Epigenetics of epithelial-to-mesenchymal transition in pancreatic carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignant diseases with late diagnosis, rapid progression, high invasiveness, and early metastasis. Epithelial-to-mesenchymal transition (EMT) is a crucial step in metastasis that enables polarized immotile epithelial cells to gain fibroblast-like mesenchymal abilities such as enhanced motility. The dynamic process of EMT in PDAC with its powerful influence on disease progression and especially metastasis is of vigorous interest in biomedical research to elucidate its signaling pathways and regulation mechanisms. It is evident that epigenetics such as histone and DNA modification or noncoding RNAs such as microRNAs and long noncoding RNAs are of high importance in initiation and progress of EMT in PDAC. This review analyzes the latest research dealing with EMT and its epigenetic regulation in PDAC and summarizes its potentials in diagnostic, prognostic, and therapeutic management.

Successful closure of defects in the upper gastrointestinal tract by endoscopic vacuum therapy (EVT): a prospective cohort study.

BACKGROUND: Perforations and anastomotic leakages of the upper gastrointestinal (GI) tract cause a high morbidity and mortality rate. Only limited data exist for endoscopic vacuum therapy (EVT) in the upper GI tract. METHODS: Fifty-two patients (37 men and 15 women, ages 41-94 years) were treated (12/2011-12/2015) with EVT for anastomotic insufficiency secondary to esophagectomy or gastrectomy (n = 39), iatrogenic esophageal perforation (n = 9) and Boerhaave syndrome (n = 4). After diagnosis, polyurethane sponges were endoscopically positioned with a total of 390 interventions and continuous negative pressure of 125 mm of mercury (mmHg) was applied to the EVT-system. Sponges were changed endoscopically twice per week. Clinical and therapy-related data and mortality were analyzed. RESULTS: After 1-25 changes of the sponge at intervals of 3-5 days with a mean of 6 sponge changes and a mean duration of therapy of 22 days, the defects were healed in 94.2 % of all patients without revision surgery. In three patients (6 %), EVT failed. Two of these patients died due to hemorrhage related to EVT. Four postinterventional strictures were observed during the follow-up of up to 4 years. CONCLUSION: Esophageal wall defects of different etiology in the upper gastrointestinal tract can be treated successfully with EVT, considering that indication for EVT should be weighed carefully. EVT can be regarded as a novel life-saving therapeutic tool.

The microRNA-200 family--a potential diagnostic marker in hepatocellular carcinoma?

BACKGROUND: Hepatocellular carcinoma (HCC) represents the main cause of death among patients with cirrhotic liver disease, but little is known about mechanisms of cirrhosis associated carcinogenesis. We investigated the diagnostic impact of microRNA-200 (miR-200) family members as important epigenetic regulators of epithelial-mesenchymal transition (EMT) to differentiate between patients with HCC and liver cirrhosis. METHODS: Expression of the miR-200 family was investigated by qRT-PCR in specimens of HCC patients with and without cirrhosis. Benign specimens with and without cirrhosis served as controls. Expression of the EMT markers ZEB-1, E-cadherin and vimentin was examined using immunohistochemistry. RESULTS: MiR-200a and miR-200b were significantly downregulated in HCC (miR-200a: -40.1% (P = 0.0002); miR-200b: -52.3% (P = 0.0002)), and in HCC cirrhotic tissue (miR-200a: -40.2% (P = 0.004); miR-200b: -51.1% (P = 0.007)) compared to liver cirrhosis. Spearman's Rho analysis revealed a significant negative correlation of miR-200a and miR-200b to the expression of the mesenchymal markers Vimentin (P < 0.007) and ZEB-1 (P < 0.0005) and a significant positive correlation to the epithelial marker E-cadherin (P < 0.0002). CONCLUSIONS: MiR-200 family members and their targets are significantly deregulated in HCC and liver cirrhosis. The miR-200 family is able to distinguish between cirrhotic and HCC tissue and could serve as an early marker for cirrhosis-associated HCC.

