Elevated Alpha 1(I) to Alpha 2(I) Collagen Ratio in Dermal Fibroblasts Possibly Contributes to Fibrosis in Systemic Sclerosis.

Systemic sclerosis (SSc) is characterized by excessive collagen deposition in the skin and internal organs. Activated fibroblasts are the key effector cells for the overproduction of type I collagen, which comprises the α1(I) and α2(I) chains encoded by COL1A1 and COL1A2, respectively. In this study, we examined the expression patterns of α1(I) and α2(I) collagen in SSc fibroblasts, as well as their co-regulation with each other. The relative expression ratio of COL1A1 to COL1A2 in SSc fibroblasts was significantly higher than that in control fibroblasts. The same result was observed for type I collagen protein levels, indicating that α2(I) collagen is more elevated than α2(I) collagen. Inhibition or overexpression of α1(I) collagen in control fibroblasts affected the α2(I) collagen levels, suggesting that α1(I) collagen might act as an upstream regulator of α2(I) collagen. The local injection of COL1A1 small interfering RNA in a bleomycin-induced SSc mouse model was found to attenuate skin fibrosis. Overall, our data indicate that α2(I) collagen is a potent regulator of type I collagen in SSc; further investigations of the overall regulatory mechanisms of type I collagen may help understand the aberrant collagen metabolism in SSc.

Genomic landscape of circulating tumour DNA in metastatic extramammary Paget's disease.

Although cancer personalized profiling by deep sequencing (CAPP-Seq) of cell-free DNA (cfDNA) has gained attention, the clinical utility of circulating tumour DNA (ctDNA) in extramammary Paget's disease (EMPD) has not been investigated. In this study, genomic alterations in the cfDNA and tumour tissue DNA were investigated in seven patients with metastatic EMPD. CAPP-Seq revealed mutations in 18 genes, 11 of which have not yet been reported in EMPD. The variant allele frequency of some of the mutated genes reflected the disease course in patients with EMPD. In one patient, the mutation was detected even though imaging findings revealed no metastasis. In another patient with triple EMPD (genital area and both axilla), cfDNA sequencing detected the mutation in a rib metastatic lesion, which was also detected in both axilla lesions but not the genital region. Investigations of the ctDNA may be useful towards the elucidation of clonal evolution in EMPD.

CXCL17-mediated downregulation of type I collagen via MMP1 and miR-29 in skin fibroblasts possibly contributes to the fibrosis in systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is characterized by excessive deposition of collagen in the skin and internal organs. Recent studies have shown that chemokine (C-X-C motif) ligands (CXCLs) are involved in the pathogenesis of SSc. OBJECTIVE: Our aim was to examine the anti-fibrotic potential of CXCL17, a newly discovered chemokine, in cultured skin fibroblasts and in a bleomycin-induced SSc mouse model. Moreover, we examined serum level of CXCL17 in patients with SSc. METHODS: Type I collagen expression was evaluated in SSc skin and cultured fibroblasts treated with CXCL17 using immunoblotting and quantitative reverse transcription-PCR. Serum CXCL17 levels were determined using enzyme-linked immunosorbent assay in 63 patients with SSc and 17 healthy subjects. A bleomycin-induced SSc mouse model was used to evaluate the effect of CXCL17 on skin fibrosis. RESULTS: CXCL17 reduced the expression of type I collagen in healthy control fibroblasts. CXCL17 also induced matrix metalloproteinase 1 (MMP1) and miR-29 expression in fibroblasts, indicating that CXCL17 regulates type I collagen expression in part via post-transcriptional mechanisms through MMP1 and miR-29. We found that local injection of CXCL17 attenuated bleomycin-induced skin fibrosis in mice. CXCL17 levels in SSc skin were lower than those in healthy controls, in contrast to the high serum CXCL17 levels in patients with SSc. The low expression of CXCL17 in SSc skin possibly affects type I collagen accumulation in this disease. CONCLUSION: Our data indicate that understanding CXCL17 signaling may lead to a better therapeutic approach for SSc.

A potential significance of circ_0024169 down regulation in angiosarcoma tissue.

