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Objective@#To study the effects of metastasis associated 1 (MTA1) on biological characteristics such as migration, invasion and proliferation of gastric cancer (GC) cells.@*Methods@#pSilencer3.1-MTA1-siRNA vector was used to establish human gastric cancer BGC-823 cell lines with constitutive MTA1-knockdown. Boyden, wound healing, clony forming assay and 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay were performed to identify the effects of MTA1-deficiency on the biological behaviors of BGC-823 cells in vitro. Simultaneously, MTA1 overexpressed BGC-823 cell line was established by pcDNA3-MTA1 plasmid transfection for reverse verification. In addition, the role of MTA1 in the tumorigenicity of gastric cancer BGC823 cells in vivo was examined by subcutaneous injection of BGC-823 cells expressing different MTA1 levels into nude mice. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot were used to detect the expression levels of integrin β1, cyclin D1 and uPAR in pSilencer3.1-MTA1-siRNA, pcDNA3-MTA1 transfected cells and control cells.@*Results@#MTA1 knocked down or upregulated BGC-823 cell lines were successfully generated by transfecting pSilencer3.1-MTA1-siRNA or pcDNA3-MTA1 vector with lipofectamine 2000, respectively. The Boyden and wound healing experiments showed metastasis and invasion ability in MTA1 knocked down cells (25±2, 12±1) were significantly decreased when compared with those of control (78±2, 50±2) and MTA1-overexpressed groups (218±2, 269±3; P<0.05). The results of MTT assay and colony forming assay were significantly decreased when compared with those of showed that MTA1 overexpressed cells grew more rapidly and formed more colonies in vitro and induced worse malignant tumors in vivo, while MTA1 knocked down cells presented the reversed phenotype[control group (1 482.41±511.90) mm3, (1.39±0.29)g; MTA1 overexpressed group [(3 158.73±1 823.22) mm3, (2.23±0.51)g; MTA1-downregulated group (711.32±284.30)mm3, (0.87±0.21) g ; P<0.05)]. In addition, RT-PCR result showed that the expression level of MTA1 was positively correlated with the known metastasis-related genes (integrinβ1, cyclinD1, uPAR).@*Conclusions@#MTA1 promotes the invasion, migration and proliferation of human gastric cancer BGC-823 cells. On the contrary, down-regulation of MTA1 significantly inhibits tumorigenicity of BGC-823 cells and induces favorable phenotypes. MTA1 may promote the malignant phenotype of BGC-23 cells via regulating the expressions of integrinβ1, cyclinD1 and uPAR.
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Objective To investigate the expression characteristic of metastasis associated 1(MTA1) protein in laryngocarcino-ma tissue and to analyze its relationship with matrix metalloproteinase-9(MMP-9) and vascular endothelial growth factor C(VEGF-C) proteinin .Methods The Western blot method was adopt to detect the expression levels of MTA1 ,MMP-9 and VEGF-C protein in the specimens of normal laryngeal mucosal tissue ,paracarcinoma tissue and tumor tissue from 40 cases of laryngocarcinoma .Re-sults Compared with the groups of laryngocarcinoma without lymph node metastasis ,paracarcinoma and normal tissue ,the expres-sion level of MTA1 protein in the laryngocarcinoma with lymph node metastasis group was significantly increased (P<0 .05) .The expression of MTA1 protein in the laryngocarcinoma tissue was significantly correlated with the lymph nodes metastasis ,tumor staging and differentiation degree of laryngocarcinoma (P<0 .05) and was positively correlated with the expression of VEGF-C and MMP-9 (P<0 .05) .Conclusion MTA1 may participate in the development ,progress and metastasis of laryngocarcinoma .Moreo-ver the regulating effect may exist among MTA1 ,MMP-9 and VEGF-C .
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To compare the expression level of metastasis associated-1 (MTA1) gene in high and low metastatic human osteosarcoma cell lines and examine the relationship of MTA 1 expression and the metastasis potentiality of osteosarcoma cells, the expression of MTA1 in MG-63 osteosarcoma cell lines with high and low metastasis potential was detected by semiquantitative TR-PCR. Boyden chamber invasion assay was used to evaluate the invasive capacity in vitro in two osteosarcoma cell lines. The low metastasis MG-63 cells were transfected with MTA1 full-length cDNA expression plasmid by lipofectamine and the changes of MTA1 expression and in vitro invasion potential were examined after the transfection. Our results showed that MG63cell line with high metastasis potential expressed significantly higher MTA1 than that of MG63 cells with low metastasis as reavealed by RT-PCR. The invasion potential of low metastasis MG63 cell line was increased after MTA 1 gene transfection. It is concluded that there may be a relationship between MTA 1 and invasive potentiality of human osteosarcoma cells, and the mechanism of MTA1 in osteosarcoma metastasis and its possible role in associated gene therapy deserve further study.
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Objective To investigate the expression of Mta-1 in bladder transitional cell carcinoma (BTCC)and to analyze its correlation with the clinical staging,pathologic grading,metastasis and recur- rence,and to explore the possible molecular mechanisms.Methods Samples of 42 cases of BTCC and 12 normal bladder mueosa tissues were examined with immunohistochemical analysis for the expression of Mta- 1,ER,u-PA and PAI-1.Endothelial cells were stained by anti-CD34,and microvascular density(MVD)of carcinoma tissue was calculated.The correlation of Mta-1 expression with the invasion,metastasis,angiogene- sis and recurrence of BTCCs was analyzed;and the correlation of Mta-1 expression with ER,u-PA,PAI-1,and MVD was also analyzed.Results The positive rate of Mta-1 expression in BTCCs was 73.8%(31/42) , while it was 0.0% in normal bladder mucosa tissues(P＜0.01).The expression level of Mta-l increased with the higher clinical stages and pathologic grades of BTCCs;it was higher in recurrence group(100.0% , 15/15)than in non-recurrence group(59.3%,16/27),and high in metastasis group(100.0%,14/14) than in non-metastasis group(60.7%,17/28)(P＜0.05).The expression level of ER increased with the lower clinical stages and pathologic grades of BTCCs;the positive rate of ER expression was 0.0% in 14 ca- ses with metastasis and was 53.6% in 13 of 28 cases without metastasis(P＜0.05);and the rate was 6.7% in 1 of 15 cases with recurrence and 44.4% in 12 of 27 cases without recurrence(P＜0.05).Negative cor- relation was found between Mta-1 and ER expression(r=-0.739,P＜0.01).The positive rate of u-PA ex- pression(59.5%,25/42)was significantly higher in BTCCs than that in normal bladder mucosa tissues (16.7%,2/12)(P＜0.05).Positive correlation was found between u-PA and Mta-1 expression(r= 0.875),while negative correlation was found between u-PA and PAI-1 expression(r=-0.535).The posi- tive rate of PAI-1 expression in normal bladder mucosa tissues(50.0%,6/12)was significantly higher than that in BTCCs(19.0%,8/42)(P＜0.05).In addition,negative correlation was found between PAI-1 and Mta-1 expression(r=-0.706).And positive correlation was found between MVD in BTCCs marked by an- ti-CD34 and Mta-1 expression(r=0.683).Conclusions Mta-1 is highly expressed in BTCCs,and it correlates closely with tumor pathologic grades,clinical stages,recurrence and metastasis.Mta-1 up-regulates the expression of u-PA and down-regulates that of PAI-1,which is associated with invasion and metastasis and acts as an angiogenic mediator in BTCCs.A negative correlation is found between Mta-1 and ER in inva- sion and metastasis of BTCCs.