Objective        To determine the effect of adenosine on the methylation of the reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) gene in human colorectal cancer SW480 cells and investigate the underlying mechanism.       Methods        SW480 cells were treated with adenosine at a dose of 0 or 3.0 mmol/L for 72 h

and then the CpG islands methylation levels of the RECK gene promoter region were detected by Bisulfite sequencing polymerase chain reaction (BSP). The RECK expression at mRNA and protein levels

the methyltransferase (DNMT1 and DNMT3a) protein expression

and cell apoptosis before and after adenosine processing were detected by RT-PCR

Western blotting

and flow cytometry respectively.       Results        After the intervention of adenosine

the RECK gene methylation levels was  significantly lower than that of the control group [(49.14±2.38)% vs (74.84±2.38)%

P0.01]. The mRNA and protein expression levels of RECK and the apoptotic rates were all significantly higher than the control group [0.335 3±0.350 2 vs 0.080 0±0.003 6

0.603 0±0.017 8 vs 0.090 0±0.003 0

(27.90±2.32)% vs (5.09±0.30)%

all P0.01]. The protein levels of methyltransferase DNMT1 and DNMT3a were significantly lower than the control group (0.141 3±0.002 1 vs 0.645 0±0.009 2

0.130 0±0.004 6 vs 0.526 7±0.009 5

both P 0.01).       Conclusion        Adenosine inhibits methyltransferase activity to reduce the DNA methylation of RECK promoter region

then enhances the mRNA and protein levels of RECK

and thus prompts the apoptosis of SW480 cells.