Notch Signaling Pathway in Pancreatobiliary Tumors.

Background and objectives: The Notch signaling pathway plays an important role both in the development of the ductal systems of the pancreas and the bile ducts as well as in cancer development and progression. The aim of this study was to examine the expression of central proteins of the Notch signaling pathway in pancreatobiliary tumors and its influence on patient survival. Materials and Methods: We compared the receptors (Notch1, Notch4), activating splicing factors (ADAM17), and target genes (HES1) of the Notch pathway and progenitor cell markers with relevance for the Notch signaling pathway (CD44, MSI1) between pancreatic adenocarcinomas (PDAC, n = 14), intrahepatic cholangiocarcinoma (iCC, n = 24), and extrahepatic cholangiocarcinoma (eCC, n = 22) cholangiocarcinomas via immunohistochemistry and ImageJ software-assisted analysis. An Immunohistochemistry (IHC)-score was determined by the percentage and intensity of stained (positive) cells (scale 0-7) and normal and malignant tissue was compared. In the IHC results, patients' (gender, age) and tumor (TNM Classification of Malignant Tumors, Union Internationale contre le Cancer (UICC) stages, grading, and lymphangitic carcinomatosa) characteristics were correlated to patient survival. Results: For eCC, the expression of CD44 (p = 0.043, IHC-score 3.94 vs. 3.54) and for iCC, the expression of CD44 (p = 0.026, IHC-score 4.04 vs. 3.48) and Notch1 (p < 0.001, IHC-score 2.87 vs. 1.78) was significantly higher in the tumor compared to non-malignant tissue. For PDAC, the expression of ADAM17 (p = 0.008, IHC-score 3.43 vs. 1.73), CD44 (p = 0.012, IHC-score 3.64 vs. 2.27), Notch1 (p = 0.012, IHC-score 2.21 vs. 0.64), and Notch4 (p = 0.008, IHC-score 2.86 vs. 0.91) was significantly higher in the tumor tissue. However, none of the analyzed Notch-signaling related components showed an association to patient survival. Conclusion: A significant overexpression of almost all studied components of the Notch signaling pathway can be found in the tumor tissue, however, without a significant influence on patient survival. Therefore, further studies are warranted to draw conclusions on Notch pathway's relevance for patient survival.

Tissue-based miRNA mapping in alcoholic liver cirrhosis: different profiles in cirrhosis with or without hepatocellular carcinoma.

Context: Alcoholic liver cirrhosis is a significant risk factor for the development of hepatocellular carcinoma (HCC). The importance of tumour-associated cirrhosis in the development or progression of HCC is not understood. MiRNAs are important regulators for HCC development, but their role in HCC due to alcoholic liver cirrhosis is unclear.Objective: The aim of this study is the detection of miRNA expression in alcoholic liver cirrhosis, tumour-associated cirrhosis, and HCC.Materials and methods: We analysed the differences in the miRNA profiles of HCC, tumour-associated cirrhosis, and cirrhosis without HCC samples from 30 patients who underwent liver transplantation because of alcoholic liver disease.Results: Microarray analyses revealed 40 significantly differentially expressed miRNAs between HCC tissue and tumour-associated cirrhosis tissue. Furthermore, the microarray analysis discovered 56 differentially expressed miRNAs in tumour-associated cirrhosis and cirrhosis without HCC.Discussion: The differences of miRNA profile in alcoholic liver cirrhosis with and without HCC could improve understanding of HCC development, as well as lead to a new diagnostic tool in HCC screening.Conclusion: We were able to show for the first time, the differences of miRNA profile as promising biomarker in HCC, tumour-associated cirrhosis, and cirrhosis without HCC in context of alcoholic liver disease.

Gender comparison of clinical, histopathological, therapeutic and outcome factors in 185,967 colon cancer patients.

