DZNep raises miR-200c expression to delay the invasion and migration of MGC-803 gastric carcinoma cells / 生理学报

The aim of the present study was to investigate the regulatory effects of histone methylation modifications on the expression of miR-200c, as well as invasion and migration of gastric carcinoma cells. Gastric carcinoma cell line, MGC-803, were treated by 2.5 μmol/L histone methyltransferase inhibitor, DZNep. The expression of miR-200c was detected by real-time quantitative PCR (qRT-PCR). The epithelial-mesenchymal transition (EMT) indicators (ZEB1/2 and E/N-cadherin), EZH2, EED, SUZ12 and H3K27me3 expressions were detected by Western blot. Cell migration and invasion abilities were detected by Transwell and scratch tests. The result showed that, compared with DMSO (control) group, DZNep significantly increased the expression of miR-200c to about 2.1 times, inhibited ZEB1, ZEB2, and N-cadherin expressions, and activated E-cadherin expression; Also, DZNep decreased the protein expressions of EZH2, EED, SUZ12 and H3K27me3; Moreover, DZNep could inhibit MGC-803 cell invasive and migrative abilities, as well as MMP9 expression. These results suggest DZNep raises miR-200c expression to delay the invasion and migration of gastric carcinoma cells, and the underlying mechanisms involve the regulations of EMT-related proteins and polycomb repressive complex 2.

Preliminary study on aberrant expression of miRNAs related to the formation of the distinction between pediatric and adult types of brainstem gliomas / 中华外科杂志

<p><b>OBJECTIVES</b>To study the different expression of miRNA between pediatric and adult types of brainstem gliomas, and to provide the target miRNAs for explore the mechanism and miRNA interference of the malignant progression of pediatric BSG.</p><p><b>METHODS</b>miRNA expression profiles in orthotopic models which could simulate the BSG heterogeneity were examined by microarray and analyzed to obtain the aberrantly expressed miRNAs. The two types of human BSG tissue were utilized to verify the microarray data by qRT-PCR and in situ hybridization for the putative causative miRNAs.</p><p><b>RESULTS</b>There were 216 miRNAs detected in both the pediatric BSG group and the adult BSG group, 39 miRNAs to be differential expressed in the pediatric BSG group versus adult group, including 10 up-regulated and 29 down-regulated. qRT-PCR and in situ hybridization indicated good consistency with that of the microarray method.</p><p><b>CONCLUSIONS</b>Aberrantly expressed miRNA may serve as putative causative involvement of malignant progression of pediatric BSG, thereby might be potentially novel targets for therapy.</p>

The effect of silencing Dicer by small interference RNA on the biological characteristics of human glioma cells / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the effect of silencing Dicer by small interference RNA (siRNA) to suppress the global microRNA (miRNAs) expression on the biological characteristics of TJ905 glioblastoma cells.</p><p><b>METHODS</b>The silencing effect of RNA interference on Dicer expression was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis and immunofluorescence staining. The cell proliferation rate and cell cycle kinetics were detected by MTT assay and flow cytometry respectively, and the cell invasive ability was evaluated by transwell assay.</p><p><b>RESULTS</b>The siRNA targeting Dicer suppressed the expression of Dicer in TJ905 cells. Meanwhile, the proliferation activity and invasive ability were significantly enhanced in cells transfected with Dicer siRNA compared to those cells transfected with scrambled siRNA and the control cells.</p><p><b>CONCLUSION</b>Suppression of Dicer expression renders the glioma cells harboring more aggressive phenotype. This preliminary finding suggests that global lower expression of miRNAs may play an oncogenic role.</p>

