title: Expression of MDR1, LRP, BCRP and Bcl-2 genes at diagnosis of childhood all: comparison with MRD status after induction therapy.
abstract: OBJECTIVE
  to investigate properties of leukemic cells by sorting out children diagnosed with ALL with different response to chemotherapy based on MRD level.
  
  
  METHODS
  We used a minimal residual disease (MRD) data on day 36 obtained with 3-colour flow cytometry as a reference. In view of MRD results, we used real-time PCR to assess expression levels of multidrug resistance associated genes MDR1, LRP and BCRP, antiapoptotic gene Bcl-2 in initial samples from children diagnosed with ALL. P-gp expression and function in initial samples were analyzed by flow cytometry.
  
  
  RESULTS
  Briefly, medians of relative expression levels of MDR1 gene were roughly comparable and in MRD(+) group came to 22.8 (0.02-26.6; n = 9) vs 24.8 (3.9-41.4; n = 10) in MRD(-) group. Bcl-2 gene showed tendency to higher expression levels in MRD(+) group with median at 5992.9 (521.0-10362.0; n = 9) compared to 3183.6 (1947.9-6581.0; n = 10) in MRD(-) group. LRP gene relative expression levels were similar in both groups and came to 1934.9 (1500.7-3490.4; n = 9) and 1408.5 (665.5-2917.1; n = 10) in MRD + and MRD(-) groups, respectively. The median of BCRP expression levels in MRD + group was considerably lower than that in MRD - group, namely 76000.0 (48196.2-169230.8; n = 9) and 227967.2 (16683.7-422222.2; n = 10), respectively, but statistical analysis showed no significant difference for this parameter.
  
  
  CONCLUSIONS
  We investigated expression of multidrug resistance genes MDR1, LRP and BCRP and antiapoptotic gene Bcl-2 in leukemic cells at diagnosis, and MRD level at the end of induction therapy, and could not find obvious relations between these parameters.
authors.affiliation: Belarusian Research Center for Pediatric Oncology and Hematology, Minsk, Belarus. januarys_v@yahoo.com
authors.forename: U U
authors.initials: UU
authors.lastname: Fedasenka
authors.forename: T V
authors.initials: TV
authors.lastname: Shman
authors.forename: V P
authors.initials: VP
authors.lastname: Savitski
authors.forename: M V
authors.initials: MV
authors.lastname: Belevcev
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018432:Drug Resistance, Multiple; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007223:Infant; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000473:pathology; D020360:Neoadjuvant Therapy; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D018365:Neoplasm, Residual / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000473:pathology; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D012074:Remission Induction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020394:Vault Ribonucleoprotein Particles / Q000235:genetics* / Q000378:metabolism; D000099187:Major Vault Protein
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein; C513055:ABCB1 protein, human; C116614:ABCG2 protein, human