INTRODUCTION: Colorectal carcinomas represent the third most common cause of cancer-related deaths in Germany. Although the incidence is significantly higher in men compared with women and gender is a well-established crucial factor for outcome in other diseases, detailed gender comparisons for colon cancer are lacking. METHODS: This retrospective population-based cohort study included all patients diagnosed with colon cancer in Germany between 2000 and 2016 who were included in the common dataset of colorectal cancer patients from the quality conference of the German Cancer Society. We compared clinical, histopathological, and therapeutic characteristics as well as overall and recurrence-free survival. RESULTS: A total of 185,967 patients were included in the study, of which 85,685 were female (46.1%) and 100,282 were male (53.9%). The proportion of women diagnosed with colon cancer decreased from 2000 to 2016 (f: 26.6 to 40.1%; m: 24.9 to 41.9%; p < 0.001), and the proportion of very old patients was especially high in women (f: 27.3%; m: 15.6%; p < 0.001). The localization in women was more right-sided (f: 45.0%, m: 36.7%; p < 0.001), and women had a higher tumor grading and a higher UICC stage (especially stage III nodal-positive) at diagnosis of primary colon cancer (UICC III: f: 22.7%, m: 21.0%; p < 0.001). We could detect a significantly better overall (hazard ratio: 0.853, lower 95%: 0.841, upper 95%: 0.864; p < 0.001) and recurrence-free survival (hazard ratio: 0.857, lower 95%: 0.845, upper 95%: 0.868; p < 0.001) in women compared with men, even though women received chemotherapy less frequently compared with men (f: 26.1%, m: 28.1%; p < 0.001). CONCLUSION: We could detect several variables that differed significantly between men and women regarding clinical, histopathological, therapeutic, and outcome factors. We believe that it is crucial to consider gender as a key factor in the diagnosis and treatment of colon cancer. Sex-specific diagnostic tools could lead to an earlier diagnosis of colon cancer in women, and ways to increase the rate of chemotherapy in women should be evaluated. Furthermore, we recommend stratifying randomized trials by gender.

The value of microparticles in detecting acute rejection episodes after liver transplantation.

CONTEXT: Non-invasive markers for diagnosis of acute rejection (AR) following liver transplantation have not been developed, yet. OBJECTIVE: We analyzed the correlation of plasma microparticle levels (MP) with AR. MATERIALS AND METHODS: MP (CD4, CD8, CD25, CD31, MHC) of 11 AR patients and 11 controls were analyzed within the first week after transplantation. RESULTS: CD4, CD8 and CD31 positive MP were higher in the AR, whereas overall MP count, CD25 and MHCI positive MP proportions did not differ between both groups. DISCUSSION AND CONCLUSION: MP dynamics within the first period of transplantation could help to clarify on-going mechanisms of immunomodulation.

Tumor-stromal cross-talk modulating the therapeutic response in pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant solid tumor with a dismal prognosis. The stroma component makes up to 90% of the tumor mass and is thought to be one of the main reasons for the tumor's high chemoresistance. Cancer associated fibroblasts (CAFs) have previously been identified to be the key stromal players. This is the first time we provide detailed in vitro experiments investigating tumor-stromal interactions when exposed to three well-known chemotherapeutic agents. METHODS: Monocultures, indirect and direct co-cultures of two PDAC cell lines (AsPC and Panc-1) and six primary patients derived CAFs were treated with gemcitabine, nab-paclitaxel and the γ-secretase-inhibitor (GSI) DAPT. The cell viability of each component was measured with XTT. Finally, IL-6 concentrations of the supernatants were analyzed. RESULTS: On the contrary to PDAC cell lines, CAF monocultures hardly responded to any treatment which suggested that stroma (CAFs) itself is more resistant to standard chemo-treatments than the epithelial cancer cells. Moreover, only a weak chemotherapeutic response was observed in direct co-cultures of cancer cells with CAFs. A change in the morphology of direct co-cultures was accompanied with the chemoresistance. CAFs were observed to build cage-like structures around agglomerates of tumor cells. High levels of IL-6 were also associated with a reduced response to therapy. Indirect co-cultures make the tumor-stromal interaction more complex. CONCLUSIONS: CAFs are highly chemoresistant. Direct cell-cell contact and high levels of IL-6 correlate with a high chemoresistance.

Large T antigen variants of human polyomaviruses 9 and 12 and seroreactivity against their N terminus.

