Tumor-suppressive microRNA-1291 directly regulates glucose transporter 1 in renal cell carcinoma.

Our recent studies of microRNA (miRNA) expression signatures demonstrated that microRNA-1291 (miR-1291) was significantly downregulated in renal cell carcinoma (RCC) clinical specimens and was a putative tumor-suppressive miRNA in RCC. The aim of the present study was to investigate the functional significance of miR-1291 in cancer cells and to identify novel miR-1291-mediated cancer pathways and target genes in RCC. Expression of miR-1291 was significantly downregulated in RCC tissues compared with adjacent non-cancerous tissues. Restoration of mature miR-1291 in RCC cell lines (A498 and 786-O) revealed significant inhibition of cell proliferation, migration and invasion, suggesting that miR-1291 functioned as a tumor suppressor. To identify miR-1291-mediated molecular pathways and targets, we used gene expression analysis (expression of RCC clinical specimens and miR-1291-transfected A498 cells) and in silico database analysis. Our data demonstrated that 79 signaling pathways were significantly regulated by tumor-suppressive miR-1291 in RCC cells. Moreover, solute career family 2 member 1 (SLC2A1) was a candidate target of miR-1291 regulation. The SLC2A1 gene provides instructions for producing glucose transporter protein type 1 (GLUT1). Luciferase reporter assays showed that miR-1291 directly regulated SLC2A1/GLUT1. In RCC clinical specimens, the expression of SLC2A1/GLUT1 mRNA was significantly higher in cancer tissues than in non-cancerous tissues. A significant inverse correlation was recognized between SLC2A1/GLUT1 and miR-1291 expression (r = -0.55, P < 0.0001). Loss of tumor-suppressive miR-1291 enhanced RCC cell proliferation, migration and invasion through targeting SLC2A1/GLUT1. The identification of novel tumor-suppressive miR-1291-mediated molecular pathways and targets has provided new insights into RCC oncogenesis and metastasis.

MicroRNA-218 inhibits cell migration and invasion in renal cell carcinoma through targeting caveolin-2 involved in focal adhesion pathway.

PURPOSE: Our microRNA expression signature of renal cell carcinoma revealed that miR-218 expression was significantly decreased in cancer tissues, suggesting that miR-218 is a candidate tumor suppressor. We investigated the functional significance of miR-218 in cancer cells and identified what are to our knowledge novel miR-218 mediated cancer pathways in renal cell carcinoma. MATERIALS AND METHODS: Gain of function studies using mature miR-218 were performed to investigate cell proliferation, migration and invasion in the A498 and 786-O renal cell carcinoma cell lines. To identify miR-218 mediated molecular pathways and responsible genes in renal cell carcinoma, we used gene expression and in silico database analyses. Loss of function assays were performed to investigate the functional significance of miR-218 target genes. RESULTS: Restoration of mature miR-218 significantly inhibited RCC cell proliferation, migration and invasion. Gene expression studies and luciferase reporter assays showed that CAV2 involved in the focal adhesion pathway was directly regulated by miR-218. A silencing study of CAV2 revealed significant inhibition of cell proliferation, migration and invasion. CAV2 mRNA and protein expression was significantly up-regulated in renal cell carcinoma clinical specimens. CONCLUSIONS: Loss of tumor suppressive miR-218 enhances cancer cell migration and invasion through dysregulation of the focal adhesion pathway, especially CAV2 as an oncogenic function in renal cell carcinoma. Tumor suppressive microRNA mediated cancer pathways and responsible genes provide new insights into the potential mechanisms of renal cell carcinoma oncogenesis and metastasis.

Downregulation of microRNA-1274a induces cell apoptosis through regulation of BMPR1B in clear cell renal cell carcinoma.

Our previous studies of the microRNA (miRNA) expression signature in clear cell renal cell carcinoma (ccRCC) indicated that miRNA-1274a (miR-1274a) was significantly upregulated in clinical specimens, suggesting that miR-1274a may act as an oncogenic miRNA in ccRCC. The aim of this study was to investigate the functional roles of miR-1274a and identify downstream tumor-suppressive targets regulated by miR­1274a in ccRCC cells. Functional studies of miR-1274a were carried out by anti-miRNA to investigate cell proliferation and apoptosis using the A498, ACHN and Caki1 ccRCC cell lines. Suppression of miR-1274a significantly inhibited cancer cell proliferation and induced apoptosis in the ccRCC cells. Gene expression data combined with in silico analysis and luciferase reporter assays demonstrated that bone morphogenetic protein receptor type 1B (BMPR1B) was directly regulated by miR-1274a. Moreover, TCGA database as well as immunohistochemistry demonstrated low expression of BMPR1B in ccRCC clinical specimens compared to that in normal kidney tissues. We conclude that loss of oncogenic miR-1274a reduced cancer cell proliferation and induced apoptosis in ccRCC through targeting BMPR1B. Our data revealing molecular pathways and a target gene regulated by oncogenic miR-1274a provide new insight into the potential mechanisms of ccRCC oncogenesis.

The microRNA expression signature of bladder cancer by deep sequencing: the functional significance of the miR-195/497 cluster.

Current genome-wide microRNA (miRNA) expression signature analysis using deep sequencing technologies can drive the discovery of novel cancer pathways regulated by oncogenic and/or tumor suppressive miRNAs. We determined the genome-wide miRNA expression signature in bladder cancer (BC) by deep sequencing technology. A total of ten small RNA libraries were sequenced (five BCs and five samples of histologically normal bladder epithelia (NBE)), and 13,190,619 to 18,559,060 clean small RNA reads were obtained. A total of 933 known miRNAs and 17 new miRNA candidates were detected in this analysis. Among the known miRNAs, a total of 60 miRNAs were significantly downregulated in BC compared with NBE. We also found that several miRNAs, such as miR-1/133a, miR-206/133b, let-7c/miR-99a, miR-143/145 and miR-195/497, were located close together at five distinct loci and constituted clustered miRNAs. Among these clustered miRNAs, we focused on the miR-195/497 cluster because this clustered miRNA had not been analyzed in BC. Transfection of mature miR-195 or miR-497 in two BC cell lines (BOY and T24) significantly inhibited cancer cell proliferation, migration and invasion, suggesting that the miR-195/497 cluster functioned as tumor suppressors in BC. Regarding the genes targeted by the miR-195/497 cluster, the TargetScan algorithm showed that 6,730 genes were putative miR-195/497 targets, and 113 significantly enriched signaling pathways were identified in this analysis. The "Pathways in cancer" category was the most enriched, involving 104 candidate target genes. Gene expression data revealed that 27 of 104 candidate target genes were actually upregulated in BC clinical specimens. Luciferase reporter assays and Western blotting demonstrated that BIRC5 and WNT7A were directly targeted by miR-195/497. In conclusion, aberrant expression of clustered miRNAs was identified by deep sequencing, and downregulation of miR-195/497 contributed to BC progression and metastasis. Tumor suppressive miRNA-mediated cancer pathways provide new insights into the potential mechanisms of BC oncogenesis.

Treatment of pustular psoriasis with granulocyte and monocyte adsorption apheresis.

We studied the efficacy of granulocyte and monocyte adsorption apheresis in 2 patients with pustular psoriasis, one localized, the other generalized. Treatment with granulocyte and monocyte adsorption apheresis resulted in remarkable clearing of the skin lesions, suggesting that this therapy is a valuable tool for treating patients with intractable skin diseases attributable to activated granulocytes. We present detailed descriptions of these patients and this novel therapy.