Citations

The contributions of mesenchymal stem cells (MSCs) to tumour growth and stroma formation are poorly understood. Tumour cells can transfer genetic information and modulate cell signalling in other cells through the release of extracellular vesicles (EVs). We examined the contribution of EV‐mediated inter‐cellular signalling between bone marrow MSCs and tumour cells in human cholangiocarcinoma, highly desmoplastic cancers that are characterized by tumour cells closely intertwined within a dense fibrous stroma. Exposure of MSCs to tumour cell–derived EVs enhanced MSC migratory capability and expression of alpha‐smooth muscle actin mRNA, in addition to mRNA expression and release of CXCL‐1, CCL2 and IL‐6. Conditioned media from MSCs exposed to tumour cell–derived EVs increased STAT‐3 phosphorylation and proliferation in tumour cells. These effects were completely blocked by anti‐IL‐6R antibody. In conclusion, tumour cell–derived EVs can contribute to the generation of tumour stroma through fibroblastic differentiation of MSCs, and can also selectively modulate the cellular release of soluble factors such as IL‐6 by MSCs that can, in turn, alter tumour cell proliferation. Thus, malignant cells can “educate” MSCs to induce local microenvironmental changes that enhance tumour cell growth.

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and it is associated with increased cardiovascular morbidity and all‐cause mortality. Our aim was to determine the impact of preexisting AF on patients undergoing liver transplantation (LT). A retrospective case‐control study was performed. Records from patients who underwent LT between January 2005 and December 2008 at Mayo Clinic Florida were reviewed. Patients with preexisting AF were identified and matched to patients who did not have a diagnosis of AF. Thirty‐two of 717 LT recipients (4.5%) had AF before LT. These patients were compared to a control group of 63 LT recipients. Pre‐LT left ventricular hypertrophy (P = 0.03), a history of congestive heart failure (P = 0.04), and a history of stroke or transient ischemic attack (P = 0.03) were significantly more prevalent in patients with AF versus controls. Intraoperative adverse cardiac events (P = 0.02) and AF‐related adverse postoperative events (P < 0.001) were more common in the recipients with known AF. Six patients with paroxysmal AF (19%) developed chronic/persistent AF postoperatively. Graft survival and patient survival were similar in the groups. Although patients with AF had a higher incidence of intraoperative cardiac events, a higher cardiovascular morbidity rate, and a complicated postoperative course, this did not affect overall graft and patient survival. Liver Transpl 21:314–320, 2015. © 2014 AASLD.

AbstractCholangiocarcinoma (CCA) is an aggressive biliary tract malignancy with limited treatment options and low survival rates. Currently, there are no curative medical therapies for CCA. Recent advances have enhanced our understanding of the genetic basis of this disease, and elucidated therapeutically relevant targets. Therapeutic efforts in development are directed at several key pathways due to genetic aberrations including receptor tyrosine kinase pathways, mutant IDH enzymes, the PI3K-AKT-mTOR pathway, and chromatin remodeling networks. A highly desmoplastic, hypovascular stroma is characteristic of CCAs and recent work has highlighted the importance of targeting this pathway via stromal myofibroblast depletion. Future efforts should concentrate on combination therapies with action against the cancer cell and the surrounding tumor stroma. As the mutational landscape of CCA is being illuminated, molecular profiling of patient tumors will enable identification of specific mutations and the opportunity to offer directed, personalized treatment options.

AbstractIntrahepatic cholangiocarcinomas (iCCA) are primary intrahepatic malignancies originating from biliary epithelia. While both hepatocellular cancer and iCCA can present as mass lesions within the liver, these cancers are distinct in their morphology, etiology, pathology, natural history and response to therapy. There is a need for accurate and sensitive molecular markers for the diagnosis of iCCA. Recent advances in elucidating molecular and genetic characteristics of iCCA offer the potential of molecular‐based diagnosis of iCCA. Specific genetic mutations of IDH1/2, BAP1, p53, and KRAS, FGFR gene fusions and alterations in microRNA have all been described in iCCA. Although there are no accurate serum or biliary biomarkers currently available for diagnosis of iCCA, several potential candidates have been identified. Knowledge of specific genetic or molecular abnormalities offers potential for individualized approaches for the treatment of patients with iCCA in the future.