Circular RNAs (circRNAs) are recently characterized non-coding RNAs that have a closed continuous loop. CircRNAs might play important roles in the oncogenesis of several cancers. However, little is known about association between circRNAs and skin tumors. In this study, we tried to demonstrate the expression change of circ_0024169 in angiosarcoma, and to elucidate correlations between circ_0024169 expression in angiosarcoma tissues and clinical manifestation. RNA expression was evaluated by quantitative real-time PCR with TaqMan systems for circ_0024169 and linear isoform CUL5. Both relative circRNA levels (corrected for EEF1A1 levels) and circRNA levels/linear RNA expression ratio were evaluated. We found that both relative circ_0024169 levels and circ_0024169/CUL5 ratio was decreased in normal human dermal microvascular endothelial cells (HDMEC) and angiosarcoma cell line in vitro, compared to squamous cell carcinoma line. circ_0024169/ CUL5 ratio was significantly reduced in angiosarcoma and pyogenic granuloma than other tumors in vivo, which were more evident than decreased relative circ_0024169 levels. On the other hand, relative circ_0024169 levels showed mild inverse correlation with the follow-up periods (duration between the first hospital visit and the last hospital visit/the date of death) of angiosarcoma patients. Taken together, circ_0024169/CUL5 ratio are likely to be useful as a diagnostic biomarker for vascular tumors, whereas circ_0024169 levels may have more potential as a prognostic marker of angiosarcoma. The future studies of the function of circRNAs may lead to the clarification of detailed mechanism of oncogenesis of angiosarcoma.

Chronic sun exposure-related fusion oncogenes EGFR-PPARGC1A in cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) differs from SCC of other organs in its strong association with chronic sun exposure. However, the specific driver mutations in cSCC remain unknown. Fusion genes in established cSCC cell lines (A431 and DJM-1) were predicted by transcriptome sequence, and validated by Sanger sequence, fluorescence in situ hybridization and G-banding. By transcriptome sequencing, we identified fusion gene EGFR-PPARGC1A in A431, which were expressed in 31 of 102 cSCCs. The lesions harboring the fusion gene tended to be located in sun-exposed areas. In vivo cutaneous implantation of EGFR-PPARGC1A-expressing NIH3T3 induced tumors resembling human cSCC, indicating its potent tumorigenicity. NIH3T3 transfected with EGFR-PPARGC1A as well as A431 showed increased cell proliferation activity. With regard to underlying mechanism, EGFR-PPARGC1A protein causes constitutive tyrosine phosphorylation, and induces the phosphorylation of wild-type full-length epidermal growth factor receptor (EGFR) by dimerization. Conversely, the RNAi-mediated attenuation of EGFR or CRISPR/Cas9-mediated knockdown of the fusion gene in A431 led to a decrease in the cell number, and may have therapeutic value. Our findings advance the knowledge concerning genetic causes of cSCC and the function of EGFR, with potential implications for new diagnostic and therapeutic approaches.

Transforming growth factor ß-inhibitor Repsox downregulates collagen expression of scleroderma dermal fibroblasts and prevents bleomycin-induced mice skin fibrosis.

Inhibition of transforming growth factor (TGF)-ß1 signalling may be one of the most reliable approaches to treat skin fibrosis of scleroderma. Although there have been many basic researches of TGF-ß blockade reagents, few of them were proved to have inhibitory effects on fibrosis both in vitro and in vivo. In this study, we randomly chose four commercially available low molecular weight compounds (Repsox, LY2109761, LY364947 and K02288) from TGF-ß1 inhibitor library, and compared their antifibrotic effects in vitro and in vivo. We demonstrated that Repsox has the most potent inhibitory effects on TGF-ß-induced expression of CTGF and collagen of cultured normal dermal fibroblasts in vitro and their constitutive overexpression of scleroderma fibroblast in vitro. In addition, Repsox could attenuate skin fibrosis by bleomycin in vivo, via the downregulation of CTGF or collagen. Our results may facilitate clinical trial of Repsox against fibrotic diseases in future.