Study on expressions of WWOX gene and p73 gene in acute lymphocytic leukemia patients / 中华检验医学杂志

ABSTRACT

Objective To investigate the clinical significance and mechanism of WW domain containing oxidoreductase (WWOX) gene and p73 gene abnormal expression in acute lymphocytic leukemia (ALL).MethodsCase-control study was used in the research.Forty-eight cases of bone marrows from ALL patients were collected,including 32 cases newly diagnosed,11 cases with complete remission and 5 case with relapse.Thirty-one cases of bone marrows from non-leukemia patients were used as control group.All the samples were collected from First Affiliated Hospital of Guangxi Medical University from July 2010 to July 2011.The doctors punctured patients' bone marrows 3 milliliters from the left of posterior superior iliac spine.Samples were bottled up with EDTA anti-coagulation tube.1 milliliter bone marrow was used to extract genome RNA with purity from 1.8 to 2.0.And then,the level of WWOX and p73 gene transcripts were tested immediately using reverse transcriptase-polymerase chain reaction (RT-PCR).Meanwhile genome DNA was also extracted from the other 2 milliliter bone marrow with purity from 1.7 to 1.9,which was used to detect the promoter methylation of WWOX gene and the first exon methylation of p73 gene by methylation PCR (MS-PCP).x2 test and Fisher's exact test were used to compare tbe methylation status of WWOX and p73 gene.Results In 31 controls,expression of WWOX and p73 gene mRNA was 94.00％.The total expression frequency of WWOX gene mRNA in 48 ALL samples was 48.00％ (23/48),much lower than control (x2 =17.434,P =0.000 ).There was significant difference (x2 =10.471,P =0.001 ) between newly diagnosed cases 34.38％ ( 11/32),complcte remission cases (90.91％,10/11 ) and control.The total expression frequency of p73 gene mRNA in 48 ALL samples was 56.00％ (27/48),much lower than control (x2 =12.697,P =0.000).There was significant difference (P =0.012 ) between newly diagnosed cases 43.75％(14/32) and complete remission cases 90.91％(10/11).It was unmethylation in 31 controls.The total methylation frequency of WWOX gene promoter region in 48 ALL samples was 44.00％(21/48),much lower than control (x2 =18.473,P =0.000).There was significant difference (P =0.012) between newly diagnosed cases 56.25％ (18/32),complete remission cases 9.09％ (1/11 ) and control.The total methylation frequency of p73 gene the first exon region in 48 ALL samples was 35.00％(17/48),much lower than control (x2 =13.990,P =0.000).There was significant difference (P =0.033) between newly diagnosed cases 46.88％ (15/32),complete remission cases 9.09％ ( 1/11 ) and control.There was a negative correlation between the expression of WWOX gene mRNA and its methylation status(r =- 0.678,P =0.000),the same as p73 gene ( r =- 0.577,P =0.000).ConclusionsThe abnormal methylation of WWOX and p73 gene may be the major mechanism of gene silence in ALL,which leads to no expression of WWOX mRNA or p73 mRNA.And the abnormal methylation of WWOX and p73 gene may be relevant with the process of occurrence and development in ALL.It may be an effective and significant to detect methylation status of WWOX gene and p73 gene for the diagnosis and treatment of ALL patients.(Chin J Lab Med,2012,35820-825)