ABSTRACT
<p><b>OBJECTIVE</b>To observe the effects of WWOX on cell attachment in ovarian cancer, and to explore its mechanisms of action.</p><p><b>METHODS</b>Attachment assay was used to assess the adhesion of wwox-transfected PEO1 cells and vector-transfected PEO1 cells that were constructed, as well as PEO1 parent cells. Alpha/beta integrin-mediated cell adhesion assays were designed to identify cells surface integrins in PEO1 clone cells. Integrin function blocking experiments were designed to further determine integrins in PEO1 clone cells according to the integrin that was selected in integrin expression profiling. FACS analysis was used to further detect the level of integrin alpha3 on the cell membrane.</p><p><b>RESULTS</b>Attachment assay showed that adhesion of WWOX-transfected PEO1 cells to fibronectin was significantly slower than that in vector-transfected controls or PEO1 parent cells, cultured on the pre-coated fibronectin for 2 hours (P<0.01). The level of membranous integrins alpha2 and alpha3 in the WWOX-transfected PEO1 cells was significantly decreased, as compared with that in vector-transfected controls (P<0.05), but there was no association with the level of functioning integrins betal or beta2 in clone cells (P>0.05). The attachment assays were repeated after pre-incubating the cells with integrin alpha2 or alpha3 function-blocking antibodies. These results showed that blocking integrin alpha3 significantly reduced the binding to fibronectin of all the PEO1 clonal lines, as compared with cells pre-incubated with a non-specific IgG antibody (P<0.05). In contrast, preincubation with alpha2 blocking antibody had very little effect on fibronectin binding in these cells (P>0.05). FACS analysis showed that membranous integrin alpha3 expression revealed a marked reduction in WWOX-transfected cells than that in vector-transfected cells.</p><p><b>CONCLUSION</b>WWOX acts as an ovarian tumor suppressor by modulating the interaction between tumor cells and the extracellular matrix, decreasing integrin activity and adhesion of tumor cells to fibronectin. This suggests an important role for loss of WWOX tumor suppressor in promoting attachment and adhesion of ovarian cancer cells on locoregional peritoneum, and further resulting in enhancing locoregional peritoneal tumor spread.</p>
Subject(s)
Female , Humans , CD18 Antigens , Metabolism , Cell Adhesion , Fibronectins , Metabolism , Integrin alpha2 , Metabolism , Integrin alpha3 , Metabolism , Integrin beta1 , Metabolism , Ovarian Neoplasms , Metabolism , Pathology , Oxidoreductases , Genetics , Metabolism , Protein Binding , Transfection , Tumor Suppressor Proteins , Genetics , Metabolism , WW Domain-Containing OxidoreductaseABSTRACT
Objective To explore epithelial ovarian cancer(EOC)antigens that are potentially useful for cancer early detection and therapy.Methods A high quality cDNA library derived from ascites tumor cells of EOC patients(3 cases of serous EOC,1 case of mucinous EOC,and 1 case of endometrial carcinoma of ovary)was constructed,and the method of combining serological analysis of recombinant cDNA expression libraries(SEREX)and suppression subtractive hybridization(SSH)was used for screening cDNA library.All of the positive clones were sequenced and bioinformatics analysis with BLAST software in GenBank was performed.Serological mini-arrays of recombinant tumor antigens(SMARTA)was used to investigate the prevalence of autoantibodies to these antigens in both 96 ovarian cancer patients and 96 cancer-free controls.Results Fifty-five positive clones encoding different antigenic genes of EOC recognized by IgG and(or)IgM were obtained.It showed that these 55 clones derived from 45 distinct genes and these genes could be grouped into 6 classes as following according to homology with known expressed sequence tag(EST):(1)known ovarian carcinoma related genes:BARD1,et al;(2)homologous genes with other tumors:TM4SF1,et al;(3)homologous genes with special tissues:ILF3,FXR1,et al;(4) homologous genes with special function:TIZ,C1 D,et al;(5)embryo originating genes:PKHD1,et al; (6)novel genes:OV-189,et al.SMARTA results showed that the positive ratio of five EOC antigens TM4SF1(28% vs 9%),CID(21% vs 6%),BARD1(23% vs 5%),FXR1(23% vs 8%),OV-189 (31% vs 13%)which reacting with their IgG autoantibodies,three antigens TIZ(26% vs 8%),FXR1 (28% vs 11%),and OV-189(18% vs 7%)which reacting with their IgM autoantibodies in patients was higher than in controls(P