Table 2.

Methylation Frequencies in Various Tumor Samples Determined by EitherNotI or AscI as a Restriction Enzyme

Tumor type[i] NotI RLGS gels AscI RLGS gels Z-test statistic for proportions[ii]
No. of methylated CpG islands No. of RLGS fragments analyzed Methylation frequency inNotI gels No. of methylated CpG islands No. of RLGS fragments analyzed Methylation frequency in AscI gels
Lung6311845.3%7816144.8%0.5833
Lung5911845.0%6216143.8%1.4669
Lung2811842.4%4916902.9%−0.8735
Lung811840.7%810080.8%−0.3234
Lung711840.6%1312051.0%−1.3079
Lung511840.3%1817341.0%−1.8470
Lung311840.3%717340.4%−0.6822
Lung111840.1%313800.2%−0.8503
Lung011840.0%516140.3%−1.9169
MB5317023.1%209232.1%1.4091
MB3217681.8%2212461.8%0.0903
MB3118251.7%2110931.9%−0.4401
MB3220161.6%1911721.6%−0.0735
MB1517410.9%1913271.4%−1.4947
MB1420180.7%914210.6%0.2140
HNSCC1317030.8%1417390.8%−0.1387
HNSCC318390.2%610090.6%−1.9625
HNSCC021260.0%112430.1%−1.3080

[i] HNSCC, head and neck squamous cell carcinomas; MB, medulloblastoma.

[ii] Z-test static value for testing the significant difference in methylation frequencies in NotI andAscI gels. All of the Z-static values are between −1.96 to +1.96, which suggest that there is no significant (p ≤ 0.05) difference in methylation frequencies inNotI and AscI gels.