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This study showed that the pathway of miR-141 targeting CXCL12β is a possible mechanism underlying inflammatory cell trafficking during colonic inflammation process. Inhibiting colonic CXCL12β expression and blocking colonic immune cell recruitment by using miRNA precursors represents a promising approach that may be valuable for CD treatment.

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Background: MicroRNA-21 is important in hepatic fibrosis development, but the mechanism is unclear. Results: MicroRNA-21 is predominantly up-regulated in activated hepatic stellate cells and could form a double negative feedback loop that links fibrogenic machinery. Conclusion:The microRNA-21-mediated loop is a main driving force for hepatic fibrosis progression. Significance: It suggests a mechanism for how microRNA-21 contributes to hepatic fibrosis.Sustained activation of hepatic stellate cells (HSCs) leads to hepatic fibrosis, which is characterized by excessive collagen production, and for which there is no available drug clinically. Despite tremendous progress, the cellular activities underlying HSC activation, especially the driving force in the perpetuation stage, are only partially understood. Recently, microRNA-21 (miR-21) has been found to be prevalently up-regulated during fibrogenesis in different tissues, although its detailed role needs to be further elucidated. In the present study, miR-21 expression was examined in human cirrhotic liver samples and in murine fibrotic livers induced by thioacetamide or carbon tetrachloride. A dramatic miR-21 increase was noted in activated HSCs. We further found that miR-21 maintained itself at constant high levels by using a microRNA-21/programmed cell death protein 4/activation protein-1 (miR-21/PDCD4/AP-1) feedback loop. Disrupting this loop with miR-21 antagomir or AP-1 inhibitors significantly suppressed fibrogenic activities in HSCs and ameliorated liver fibrosis. In contrast, reinforcing this loop with small interfering RNA (siRNA) against PDCD4 promoted fibrogenesis in HSCs. Further analysis indicated that the up-regulated miR-21 promoted the central transforming growth factor-␤ (TGF-␤) signaling pathway underlying HSC activation. In summary, we suggest that the miR-21/PDCD4/AP-1 autoregulatory loop is one of the main driving forces for hepatic fibrosis progression. Targeting this aberrantly activated feedback loop may provide a new therapeutic strategy and facilitate drug discovery against hepatic fibrosis.Hepatic fibrosis is a wound healing process in response to chronic liver injuries that leads to unbalanced extracellular matrix (ECM) 3 deposition and resolution. The persistent activation of wound healing responses causes quantitative and qualitative changes in the ECM components and could finally distort liver parenchyma and vascular architecture, which could impair liver function and potentially lead to liver failure and hepatocellular carcinoma. Following liver injury, quiescent hepatic stellate cells (HSCs) transdifferentiate into myofibroblast-like cells that are characterized by the expression of smooth muscle ␣-actin (␣-SMA) and enhanced production of ECM (1). Despite the tremendous progress in understanding the mechanisms during fibrogenesis, the driving force underlying the persistent fibrogenic activities is still only partially understood.Extensive studies have suggested the central role of feedback networks in dictating disease progressi...

MicroRNAs (miRNAs) are naturally occurring, small non-coding RNAs that mediate posttranscriptional regulation. Based on the level of sequence complementarity, miRNAs lead to the degradation of target mRNAs or the suppression of mRNA translation, thereby inhibiting the synthesis of proteins and achieving the regulation of genes. miRNAs, which exhibit tissue-and temporal-specific expression, are important negative regulatory RNAs that decrease the levels of other functional genes. miRNAs play a crucial role in disease progression and prognosis and thus exhibit potential for developing novel therapeutics. Due to the instability of miRNAs and their complex environment, including degradation by nucleases in vivo, the safety and effectiveness of miRNA delivery has become the focus of recent attention. Therefore, we discuss some representative advances related to the application of viral-and nonviral-mediated miRNA delivery systems and provide a new perspective on the future of miRNA-based therapeutic strategies.

Osteosarcoma is the most common primary bone malignancy, and the lung is the most frequent site of metastasis. The limited understanding of the tumoral heterogeneity and evolutionary process of genomic alterations in pulmonary metastatic osteosarcoma impedes development of novel therapeutic strategies. Here we systematically illustrate the genomic disparities between primary tumors and corresponding pulmonary metastatic tumors by multiregional whole-exome and whole-genome sequencing in 86 tumor regions from 10 patients with osteosarcoma. Metastatic tumors exhibited a significantly higher mutational burden and genomic instability compared with primary tumors, possibly due to accumulation of mutations caused by a greater number of alterations in DNA damage response genes in metastatic tumors. Integrated analysis of the architecture and relationships of subclones revealed a dynamic mutational process and diverse dissemination patterns of osteosarcoma during pulmonary metastasis (6/10 with linear and 4/10 with parallel evolution-ary patterns). All patients demonstrated more significant intertumoral rather than intratumoral heterogeneity between primary tumors and metastatic tumors. Mutated genes were enriched in the PI3K-Akt pathway at both the early and late stages of tumor evolution and in the MAPK pathway at the metastatic stage. Conversely, metastatic tumors showed improved immunogenicity, including higher neoantigen load, elevated PD-L1 expression, and tumor-infiltrating lymphocytes than the corresponding primary tumors. Our study is the first to report the dynamic evolutionary process and temporospatial tumor heterogeneity of pulmonary metastatic osteosarcoma, providing new insights for diagnosis and potential therapeutic strategies for pulmonary metastasis.Significance: High-throughput sequencing of primary and metastatic osteosarcoma provides new insights into the diagnosis of and potential clinical therapeutic strategies for pulmonary metastasis.

The ability of TNP-470, a synthetic analog of fumagillin which has been described as an anti-angiogenic agent, to potentiate cytotoxic cancer therapies was investigated in vivo in the murine FSaIIC fibrosarcoma and the Lewis lung carcinoma. TNP-470 was more toxic toward FSaIIC tumor cells from tumors treated in vivo than toward bone-marrow CFU-GM from the same animals. TNP-470 had a dose-modifying effect on the toxicity of cyclophosphamide toward FSaIIC tumor cells which amounted to an 8-fold increase in tumor-cell killing at a cyclophosphamide dose of 500 mg/kg. Treatment with TNP-470 and minocycline increased the permeability of the FSaII fibrosarcoma in vivo to the fluorescent dye Hoechst 33342 and increased the killing of both the bright and the dim tumor cells by cyclophosphamide. TNP-470, especially in combination with minocycline, formed a highly effective modulator combination for treatment of the Lewis lung carcinoma with cytotoxic cancer therapies against primary and metastatic disease. The combination of TNP-470/minocycline and cyclophosphamide led to 40 to 50% long-term survivors in Lewis-lung-carcinoma-bearing animals. Our results indicate that the use of anti-angiogenic modulators in cancer therapy is a very promising area for further study.

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