To explore the clinical significance of seven diabetes-related serum microRNAs (miR-9, miR-29a, miR-30d, miR34a, miR-124a, miR146a and miR375) during the pathogenesis of type 2 diabetes (T2D), 56 subjects were recruited to this study: 18 cases of newly diagnosed T2D (n-T2D) patients, 19 cases of pre-diabetes individuals (impaired glucose tolerance [IGT] and/or impaired fasting glucose [IFG]) and 19 cases of T2D-susceptible individuals with normal glucose tolerance (s-NGT). Serum miRNAs were determined by real-time RT-PCR. Expression levels of single miRNAs and the expression signatures of miRNAs as a panel were analysed among the three groups. In n-T2D, all 7 miRNAs were significantly up-regulated compared with s-NGT and five were significantly up-regulated compared with pre-diabetes, while miRNA expression was not significantly different between s-NGT and pre-diabetes. By Canonical discriminant analysis, 70.6% of n-T2D subjects (12/17) were recognized by canonical discriminant function, while s-NGT and pre-diabetes subjects could not be discriminated from each other. Similar results were found in Hierarchical Clustering analysis based on the expression levels of all seven miRNAs. In different statistical analysis, miR-34a always showed the most significant differences. We conclude that the expression levels of seven diabetes-related miRNAs in serum were significantly elevated in n-T2D compared with pre-diabetes and/or s-NGT, and the latter two groups featured similar expression patterns of these miRNAs, suggesting that during the pathogenesis of T2D, the peripheral diabetes-related miRNAs have not changed significantly from s-NGT at pre-diabetic stage.

Obesity is associated with a state of chronic, low-grade inflammation characterized by abnormal cytokine production and macrophage infiltration into adipose tissue, which may contribute to the development of insulin resistance. During immune responses, tissue infiltration by macrophages is dependent on the expression of osteopontin, an extracellular matrix protein and proinflammatory cytokine that promotes monocyte chemotaxis and cell motility. In the present study, we used a murine model of diet-induced obesity to examine the role of osteopontin in the accumulation of adipose tissue macrophages and the development of insulin resistance during obesity. Mice exposed to a high-fat diet exhibited increased plasma osteopontin levels, with elevated expression in macrophages recruited into adipose tissue. Obese mice lacking osteopontin displayed improved insulin sensitivity in the absence of an effect on diet-induced obesity, body composition, or energy expenditure. These mice further demonstrated decreased macrophage infiltration into adipose tissue, which may reflect both impaired macrophage motility and attenuated monocyte recruitment by stromal vascular cells. Finally, obese osteopontin-deficient mice exhibited decreased markers of inflammation, both in adipose tissue and systemically. Taken together, these results suggest that osteopontin may play a key role in linking obesity to the development of insulin resistance by promoting inflammation and the accumulation of macrophages in adipose tissue.

LncRNAs have critical roles in various biological processes ranging from embryonic development to human diseases, including cancer progression, although their detailed mechanistic functions remain illusive. The lncRNA linc-ROR has been shown to contribute to the maintenance of induced pluripotent stem cells and embryonic stem cells. In this study, we discovered that linc-ROR was upregulated in breast tumor samples, and ectopic overexpression of linc-ROR in immortalized human mammary epithelial cells induced an epithelial-to-mesenchymal transition (EMT) program. Moreover, we showed that linc-ROR enhanced breast cancer cell migration and invasion, which was accompanied by generation of stem cell properties. Contrarily, silencing of linc-ROR repressed breast tumor growth and lung metastasis in vivo. Mechanistically, our data revealed that linc-ROR was associated with miRNPs and functioned as a competing endogenous RNA to mi-205. Specifically, linc-ROR prevented the degradation of mir-205 target genes, including the EMT inducer ZEB2. Thus our results indicate that linc-ROR functions as an important regulator of EMT and can promote breast cancer progression and metastasis through regulation of miRNAs. Potentially, the findings of this study implicate the relevance of linc-ROR as a possible therapeutic target for aggressive and metastatic breast cancers.

Tumor-associated macrophages (TAMs) are the most abundant inflammatory infiltrates in the tumor microenvironment and contribute to lymph node (LN) metastasis. However, the precise mechanisms of TAMs-induced LN metastasis remain largely unknown. Herein, we identify a long noncoding RNA, termed Lymph Node Metastasis Associated Transcript 1 (LNMAT1), which is upregulated in LN-positive bladder cancer and associated with LN metastasis and prognosis. Through gain and loss of function approaches, we find that LNMAT1 promotes bladder cancer-associated lymphangiogenesis and lymphatic metastasis. Mechanistically, LNMAT1 epigenetically activates CCL2 expression by recruiting hnRNPL to CCL2 promoter, which leads to increased H3K4 tri-methylation that ensures hnRNPL binding and enhances transcription. Furthermore, LNMAT1-induced upregulation of CCL2 recruits macrophages into the tumor, which promotes lymphatic metastasis via VEGF-C excretion. These findings provide a plausible mechanism for LNMAT1-modulated tumor microenvironment in lymphatic metastasis and suggest that LNMAT1 may represent a potential therapeutic target for clinical intervention in LN-metastatic bladder cancer.