Inhibitory effect of knocking down microRNA-221 and microRNA-222 on glioma cell growth in vitro and in vivo / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the inhibitory effect of knocking down microRNA(miR)-221 and miR-222 on human glioma cell growth and its possible mechanism.</p><p><b>METHODS</b>miRNA-221/222 antisense oligonucleotides (antisense miR221/222) were transfected into human glioma U251 cells by lipofectamine. Northern blot analysis was conducted to detect the mRNA expression of miR-221/222 in the control and transfected cell groups. The proliferation activity of cells was determined by MTT assay. Cell invasion ability was examined by transwell assay, and cell cycle kinetics and apoptosis were detected with flow cytometry. The expression of relevant proteins was analyzed by Western blotting. The therapeutic efficacy of antisense miR221/222 on the growth of xenograft tumors in nude mice were also observed.</p><p><b>RESULTS</b>In the antisense miR-221/222-transfected cells, the expression of miR-221/222 was significantly reduced; the cell invasion ability was suppressed, cell cycle was blocked at G(0)/G(1) phase, and apoptotic cells were increased. The growth of xenograft tumors treated with antisense miR-221/222 was also inhibited. In antisense miR-221/222 treated tumor cells, the expression of bcl-2 was down-regulated while connexin43, p27, PUMA, caspase-3, PTEN, TIMP3 and Bax up-regulated, and p53 expression not changed.</p><p><b>CONCLUSION</b>There is a significant inhibitory effect of antisense miR-221/222 on the growth of human glioma U251 cells. miR-221/222 may be considered as a candidate target for gene therapy of human gliomas.</p>

Study on the anti-invasion effect of SEPT7 gene for U251MG glioma cell in vitro / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the anti-invasion effect of SEPT7 gene on U251MG glioma cells and its possible molecular mechanism.</p><p><b>METHODS</b>Recombinant adenovirus vector carrying SEPT7 gene (rAd5-SEPT7) was transduced to human glioma cell line U251MG, and empty adenovirus vector was used as control. Tumor invasion was examined by Transwell method and 3 D-Matrigel assay, and tumor cell migration by wound-healing method and 2 D-Matrigel assay. Three major molecular events associated with cell motility and migration, including changes of expression in MMP2, MMP9, MT1-MMP, TIMP1 and TIMP2, the alteration of integrin alpha(v)beta(3) expression, and the structural change of cytoskeleton protein, tubulin-alpha, in U251 cells transduced with rAd5-SEPT7 were studied by Western blotting, immunofluorescence and laser scanning confocal microscope, respectively.</p><p><b>RESULTS</b>The invasive and migratory capabilities of cells transduced with rAd5-SEPT7 were inhibited. The expression of extracellular matrix metalloproteinases MMP-2, MMP-9, MT1-MMP and integrin alpha(v)beta(3) was significantly decreased, while the expression of matrix metalloproteinase inhibitor TIMP1, TIMP2 was upregulated. Intracellular cytoskeleton protein-tubulin-alpha in U251 cells exhibited prominent morphological changes which including the appearance of distortion and aggregation resulting from redistribution of tubulin-alpha, and this feature of alteration was similar to the tubulin-alpha structure in normal non-tumor cells.</p><p><b>CONCLUSION</b>SEPT7 gene can inhibit the invasion and migration ability of U251 glioma cells. Its molecular mechanism may include that SEPT7 gene reverses the imbalanced state of MMPs/TIMPs, downregulates the expression of integrin alpha(v)beta(3) and alters the structure of tubulin-alpha of U251MG glioma cells. It is suggested that SEPT7 gene could be a good candidate for gene therapy of gliomas.</p>

A study on the chemical constituents from Polyporus ellissi / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of Polyporus ellissi.</p><p><b>METHOD</b>Silica gel column chromatography was applied for the isolation and purification of the constituents. The structures were established by means of spectroscopic and chemical data.</p><p><b>RESULT</b>Six compounds were obtained and identified as cerebroside B (I), cerebroside D (II), ergosterol peroxide (III), 9(11)-dehydroergosterol peroxide (IV), mannitol (V) and palmitate-1-glycerol (VI).</p><p><b>CONCLUSION</b>Compounds (I) and (II) were isolated from the genus Polyporus for the first time.</p>