ABSTRACT
<p><b>OBJECTIVE</b>To screen potential serum marker proteins of osteosarcoma, and to make a preliminary bioinformatics analysis of RNA polymerase III polypeptide F (POLR3F).</p><p><b>METHODS</b>Gene chip and SELDI-TOF MS was used to screen genes differentially expressed in osteosarcoma. The associations of potential biomarkers from SELDI data and microarray analysis were further inferred by link-test to identify biomarkers that could likely be used for diagnosis. MATLAB was used to search transcription factors binding site in the promoter region and miRNAs binding site in 3'-UTR of POLR3F, respectively.</p><p><b>RESULTS</b>653 differentially expressed genes were found in osteosarcoma cells, while six differentially expressed protein peaks with significant statistical significances were detected by SELDI-TOF MS in patient's serum. 13 potential biomarkers for early diagnosis of osteosarcoma were screened by link-test. A conserved STAT3 binding site and a miRNA target site were found in proximal promoter regions and 3'-UTR region of POLR3F, respectively.</p><p><b>CONCLUSIONS</b>Link-test is a effective method to identify osteosarcoma biomarkers from both microarray and SELDI-TOF MS database. The results confirmed that POLR3F may be a promising biomarker for early diagnosis and a therapy target of osteosarcoma.</p>