[Methylation status of RASSF1A and DAPK promoter in retinoblastoma].
OBJECTIVE
To investigate the methylation status of RASSF1A or DAPK promoter in retinoblastoma tissue or peripheral blood from retinoblastoma patients.


METHODS
It was an experimental study on the paraffin-embedded retinoblastoma tissue sections, and a case-control study on retinoblastoma cases and normal control people. Methylation status of RASSF1A and DAPK promoter in 28 RB tissues and 9 available peripheral blood samples of RB patients were detected by methylation specific polymerase chain reaction (MSP). Normal retinal tissues from five donor cadaver eyes and normal-peripheral blood samples from five healthy volunteers matched on age and sex were used as controls. The differences of methylation rate among different groups were analyzed statistically by Fisher's exact probability test.


RESULTS
The percentage of RASSF1A hypermethylation in RB tissues (60.7%) was statistically higher than in normal retinal tissue 0% (0/5) and adjacent non-neoplastic retinal tissue 17.9% (5/28) (P < 0.01), the hypermethylation percentage in unilateral RB group was higher than bilateral RB group either. Meanwhile, RASSF1A hypermethylation in peripheral blood was detected in 2 of 9 RB cases, showing no statistics difference compared with that of normal person. However, no DAPK promoter hypermethylation was found in all RB tissues and peripheral blood from retinoblastoma patients.


CONCLUSIONS
RASSF1A promoter hypermethylation was frequently present in retinoblastoma, which may play an important role during the pathogenesis of retinoblastoma.
Liu
Ru
R
Department of Ophthalmology, Second Xiangya Hospital, Central-South University, Changsha 410011, China.
Gao
Ling
L
Lu
Guang-Xiu
GX
Tang
Luo-Sheng
LS
Zhu
Xiao-Hua
XH
Wang
Jian
J
D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D064550:Death-Associated Protein Kinases; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007223:Infant; D008297:Male; D008745:Methylation; D011401:Promoter Regions, Genetic; D012175:Retinoblastoma / Q000235:genetics* / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
D051017:Apoptosis Regulatory Proteins; C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases