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>

Construction of recombinant adenovirus vector expressing shRNAs targeting COX-2, AKT1 and PIK3R1 gene and its inhibition effect on proliferation of human gastric adenocarcinoma / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To construct a recombinant adenovirus vector that expresses small hairpin RNAs (shRNA) against COX-2, AKT1 and PIK3R1 gene and to evaluate its potential for suppressing the cell proliferation of human gastric adenocarcinoma SGC701 cell in vitro and in vivo, which will enable the development of a gene therapy protocol for the treatment of human gastric adenocarcinoma.</p><p><b>METHODS</b>Three strips of shRNA targeting AKT1, COX-2 and PIK3R1, was subcloned into adenovirus expression vector. After verification, it was amplified and titered. The recombinant adenovirus expression vector was infected into human gastric adenocarcinoma SGC7901 cells in vitro and the infected cells were injected in nude mice. The mRNA and protein expression levels of AKT1, COX-2 and PIK3R1 were determined by real-time PCR and Western blot respectively. Cell proliferation in vitro was determined by methyl thiazolyltetrazolium (MTT) assay and flow cytometry, tumor growth in vivo was measured by volume of tumor in nude mice.</p><p><b>RESULTS</b>Restriction digestion and sequencing analysis showed that the rAd5-C-A-P adenovirus expression vector was constructed successfully. It significantly inhibited the expression of AKT1, COX-2 and PIK3R1, and cell growth was inhibited over 70% as indicated by MTT assay and accompanied with G0/G1 phase arrest. Cell growth on matrigel matrix showed that the rAd5-C-A-P transfected cells were detached from the matrix or grew in a scattered clustering pattern, indicating poor cell growth activities in 2-D matrigel. Tumor growth in nude mice in the C + A + P group was inhibited (P<0.01).</p><p><b>CONCLUSION</b>shRNA targeting COX-2, AKT1 and PIK3R1 down regulated significantly the expression of the three genes in a sequence-specific manner, exerted proliferation inhibition effect on SGC7901 cells in vitro and in vivo.</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>

Differential expression of Notch1 and Notch2 in astrocytoma and medulloblastoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To detect the differential expression of Notch1 and Notch2 in human astrocytoma and medulloblastoma; and to study the role of Notch1 and Notch2 in the development of both tumors.</p><p><b>METHODS</b>Immunohistochemical staining (SP method) and Western blot analysis were used to detect Notch1 and Notch2 expression in tissue arrays and freshly resected samples of normal brain tissue, astrocytoma and medulloblastoma.</p><p><b>RESULTS</b>Notch1 and Notch2 were negative in normal human brain tissue. Notch1 was highly expressed (total positive rate 80.0%, 48/60) while Notch2 was not detected in grade IV astrocytomas and sporadically observed in lower grade astrocytomas (total positive rate 10.0%, 6/60). The percentage of positive tumor cells and expression level of Notch1 increased with higher histologic grade (r = 0.859, P < 0.05). On the other hand, overexpression of Notch2 was detected in medulloblastoma (9/10) in contrast with lower expression of Notch1 (2/10).</p><p><b>CONCLUSIONS</b>Notch1 and Notch2 show differential expression in astrocytoma and medulloblastoma. This may be related to their different functional activities during the process of brain development.</p>

Influence of SEPT7 on biological characters of glioma cell line TJ905 / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the influence of SEPT7 on biological characters of gliomas cells TJ905.</p><p><b>METHODS</b>Recombinant SEPT7 constructs was transfected to human glioblastoma cell line TJ905 in which SEPT7 expression is absent. The positive clones were identified by RT-PCR and Western blot analysis. The cell proliferation was determined by MTT assay and flow cytometry, cell apoptosis was detected with Annexin V staining and cell invasion was evaluated by motility in three-dimensional culture. Moreover, the molecules regulating the cell cycle progression were examined by immunofluorescence staining and Western blot analysis.</p><p><b>RESULTS</b>When SEPT7 was successfully transfected to TJ905 cells, the cell proliferation activity of TJ905 cell was inhibited, the cell cycle was arrested in G0/G1 phase and S phase fraction (SPF) was lowered, the positive regulatory molecules for cell cycle progression including cyclin D1, CDk4, cyclin E and CDk2 were downregulated while the negative modulators including p16 and p21 were upregulated, apoptotic cells were increased and cell invasive ability was attenuated.</p><p><b>CONCLUSIONS</b>Transfection of SEPT7 construct into the glioma cells TJ905 is able to inhibit the proliferation activity and invasive ability of TJ905 cell and to induce cell apoptosis. These results revealed that SEPT7 exerted the suppressive effect on the glioma cell growth and invasion, and induced apoptosis, and suggested that SEPT7 as a gene of glioma suppressor.</p>

The application of tunica vaginalis flap in urethral repair / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the application of tunica vaginalis flap in repairing the deformity of urethra and urethral fistulas.</p><p><b>METHODS</b>Tunica vaginalis flap from the scrotum were used to wrap the reconstructed urethra in the 38 cases of hypospadias urethroplasty and urethral fistulas repair from 2002.</p><p><b>RESULTS</b>All of cases were followed up for six months to one year. There was a fistula reoccurred after epispadias fistula repair, the repair was successful in other patients. There was no recurrent fistulas or urethral strictures. Penile cosmesis was excellent and erected well.</p><p><b>CONCLUSIONS</b>The application of tunica vaginalis flap in urethral repair can raise achievement ratio and reduce the incidence of urethral fistulas. The flap is ease to mobilize with no harmful effects on the testicles.</p>

Construction of multifunctonal nano-delivery system crossing blood brain barrier / 中国医学科学院学报

<p><b>OBJECTIVE</b>To construct multifunctonal nano-delivery system crossing the blood brain barrier (BBB).</p><p><b>METHODS</b>The magnetic nanoparticles were preprared with O-carboxylmethylated chitosan (O-CMC) and conjugated with a peptide sequence from the human immunodeficiency virus 1-tat protein and transferrin (Tf), and anti-tumor drug methotrexate (MTX), and thus constructed a O-CMC magnetic nanoparticles carrier system conjugating with Tat and Tf (O-MNPs-Tat-Tf) that combines multiple functions including crossing BBB, magnetism, receptor-mediated dual targets and anti-tumor capabilities. The appearance, diameter, and magnetism of MTX-O-MNPs-Tat-Tf carrier system were characterized with transmission electronic microscopy, atomic force microscopy and vibrating samples magnetometer. The cytotoxicity of MTX-loaded O-MNPs-Tat-Tf was investigated with C6 glioma cells. The ability of O-MNPs-Tat-Tf crossing BBB was investigated in rats by single photon emission computed tomography.</p><p><b>RESULTS</b>The mean particle diameter was 75 nm, along with good anti-tumor property. The multi-functioned carrier system successfully crossed the BBB in rat.</p><p><b>CONCLUSION</b>The establishment of MTX-O-MNPs-Tat-Tf carrier model implies a promising future for its application in therapy of cerebral diseases.</p>

Correction of pediatric concealed penis by using a modified Devine' s technique / 中华整形外科杂志

<p><b>OBJECTIVE</b>To discuss the diagnosis of pediatric concealed penis and evaluate the results after the correction of the pediatric concealed penis.</p><p><b>METHODS</b>Twenty patients with pediatric concealed penis were treated by using a modified Devine's technique.</p><p><b>RESULTS</b>The appearance with a straightening penile was achieved in all of the patients. All of the patients recovered well after the operation without any complications.</p><p><b>CONCLUSIONS</b>The modified Devine' s technique could be a safe and effective method for the correction of the pediatric concealed penis with satisfactory outcome.</p>

