Regulation of muscle mass by microRNAs / 体力科学

Skeletal muscle is a vital tissue not only for maintaining posture and body movements but also for energy metabolism in human body. Skeletal muscle is highly plastic in response to various stimuli, resistance exercise or anabolic hormones can increase muscle mass, which is termed “muscle hypertrophy”. Contrary, immobility, aging and severe illness can reduce muscle mass, which is termed “muscle atrophy”. Loss of skeletal muscle mass is associated with loss of independent living, the morbidity of a variety of diseases and mortality throughout life. Therefore, understanding mechanisms that regulate skeletal muscle mass is essential for improving the quality of life. Recent studies reported microRNAs (miRNAs), which is a class of non-coding RNAs, play a crucial role in the regulation of muscle mass. This review provides a current understanding of the function of miRNAs in regulation of skeletal muscle mass.

A sinonasal yolk sac tumor in an adult

Yolk sac tumors (YSTs), which are also called endodermal sinus tumors, are malignant tumors of germ cell origin. These tumors usually occur in the gonads, but 20% of cases have been reported at extragonadal sites. The head and neck is a rarely affected region that accounts for just 1% of all malignant tumors of germ cell origin. In addition, YSTs arise mostly in childhood. We present a rare pathologically pure case of primary adult YST in the sinonasal area. A 45-year-old male patient presented with a rapidly growing mass in the nasal cavity, which caused nasal obstruction and bloody post-nasal drip. The histopathologic features indicated pure YST, and immunohistochemical analysis revealed positive reactivity for Sal-like protein 4 and alpha-fetoprotein. Herein, we discuss the clinical, radiologic, and histologic features of this YST and review other cases of sinonasal YST in adults.

Spatial Distribution and Prognostic Implications of Tumor-Infiltrating FoxP3- CD4+ T Cells in Biliary Tract Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The clinical implications of tumor-infiltrating T cell subsets and their spatial distribution in biliary tract cancer (BTC) patients treated with gemcitabine plus cisplatin were investigated. @*Materials and Methods@#A total of 52 BTC patients treated with palliative gemcitabine plus cisplatin were included. Multiplexed immunohistochemistry was performed on tumor tissues, and immune infiltrates were separately analyzed for the stroma, tumor margin, and tumor core. @*Results@#The density of CD8+ T cells, FoxP3- CD4+ helper T cells, and FoxP3+ CD4+ regulatory T cells was significantly higher in the tumor margin than in the stroma and tumor core. The density of LAG3- or TIM3-expressing CD8+ T cell and FoxP3- CD4+ helper T cell infiltrates was also higher in the tumor margin. In extrahepatic cholangiocarcinoma, there was a higher density of T cell subsets in the tumor core and regulatory T cells in all regions. A high density of FoxP3- CD4+ helper T cells in the tumor margin showed a trend toward better progression-free survival (PFS) (p=0.092) and significantly better overall survival (OS) (p=0.012). In multivariate analyses, a high density of FoxP3- CD4+ helper T cells in the tumor margin was independently associated with favorable PFS and OS. @*Conclusion@#The tumor margin is the major site for the active infiltration of T cell subsets with higher levels of LAG3 and TIM3 expression in BTC. The density of tumor margin-infiltrating FoxP3- CD4+ helper T cells may be associated with clinical outcomes in BTC patients treated with gemcitabine plus cisplatin.

Lymph node size and its association with nodal metastasis in ductal adenocarcinoma of the pancreas

Background@#Although lymph node metastasis is a poor prognostic factor in patients with pancreatic ductal adenocarcinoma (PDAC), our understanding of lymph node size in association with PDAC is limited. Increased nodal size in preoperative imaging has been used to detect node metastasis. We evaluated whether lymph node size can be used as a surrogate preoperative marker of lymph node metastasis. @*Methods@#We assessed nodal size and compared it to the nodal metastatic status of 200 patients with surgically resected PDAC. The size of all lymph nodes and metastatic nodal foci were measured along the long and short axis, and the relationships between nodal size and metastatic status were compared at six cutoff points. @*Results@#A total of 4,525 lymph nodes were examined, 9.1% of which were metastatic. The mean size of the metastatic nodes (long axis, 6.9±5.0 mm; short axis, 4.3±3.1 mm) was significantly larger than that of the non-metastatic nodes (long axis, 5.0±4.0 mm; short axis, 3.0±2.0 mm; all p<.001). Using a 10 mm cutoff, the sensitivity, specificity, positive predictive value, overall accuracy, and area under curve was 24.8%, 88.0%, 17.1%, 82.3%, and 0.60 for the long axis and 7.0%, 99.0%, 40.3%, 90.6%, and 0.61 for the short axis, respectively. @*Conclusions@#The metastatic nodes are larger than the non-metastatic nodes in PDAC patients. However, the difference in nodal size was too small to be identified with preoperative imaging. The performance of preoperative radiologic imaging to predict lymph nodal metastasis was not good. Therefore, nodal size cannot be used a surrogate preoperative marker of lymph node metastasis.

Enhanced skin wound healing by a sustained release of growth factors contained in platelet-rich plasma

Platelet-rich plasma (PRP) contains growth factors that promote tissue regeneration. Previously, we showed that heparin-conjugated fibrin (HCF) exerts the sustained release of growth factors with affinity for heparin. Here, we hypothesize that treatment of skin wound with a mixture of PRP and HCF exerts sustained release of several growth factors contained in PRP and promotes skin wound healing. The release of fibroblast growth factor 2, platelet-derived growth factor-BB, and vascular endothelial growth factor contained in PRP from HCF was sustained for a longer period than those from PRP, calcium-activated PRP (C-PRP), or a mixture of fibrin and PRP (F-PRP). Treatment of full-thickness skin wounds in mice with HCF-PRP resulted in much faster wound closure as well as dermal and epidermal regeneration at day 12 compared to treatment with either C-PRP or F-PRP. Enhanced skin regeneration observed in HCF-PRP group may have been at least partially due to enhanced angiogenesis in the wound beds. Therefore, this method could be useful for skin wound treatment.