Abnormal Expression of Receptor Tyrosine Kinase Mer in Adult Acute Leukemia.

Abstract BACKGROUND & OBJECTIVE Mer was found a proto-oncogene in some solid tumor. it belongs to Axl receptor tyrosine kinase family. This study was to detect Mer expression in 57 adult acute leukemia patients’ bone marrow (32 AML and 25 ALL patients) and normal control. Methods Flow cytometry with anti-CD15, CD3, CD19 and CD14 antibody were used to detect Mer expression on granulocytes, T-lymphocytes, B-lymphocytes and monocytes in normal bone marrow. Mer expression on leukemia cells of patients’ bone marrow samples were also analysed by flow cytometry, and RT-PCR was used to verify parts of Mer mRNA level expreesion in mononuclearcell of bone marrow samples. Results Flow cytometry showed that in normal bone marrow, there was no Mer expressed on granulocytes, T-lymphocytes and B-lymphocytes; and middle-expression on monocytes(37.5%). In all 32 AML patients, there were 23 Mer positive(71.8%), Mer expression level was high in 3 AML patients, middle in 8 AML patients, low in 12 AML patients and very low/negative in left 9 AML patients. Among 3 Mer high Expression AML patients, the FAB typping were all M1, and all of them had the high expression level of CD34 and CD117. In all 25 ALL patients, there were 16 Mer positive(64.0%), Mer expression level was high in 1 ALL patients, middle in 6 ALL patients, low in 9 ALL patients and very low/negative in left 9 ALL patients. The results of RT-PCR was similar to flow cytometry Conclusion Mer was ectopic expression parts of adults acute leukemia patients, and may related to genesis and development of acute leukemia.