title: Retinoic acid induces changes in c-fgr proto-oncogene mRNA levels in Burkitt's lymphoma cells.
abstract: The c-fgr proto-oncogene is expressed in Burkitt's lymphoma (BL) cell and cell lines derived from them. When Epstein-Barr virus (EBV)-negative BL cell lines that contain low levels of c-fgr mRNA are infected with EBV, transcription of the c-fgr gene is further induced. In this paper we show that treatment of EBV-negative and EBV-positive BL cell lines with all-trans retinoic acid also stimulates an increase in c-fgr mRNA levels, varying between 2- and 13-fold depending on the cell line. An increase is detectable 12 to 48 h after treatment, depending on the cell line, suggesting that the c-fgr gene is not regulated directly by retinoic acid but responds to other retinoic acid-induced changes in the cell. We also show that treatment of BL cell lines with all-trans retinoic acid either results in a dose-dependent decrease in growth rate, or has no effect on growth, depending on the cell line. It has previously been suggested that the c-fgr gene product might have a role in regulating the growth of BL cells, since treatment of the EBV-positive BL cell line Daudi with alpha-interferon results in a decrease in c-fgr mRNA levels followed by a decrease in growth rate. Our data indicate that there is no general correlation between c-fgr mRNA levels and growth rate in BL cells and so argue against a role for the c-fgr gene product in growth regulation in these cells.
authors.affiliation: Department of Biochemistry and Molecular Biology, Bland Sutton Institute, University College and Middlesex School of Medicine, London, United Kingdom.
authors.forename: L
authors.initials: L
authors.lastname: Faulkner
authors.forename: D R
authors.initials: DR
authors.lastname: Katz
authors.forename: P M
authors.initials: PM
authors.lastname: Brickell
mesh_terms: D002051:Burkitt Lymphoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D002471:Cell Transformation, Neoplastic; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D004854:Herpesvirus 4, Human; D006801:Humans; D000090063:Proto-Oncogene Mas; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D012333:RNA, Messenger; D014212:Tretinoin