and histological markers of severity and overall survival data. CONCLUSIONS: The relevance of SPARC expression in pancreato-biliary carcinomas though may still be important for therapeutic decision making, it is not responsible for peritumoral stromal desmoplasia in these tumors and it does not have any significant prognostic implication.

The usefulness of lymphoid enhancer-binding factor 1 and androgen receptor in diagnosing solid pseudopapillary neoplasm of the pancreas on cytopathology.

BACKGROUND: Solid pseudopapillary neoplasm (SPN) is an uncommon tumor that is challenging to diagnose on cytology due to morphologic overlap with other pancreatic neoplasms. Recently, putative diagnostic markers for SPN have been reported in the surgical pathology literature, with nuclear positivity for lymphoid enhancer-binding factor 1 (LEF1) and androgen receptor (AR) identified in >90% and >80% of cases, respectively. In the current study, the authors sought to evaluate the sensitivity and specificity of LEF1 and AR on SPN cytology specimens and available corresponding surgical resection specimens. METHODS: Immunohistochemistry was performed using monoclonal antibodies against LEF1 and AR on 19 SPN cytology cases and 15 corresponding follow-up surgical resection specimens from 2 institutions. To evaluate specificity, the authors stained 23 non-SPN tumors diagnosed on cytology with corresponding surgical specimens (4 acinar cell carcinomas, 9 pancreatic neuroendocrine tumors, and 10 ductal adenocarcinomas). Positivity for LEF1 and AR was defined as any nuclear staining within neoplastic nuclei. RESULTS: LEF1 was found to be positive in 18 of 19 cytology cases (94.7%) and 15 of 15 corresponding surgical resection specimens (100%). AR was positive in 4 of 16 cytology cases (25.0%) and 4 of 15 corresponding surgical resection specimens (26.7%). Among non-SPN tumors, LEF1 demonstrated a specificity of 87% whereas the specificity for AR was 100%. CONCLUSIONS: LEF1 for SPN on cytology material was found to demonstrate a sensitivity of 94.7% and a specificity of 87%. Although AR was found to have a specificity of 100%, its sensitivity was lower (25%). LEF1 could be a valuable immunostain on cytology cell block material for the diagnosis of SPN. However, the same may not hold true for AR.

Meflin-Positive Cancer-Associated Fibroblasts Inhibit Pancreatic Carcinogenesis.

Cancer-associated fibroblasts (CAF) constitute a major component of the tumor microenvironment. Recent observations in genetically engineered mouse models and clinical studies have suggested that there may exist at least two functionally different populations of CAFs, that is, cancer-promoting CAFs (pCAF) and cancer-restraining CAFs (rCAF). Although various pCAF markers have been identified, the identity of rCAFs remains unknown because of the lack of rCAF-specific marker(s). In this study, we found that Meflin, a glycosylphosphatidylinositol-anchored protein that is a marker of mesenchymal stromal/stem cells and maintains their undifferentiated state, is expressed by pancreatic stellate cells that are a source of CAFs in pancreatic ductal adenocarcinoma (PDAC). In situ hybridization analysis of 71 human PDAC tissues revealed that the infiltration of Meflin-positive CAFs correlated with favorable patient outcome. Consistent herewith, Meflin deficiency led to significant tumor progression with poorly differentiated histology in a PDAC mouse model. Similarly, genetic ablation of Meflin-positive CAFs resulted in poor differentiation of tumors in a syngeneic transplantation model. Conversely, delivery of a Meflin-expressing lentivirus into the tumor stroma or overexpression of Meflin in CAFs suppressed the growth of xenograft tumors. Lineage tracing revealed that Meflin-positive cells gave rise to α-smooth muscle actin-positive CAFs that are positive or negative for Meflin, suggesting a mechanism for generating CAF heterogeneity. Meflin deficiency or low expression resulted in straightened stromal collagen fibers, which represent a signature for aggressive tumors, in mouse or human PDAC tissues, respectively. Together, the data suggest that Meflin is a marker of rCAFs that suppress PDAC progression. SIGNIFICANCE: Meflin marks and functionally contributes to a subset of cancer-associated fibroblasts that exert antitumoral effects.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/20/5367/F1.large.jpg.

The insulin-like growth factor binding protein-3 and its death receptor in pancreatic ductal adenocarcinoma poor prognosis.

Insulin-like growth factor binding protein-3 (IGFBP-3) and its newly discovered death receptor (IGFBP-3R) have been reported to involve in a wide variety of cancers. However, their role in pancreatic ductal adenocarcinoma (PDAC) has not been elucidated yet. Here, 478 pancreatic cancers were screened for primary PDAC tumors. The samples were evaluated using quantitative reverse-transcriptase polymerase chain reaction, western blotting, and immunohistochemistry staining. The results indicated that relative IGFBP-3 mRNA expression and its protein level were reduced stage dependently in the PDAC tumors (p < .001 and p < .05, respectively). The subcellular distribution of IGFBP-3 was mainly nuclear only in Stage 0 + 1 (about 150% compared to adjacent normal tissues [p < .05]). The value for IGFBP-3R messenger RNA (mRNA) and protein were also reduced in tumors in compared to adjacent normal pancreatic tissues (p < .05). The Kaplan-Meier analysis also showed that mRNA expression of IGFBP-3 and IGFBP-3R was positively associated with survival, (p = .001). In addition, there is a strong association between low expression of IGFBP-3 and tumor size (p = .032), the lymphatic invasion (p = .001), the TNM (tumor, node, metastasis) staging (p = .001), tumor differentiation (p = .001), and PNI status (p = .021). Down-regulation of IGFBP-3R was also correlated with the tumor size (p = .01), the lymphatic invasion (p = .012) TNM staging (p = .001), tumor differentiation (p = .021) and PNI status (p = .038). In conclusion, IGFBP-3 and its receptor were down-regulated and their expression was associated with poor prognosis of PDAC.