Expression vector for the inhibitor of growth-1 gene is constructed and the NLS-GFP fusion protein expresses in MRC-5 cells / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To construct the NLS(ING1)-GFP vector, transfer it into MRC-5 cells and establish a cell model expressing NLS (ING1)-GFP fusion protein.</p><p><b>METHODS</b>Firstly, cDNA fragment of nuclear locating sequence (NLS) of inhibitor of growth-1 gene (ING1) was gained by RT-PCR and inserted into multi-clone site of pEGFP-C1 to construct the NLS (ING1)-GFP expression vector. Then the vector was used to transfect the MRC-5 cells to observe the subcellular signal localization of green fluorescence protein (GFP).</p><p><b>RESULTS</b>We successfully constructed the expressing vector of NLS (ING1)-GFP fusion protein. After transferring the fusion expressing vector into MRC-5 cells, we observed that green fluorescence signal located in the cell nucleus. However, the green fluorescence signal located in the cytoplasm in MRC-5 cells transfected with pEGFP-C1 control only expressing GFP.</p><p><b>CONCLUSION</b>In living cells, physiologically p33 ING1b locates absolutely in nucleus. The p33(ING1b) NLS plays a decisive role in the transporting process of subcellular localization.</p>

Study on the expression of epidermal growth factor receptor and p53 in astrocytic gliomas: evidence for a distinct genetic pathway / 中华病理学杂志

<p><b>OBJECTIVE</b>To study further the most important and frequent genetic alterations of p53 and epidermal growth factor receptor (EGFR) in astrocytic gliomas.</p><p><b>METHODS</b>(1) EGFR expression was examined in samples collected from 37 astrocytic gliomas and 6 normal brain tissue using reverse transcriptase polymerase chain reaction and immunohistochemical staining. (2) p53 gene mutation and accumulation were detected simultaneously in the same specimens using PCR-SSCP, DNA sequencing and immunohistochemical staining.</p><p><b>RESULTS</b>The frequency of p53 mutation in diffuse astrocytomas, anaplastic astrocytomas, primary glioblastomas and secondary glioblastomas was 1/10, 4/19 (21.1%), 4/6 and 2/2, respectively and the frequency of EGFR overexpression was 5/10, 10/19 (52.6%), 5/6 and 2/2, respectively. Both p53 accumulation and EGFR overexpression increased accompanied by a successive increase of degree of the glioma malignancy.</p><p><b>CONCLUSIONS</b>EGFR overexpression is not infrequently seen, however, p53 mutation is rarely seen in the low grade gliomas. Both p53 gene mutation and EGFR overexpression are often associated with primary and secondary glioblastoma. Consequently, EGFR overexpression and p53 gene mutation are not mutually exclusive in astrocytic gliomagenesis but synergistically to promote the glioma progression.</p>

Preliminary analysis on the gene expression profiles of medulloblastomas by use of cDNA array / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular genesis of medulloblastomas with cDNA array.</p><p><b>METHODS</b>Four samples of medulloblastomas and 1 sample of normal brain tissue were collected freshly. After total RNA extraction, the (32)P targeted cDNA probes were converted and then hybridized with Atlas Human Cancer Array 1.2. The gene expression profiles were acquired through autoradiography. The discrepancy between the tumor and the normal brain tissue was analyzed with Atlas Image 1.01a.</p><p><b>RESULTS</b>In comparison with the genes in the normal brain tissue, 6 down-regulated and 35 up-regulated genes in the medulloblastomas were revealed by means of the microarrays and autoradiography, and were verified by reverse transcriptase-PCR. The regulatory trends of most differential expression genes were in compliance with the biological features of this tumor.</p><p><b>CONCLUSION</b>Medulloblastomas are diseases involving multiple genes with some molecular pathological mechanisms different from the astrocytic gliomas. There are complex interrelationships between these genes, which need to be further researched.</p>

Preliminary study on the gene expression profiles of ependymomas with cDNA array / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the differential gene expression of ependymomas.</p><p><b>METHODS</b>Four fresh samples of ependymomas and 1 of normal brain tissue were collected during operation. The extracted total RNAs were converted as (32)P tagged cDNA probes, which were then hybridized with the Atlas Human Cancer Array, producing the array based hybridization maps following the protocol provided with the kit. A set of special software was applied to the analysis and RT-PCR was performed to test the result.</p><p><b>RESULT</b>In comparison with the normal brain tissue, there were 31 upregulated gene and 1 downregulated gene in ependymomas, most of which were firstly found to be differentially expressed in this kind of tumor.</p><p><b>CONCLUSION</b>The discrepancy of gene expression profiles between ependymomas and normal brain tissues is highly put through and effectively detected with cDNA array, which provides new information for the further research on the molecular mechanisms of this lesion.</p>