Signal transducer and activator of transcription 3 (Stat3) has been shown to play a role in intestinal regeneration and colitis-associated colon carcinogenesis. However, the role of Stat3 in the Wnt-driven sporadic intestinal tumorigenesis remains poorly understood. We examined the roles of Stat3 in intestinal regeneration and tumorigenesis by organoid culture experiments using Stat3 mouse-derived intestinal epithelial cells in which Stat3 was disrupted. The regeneration of intestinal mucosa and organoid formation were significantly suppressed by Stat3 disruption, which was compensated by Wnt activation. Furthermore, once organoids were recovered, Stat3 was no longer required for organoid growth. These results indicate that Stat3 and Wnt signaling cooperatively protect epithelial cells at the early phase of intestinal regeneration. In contrast, intestinal tumorigenesis was not suppressed by Stat3 disruption in adenomatous polyposis coli ( Apc) and Apc Tgfbr2 mice, thus indicating that Stat3 is not required for Wnt activation-driven intestinal tumorigenesis. Mechanistically, Itga5 and Itga6 were down-regulated by Stat3 disruption, and focal adhesion kinase (FAK) activation was also suppressed. Notably, FAK inhibitor suppressed the organoid formation of wild-type epithelial cells. These results indicate that Stat3 is indispensable for the survival of epithelial cells through the activation of integrin signaling and the downstream FAK pathway; however, it is not required for the Wnt signaling-activated normal or tumor epithelial cells.-Oshima, H., Kok, S.-Y., Nakayama, M., Murakami, K., Voon, D. C.-C., Kimura, T., Oshima, M. Stat3 is indispensable for damage-induced crypt regeneration but not for Wnt-driven intestinal tumorigenesis.

Background The Australian black swan (Cygnus atratus) is an iconic species with contrasting plumage to that of the closely related northern hemisphere white swans. The relative geographic isolation of the black swan may have resulted in a limited immune repertoire and increased susceptibility to infectious diseases, notably infectious diseases from which Australia has been largely shielded. Unlike mallard ducks and the mute swan (Cygnus olor), the black swan is extremely sensitive to highly pathogenic avian influenza. Understanding this susceptibility has been impaired by the absence of any available swan genome and transcriptome information. Results Here, we generate the first chromosome-length black and mute swan genomes annotated with transcriptome data, all using long-read based pipelines generated for vertebrate species. We use these genomes and transcriptomes to show that unlike other wild waterfowl, black swans lack an expanded immune gene repertoire, lack a key viral pattern-recognition receptor in endothelial cells and mount a poorly controlled inflammatory response to highly pathogenic avian influenza. We also implicate genetic differences in SLC45A2 gene in the iconic plumage of the black swan. Conclusion Together, these data suggest that the immune system of the black swan is such that should any avian viral infection become established in its native habitat, the black swan would be in a significant peril.

No abstract

Canine malignant melanoma is a common cancer with a high mortality rate and is a clinically important disease. DNA methylation has been considered to be a potential tumorigenic mechanism through aberrant DNA methylation at promoter region which represses gene transcription. Global hypomethylation could also facilitate chromosome instability. There are few reports regarding DNA methylation in canine malignant melanoma; therefore, the purpose of this study was to examine DNA methylation status of long interspersed nucleotide element-1 (LINE-1) to be a surrogate marker of genome-wide methylation changes in this disease. We measured levels of DNA methylation of two adjacent cytosine-guanine sites on CpG island (CGI) at the putative promoter of canine LINE-1 sequence by bisulphite-pyrosequencing in 41 canine melanoma patient samples as well as six cell lines compared with normal mucosae. The survival rates were obtained from owners or medical records. We found DNA methylation levels of LINE-1 in normal mucosae were methylated. Interestingly, both melanoma cell lines and clinical melanoma samples showed remarkable hypomethylation. In addition, patients with lower LINE-1 methylation showed worse prognosis than those with higher LINE-1 methylation, though the difference did not reach statistical significance (P = .09). Here, we demonstrate that hypomethylation of LINE-1 is an epigenetically aberrant feature in canine melanoma with possible prognostic value.

In this study, a probabilistic analysis to predict landslide runout based on an inventory of snowmelt-induced landslide disasters with consideration of differences in the topographic features of travel paths was conducted. The inventory included 76 landslides that occurred during snowfall/snowmelt periods between 1947 and 2012. These landslides were divided into three groups based on a topographic classification using GIS analysis. The probability of a landslide traveling for a specific distance and its traveling ratio were examined for each group by fitting the empirical cumulative distributions to exponential distribution functions. The fitted exponential distribution functions and outcomes of the estimations were very similar for landslides traveling along floodplain (FP) and slope (SL), despite differences in the slope gradients of the travel paths. The probability that landslide runout would exceed the criteria of the Sediement Disaster Prone Areas (SDPAs) was <1% for the FP and SL groups. In contrast, landslides traveling along headwater channel (HC) were likely to travel further than the criteria, particularly in landslide-initiated debris flows. Even if their travel distances was restricted to the movement of displaced mass by initial landslides, HC landslides tended to travel further than the other landslide groups.