The tumour antigens (TAgs) of mammalian polyomaviruses (PyVs) are key proteins responsible for modulating the host cell cycle and are involved in virus replication as well as cell transformation and tumour formation. Here we aimed to identify mRNA sequences of known and novel TAgs encoded by the recently discovered human polyomaviruses 9 and 12 (HPyV9 and HPyV12) in cell culture. Synthetic viral genomes were transfected into human and animal cell lines. Gene expression occurred in most cell lines, as measured by quantitative PCR of cDNA copies of mRNA encoding major structural protein VP1. Large TAg- and small TAg-encoding mRNAs were detected in all cell lines, and additional spliced mRNAs were identified encoding TAg variants of 145 aa (HPyV9) and 84 aa (HPyV12). Using as antigens in ELISA the N-terminal 78 aa common to all respective TAg variants of HPyV9 and HPyV12, seroreactivity of 100 healthy blood donors, 54 patients with malignant diseases of the gastrointestinal tract (GIT) and 32 patients with non-malignant diseases of the GIT was analysed. For comparison, the corresponding TAg N termini of BK PyV (BKPyV) and Merkel cell PyV (MCPyV) were included. Frequent reactivity against HPyV9, HPyV12 and BKPyV TAgs, but not MCPyV TAg, was observed in all tested groups. This indicates expression activity of the early region of three human PyVs in healthy and diseased subjects.

Bile: miRNA pattern and protein-based biomarkers may predict acute cellular rejection after liver transplantation.

CONTEXT: Bile rather than blood depicts the local inflammation in the liver and may improve prediction and diagnosis of acute cellular rejection (ACR) after liver transplantation (OLT). METHODS: Secretome and miRNAs were analyzed during the first two weeks and on clinical suspicion of ACR in the bile of 45 OLT recipients. RESULTS: Levels of CD44, CXCL9, miR-122, miR-133a, miR-148a and miR-194 were significantly higher in bile of patients who developed ACR within the first 6 months after OLT and during ACR. CONCLUSION: Analysis of secretome and miRNA in bile could improve our understanding of the local inflammatory process during rejection.

Single Pass Albumin Dialysis-A Dose-Finding Study to Define Optimal Albumin Concentration and Dialysate Flow.

Several artificial liver support concepts have been evaluated both in vitro and clinically. Single pass albumin dialysis (SPAD) has shown to be one of the most simple approaches for removing albumin-bound toxins and water-soluble substances. Being faced with acute liver failure (ALF) in everyday practice encouraged our attempt to define the optimal conditions for SPAD more precisely in a standardized experimental setup. Albumin concentration was adjusted to either 1%, 2%, 3%, or 4%, while the flow rate of the dialysate was kept constant at a speed of 700 mL/h. The flow rate of the dialysate was altered between 350, 500, 700, and 1000 mL/h, whereas the albumin concentration was continuously kept at 3%. This study revealed that the detoxification of albumin-bound substances could be improved by increasing the concentration of albumin in the dialysate with an optimum at 3%. A further increase of the albumin concentration to 4% did not lead to a significant increase in detoxification. Furthermore, we observed a gradual increase of the detoxification efficiency for albumin-bound substances, from 350 mL/h to 700 mL/h (for bilirubin) or 1000 mL/h (for bile acids) of dialysate flow. Water-soluble toxins (ammonia, creatinine, urea, uric acid) were removed almost completely, regardless of albumin concentration or flow rate. In conclusion, this study confirmed that SPAD is effective in eliminating albumin-bound as well as water-soluble toxins using a simulation of ALF. Furthermore, this project was successful in evaluating the most effective combination of albumin concentration (3%) and dialysate flow (700 mL/h-1000 mL/h) in SPAD for the first time.

Diagnosis of HCC for patients with cirrhosis using miRNA profiles of the tumor-surrounding tissue - A statistical model based on stepwise penalized logistic regression.

The presence of hepatocellular carcinoma (HCC) is a significant complication of cirrhosis because it changes the prognosis and the treatment of the patients. By now, contrast-enhanced CT and MR scans are the most reliable tools for the diagnosis of HCC; however, in some cases, a biopsy of the tumor is necessary for the final diagnosis. The aim of the study was to develop a diagnostic tool using the microRNA (miRNA) profiles of the tissue surrounding the HCC tumor combined with clinical parameters in statistical models. At a transplantation setting, 32 patients with HCC and cirrhosis (B) were compared to 22 patients suffering from cirrhosis only (A). The diagnosis and exclusion of HCC was confirmed following the histopathological examination of the explanted liver. The HCC patients were significantly older than the patients with cirrhosis only (B: 60.6 and A: 49.9, p<0.001) and showed higher levels of ALT (A: 0.76µkat/l, B: 1.02µkat/, p=0.006) and AFP (A: 5.8ng/ml, B: 70.3ng/ml, p<0.001), whereas the bilirubin levels were higher in the cirrhosis only group (p=0.002). Using age (cut-off 50.23years) and AFP (cut-off 4.2ng/ml) thresholds, the levels of expression of miR-1285-3p and miR-943 differentiated between the patients with HCC and cirrhosis from those with cirrhosis only with an accuracy of 96.3%. This is the first report about the use of stepwise penalized logistic regression and decision tree analyses of miRNA expressions in the tumor-surrounding tissue combined with clinical parameters for the diagnosis of HCC.

