en 32153735 <p>Background: Placenta-specific 1 (PLAC1), as a new Cancer/Testis Antigen (CTA), is frequently expressed in a variety of cancers and localized to cytoplasm and plasma membrane. Surface expression of cancer target antigens is of great importance that enables antibody-mediated cancer immunotherapy. The aim of the current study was to express the intact human PLAC1 protein on plasma membrane of a eukaryotic cell as a model for future anti-PLAC1-based cancer immunotherapy.</p> <p>Methods: In the first approach, entire human PLAC1 gene including its own Signal Peptide (SP) was cloned into pIRES2-EGFP and LeGO-iG2 vectors and expressed in CHO-K1 cells. In the second approach, cytosolic and Signal-Anchor (SA) sequence of Transferrin Receptor Protein 1 (TFR1) were fused to extracellular portion of PLAC1 and expressed as above. Expression of PLAC1 was then assessed using Reverse Transcription Polymerase Chain Reaction (RT-PCR), Western Blot (WB), Immunocytochemistry (ICC), Immunofluorescence (IF) and Flow Cytometry (FC).</p> <p>Results: The first approach resulted in the expression of PLAC1 in submembranous but not in the surface of transfected CHO-K1 cells. Using the chimeric human PLAC1 construct, the same intracellular expression pattern was observed.</p> <p>Conclusion: These results indicated that there are some yet unknown PLAC1 localization signals employed by cancer cells for surface expression of PLAC1.</p> Eukaryotic cells, PLAC1 protein expression, Protein transport 24 31 https://www.ajmb.org/En/Article.aspx?id=10402 https://www.ajmb.org/PDF/En/FullText/10402.pdf JafarMahmoudianNanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences (TUMS), Tehran, Iran21539MahboobehNazariMonoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran11474RoyaGhodsDepartment of Molecular Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran8MahmoodJeddi-TehraniMonoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran15Seyed NaserOstadDepartment of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences (TUMS), Tehran, Iran153Mohammad HosseinGhahremaniDepartment of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences (TUMS), Tehran, Iran692SedighehVafaeiReproductive Immunology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran21541Mohammad MehdiAmiriDepartment of Immunology, School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran21542Amir-HassanZarnaniImmunology Research Center (IRC), Iran University of Medical Sciences (IUMS), Tehran, Iran7