Long-Term Quality of Life after COVID-19 Infection: Cross-Sectional Study of Health Care Workers.

(1) Background: Post-COVID syndrome is defined as symptoms that occur simultaneously with or after a COVID-19 infection, last for 12 weeks, and are not due to another diagnosis. Limited data are available on people's long-term quality of life following a COVID-19 infection. The aim of this cross-sectional study was to investigate the long-term quality of life after COVID-19 among employees of a hospital in Germany and to identify risk factors. (2) Methods: A monocentric, cross-sectional study was conducted using the validated and digitized WHOQOL-BREF questionnaire via Netigate® between 10/2022 and 02/2023. Data on the quality of life and global health status were collected in the following four domains: physical health, mental health, social relationships, and the environment. (3) Results: The response rate was 73.8 % (923/1250). Furthermore, 63.4 % of the hospital staff respondents reported at least one persistent symptom after a COVID-19 infection, leading to significant differences in quality of life. Pre-existing conditions, persistent symptoms, and disabilities after a COVID-19 infection as well as a high BMI, no partnership, and a low educational level were found to significantly contribute to a low long-term quality of life. (4) Conclusions: Obesity, a lack of partnership, and a low level of education were independent risk factors for a lower quality of life post-COVID-19 infection in this cohort of hospital staff. Further multicenter studies are required to validate the incidence and their suitability as independent risk factors for post-COVID syndrome.

Pancreatoduodenectomy--current status of surgical and perioperative techniques in Germany.

BACKGROUND: Pancreatoduodenectomy in Germany is performed by a broad range of hospitals. A diversity of operative techniques is employed as no guidelines exist for intra- and perioperative management. We carried out a national survey to determine the de facto German standards for pancreatoduodenectomy, assess quality assurance measures, and identify relevant issues for further investigation. METHODS: A questionnaire evaluating major outcome variables, case load, preferred surgical procedures, and perioperative management during pancreatoduodenectomy was developed and sent to 211 German hospitals performing >12 pancreatoduodenectomies per year (requirement for certification as a pancreas center). Statistical analysis was carried out using the Fisher Exact, Mann-Whitney U, and Spearman tests. RESULTS: The final response rate was 86 % (182/211). The preferred technique and de facto German standard for pancreatoduodenectomy was pylorus-preserving pancreatoduodenectomy with pancreatojejunostomy carried out via duct-to-mucosa anastomosis with interrupted sutures using PDS 4.0. The minority of German pancreas centers were certified (18-48 %). The certification rate increased with higher capacity levels and case load (P < 0.05); however, significant correlations between the fistula rate and hospital case load, hospital capacity level, or hospital certification status were not seen. CONCLUSION: This study revealed a distinct variety of management strategies for pancreatic surgery and available evidence-based data was not necessarily translated into clinical practice. The limited certification rate represented a shortcoming of quality assurance. The data emphasize the need for further trials to answer the questions whether hospital certifications and omission of drains improve outcome after pancreatoduodenectomy and for the establishment of guidelines for pancreatoduodenectomy.

Epigenetic markers for chemosensitivity and chemoresistance in pancreatic cancer--a review.

Adjuvant first-line gemcitabine monochemotherapy presents a standard treatment for patients with advanced pancreatic adenocarcinoma and improves overall survival in chemosensitive patients. Nonetheless, 6-month progression-free survival remains below 15%, despite interdisciplinary approaches. The success of gemcitabine treatment is disappointing and-in the absence of reliable tumor markers--challenging to quantify. Epigenetic alterations have been recently identified to take on important roles in cancer development and possibly cancer treatment. In this context, microRNAs are becoming increasingly acknowledged as useful biomarkers for classifying cancers and providing information on their chemo- and radiosensitivity. This review illustrates the potential of genetic and epigenetic markers in the prediction of chemosensitivity in pancreatic cancer patients and in the monitoring of their response rates to adjuvant therapy.

Small extracellular vesicle non-coding RNAs in pancreatic cancer: molecular mechanisms and clinical implications.

Pancreatic cancer has the worst prognosis among common tumors which is attributed to its aggressive phenotype, diagnosis at advanced, inoperable stages, and resistance to systemic therapy. Non-coding RNAs (ncRNAs) such as microRNAs, long non-coding RNAs, and circular RNAs have been established as important regulators of gene expression and their deregulation has been implicated in multiple diseases and foremost cancer. In the tumor microenvironment, non-coding RNAs can be distributed among cancer cells, stromal cells, and immune cells via small extracellular vesicles (sEVs), thereby facilitating intercellular communication and influencing major cancer hallmarks such as angiogenesis, evasion of the immune system, and metastatic dissemination. Furthermore, sEV-ncRNAs have shown promising potential as liquid biopsies with diagnostic and prognostic significance. In this review, we summarize the role of sEVs as carriers of ncRNAs and underlying molecular mechanisms in pancreatic cancer. Moreover, we review the potential of sEV-ncRNAs as biomarkers and highlight the suitability of sEVs as delivery vehicles for ncRNA-based cancer therapy.

Postoperative pancreatic fistula affects recurrence-free survival of pancreatic cancer patients.

PURPOSE: Postoperative pancreatic fistula (POPF) with reported incidence rates up to 45% contributes substantially to overall morbidity. In this study, we conducted a retrospective evaluation of POPF along with its potential perioperative clinical risk factors and its effect on tumor recurrence. METHODS: Clinical data on patients who had received pancreatoduodenectomy (PD), distal pancreatectomy (DP), or duodenum-preserving pancreatic head resection (DPPHR) were prospectively collected between 2007 and 2016. A Picrosirius red staining score was developed to enable morphological classification of the resection margin of the pancreatic stump. The primary end point was the development of major complications. The secondary end points were overall and recurrence-free survival. RESULTS: 340 patients underwent pancreatic resection including 222 (65.3%) PD, 87 (25.6%) DP, and 31 (9.1%) DPPHR. Postoperative major complications were observed in 74 patients (21.8%). In multivariable logistic regression analysis, POPF correlated with body mass index (BMI) (p = 0.025), prolonged stay in hospital (p<0.001), high Picrosirius red staining score (p = 0.049), and elevated postoperative levels of amylase or lipase in drain fluid (p≤0.001). Multivariable Cox regression analysis identified UICC stage (p<0.001), tumor differentiation (p<0.001), depth of invasion (p = 0.001), nodal invasion (p = 0.001), and the incidence of POPF grades B and C (p = 0.006) as independent prognostic markers of recurrence-free survival. CONCLUSION: Besides the known clinicopathological risk factors BMI and amylase in the drain fluid, the incidence of POPF correlates with high Picrosirius red staining score in the resection margins of the pancreatic stumps of curatively resected pancreatic ductal adenocarcinoma (PDAC). Furthermore, clinically relevant POPF seems to be a prognostic factor for tumor recurrence in PDAC.

Impact of circulating tumor DNA in hepatocellular and pancreatic carcinomas.

Hepatocellular carcinoma (HCC) and pancreatic cancer (PC) belong to the most lethal malignancies worldwide. Despite advances in surgical techniques and perioperative multidisciplinary management, the prognosis of both carcinoma entities remains poor mainly because of rapid tumor progression and early dissemination with diagnosis in advanced tumor stages with poor sensitivity to current therapy regimens. Both highly heterogeneous visceral carcinomas exhibit unique somatic alterations, but share common driver genes and mutations as well. Recently, circulating tumor DNA (ctDNA) could be identified as a liquid biopsy tool with huge potential as non-invasive biomarker in early diagnosis and prognosis. CtDNA released from necrotic or apoptotic cells of primary tumors, metastasis, and circulating tumor cells can reveal genetic and epigenetic alterations with tumor-specific and individual mutation and methylation profiles. In this article, we focus on clinical impact of ctDNA as potential biomarker in patients with HCC and PC.

Potential of Exosomal microRNA-200b as Liquid Biopsy Marker in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor entity, characterized by rapid disease progression, early metastatic dissemination, and late diagnosis at advanced tumor stages. Recently, we explored the clinical impact of several microRNAs (miR) associated with proliferation, epithelial-to-mesenchymal transition (EMT), and chemoresistance in tissue and blood serum specimens of PDAC patients. Here, we evaluated the potential of these miRs as diagnostic and prognostic biomarkers in PDAC in serum exosomes and their respective EpCAM-positive (epithelial cell adhesion molecule) subset. Expression analysis by RT-qRT-PCR (real-time quantitative reverse transcription polymerase chain reaction) revealed an overexpression of miR-200b and miR-200c in serum exosomes of PDAC patients as compared to healthy controls (p < 0.001; p = 0.024) and patients with chronic pancreatitis (p = 0.005; p = 0.19). Receiver operating characteristic (ROC) curve analysis showed that a biomarker panel consisting of miR-200b and miR-200c from total and EpCAM-positive serum exosomes enhanced the diagnostic accuracy of carbohydrate antigen 19-9 (CA.19-9) to 97% (p < 0.0001). Univariate survival analysis revealed a correlation between shorter overall survival (OS) and high expression of miR-200c in total serum exosomes (p = 0.038) and miR-200b in EpCAM-positive serum exosomes (p = 0.032), whereas EpCAM exosomal miR-200b was also indicative of shorter OS in the subgroup of patients treated with curative intent (p = 0.013). Multivariate survival analysis showed that miR-200b derived from EpCAM-positive serum exosomes might serve as an independent prognostic factor in PDAC (p = 0.044). Our findings indicate a potential role of exosomal miR-200 as diagnostic and prognostic liquid biopsy marker in PDAC and call for validation in a larger, multicenter setting.

Tumor-Suppressive miR-192-5p Has Prognostic Value in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by fast tumor progression and diagnosis at advanced, inoperable stages. Previous studies could demonstrate an involvement of miR-192-5p in epigenetic regulation of visceral carcinomas. Due to contradictory results, however, the clinical utility of miR-192-5p in PDAC has yet to be determined. MiR-192-5p expression was analyzed by RT-qRT-PCR in human PDAC and benign tissue (n = 78), blood serum (n = 81) and serum exosomes (n = 74), as well as in PDAC cell lines (n = 5), chemoresistant cell clones (n = 2), and pancreatic duct cell line H6c7. Analysis of EMT-associated (epithelial-to-mesenchymal transition) proteins was performed by immunohistochemistry and Western blot. MiR-192-5p was deregulated in PDAC as compared to healthy controls (HCs), with downregulation in macrodissected tissue (p < 0.001) and upregulation in blood serum of PDAC UICC (Union for International Cancer Control) stage IV (p = 0.016) and serum exosomes of PDAC UICC stages II to IV (p < 0.001). MiR-192-5p expression in tumor tissue was significantly lower as compared to corresponding peritumoral tissue (PDAC UICC stage II: p < 0.001; PDAC UICC stage III: p = 0.024), while EMT markers ZEB1 and ZEB2 were more frequently expressed in tumor tissue as compared to peritumoral tissue, HCs, and chronic pancreatitis. Tissue-derived (AUC of 0.86; p < 0.0001) and exosomal (AUC of 0.83; p = 0.0004) miR-192-5p could differentiate between PDAC and HCs with good accuracy. Furthermore, high expression of miR-192-5p in PDAC tissue of curatively resected PDAC patients correlated with prolonged overall and recurrence-free survival in multivariate analysis. In vitro, miR-192-5p was downregulated in gemcitabine-resistant cell clones of AsPC-1 (p = 0.029). Transient transfection of MIA PaCa-2 cells with miR-192-5p mimic resulted in downregulation of ZEB2. MiR-192-5p seems to possess a tumor-suppressive role and high potential as a diagnostic and prognostic marker in PDAC.

Clinical impact of circulating LAPTM4B-35 in pancreatic ductal adenocarcinoma.

PURPOSE: LAPTM4B is upregulated in a wide range of cancers associated with poor prognosis. However, the clinical impact of LAPTM4B as diagnostic and prognostic marker in pancreatic ductal adenocarcinoma (PDAC) remains unknown. Thus, the aim of the present study was to investigate the expression of LAPTM4B as circulating marker in PDAC. METHODS: Expression analysis of LAPTM4B-35 in pancreatic tissue and preoperative blood serum samples of 169 patients with PDAC UICC Stages I-IV (n = 98), chronic pancreatitis (n = 41), and healthy controls (n = 30) by immunohistochemistry, Western blot, and ELISA. Descriptive and explorative statistical analyses of LAPTM4B-35's potential as diagnostic and prognostic marker in PDAC. RESULTS: Expression of LAPTM4B-35 was significantly increased in tumor tissue and corresponding blood serum samples of patients with PDAC (each p < 0.001) and it could well discriminate PDAC from healthy controls and chronic pancreatitis (p < 0.001; p = 0.0037). LAPTM4B-35 in combination with CA.19-9 outperforms the diagnostic accuracy with an AUC of 0.903 (p < 0.001), sensitivity of 82%, and specificity of 92%. Kaplan-Meier survival analysis revealed an improved overall survival in PDAC UICC I-IV with low expression of circulating LAPTM4B-35 (17 versus 10 months, p = 0.039) as well as an improved relapse-free survival in curatively treated PDAC UICC I-III (16 versus 10 months; p = 0.037). Multivariate overall and recurrence-free survival analyses identified LAPTM4B-35 as favorable prognostic factor in PDAC patients (HR 2.73, p = 0.021; HR 3.29, p = 0.003). CONCLUSION: LAPTM4B-35 is significantly deregulated in PDAC with high diagnostic and prognostic impact as circulating tumor marker.

Long-Term Quality of Life Assessment After Successful Endoscopic Vacuum Therapy of Defects in the Upper Gastrointestinal Tract Quality of Life After EVT.

BACKGROUND: Accumulating evidence indicates that anastomotic leakages and perforations of the upper gastrointestinal tract (uGIT) can be treated successfully with endoscopic vacuum therapy (EVT). So far, no data is available regarding the long-term quality of life (QoL) after successful EVT of defects in the uGIT. METHODS: We present a prospective survey on long-term Qol of 52 patients treated by EVT for defects of the uGIT. Results are compared with 63 of 221 patients treated by esophagectomy without anastomotic insufficiency (w/o EVT) between 12/2011 and 12/2015. The Gastrointestinal Quality of Life-Index (GIQLI) score was determined by a 36-item questionnaire of 25 respondents with EVT and 50 respondents w/o EVT. RESULTS: The response rate was 78.95% (75/95) including 25 survey respondents who were treated with EVT for anastomotic insufficiency secondary to esophagectomy or gastrectomy (n = 19), iatrogenic esophageal perforation (n = 4), and Boerhaave syndrome (n = 2) and 50 respondents with complication-free esophagectomy w/o EVT. The median follow-up was 19 months for EVT patients and 21 months for patients w/o EVT. Except for "social function" (p = 0.009) in favor for patients w/o EVT, the median GIQLI score did not differ significantly between both study groups concerning the categories 'symptoms', 'emotions', 'physical functions', and 'medical treatment' resulting in a total median GIQLI score of 83 in EVT versus 96.5 in patients w/o EVT (p = 0.185). Spearman Rho analysis revealed that a high GIQLI score correlated with a low ASA score (p < 0.001), a benign pathology (p = 0.001), and a hospital stay less than 21 days (p < 0.001). CONCLUSION: EVT in the uGIT is well tolerated by the patients and accompanied by a satisfactory long-term QoL.

