[Detection of phosphotyrosine in bcr-abl-positive cells with PY20 antibody and its clinical applications].
OBJECTIVE
To explore the specificity of anti-phosphotyrosine monoclonal antibody PY20 in bcr-abl+ cells and its possible clinical applications.


METHODS
Bcr-abl cell lines( K562, MEG-01) and bcr-abl- cells lines( Jurkat, MCF-7 )were stained with PY20. Phosphotyrosine protein of K562 and MEG-01 cells was detected by flow cytometry before and after treatment with imatinib. Phosphotyrosine protein in bone marrow cells from 49 patients with chronic myeloid leukemia (CML), Ph+ acute lymphoblastic leukemia(Ph(+) -ALL), Ph- ALL, acute myeloid leukemia (AML-M1, M2, M3, M5, FAB classification), chronic lymphocytic leukemia (CML) and 3 normal donor. Positive cells over 5% of total cells was considered positive cases for phosphotyrosine protein. The level of tyrosine phosphorylation was determined by median fluorescence intensity (MFI).


RESULTS
Bcr-abl cell lines and marrow cells from 10 CML patients and 8 ALL patients were all PY20-positive, while bcr-abl- cell lines and marrow cells from 18 leukemia patients and 3 normal donor were all PY20-negative. MFI decreased remarkably after blocked by imatinib in K562 cells and MEG-01 cells. The positive cell percent of marrow cells from 10 newly diagnosed CML patients and 9 imatinib-sensitive CML patients was (54.20 +/- 19.82)% and (14.84 +/- 6.17)% (P < 0.05), while that of 2 cases of imatinib-resistant was 64.3% and 57.2%. There was significant difference of MFI between imatinib-resistant patients and imatinib-sensitive patients (99.42 +/- 4.87 vs 46.41 +/- 4.67, P < 0.01).


CONCLUSIONS
PY20 monoclonal antibody is highly specific for bcr-abl+ cells. It might be useful in rapid detection of bcr-abl+ cells and sensitivity to imatinib of CML patients.
Zhu
Hong-Hu
HH
Institute of Hematology, People's Hospital, Peking University, Beijing 100044, China.
Liu
Yan-Rong
YR
Qin
Ya-Zhen
YZ
Chang
Yan
Y
Li
Jin-Lan
JL
Ruan
Guo-Rui
GR
Jiang
Bin
B
Chen
Shan-Shan
SS
Lu
Dao-Pei
DP
D000911:Antibodies, Monoclonal / Q000032:analysis*; D001854:Bone Marrow Cells / Q000378:metabolism; D005434:Flow Cytometry; D016044:Fusion Proteins, bcr-abl / Q000032:analysis*; D006801:Humans; D020014:K562 Cells; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000378:metabolism; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism; D019000:Phosphotyrosine / Q000032:analysis* / Q000276:immunology
D000911:Antibodies, Monoclonal; D019000:Phosphotyrosine; D016044:Fusion Proteins, bcr-abl