AIM:To detect tumor-associated DNA changes in stool samples among Iranian patients with colorectal cancer(CRC)compared to healthy individuals using BAT-26,p16 hypermethylation and long DNA markers.METHODS:Stool DNA wa...AIM:To detect tumor-associated DNA changes in stool samples among Iranian patients with colorectal cancer(CRC)compared to healthy individuals using BAT-26,p16 hypermethylation and long DNA markers.METHODS:Stool DNA was isolated from 45 subjects including 25 CRC patients and 20 healthy individuals using a new,fast and easy extraction method.Long DNA associated with tumor was detected using polymerase chain reaction method.Microsatellite studies were performed utilizing denaturating polyacrylamide gel to determine the instability of BAT-26.Methylation status of p16 promoter was analyzed using methylation-specific PCR(MSP).RESULTS:The results showed a significant difference in existence of long DNA(16 in patients vs 1 in controls,P < 0.001)and p16(5 in patients vs none in controls,P = 0.043)in the stool samples of two groups.Long DNA was detected in 64% of CRC patients;whereas just one of the healthy individuals was positive for Long DNA.p16 methylation was found in 20% of patients and in none of healthy individuals.Instability of BAT-26 was not detected in any of stool samples.CONCLUSION:We could detect colorectal cancer related genetic alterations by analyzing stool DNA witha sensitivity of 64% and 20% and a specificity of 95% and 100% for Long DNA and p16 respectively.A non-invasive molecular stool-based DNA testing can provide a screening strategy in high-risk individuals.However,additional testing on more samples is necessary from Iranian subjects to determine the exact specificity and sensitivity of these markers.展开更多
基金Supported by a grant from the vice chancellor for research at Mashhad University of Medical Sciences,NO. 84082
文摘AIM:To detect tumor-associated DNA changes in stool samples among Iranian patients with colorectal cancer(CRC)compared to healthy individuals using BAT-26,p16 hypermethylation and long DNA markers.METHODS:Stool DNA was isolated from 45 subjects including 25 CRC patients and 20 healthy individuals using a new,fast and easy extraction method.Long DNA associated with tumor was detected using polymerase chain reaction method.Microsatellite studies were performed utilizing denaturating polyacrylamide gel to determine the instability of BAT-26.Methylation status of p16 promoter was analyzed using methylation-specific PCR(MSP).RESULTS:The results showed a significant difference in existence of long DNA(16 in patients vs 1 in controls,P < 0.001)and p16(5 in patients vs none in controls,P = 0.043)in the stool samples of two groups.Long DNA was detected in 64% of CRC patients;whereas just one of the healthy individuals was positive for Long DNA.p16 methylation was found in 20% of patients and in none of healthy individuals.Instability of BAT-26 was not detected in any of stool samples.CONCLUSION:We could detect colorectal cancer related genetic alterations by analyzing stool DNA witha sensitivity of 64% and 20% and a specificity of 95% and 100% for Long DNA and p16 respectively.A non-invasive molecular stool-based DNA testing can provide a screening strategy in high-risk individuals.However,additional testing on more samples is necessary from Iranian subjects to determine the exact specificity and sensitivity of these markers.
