RESUMEN
<p><b>OBJECTIVE</b>To search for the genes which could interact with newly found homo sapiens cross-immune reaction antigen (PCIA1) gene and accordingly to provide insights into the study of the gene function.</p><p><b>METHODS</b>The Stratagene's BacterioMatch Two-Hybrid System and BacterioMatch Fetal Kidney Library were adopted and the recombinant bait plasmid pBT-PCIA1 was cotransformated with the target plasmid pTRG-cDNA library DNA into the reporter stain. After screening and isolation of positive pTRG clones, the target genes were identified by DNA sequencing and bioinformation analysis.</p><p><b>RESULTS</b>Among all the seven detected target genes, three genes' function were not known, the other four genes had important functions. Their mutations or abberant expression resulted in severe diseases and overexpression of ACTN4 (actinin, alpha 4), PSAP (prosaposin) or EIF3S10 (eukaryotic translation initiation factor 3, subunit 10 theta) could promote tumor development and progression.</p><p><b>CONCLUSION</b>The bacterial two-hybrid system technique is an efficient method, which can provides insights into the study of novel genes' function by detecting protein-protein interactions. This study indicates that PCIA1 gene expression correlates with tumor formation, invasion and metastasis.</p>