title: Increased expression of multidrug resistance gene (MDR1) at relapse in a child with acute lymphoblastic leukemia.
abstract: Modern treatment protocols lead to complete remission in a high proportion of patients with childhood acute lymphoblastic leukemia (ALL). However, a large number of them show a relapse of the disease. Treatment failure in these patients is mainly attributable to de novo or acquired resistance to a wide variety of cytotoxic drugs, which is called multi drug resistance (MDR). Expression of multi drug resistance 1 gene (MDR1) is implicated in the drug-resistance mechanism. In order to contribute further information we present a rare case of a 15-month old girl with newly diagnosed CALLA positive pre-B acute lymphoblastic leukemia with favourable prognostic factors at diagnosis who experienced a relapse of the disease. Using reverse transcriptase polymerase chain reaction method, m-RNA expression of the MDR1 gene upon relapse, was five-fold compared with that at diagnosis. This is the first report on increased mRNA expression at relapse in a paired sample of a child with ALL in our region.
authors.affiliation: Second Department of Pediatrics, Division of Pediatric Hematology and Oncology, Aristotle University of Thessaloniki, Thessaloniki, Greece. makourti@med.auth.gr
authors.forename: Maria
authors.initials: M
authors.lastname: Kourti
authors.forename: Norma
authors.initials: N
authors.lastname: Vavatsi
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Gombakis
authors.forename: George
authors.initials: G
authors.lastname: Tzimagiorgis
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Sidi
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Koliouskas
authors.forename: Fani
authors.initials: F
authors.lastname: Athanassiadou
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007223:Infant; D015260:Neprilysin; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000473:pathology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D012008:Recurrence
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012333:RNA, Messenger; D015260:Neprilysin