A study of the relationship between expression level of TRF1 protein and telomerase activity in human acute leukemia.
OBJECTIVE
To study the expression level of TRF1 (telomeric repeat binding factor 1) protein in human acute leukemia and relationship between expression level of TRF1 protein and telomerase.


METHODS
A quantitative Western-Blot technique was developed using anti-TRF1(33-277) monoclonal antibody and GST-TRF1 purity protein as a standard to further determine the expression level of TRF1 protein in total proteins extracted from clinical specimens.


RESULTS
Bone marrow tissues of 20 acute leukemia patients were studied, 11 healthy donors' bone marrows were taken as a control. The expression level of TRF1 protein was significantly higher (P<0.01) in normal bone marrow ((2.217+/-0.462) microg/microl) than that of acute leukemia patients ((0.754+/-0.343) microg/microl). But there was no remarkable difference between ALL and ANLL patients ((0.618+/-0.285) microg/microl vs (0.845+/-0.359) microg/microl, P>0.05). After chemotherapy, TRF1 expression level of patients with complete remission elevated ((0.772+/-0.307) microg/microl vs (1.683+/-0.344) microg/microl, P<0.01), but lower than that of normal ((2.217+/-0.462) microg/microl, P<0.01). There was no significantly difference after chemotherapy ((0.726+/-0.411) microg/microl vs (0.895+/-0.339) microg/microl, P>0.05). TRF1 expression level of patients with complete remission is higher than that of patients without complete remission ((1.683+/-0.344) microg/microl vs (0.895+/-0.339) microg/microl, P<0.01). All samples were determined for telomerase activity. It was confirmed that the activity of telomerase in normal bone marrow was lower than that of acute leukemia patients ((0.125+/-0.078) microg/microl vs (0.765+/-0.284) microg/microl, P<0.01). There was no significant difference of expression level of TRF1 protein between ALL and ANLL patients ((0.897+/-0.290) microg/microl vs (0.677+/-0.268) microg/microl, P>0.05). After chemotherapy, telomerase activity of patients with complete remission decreased ((0.393+/-0.125) microg/microl), but was still higher than that of normal ((0.125+/-0.078) microg/microl, P<0.01).


CONCLUSIONS
The expression level of TRF1 protein has correlativity to the activity of telomerase (P<0.001).
Shi
Ji-min
JM
Department of Hematology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
Huang
He
H
Chen
Qiao-fang
QF
Lin
Mao-fang
MF
D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000737:chemistry; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000378:metabolism; D002648:Child; D004305:Dose-Response Relationship, Drug; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000201:enzymology*; D012074:Remission Induction; D019098:Telomerase / Q000096:biosynthesis* / Q000378:metabolism; D035321:Telomeric Repeat Binding Protein 1 / Q000096:biosynthesis*; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D035321:Telomeric Repeat Binding Protein 1; D019098:Telomerase