Abstract Hepatocellular cancer (HCC) is a highly treatment-refractory cancer and is also highly resistant to adverse cellular stress. Although cell behavior can be modulated by noncoding RNAs (ncRNA) within extracellular vesicles (EV), the contributions of long noncoding RNAs (lncRNAs) are largely unknown. To this end, the involvement and functional roles of lncRNAs contained within EVs during chemotherapeutic stress in human HCC were determined. Expression profiling identified a subset of lncRNAs that were enriched in tumor cell–derived vesicles released from two different cell lines. Of these, lincRNA-VLDLR (linc-VLDLR) was significantly upregulated in malignant hepatocytes. Exposure of HCC cells to diverse anticancer agents such as sorafenib, camptothecin, and doxorubicin increased linc-VLDLR expression in cells as well as within EVs released from these cells. Incubation with EVs reduced chemotherapy-induced cell death and also increased linc-VLDLR expression in recipient cells. RNAi-mediated knockdown of linc-VLDLR decreased cell viability and abrogated cell-cycle progression. Moreover, knockdown of VLDLR reduced expression of ABCG2 (ATP-binding cassette, subfamily G member 2), whereas overexpression of this protein reduced the effects of VLDLR knockdown on sorafenib-induced cell death. Here, linc-VLDLR is identified as an EV-enriched lncRNA that contributes to cellular stress responses. Implications: These findings provide new insight into the role of EVs and demonstrate the capacity of lncRNAs to mediate chemotherapeutic stress response in HCC. Mol Cancer Res; 12(10); 1377–87. ©2014 AACR.

The microRNAs (miRNAs) are small noncoding RNAs that are potent regulators of gene expression and can regulate several diverse biological functions. This minireview provides an overview of recent studies that have examined the role and involvement of miRNAs in cholangiocarcinomas. These studies provide evidence for deregulated expression of miRNA and are providing new insights into the potential contribution of these in the pathogenesis of cholangiocarcinoma.

AbstractBackground & AimsNon‐ischaemic cardiomyopathy (NIC) is an early complication of liver transplantation (LT). Our aims were to define the prevalence, associated clinical factors, and prognosis of this condition.MethodsA retrospective study was performed on patients undergoingLTat our institution from January 2005 to December 2012. Patients who developedNICwere identified. Data collected included demographic and clinical data.ResultsA total 1460 transplants were performed in this period and seventeen patients developedNIC. Pretransplant medianQTc interval was 459 (range, 405–530), and median E/A ratio was 1 (range, 0.71–1.67). Fourteen patients (82%) were severely malnourished and required nutritional support. Thirteen patients (76%) had renal insufficiency. Median time to onset was 2 days post‐transplant (range, 0–20). Echocardiograms showed global left ventricular hypokinesis and a decrease in ejection fraction (EF) from a median of 65% (range, 50–81) pretransplant to a median of 21% (range, 15–32). Median raw model for end‐stage liver disease (MELD) score was 29 in patients withNICvs. 18 in patients without cardiomyopathy (P = 0.01). There was no significant difference between recipients withNICvs. recipients without cardiomyopathy regarding donor age, donor risk index, and cold and warm ischaemia time. Recovery of cardiac function occurred in 16 patients, with a medianEFof 44% (range, 25–65%) at the time of discharge. The last echocardiogram available showed a medianEFof 59% (range, 49–73%). One‐year survival of NIC patients was 94.1%.ConclusionNon‐ischaemic cardiomyopathy is a rare complication afterLT. Patients withNICare critically ill, with highMELDscore, and severe malnutrition.