title: Circulating soluble LR11/SorLA levels are highly increased and ameliorated by chemotherapy in acute leukemias.
abstract: BACKGROUND
  LR11/SorLA, a receptor interacting with CD87 on monocytes and macrophages, is highly expressed on human immature hematopoietic stem cells. However, it is unknown whether LR11 is expressed on premature leukemic cells, and whether the levels of circulating soluble LR11 (sLR11) shed from leukemic cells correlate with disease state.
  
  
  METHODS
  The expression of LR11 on leucocytes and leukemic cells was examined by flow cytometry. Serum sLR11 levels were measured by ELISA in patients with various hematological diseases, including 43 acute myeloid leukemia (AML) and 23 acute lymphoblastic leukemia (ALL) patients. Data were subjected to statistical analysis for validation of sLR11 levels and patients' clinical data.
  
  
  RESULTS
  LR11 is specifically expressed in monocytes, and surface levels on leukemic cells are highly induced in both AML and ALL. sLR11 levels of acute leukemia patients were significantly increased (P<0.001) (ALL, 73.5±93.5 ng/ml; AML, 26.8±29.1 ng/ml) in comparison to controls (9.2±3.3 ng/ml). Patients with AML and ALL in remission showed significantly decreased sLR11 levels to below 20 ng/ml.
  
  
  CONCLUSIONS
  LR11 and its released soluble form are strongly elevated in acute leukemias. Remarkably, this increase in circulating sLR11 levels is ameliorated at complete remission.
authors: Department of Hematology, Chiba University Hospital, Chiba, Japan.
authors: Shio
authors: S
authors: Sakai
authors: Chiaki
authors: C
authors: Nakaseko
authors: Masahiro
authors: M
authors: Takeuchi
authors: Chikako
authors: C
authors: Ohwada
authors: Naomi
authors: N
authors: Shimizu
authors: Shokichi
authors: S
authors: Tsukamoto
authors: Takeharu
authors: T
authors: Kawaguchi
authors: Meizi
authors: M
authors: Jiang
authors: Yasunori
authors: Y
authors: Sato
authors: Hiroyuki
authors: H
authors: Ebinuma
authors: Koutaro
authors: K
authors: Yokote
authors: Atsushi
authors: A
authors: Iwama
authors: Isamu
authors: I
authors: Fukamachi
authors: Wolfgang Johann
authors: WJ
authors: Schneider
authors: Yasushi
authors: Y
authors: Saito
authors: Hideaki
authors: H
authors: Bujo
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics*; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D026502:LDL-Receptor Related Proteins / Q000097:blood / Q000235:genetics*; D015470:Leukemia, Myeloid, Acute / Q000097:blood* / Q000188:drug therapy / Q000235:genetics; D026901:Membrane Transport Proteins / Q000097:blood / Q000235:genetics*; D009000:Monocytes / Q000378:metabolism / Q000473:pathology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood* / Q000188:drug therapy / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012074:Remission Induction; D012995:Solubility
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D026502:LDL-Receptor Related Proteins; D026901:Membrane Transport Proteins; C102582:SORL1 protein, human