ABSTRACT
Objective To detect mutations in the ARAD1 gene in a pedigree with dyschromatosis symmetrica hereditaria (DSH).Methods Genomic DNA was extracted from the peripheral blood of 8 family members (including 5 patients with DSH and 3 unaffected members) in the pedigree with DSH,as well as 100 unrelated healthy controls.All the 15 exon sequences of the ADAR1 gene were amplified by polymerase chain reaction (PCR)followed by direct sequencing.Then,mutations were detected in comparison with the standard sequence of the ADAR1 gene in Genebank.Results A nonsense mutation C.1420C ＞ T (p.Arg474X) was identified at position 1 420 in exon 2 of the ADAR1 gene in the 5 patients with DSH,but not in the 3 unaffected members or 100 unrelated healthy controls.Conclusion The nonsense mutation C.1420C ＞ T in the ADAR1 gene is the causative mutation in the pedigree with DSH.
ABSTRACT
Objective To observe the impact of RNA interference-induced ADAR1 down-regulation on cell proliferation of liver cancer.Methods Small interfering RNA (siRNA) was transfected into liver cancer cell line SMMC-7721.ADAR1 expression was detected by RT-PCR and Western blotting.Cell proliferation was determined by methyl thiazol tetrazolium (MTT) assay.Results After transfection for 24,48,and 72 h,ADAR1 mRNA expression was 0.612 ± 0.086,0.264 ± 0.018,0.156 ± 0.063 in experimental group and 1.032 ± 0.107,0.898 ± 0.092,0.968 ± 0.074 in control group,respectively.Experimental group had significantly lower ADAR1 mRNA than the other groups (P ＜ 0.05),and there was no statistically significant difference between control and blank group (P ＞ 0.05).ADAR1 protein relative expression was 0.684 ± 0.079,0.324 ± 0.042,0.145 ± 0.058 in experimental group and 1.002 ± 0.092,0.917 ± 0.068,0.972 ± 0.073 in control group,respectively,which was statistically significant (P ＜ 0.05).After transfection with siRNA,the proliferation ability of SMMC-7721 cells was enormously inhibited (P ＜ 0.05).Conclusion ADAR1 mRNA and protein level could be significantly decreased by specific RNA interference,and cell proliferation in SMMC-7721 cells were also greatly inhibited.