The ambiguous role of microRNA-205 and its clinical potential in pancreatic ductal adenocarcinoma.

PURPOSE: Early treatment of pancreatic ductal adenocarcinoma (PDAC) is significantly delayed due to the lack of liquid biopsy markers for early diagnosis at surgically resectable tumor stages. Recent studies suggest that microRNA-205 (miR-205) is involved in PDAC progression by post-transcriptional regulation of epithelial-to-mesenchymal transition (EMT). However, the clinical potential of miR-205 as diagnostic and prognostic marker remains undefined and its exact role in PDAC is still ambiguous. This retrospective study is a substantial contribution to this on-going scientific discussion. METHODS: Expression analysis of miR-205 and its molecular targets in PDAC cell lines (n = 5), human tissue (n = 73), and blood serum samples (n = 85) by qRT-PCR, tissue microarray immunohistochemistry, and western blot. Descriptive and explorative statistical analysis of miR-205's clinical potential for diagnosis and prognosis of PDAC. RESULTS: The expression of miR-205 differs more than 2000-fold (p < 0.001) between epithelial and mesenchymal-like human PDAC cell lines correlating with EMT-marker expression of E-cadherin, vimentin, fibronectin, and ZEB-1. Expression of miR-205 is significantly upregulated in carcinoma tissue (eightfold, p = 0.028) and serum (2.3-fold, p = 0.023) of PDAC patients compared to age-matched healthy controls. In our patient collective circulating miR-205 in combination with CA.19-9 outperforms the diagnostic accuracy of CA.19-9 alone with an AUC of 0.890 (p < 0.001), sensitivity of 0.867, and specificity of 0.933. Though non-significant, low expression of circulating miR-205 is more frequent in advanced tumor stages combined with a worse overall survival (6.9 vs. 11.9 months, p = 0.176). CONCLUSION: Besides its controversial role in carcinogenesis, miR-205 shows high potential as a solid and liquid biopsy marker in PDAC. This result is an urgent call for larger confirmatory multi-center studies.

Circulating microRNA-99 family as liquid biopsy marker in pancreatic adenocarcinoma.

PURPOSE: Recently, we identified the microRNA-99 family as unfavorable prognostic factor in patients with pancreatic ductal adenocarcinoma (PDAC). The aim of this study is to evaluate its value as circulating biomarker for PDAC. METHODS: Tissue and corresponding preoperative blood samples of 181 patients with PDAC UICC Stages I-IV (n = 90), intraductal papillary mucinous neoplasm (IPMN, n = 11), chronic pancreatitis (n = 40), pancreatic cystadenoma (n = 20), and age-matched healthy blood serum controls (n = 20) were collected between 2014 and 2017 prospectively. Expression of microRNA-21 as confirmatory marker and the microRNA-99 family, consisting of microRNA-99a, -99b, and -100, was analyzed by qRT-PCR. Target analysis of insulin-like growth factor 1 receptor (IGF1R) was performed using tissue array immunohistochemistry and Western blotting. RESULTS: Expression of microRNA-99 family members was significantly increased in macrodissected tumor tissue and corresponding blood serum samples (p < 0.05) of patients with PDAC of all stages. Correspondingly, its target protein IGF1R was upregulated (p < 0.001) in carcinoma tissue. Circulating and tissue-related microRNA-100 could well discriminate PDAC from healthy samples with area under the receiver operating characteristic (ROC) curve (AUC) values of 0.81 and 0.85, respectively. Low expression of circulating microRNA-100 was associated with significantly improved overall survival (p = 0.004) and recurrence-free survival (p = 0.03) in multivariate analyses. Circulating microRNA-21 was overexpressed in PDAC with fair discrimination between PDAC and healthy controls (AUC = 0.71) and decreased overall survival (p = 0.046) and recurrence-free survival (p = 0.03) in PDAC patients. CONCLUSIONS: Multivariate survival and ROC analyses identified circulating microRNA-100 as potential diagnostic and prognostic marker in PDAC patients.

