| OBJECTIVEInhibitor of apoptosis proteins (IAP) is a class containing many members of inhibitor of apoptosis protein family.IAP in inhibiting apoptosis and promoting tumor cell proliferation play an important role. Livin is a new member of the IAP family, Like other IAP family proteins, Livin interacts with downstream caspases, such as caspase-3, caspase-7, and caspase-9, leading to their inactivation and degradation. livin is highly expressed in cancer cells and transformed cells, but show little or no expression in normal differentiated tissues. These anti-apoptotic genes might contribute to the development and progression of cancer. This specific expression makes Livin become a hot international research .The members of the Casitas B-lineage lymphoma (Cbl) family, c-Cbl, Cbl-b, and Cbl-3, are a class of widely distributed intracellular protein . Cbl family contain an N-terminal phosphotyrosine-binding (PTB) domain that allows direct interaction with activated RTKs, and a RING finger domain that classifies Cbl proteins as E3 ubiquitin ligases. Therefore under normal circumstances the role of negative regulation of this PTK for the maintenance of intracellular stability mechanism is important. It has been reported that these oncogenic mutants of Cbl interact with activated RTKs and function in a dominant-negative fashion. c-cbl has recently been proved to be a new RING Finger-type ubiquitin ligase E3 in the ubiquitin - proteasome pathway . c-cbl can mediats receptor tyrosine kinase and non-receptor tyrosine kinase receptor degradation. At present, the research of livin gene and c-cbl gene in leukemia is still less . This study intended to investigate the expression,clinical significance of livin and c-cbl.METHODS1. Cell Culture cultivate the resuscitative M14 cell in DMEM high glucose medium with 37℃, 5% CO2 and extract total RNA for Livin gene positive control in RT-PCR of detection of livin.2. connect the cloned gene fragment of livin to the plasmid PMD20-T vector and construct positive control plasmid.3. The expression of Livin and c-cbl mRNA were measured in bone marrow cells or peripheral blood cells from 67 adult patients with acute leukemia and 13 patients with chronic granulocytic leukemia by reverse transcription polymers chain reaction(RT-PCR). 20 healthy samples were selected as normal controls(NC)RESULTS1. We successfully established a stable and specific RT-PCR method for detection of livin and c-cbl mRNA.2.Positive rate of livin mRNA expression is 68.1% (32 of 47 ) in patients with ANNL; 61.5% in patients(8/13) with CML;75.0% (15 of 20) in patients with ALL. Expression of livin mRNA is negative in 20 control persons. Comparing the positive rates of livin mRNA expression among ANLL, CML and ALL, the differences were not statistically significant (P>0.05).3.Negative rate of c-cbl mRNA expression is 42.6% (20of 47 ) in patients with ANNL, Positive rate of c-cbl mRNA expression is 100% in 20 control persons, The results showed that the mRNA level of c-cbl gene in ANLL patients was significantly lower than that in NC. Negative rate of c-cbl mRNA expression is 45.0% (9of 20 ) in patients with ALL;38.5% in patients(5/13) with CML. Comparing the positive rates of C-CBL mRNA expression among ANLL, CML and ALL, the differences were not statistically significant (P>0.05).CONCLUSIONS1 The level of Livin mRNA in newly diagnosed acute leukemia patients was significantly higher than that of normal controls.The level of relapsed patients was higher than that of normal controls.The CR rate of Livin-group was higher than that of Livin+cases. It seems that high expression of livin gene may be used as a marker of poor prognosis in acute leukemia. 2 The level of c-cbl mRNA in newly diagnosed acute leukemia patients was significantly lower than that of normal controls.The level of relapsed patients was lower than that of normal controls.The CR rate of c-cbl-group was lower than that of c-cbl+cases. It seems that low expression of c-cbl gene may be used as a marker of poor prognosis in acute leukemia. 3 The level of Livin mRNA in chronic granulocytic leukemia was significantly higher than that of normal controls , the level of c-cbl mRNA was significantly lower than that of normal controls.It may be that the development of CML is related with livin and c-cbl.
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