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

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

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

Challenges in pancreatic adenocarcinoma surgery - National survey and current practice guidelines.

BACKGROUND:Pancreatic ductal adenocarcinoma (PDAC) remains one of the most deadly cancers in Europe and the USA. There is consensus that radical tumor surgery is the only viable option for any long-term survival in patients with PDAC. So far, limited data are available regarding the routine surgical management of patients with advanced PDAC in the light of surgical guidelines. METHODS:A national survey on perioperative management of patients with PDAC and currently applied criteria on their tumor resectability in German university and community hospitals was carried out. RESULTS:With a response rate of 81.6% (231/283) a total of 95 (41.1%) participating departments practicing pancreatic surgery in Germany are certified as competence and reference centers for surgical diseases of the pancreas in 2016. More than 95% of them indicate to carry out structured and interdisciplinary therapies along with an interdisciplinary pre- and postoperative tumor board. The majority of survey respondents prefer the pylorus-preserving partial pancreatoduodenectomy (93.1%) with standard lymphadenectomy for cancer of the pancreatic head. Intraoperative histological evaluation of the resection margins is used regularly by 99% of the survey respondents. 98.7% of survey respondents carry out partial or complete vein resection, 126 respondents (54.5%) would resect tumor adjacent arteries, and 102 respondents (44.2%) would perform metastasectomy if complete PDAC resection (R0) is possible. CONCLUSION:Evidence-based and standardized pancreatic surgery is practiced by a large number of hospitals in Germany. However, a significant number of survey respondents support an extended radical tumor resection in patients with advanced PDAC even when not indicated by current clinical guidelines

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

PurposePostoperative 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.MethodsClinical 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.Results340 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 (pConclusionBesides 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

Circulating microRNA-200 Family as Diagnostic Marker in Hepatocellular Carcinoma.

In this clinical study, we aimed to evaluate the role of circulating microRNA-200 family as a non-invasive tool to identify patients with cirrhosis-associated hepatocellular carcinoma (HCC).Prognosis of HCC remains poor with increasing incidence worldwide, mainly related to liver cirrhosis. So far, no reliable molecular targets exist for early detection of HCC at surgically manageable stages. Recently, we identified members of the microRNA-200 family as potential diagnostic markers of cirrhosis-associated HCC in patient tissue samples. Their value as circulating biomarkers for HCC remained undefined.Blood samples and clinicopathological data of consecutive patients with liver diseases were collected prospectively. Expression of the microRNA-200 family was investigated by qRT-PCR in blood serum samples of 22 HCC patients with and without cirrhosis. Serum samples of patients with non-cancerous chronic liver cirrhosis (n = 22) and of healthy volunteers (n = 15) served as controls.MicroRNA-141 and microRNA-200a were significantly downregulated in blood serum of patients with HCC compared to liver cirrhosis (p<0.007) and healthy controls (p<0.002). MicroRNA-141 and microRNA-200a could well discriminate patients with cirrhosis-associated HCC from healthy volunteers with area under the receiver-operating characteristic curve (AUC) values of 0.85 and 0.82, respectively. Additionally, both microRNAs could differentiate between HCC and non-cancerous liver cirrhosis with a fair accuracy.Circulating microRNA-200 family members are significantly deregulated in patients with HCC and liver cirrhosis. Further studies are necessary to confirm the diagnostic value of the microRNA-200 family as accurate serum marker for cirrhosis-associated HCC

Criteria for tumor resectability.

<p>Intraoperative decision and percentages of surgical (non-) resectability in PDAC.</p

Questionnaire consisting of twelve question blocks with a total of 34 parameters.

<p>Questionnaire consisting of twelve question blocks with a total of 34 parameters.</p

The Interaction between Laminin-332 and α3β1 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-β (TGF-β), 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 α3β1 integrin, the principal laminin-332-receptor. Beyond its role as novel CAF marker protein, integrin α3β1 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 α3β1 integrin-laminin-332 interaction of CAFs which promotes and sustains differentiation of CAFs and promotes carcinoma invasion

MicroRNA Profiling Implies New Markers of Gemcitabine Chemoresistance in Mutant p53 Pancreatic Ductal Adenocarcinoma.

No reliable predictors of susceptibility to gemcitabine chemotherapy exist in pancreatic ductal adenocarcinoma (PDAC). MicroRNAs (miR) are epigenetic gene regulators with tumorsuppressive or oncogenic roles in various carcinomas. This study assesses chemoresistant PDAC for its specific miR expression pattern.Gemcitabine-resistant variants of two mutant p53 human PDAC cell lines were established. Survival rates were analyzed by cytotoxicity and apoptosis assays. Expression of 1733 human miRs was investigated by microarray and validated by qRT-PCR. After in-silico analysis of specific target genes and proteins of dysregulated miRs, expression of MRP-1, Bcl-2, mutant p53, and CDK1 was quantified by Western blot.Both established PDAC clones showed a significant resistance to gemcitabine (p<0.02) with low apoptosis rate (p<0.001) vs. parental cells. MiR-screening revealed significantly upregulated (miR-21, miR-99a, miR-100, miR-125b, miR-138, miR-210) and downregulated miRs (miR-31*, miR-330, miR-378) in chemoresistant PDAC (p<0.05). Bioinformatic analysis suggested involvement of these miRs in pathways controlling cell death and cycle. MRP-1 (p<0.02) and Bcl-2 (p<0.003) were significantly overexpressed in both resistant cell clones and mutant p53 (p = 0.023) in one clone.Consistent miR expression profiles, in part regulated by mutant TP53 gene, were identified in gemcitabine-resistant PDAC with significant MRP-1 and Bcl-2 overexpression. These results provide a basis for further elucidation of chemoresistance mechanisms and therapeutic approaches to overcome chemoresistance in PDAC