microRNA signatures in peripheral blood fail to detect acute cellular rejection after liver transplantation.

OBJECTIVE: We investigated whether microRNA signatures in whole blood samples are associated with acute cellular rejection (ACR) after liver transplantation. MATERIALS AND METHODS: Blood samples were collected using Paxgene technology and analyzed by microarrays and quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: microRNA signatures failed to distinguish between 19 patients with ACR and 16 controls. Let-7b-5p and let-7c were upregulated in a subgroup of patients with ACR during the 6th and 7th postoperative days but failed in an independent validation of 20 patients. CONCLUSION: microRNA signatures in whole blood processed by Paxgene technology are not suited for the detection of ACR after liver transplantation.

CD44 and CXCL9 serum protein levels predict the risk of clinically significant allograft rejection after liver transplantation.

The diagnosis of acute cellular rejection (ACR) after liver transplantation is based on histological analysis of biopsies because noninvasive biomarkers for allograft rejection are not yet established for clinical routines. CD31, CD44, and chemokine (C-X-C motif) ligand (CXCL) 9 have previously been described as biomarkers for cross-organ allograft rejection. Here, we assessed the predictive and diagnostic value of these proteins as serum biomarkers for clinically significant ACR in the first 6 months after liver transplantation in a prospective study. The protein levels were measured in 94 patients immediately before transplantation, at postoperative days (PODs) 1, 3, 7, and 14 and when biopsies were performed during episodes of biochemical graft dysfunction. The CD44 serum protein levels were significantly lower at POD 1 in patients who experienced histologically proven ACR in the follow-up compared with patients without ACR (P < 0.001). CXCL9 was significantly higher before transplantation (P = 0.049) and at POD 1 (P < 0.001) in these patients. Low CD44 values (cutoff, <200.5 ng/mL) or high CXCL9 values (cutoff, >2.7 ng/mL) at POD 1 differentiated between rejection and no rejection with a sensitivity of 88% or 60% and a specificity of 61% or 79%, respectively. The combination of both biomarker cutoffs at POD 1 had a positive predictive value of 91% and a negative predictive value of 67% for clinically significant ACR. Moreover, CD44 was significantly lower at the time of ACR (P < 0.001) and differentiated the rejection group from patients with graft dysfunction due to other reasons. Our results suggest that CD44 and CXCL9 may serve as predictive biomarkers to identify liver allograft recipients at risk for clinically significant ACR.

Genotypic and phenotypic characterization of side population of gastric cancer cell lines.

The side population (SP) of tumor cell lines shares characteristics with tumor stem cells. The objective of this study was to phenotypically and genotypically characterize the SP of gastric cancer cell lines. SP cells were obtained from AGS and MKN45 gastric cancer cells using Hoechst 33342 staining and fluorescence-activated cell sorting. The cells were subsequently studied morphologically at cytology and immunocytochemistry, on the transcriptional level via gene array, and in cell culture using recultivation assays. Genes differentially expressed in SP cells were evaluated at immunohistochemistry in tissue samples from 486 patients with gastric cancer. The SP cells were smaller and rounder then non-SP cells. SP cells self-renewed in recultivation experiments and differentiated into SP and non-SP cells. Recultivated SP and non-SP cells exhibited distinct phenotypes in culture insofar as cell shape and colony formation. SP cells demonstrated increased levels of the stem cell markers CD133 and Musashi-1. Transcriptional analyses demonstrated that SP cells express genes that encode for stem cell properties including FZD7, HEY1, SMO, and ADAM17. It was observed that ADAM17 and FZD7 are differentially expressed in human gastric cancer, and FZD7-positive cancers are associated with significantly shorter patient survival. In conclusion, human gastric cancer cell lines enclose a phenotypically and genotypically distinct cell population with tumor stem cell features. Phenotypic characteristics of this distinct cell population are also present in gastric cancer tissue, and correlate with patient survival.

