title: The placental specific gene, PLAC1, is induced by the Epstein-Barr virus and is expressed in human tumor cells.
abstract: BACKGROUND
  The Epstein-Barr virus (EBV) is a causal agent in a number of malignancies in humans including hematopoietic tumors and non-hematopoietic tumors. Burkitt's lymphoma cell lines containing the Epstein-Barr virus have been shown to form tumors in nude mice while clonal derivatives of such cell lines in which the viral genome has been lost do not (JID 177: 1194-1201, 1998; JV 72: 9150-9156, 1998; JV 68: 6069-6073, 1994). The re-introduction of EBV into these EBV negative BLs reconstitutes the tumor phenotype. Thus, EBV-induced cellular genes play critical role in EBV-related tumors.
  
  
  RESULTS
  In an attempt to identify cellular genes regulated by EBV that may contribute to its tumorigenic properties, we have enforced genome loss in the Burkitt's lymphoma (BL) line, MutuI, by introducing a dominant negative form of the episomal replication factor, EBNA1 and carried out gene array analysis. One of the genes identified by this analysis is PLAC1, a gene originally identified as being expressed exclusively in placental tissue. Real time RT-PCR analysis verified higher expression in EBV positive vs. EBV negative Mutu clones. Analysis of a panel of RNAs from 20 normal tissues demonstrated the highest level of expression in placenta but significant expression was also observed in testis and brain cerebellum. PLAC1 expression was also observed in non-BL tumor cell lines derived from breast, ovary, and prostate. Lastly, expression of PLAC1 was found to be higher in some primary breast tumors compared to normal adjacent tissues.
  
  
  CONCLUSIONS
  This data suggests that the EBV-induced PLAC1 is a member of the cancer/testis group of tumor antigens.
authors.forename: Xia
authors.initials: X
authors.lastname: Wang
authors.forename: Melody C
authors.initials: MC
authors.lastname: Baddoo
authors.affiliation: Section of Pulmonary Diseases, Critical Care and Environmental Medicine, Department of Medicine, SL9, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA. qyin@tulane.edu.
authors.forename: Qinyan
authors.initials: Q
authors.lastname: Yin
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D020869:Gene Expression Profiling; D004854:Herpesvirus 4, Human / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D008297:Male; D046228:Microarray Analysis; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000096:biosynthesis*; D060888:Real-Time Polymerase Chain Reaction; D015533:Transcriptional Activation
chemical_list: C415583:PLAC1 protein, human; D011257:Pregnancy Proteins