BackgroundAbnormal activation of endochondral bone formation in soft tissues causes significant medical diseases associated with disability and pain. Hyperactive mutations in the bone morphogenetic protein (BMP) type 1 receptor ACVR1 lead to fibrodysplasia ossificans progressiva (FOP), a rare genetic disorder characterized by progressive ossification in soft tissues. However, the specific cellular mechanisms are unclear. In addition, the difficulty obtaining tissue samples from FOP patients and the limitations in mouse models of FOP hamper our ability to dissect the pathogenesis of FOP.MethodsTo address these challenges and develop a “disease model in a dish”, we created human induced pluripotent stem cells (iPS cells) derived from normal and FOP dermal fibroblasts by two separate methods, retroviral integration or integration-free episomal vectors. We tested if the ability to contribute to different steps of endochondral bone formation was different in FOP vs. control iPS cells.ResultsRemarkably, FOP iPS cells showed increased mineralization and enhanced chondrogenesis in vitro. The mineralization phenotypes could be suppressed with a small-molecule inhibitor of BMP signaling, DMH1. Our results indicate that the FOP ACVR1 R206H mutation favors chondrogenesis and increases mineral deposition in vitro.ConclusionsOur findings establish a FOP disease cell model for in vitro experimentation and provide a proof-of-concept for using human iPS cell models to understand human skeletal disorders.

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Background and AimsThe hepatitis C virus (HCV) invariably shows wide heterogeneity in infected patients, referred to as a quasispecies population. Massive amounts of genetic information due to the abundance of HCV variants could be an obstacle to evaluate the viral genetic heterogeneity in detail.MethodsUsing a newly developed massive-parallel ultra-deep sequencing technique, we investigated the viral genetic heterogeneity in 27 chronic hepatitis C patients receiving peg-interferon (IFN) α2b plus ribavirin therapy.ResultsUltra-deep sequencing determined a total of more than 10 million nucleotides of the HCV genome, corresponding to a mean of more than 1000 clones in each specimen, and unveiled extremely high genetic heterogeneity in the genotype 1b HCV population. There was no significant difference in the level of viral complexity between immediate virologic responders and non-responders at baseline (p = 0.39). Immediate virologic responders (n = 8) showed a significant reduction in the genetic complexity spanning all the viral genetic regions at the early phase of IFN administration (p = 0.037). In contrast, non-virologic responders (n = 8) showed no significant changes in the level of viral quasispecies (p = 0.12), indicating that very few viral clones are sensitive to IFN treatment. We also demonstrated that clones resistant to direct-acting antivirals for HCV, such as viral protease and polymerase inhibitors, preexist with various abundances in all 27 treatment-naïve patients, suggesting the risk of the development of drug resistance against these agents.ConclusionUse of the ultra-deep sequencing technology revealed massive genetic heterogeneity of HCV, which has important implications regarding the treatment response and outcome of antiviral therapy.

Abstract. The present study aimed to examine the impact of sarcopenia, defined as low muscle mass on computed tomography (CT), prior to sorafenib therapy on the clinical outcomes of patients with hepatocellular carcinoma (HCC) receiving sorafenib therapy. In total, 232 patients with unresectable HCC (median age, 72 years) were analyzed, and the extent of sarcopenia was assessed using CT. Cross-sectional areas (cm 2 ) of the skeletal muscles at the third lumbar vertebra level were determined by manual outlining on the CT images. The cross-sectional areas were normalized for height [skeletal rates, progression-free survival (PFS) rates and best treatment response of the sarcopenia group were retrospectively compared with those of the non-sarcopenia group, and the factors associated with OS and PFS were examined. Sarcopenia was observed in 151 patients (65.1%). There were 165 patients with Child-Pugh A and 67 with Child-Pugh B cirrhosis. In the sarcopenia group, the median treatment duration was 66 days, whereas in the non-sarcopenia group it was 103 days (P=0.001). The median OS time was 174 days in the sarcopenia group and 454 days in the non-sarcopenia group (P<0.0001). The median PFS was 77 days in the sarcopenia group and 106 days in the non-sarcopenia group (P=0.0131). Multivariate analysis identified sarcopenia to be an independent predictor of OS (hazard ratio, 0.365; P<0.0001). The objective response rate and disease control rate in the sarcopenia group were significantly lower, compared with those in the non-sarcopenia group (P=0.0146 and P=0.0151, respectively). In conclusion, sarcopenia may be an indicator of poor clinical course in patients with HCC receiving sorafenib. IntroductionHepatocellular carcinoma (HCC) is one of the major causes of cancer-associated mortality worldwide, accounting for 5.7% of all newly diagnosed malignancies (1-5). The annual incidence rates of HCC are the highest in East Asia and Sub-Saharan Africa, where >80% of all known cases develop (1-5). Advances in treatments for HCC during the last few decades markedly improved the prognosis of the disease (1,2,4,5). However, a curative therapy such as surgical resection may be applied to a limited number (<20%) of patients with HCC (5,6). Sorafenib is a multi-kinase inhibitor that suppresses cancer growth and cell proliferation (7,8). Two pivotal randomized phase III studies, namely the Sorafenib HCC Assessment Randomized Protocol study (7)

Background and AimsAlthough the advent of ultra-deep sequencing technology allows for the analysis of heretofore-undetectable minor viral mutants, a limited amount of information is currently available regarding the clinical implications of hepatitis B virus (HBV) genomic heterogeneity.MethodsTo characterize the HBV genetic heterogeneity in association with anti-viral therapy, we performed ultra-deep sequencing of full-genome HBV in the liver and serum of 19 patients with chronic viral infection, including 14 therapy-naïve and 5 nucleos(t)ide analogue(NA)-treated cases.ResultsMost genomic changes observed in viral variants were single base substitutions and were widely distributed throughout the HBV genome. Four of eight (50%) chronic therapy-naïve HBeAg-negative patients showed a relatively low prevalence of the G1896A pre-core (pre-C) mutant in the liver tissues, suggesting that other mutations were involved in their HBeAg seroconversion. Interestingly, liver tissues in 4 of 5 (80%) of the chronic NA-treated anti-HBe-positive cases had extremely low levels of the G1896A pre-C mutant (0.0%, 0.0%, 0.1%, and 1.1%), suggesting the high sensitivity of the G1896A pre-C mutant to NA. Moreover, various abundances of clones resistant to NA were common in both the liver and serum of treatment-naïve patients, and the proportion of M204VI mutants resistant to lamivudine and entecavir expanded in response to entecavir treatment in the serum of 35.7% (5/14) of patients, suggesting the putative risk of developing drug resistance to NA.ConclusionOur findings illustrate the strong advantage of deep sequencing on viral genome as a tool for dissecting the pathophysiology of HBV infection.