Speckle Tracking Analysis Reveals Altered Left Atrial and Ventricular Myocardial Deformation in Patients with End-Stage Liver Disease.

BACKGROUND: Cardiac function can be influenced by liver cirrhosis and should be thoroughly evaluated before liver transplantation. We investigated left ventricular (LV) and, for the first time, left atrial (LA) strain and strain rate in end-stage liver cirrhosis patients of different etiologies. METHODS: This retrospective, cross-sectional study evaluated left heart function in 80 cirrhosis patients and 30 controls using standardized echocardiographic techniques and speckle tracking technology (STE) analysis. Serum markers of liver function were used for correlation analysis. RESULTS: While conventional parameters demonstrated no alteration in systolic function, speckle tracking analysis showed a significant increase in LV longitudinal strain throughout all cardiac layers, with significant correlation to model of end-stage liver disease (MELD) score. LA reservoir and conduit strain as well as LA strain rate in all phases were significantly reduced in end-stage liver disease (ESLD) patients compared to control. STE for the evaluation of LA phasic function seemed to be more sensitive than volumetric methods. Kaplan-Meier curves showed a trend towards reduced post-transplant survival in patients with a reduced LA reservoir and conduit strain. CONCLUSION: STE analysis detected increased LV and decreased LA deformation in cirrhosis patients, thus proving to be highly sensitive to cardiac changes and useful for more precise cardiac evaluation.

Epithelial response to IFN-γ promotes SARS-CoV-2 infection.

SARS-CoV-2, the agent that causes COVID-19, invades epithelial cells, including those of the respiratory and gastrointestinal mucosa, using angiotensin-converting enzyme-2 (ACE2) as a receptor. Subsequent inflammation can promote rapid virus clearance, but severe cases of COVID-19 are characterized by an inefficient immune response that fails to clear the infection. Using primary epithelial organoids from human colon, we explored how the central antiviral mediator IFN-γ, which is elevated in COVID-19, affects epithelial cell differentiation, ACE2 expression, and susceptibility to infection with SARS-CoV-2. In mouse and human colon, ACE2 is mainly expressed by surface enterocytes. Inducing enterocyte differentiation in organoid culture resulted in increased ACE2 production. IFN-γ treatment promoted differentiation into mature KRT20+ enterocytes expressing high levels of ACE2, increased susceptibility to SARS-CoV-2 infection, and resulted in enhanced virus production in infected cells. Similarly, infection-induced epithelial interferon signaling promoted enterocyte maturation and enhanced ACE2 expression. We here reveal a mechanism by which IFN-γ-driven inflammatory responses induce a vulnerable epithelial state with robust replication of SARS-CoV-2, which may have an impact on disease outcome and virus transmission.

Safety of transanal ileal pouch-anal anastomosis for ulcerative colitis: a retrospective observational cohort study.

BACKGROUND: Colectomy with transanal ileal pouch-anal anastomosis (taIPAA) is a surgical technique that can be used to treat benign colorectal disease. Ulcerative colitis is the most frequent inflammatory bowel disease (IBD) and although pharmacological therapy has improved, colectomy rates reach up to 15%. The objective of this study was to determine anastomotic leakage rates and treatment after taIPAA as well as short- and long-term pouch function. METHODS: We conducted a retrospective analysis of a prospective database of all patients undergoing taIPAA at an academic tertiary referral center in Germany, between 01/03/2015 and 31/08/2019. Patients with indications other than ulcerative colitis or with adjuvant chemotherapy following colectomy for colorectal carcinoma were excluded for short- and long-term follow up due to diverging postoperative care yet considered for evaluation of anastomotic leakage. RESULTS: A total of 22 patients undergoing taIPAA during the study time-window were included in analysis. Median age at the time of surgery was 32 ± 12.5 (14-54) years. Two patients developed an anastomotic leakage at 11 days (early anastomotic leakage) and 9 months (late anastomotic leakage) after surgery, respectively. In both patients, pouches could be preserved with a multimodal approach. Twenty patients out of 22 met the inclusion criteria for short and long term follow-up. Data on short-term pouch function could be obtained in 14 patients and showed satisfactory pouch function with only four patients reporting intermittent incontinence at a median stool frequency of 9-10 times per day. In the long-term we observed an inflammation or "pouchitis" in 11 patients and a pouch failure in one patient. CONCLUSION: Postoperative complication rates in patients with benign colorectal disease remain an area of concern for surgical patient safety. In this pilot study on 22 selected patients, taIPAA was associated with two patients developing anastomotic leakage. Future large-scale validation studies are required to determine the safety and feasibility of taIPAA in patients with ulcerative colitis.

