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As an outcome of chronic liver disease, liver fibrosis involves the activation of hepatic stellate cells (HSCs) caused by a variety of chronic liver injuries. It is important to explore approaches to inhibit the activation and proliferation of HSCs for the treatment of liver fibrosis. PLK1 is overexpressed in many human tumour cells and has become a popular drug target in tumour therapy. Therefore, further study of the function of PLK1 in the cell cycle is valid. In the present study, we found that PLK1 expression was elevated in primary HSCs isolated from CCl4‐induced liver fibrosis mice and LX‐2 cells stimulated with TGF‐β1. Knockdown of PLK1 inhibited α‐SMA and Col1α1 expression and reduced the activation of HSCs in CCl4‐induced liver fibrosis mice and LX‐2 cells stimulated with TGF‐β1. We further showed that inhibiting the expression of PLK1 reduced the proliferation of HSCs and promoted HSCs apoptosis in vivo and in vitro. Furthermore, we found that the Wnt/β‐catenin signalling pathway may be essential for PLK1‐mediated HSCs activation. Together, blocking PLK1 effectively suppressed liver fibrosis by inhibiting HSC activation, which may provide a new treatment strategy for liver fibrosis. [ABSTRACT FROM AUTHOR]

Temozolomide (TMZ) is a promising chemotherapeutic agent for treating glioblastomas. However, resistance develops quickly and with a high frequency. Efforts to overcome chemoresistance are, therefore, critically needed. In present study, a poly(amidoamine; PAMAM) dendrimer was used as a vector to deliver microRNA-21 inhibitor (miR-21i) into U87 cells and the chemosensitivity of the combination effect of miR-21i and TMZ for glioma therapy was investigated. Flow cytometry analysis showed the uptake efficiency of microRNA-21 inhibitor after complexation with PAMAM. Real-time PCR and in situ hybridization indicated that, compared with TMZ or miR-21i treated cells, cells simultaneously treated with miR-21i and TMZ showed a remarkable decrease in the microRNA-21 (miR-21) level. The transfection of miR-21i enhanced the chemosensitivity by significantly decreasing the IC50 value of TMZ to glioma cells. Knockdown of miR-21 promoted the cells' apoptosis, and at the same time, inhibited cell invasion. In conclusion, the combination treatment of glioma cells with TMZ and miR-21i could yield a synergistic effect in inhibition of human glioma cell line. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012 [ABSTRACT FROM AUTHOR]