Clinical Impact of Epithelial-to-Mesenchymal Transition Regulating MicroRNAs in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive carcinoma entities worldwide with early and rapid dissemination. Recently, we discussed the role of microRNAs as epigenetic regulators of Epithelial-to-Mesenchymal Transition (EMT) in PDAC. In this study, we investigated their value as diagnostic and prognostic markers in tissue and blood samples of 185 patients including PDAC, non-malignant pancreatic disorders, and age-matched healthy controls. Expression of the microRNA-200-family (microRNAs -141, -200a, -200b, -200c, -429) and microRNA-148a was significantly downregulated in tissue of PDAC Union internationale contre le cancer (UICC) Stage II. Correspondingly, stromal PDAC tissue showed strong expression of Fibronectin, Vimentin, and ZEB-1 (Zinc finger E-box-binding homeobox) versus low expression of E-cadherin. Transient transfection of microRNA-200b and microRNA-200c mimics resulted in the downregulation of their key target ZEB-1. Inversely, blood serum analyses of patients with PDAC UICC Stages II, III, and IV showed a significant over-expression of microRNA-200-family members, microRNA-148a, microRNA-10b, and microRNA-34a. Correspondingly, Enzyme-linked Immunosorbent Assay (ELISA) analyses revealed a significant over-expression of soluble E-cadherin in serum samples of PDAC patients versus healthy controls. The best diagnostic accuracy to distinguish between PDAC and non-PDAC in this patient collective could be achieved in tissue by microRNA-148a with an area under the receiver-operating-characteristic (ROC) curve (AUC) of 0.885 and in blood serum by a panel of microRNA-141, -200b, -200c, and CA.19-9 with an AUC of 0.890. Both diagnostic tools outreach the diagnostic performance of the currently most common diagnostic biomarker CA.19-9 (AUC of 0.834). Kaplan Meier survival analysis of this patient collective revealed an improved overall survival in PDAC patients with high expression of tissue-related microRNA-34a, -141, -200b, -200c, and -429. In conclusion, EMT-regulating microRNAs have great potential as liquid and solid biopsy markers in PDAC patients. Their prognostic and therapeutic benefits remain important tasks for future studies.

The Interaction between Laminin-332 and α3ß1 Integrin Determines Differentiation and Maintenance of CAFs, and Supports Invasion of Pancreatic Duct Adenocarcinoma Cells.

Ranking among the most lethal tumour entities, pancreatic duct adenocarcinoma cells invade neighbouring tissue resulting in high incidence of metastasis. They are supported by tumour stroma fibroblasts which have undergone differentiation into cancer-associated fibroblasts (CAFs). Stiffness of cell substratum, cytokines, such as transforming growth factor-ß (TGF-ß), and stromal matrix proteins, such as laminin-332, are factors which promote CAF differentiation. In a spheroid culture system, differentiation of CAFs was analysed for laminin-332 production, laminin-binding integrin repertoire, adhesion and migration behaviour, and, in heterospheroids, for their interplay with the pancreatic duct adenocarcinoma AsPC-I cells. Our data reveal that CAFs produce laminin-332 thus contributing to its ectopic deposition within the tumour stroma. Moreover, CAF differentiation correlates with an increased expression of α3ß1 integrin, the principal laminin-332-receptor. Beyond its role as novel CAF marker protein, integrin α3ß1 crucially determines differentiation and maintenance of the CAF phenotype, as knock-out of the integrin α3 subunit reversed the CAF differentiated state. AsPC-I cells co-cultured in heterospheroids with integrin α3-deficient CAFs invaded less than from heterospheroids with wild-type CAFs. This study highlights the role of integrin α3ß1 integrin-laminin-332 interaction of CAFs which promotes and sustains differentiation of CAFs and promotes carcinoma invasion.