The expression of miR-124 increases in aged skin to cause cell senescence and it decreases in squamous cell carcinoma.

Skin senescence is induced by various factors including intrinsic aging and extrinsic aging. The current study compared the expression of microRNAs in young facial skin and senescent facial skin, and this study identified skin aging-related microRNAs. According to the results from a microRNA PCR Array, miR-124 was the microRNA that increased the most in senescent skin compared to young skin. Real-time PCR with a greater number of samples indicated that the increase in miR-124 levels in senescent facial skin was statistically significant. In situ hybridization was performed, and results indicated that the signal for miR-124 was evident in keratinocytes of senescent skin but not in those of young skin. The morphology of cultured normal human epidermal keratinocytes (NHEKs) transfected with a miR-124 mimic changed to an enlarged and irregular shape. In addition, the number of NHEKs positive for senescence-associated ß-galactosidase (SA-ß-gal) increased significantly as a result of the overexpression of the miR-124 mimic. The expression of miR-124 increased in UVB-irradiated NHEKs compared to controls in a dose-dependent manner. Expression of miR-124 in A431, a human cutaneous squamous cell carcinoma (SCC) cell line, decreased significantly compared to that in NHEKs. Forced overexpression of miR-124 as a result of the transfection of a miR-124 mimic in A431 resulted in the significant suppression of the proportion of cancer cells. The current results indicated that miR-124 increases as a result of cell senescence and that it decreases during tumorigenesis. The effect of supplementation of miR-124 in an SCC cell line suggests that senescence induction therapy with microRNA may be a new therapeutic approach for treatment of SCC.

Establishment and gene expression analysis of disease-derived induced pluripotent stem cells of scleroderma.

BACKGROUND: We recently generated induced pluripotent stem cells (iPSCs) from cultured dermal fibroblasts of systemic sclerosis (SSc-iPSC) to study the disease mechanisms. OBJECTIVE: In the present study, we have performed gene expression analysis using cultured SSc dermal fibroblasts, SSc-iPSC, and fibroblasts re-differentiated from SSc-iPSC (SSc-iPSC-FB). METHODS: mRNA and protein levels of collagen and integrins were analyzed using PCR array, PCR, immunoblotting, and immunofluorescence. RESULTS: We compared expression pattern of TGF-ß-related genes between normal iPSC (NS-iPSC) and SSc-iPSC by PCR array, and found constitutive and significant down-regulation of S100A8, Smad6, and TGF-ß2 in SSc-iPSC. The expression of these genes was not altered in cultured SSc fibroblasts or SSc-iPSC-FB compared to NS fibroblasts or NS-iPSC-FB, respectively. On the other hand, the expression of collagen, integrin α and ß was up-regulated in SSc fibroblasts, while SSc-iPSC-FB showed normalized levels of collagen and integrin ß. CONCLUSIONS: So far, there have been no reports investigating disease-derived iPSCs of SSc. Our results suggest that S100A8, Smad6, and TGF-ß2 may be the key molecules of this disease. On the other hand, the normalization of collagen and integrins by iPSC reprogramming suggests that epigenetic modifications of genes may play a role in the mechanism of collagen accumulation seen in SSc fibroblasts, and that gene reprogramming may become novel therapeutic approach. As the limitation of this study, we established only one iPSC line from each patient, which may not be enough to discuss disease-specific phenotypes. Larger studies including increased number of iPSC lines are needed in the future.

NUP160-SLC43A3 is a novel recurrent fusion oncogene in angiosarcoma.

Angiosarcoma is a malignant vascular tumor originating from endothelial cells of blood vessels or lymphatic vessels. The specific driver mutations in angiosarcoma remain unknown. In this study, we investigated this issue by transcriptome sequencing of patient-derived angiosarcoma cells (ISO-HAS), identifying a novel fusion gene NUP160-SLC43A3 found to be expressed in 9 of 25 human angiosarcoma specimens that were examined. In tumors harboring the fusion gene, the duration between the onset of symptoms and the first hospital visit was significantly shorter, suggesting more rapid tumor progression. Stable expression of the fusion gene in nontransformed human dermal microvascular endothelial cells elicited a gene-expression pattern mimicking ISO-HAS cells and increased cell proliferation, an effect traced in part to NUP160 truncation. Conversely, RNAi-mediated attenuation of NUP160 in ISO-HAS cells decreased cell number. Confirming the oncogenic effects of the fusion protein, subcutaneous implantation of NUP160-SLC43A3-expressing fibroblasts induced tumors resembling human angiosarcoma. Collectively, our findings advance knowledge concerning the genetic causes of angiosarcoma, with potential implications for new diagnostic and therapeutic approaches.