Role of extracellular matrix structural components and tissue mechanics in the development of postoperative pancreatic fistula.

Radical resection remains the only curative treatment option in pancreatic cancer. Postoperative pancreatic fistulas (POPF) occur in up to 30% of patients leading to prolonged hospital-stay, increased cost of care and morbidity and mortality. Mechanical properties of the pancreas are associated with POPF. The aim of this study is to analyze the role of extracellular matrix (ECM) and tissue mechanics in the risk of POPF. Biopsies of 41 patients receiving a partial pancreas-resection are analyzed. Clinical data, ECM components and mechanical properties are correlated with POPF. Preoperative cholestasis is correlated with reduced risk of POPF, which comes along with a dilatation of the pancreatic duct and significantly higher content of collagen I. Patients developing POPF exhibited a degenerated tissue integrity, with significantly lower content of fibronectin and a trend for lower collagen I, III, IV and hyaluronic acid. This correlated with a soft tactile sensation of the surgeon during the intervention. However, this was not reflected with tissue mechanics evaluated by ex vivo uniaxial compression testing, where a significantly higher elastic modulus and no effect on the stress relaxation time were found. In conclusion, patients with cholestasis seem to have a lower risk for POPF, and an increase in collagen I. A degenerated matrix with lower content of structural ECM components correlates with increased risk of POPF. However, ex vivo uniaxial compression testing failed to clearly explain the link of ECM properties and POPF.

Cancer Associated Fibroblasts Derived from Pancreatic Adenocarcinoma and Their Role in Cell Migration.

BACKGROUND/AIM: Pancreatic ductal adenocarcinoma (PDAC) shows poor survival and early systemic dissemination. Cancer associated fibroblasts (CAFs) enhance migration and invasion of cancer cells. We aimed to investigate the role of CAFs in cell migration and their underlying paracrine effects. MATERIALS AND METHODS: Using Transwell® migration assays, PDAC cells (PANC-1) and three distinct types of fibroblasts were analyzed: CAFs, genetically transformed human foreskin-fibroblasts (BJeLR), and non-transformed human foreskin-fibroblasts (VH7). IL6 in the culture supernatant was measured to investigate paracrine communication in monocultures and direct/indirect cocultures. RESULTS: CAFs showed a significantly higher capacity to migrate in vitro when compared to benign fibroblasts (p=0.009). They also facilitated the migration of PDAC cells in coculture (p=0.001). Neither BJeLR, nor VH7 displayed such features. This was accompanied by a significant increase in IL-6 when CAFs were cocultured with PANC-1 (p=0.009). CONCLUSION: CAFs are a key element of intra-tumoral migration and should be further investigated as a potential therapeutic target.

Ischemic-Type Biliary Lesions After Liver Transplant: Factors Causing Early-Onset Versus Late-Onset Disease.

OBJECTIVES: Biliary complications such as an ischemic-type biliary lesion can increase morbidity and mortality after liver transplant. Former studies have investigated several risk factors, but the underlying pathomechanism remains unclear. The focus of this study was to investigate factors causing early-onset (< 12 mo after liver transplant) versus late-onset ischemic-type biliary lesions (> 12 mo after liver transplant). MATERIALS AND METHODS: This retrospective study included 641 patients. Patients were grouped to those who developed ischemic-type biliary lesion and those who did not. Patients developing ischemic-type biliary lesions were further subgrouped into those diagnosed early (< 12 mo) and late (> 12 mo) after liver transplant. We analyzed demographic data, characteristics, and comorbidities of the recipients and donors, operative variables, and postoperative course, as well as laboratory values. RESULTS: The incidence of ischemic-type biliary lesions was 4.9%. Retransplant was performed more frequently in patients developing ischemic-type biliary lesions. The number of transfusions of blood products was higher in ischemic-type biliary lesion patients, especially in the early-onset ischemic-type biliary lesion group. Bilirubin levels were higher in patients with ischemic-type biliary lesions starting from day 7 after the operation, particularly in the early-onset group. Survival tended to be best in the late-onset ischemic-type biliary lesion group; however, this difference was not significant. CONCLUSIONS: This study serves as a supplement to current data and the understanding of ischemic-type biliary lesions with emphasis on the relevance of disease onset and causes. We could in fact determine transfusion of blood products as a determinant of an early onset of ischemic-type biliary lesion. Bilirubin could be a surrogate marker for ischemic-type biliary lesions, especially in its early-onset form.

