lation of BALB/c mice with rhesus rotavirus (RRV) in the newborn period results in biliary epithelial cell (cholangiocyte) infection and the murine model of biliary atresia. Rotavirus infection of a cell requires attachment, which is governed in part by cell-surface expression of integrins such as ␣2␤1. We hypothesized that cholangiocytes were susceptible to RRV infection because they express ␣2␤1. RRV attachment and replication was measured in cell lines derived from cholangiocytes and hepatocytes. Flow cytometry was performed on these cell lines to determine whether ␣2␤1 was present. Cholangiocytes were blocked with natural ligands, a monoclonal antibody, or small interfering RNA against the ␣2-subunit and were infected with RRV. The extrahepatic biliary tract of newborn mice was screened for the expression of the ␣2␤1-integrin. Newborn mice were pretreated with a monoclonal antibody against the ␣2-subunit and were inoculated with RRV. RRV attached and replicated significantly better in cholangiocytes than in hepatocytes. Cholangiocytes, but not hepatocytes, expressed ␣2␤1 in vitro and in vivo. Blocking assays led to a significant reduction in attachment and yield of virus in RRV-infected cholangiocytes. Pretreatment of newborn pups with an anti-␣2 monoclonal antibody reduced the ability of RRV to cause biliary atresia in mice. Cell-surface expression of the ␣2␤1-integrin plays a role in the mechanism that confers cholangiocyte susceptibility to RRV infection. rhesus rotavirus; bile ducts; cholangiopathy BILIARY ATRESIA (BA) is a unique disease of infancy in which affected children develop fibroinflammatory obliteration of the biliary tract. It is the most common indication for pediatric liver transplantation (24). Because pathogenic viruses have been found in the livers of children afflicted with biliary atresia (10,12,18,26,29), a proposed etiology for biliary atresia is perinatal infection by a virus triggering inflammatory destruction of the biliary epithelium (3,23,32). A murine model of biliary atresia (30) supports a viral pathogenesis where newborn mice infected with rhesus rotavirus (RRV) develop inflammation within the portal tract (31) and extrahepatic bile duct obstruction (9, 27).Recently, it has been shown that in the murine model of biliary atresia, RRV targeted the biliary epithelial cell (cholangiocyte) for infection (1, 31). To determine the basis for cholangiocyte susceptibility to RRV, an in vitro model of RRV infection of the two dominant cell types found within the liver (cholangiocytes and hepatocytes) was established. Consistent with the in vivo findings, RRV was better able to replicate in cholangiocytes than hepatocytes. Because the ability of rotavirus to infect cells appears to be regulated by cell-surface expression of the integrins ␣ 2 ␤ 1 , ␣ 4 ␤ 1 , ␣ v ␤ 3 , and ␣ x ␤ 2 , which serve as viral receptors (8,13,14,16,21), the cholangiocyte was surveyed for integrin expression and found to uniquely express the ␣ 2 ␤ 1 -integrin when compared with hepatocytes. Based on this informat...

Biliary atresia (BA) is a disease of the newborn which results in obstruction of the biliary tree. The cause of BA remains unknown; however, recent studies using the murine model of biliary atresia have found that rotavirus infection of the biliary epithelial cell (cholangiocyte) triggers an inflammatory response. We hypothesized that rotavirus infection of cholangiocytes results in the release of chemokines, important mediators of the host immune response. Methods In vivo, Balb/c pups were injected with rhesus rotavirus (RRV) or saline, and, their extrahepatic bile ducts were microdissected 2,5, 7, and 14 days after injection. Next, an immortalized cholangiocyte cell line (mCl) was incubated with RRV or serum free media. Qualitative and quantitative chemokine assement was performed using ELISA, PCR, and immunohistchemistry. Results In vivo, increased levels of the chemokines MIP-2, MCP-1, KC and RANTES were found in RRV-infected murine bile ducts. In vitro, infected mCl cells produced increasing amounts of these same chemokines in relation to dose and time. Conclusion These novel results suggest that chemokine expression by RRV-infected cholangiocytes may trigger a host inflammatory process that causes bile duct obstruction. Understanding how viral infection initiates this response may shed light on the pathogenesis of biliary atresia.

Background: Hepatocellular carcinoma (HCC) is often a chemoresistant neoplasm with a poor prognosis. Pediatric HCC may reflect unique biological and clinical heterogeneity.Procedure: An IRB-approved retrospective institutional review of patients with HCC treated between 2004 and 2015 was undertaken. Clinical, radiographic, and histologic data were collected from all patients.

Pediatric and adolescent patients with upfront, completely resected HCC can be effectively treated without chemotherapy. LT should be considered for nonmetastatic HCC, especially in the context of pre-existing chronic liver disease, even when the tumor exceeds MC. Distinct pediatric selection criteria are needed to identify patients most suitable for LT.

Background Hepatocellular carcinoma (HCC) is a rare cancer in children, with various histologic subtypes and a paucity of data to guide clinical management and predict prognosis. Methods A multi‐institutional review of children with hepatocellular neoplasms was performed, including demographic, staging, treatment, and outcomes data. Patients were categorized as having conventional HCC (cHCC) with or without underlying liver disease, fibrolamellar carcinoma (FLC), and hepatoblastoma with HCC features (HB‐HCC). Univariate and multivariate analyses identified predictors of mortality and relapse. RESULTS In total, 262 children were identified; and an institutional histologic review revealed 110 cHCCs (42%; 69 normal background liver, 34 inflammatory/cirrhotic, 7 unknown), 119 FLCs (45%), and 33 HB‐HCCs (12%). The authors observed notable differences in presentation and behavior among tumor subtypes, including increased lymph node involvement in FLC and higher stage in cHCC. Factors associated with mortality included cHCC (hazard ratio [HR], 1.63; P = .038), elevated α‐fetoprotein (HR, 3.1; P = .014), multifocality (HR, 2.4; P < .001), and PRETEXT (pretreatment extent of disease) stage IV (HR, 5.76; P < .001). Multivariate analysis identified increased mortality in cHCC versus FLC (HR, 2.2; P = .004) and in unresectable tumors (HR, 3.4; P < .001). Disease‐free status at any point predicted survival. Conclusions This multi‐institutional, detailed data set allowed a comprehensive analysis of outcomes for children with these rare hepatocellular neoplasms. The current data demonstrated that pediatric HCC subtypes are not equivalent entities because FLC and cHCC have distinct anatomic patterns and outcomes in concert with their known molecular differences. This data set will be further used to elucidate the impact of histology on specific treatment responses, with the goal of designing risk‐stratified algorithms for children with HCC. Lay Summary This is the largest reported granular data set on children with hepatocellular carcinoma. The study evaluates different subtypes of hepatocellular carcinoma and identifies key differences between subtypes. This information is pivotal in improving understanding of these rare cancers and may be used to improve clinical management and subsequent outcome in children with these rare malignancies.