CD73 expression in normal and pathological human hepatobiliopancreatic tissues.

BACKGROUND: The tumor-expressed CD73 ectonucleotidase generates immune tolerance and promotes invasiveness via adenosine production from degradation of AMP. While anti-CD73 blockade treatment is a promising tool in cancer immunotherapy, a characterization of CD73 expression in human hepatobiliopancreatic system is lacking. PATIENTS AND METHODS: CD73 expression was investigated by immunohistochemistry in a variety of non-neoplastic and neoplastic conditions of the liver, pancreas, and biliary tract. RESULTS: CD73 was expressed in normal hepatobiliopancreatic tissues with subcellular-specific patterns of staining: canalicular in hepatocytes, and apical in cholangiocytes and pancreatic ducts. CD73 was present in all hepatocellular carcinoma (HCC), in all pancreatic ductal adenocarcinoma (PDAC), and in the majority of intra and extrahepatic cholangiocellular carcinomas, whereas it was detected only in a subset of pancreatic neuroendocrine neoplasms and almost absent in acinar cell carcinoma. In addition to the canonical pattern of staining, an aberrant membranous and/or cytoplasmic expression was observed in invasive lesions, especially in HCC and PDAC. These two entities were also characterized by a higher extent and intensity of staining as compared to other hepatobiliopancreatic neoplasms. In PDAC, aberrant CD73 expression was inversely correlated with differentiation (p < 0.01) and was helpful to identify isolated discohesive tumor cells. In addition, increased CD73 expression was associated with reduced overall survival (HR 1.013) and loss of E-Cadherin. CONCLUSIONS: Consistent CD73 expression supports the rationale for testing anti-CD73 therapies in patients with hepatobiliopancreatic malignancies. Specific patterns of expression could also be of help in the routine diagnostic workup.

Pancreatic cancer arising in the remnant pancreas is not always a relapse of the preceding primary.

This study aimed to understand the biology of pancreatic ductal adenocarcinoma that arises in the remnant pancreas after surgical resection of a primary pancreatic ductal adenocarcinoma, using integrated histological and molecular analysis. Patients who underwent a completion pancreatectomy for local recurrence following resection of a primary pancreatic ductal adenocarcinoma were studied with histological analysis and next-generation sequencing of the primary and the recurrent cancer. Of six patients that met the inclusion criteria, three cases were classified as "true" recurrences, i.e., the primary and the cancer in the remnant pancreas shared both morphological features and molecular alterations. Two cases were identified as having independent cancers that exhibited different histological and molecular profiles. In the remaining case, the relationship could not be determined. Pancreatic ductal adenocarcinoma that arises in the remnant pancreas can be either a second primary or a "true" relapse of the preceding primary. The differentiation of second primaries from local recurrences may have important implications for patient management.

Plasminogen Activator Inhibitor 1 as a Poor Prognostic Indicator in Resectable Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Plasminogen activator inhibitor 1 (PAI-1) was previously established to impact several phenotypes in many kinds of cancer, including pancreatic cancer. However, its prognostic significance in pancreatic ductal adenocarcinoma (PDAC) needs support of further evidence. This study was designed to address the issue. METHODS: PAI-1 expression was detected by tissue microarray-based immunohistochemical staining in formalin-fixed paraffin-embedded specimens from 93 PDAC patients with surgical resection from September 2004 to December 2008. Its relationships with clinicopathologic variables and tumor-specific survival (TSS) were further evaluated using Chi-square, Kaplan-Meier, log-rank, as well as Cox regression analyses. RESULTS: Expression of PAI-1 was much higher in tumor than that in nontumor tissues, based on comparison of all samples and 74 matched ones (95 [47.5, 180] vs. 80 [45, 95], Z = -2.439, P = 0.015 and 100 [46.9, 182.5] vs. 80 [45, 95], Z = -2.594, P = 0.009, respectively). In addition, tumoral PAI-1 expression was positively associated with N stage (22/35 for N1 vs. 21/51 for N0, χ2 = 3.903, P = 0.048). Univariate analyses showed that TSS of patients with high PAI-1 tumors was significantly poorer than that of those with low PAI-1 tumors (log rank value = 19.00, P < 0.0001). In multivariate Cox regression test, PAI-1 expression was identified as an independent predictor for long-term prognosis of resectable PDAC (hazard ratio = 2.559, 95% confidence interval = 1.499-4.367, P = 0.001). CONCLUSION: These results suggest that expression of PAI-1 is upregulated in PDAC and might serve as a poor prognostic indicator.