Initial Experience with the Safe Implementation of Transanal Total Mesorectal Excision (TaTME) as a Standardized Procedure for Low Rectal Cancer.

INTRODUCTION: The laparoscopic approach for TME is proven to be non-inferior in oncological outcome compared to open surgery. Anatomical limitations in the male and obese pelvis with resulting pathological shortcomings and high conversion rates were stimuli for alternative approaches. The transanal approach for TME (TaTME) was introduced to overcome these limitations. The aim of this study was to evaluate the outcomes of TaTME for mid and low rectal cancer at our center. METHODS: TaTME is a hybrid procedure of simultaneously laparoscopic and transanal mesorectal excision. A retrospective analysis of all consecutive TaTME procedures performed at our center for mid and low rectal cancer between December 2014 and January 2020 was conducted. RESULTS: A total of 157 patients underwent TaTME, with 72.6% receiving neoadjuvant chemoradiation. Mean tumor height was 6.1 ± 2.3 cm from the anal verge, 72.6% of patients had undergone neoadjuvant chemoradiotherapy, and 34.2% of patients presented with a threatened CRM upon pretherapeutic MRI. Abdominal conversion rate was 5.7% with no conversion for the transanal dissection. Early anastomotic leakage occurred in 7.0% of the patients. Mesorectum specimen was complete in 87.3%, R1 resection rate was 4.5% (involved distal resection margin) and in 7.6%, the CRM was positive. The three-year local recurrence rate of 58 patients with a follow-up ≥ 36 months was 3.4%. Overall survival was 92.0% after 12 months, and 82.2% after 36 months. CONCLUSION: TaTME can be performed safely with acceptable long-term oncological outcome. Low rectal cancer can be well addressed by TaTME, which is an appropriate alternative with low conversion, local recurrence, adequate mesorectal quality and CRM positivity rates.

Characterization of Pancreatic and Biliary Cancer Stem Cells in Patient-derived Tissue.

BACKGROUND/AIM: Pancreatic ductal adenocarcinoma (PDAC) and extrahepatic cholangio-carcinoma (eCC) represent two cancer entities with devastating prognoses. Despite recent progress in research and treatment, therapy remains challenging. Cancer stem cells (CSCs) have been shown to play an important role in metastasis and chemoresistance. Therefore, CSCs may play a promising role as a potential therapeutic target. MATERIALS AND METHODS: A total of 31 patients (23 PDAC, 8 eCC) were included in the study. CSCs were analyzed in a single-cell suspension of tumor samples via fluorescence-activated cell scanning (FACS) with a functional Hoechst 33342 staining as well as a cell surface marker staining of the CSC-panel (CD24, CD44 and EpCAM) and markers to identify fibroblasts, leukocytes and components of the notch signaling pathway. Furthermore, the potential presence of CSCs among primary cancer-associated fibroblasts (CAFs) was assessed using the same FACS-panel. RESULTS: We showed that CSCs are present in patient-derived dissociated tumor tissue. The functional and surface marker profile of CSC-detection did in fact correlate. The amount of CSCs was significantly correlated with tumor characteristics such as a higher UICC stadium and nodal invasion. CSCs were not restricted to the epithelial cell fraction in tumor tissues, which has been verified in independent analysis of primary cell cultures of CAFs. CONCLUSION: Our study confirms the in vivo presence of CSCs in PDAC and eCC, stating a clinical significance thereof and thus their plausibility as therapeutic targets. In addition, stem-like cells also seem to constitute a part of the CAFs.