Additional file 2 of Mass spectrometric profiling of DNA adducts in the human stomach associated with damage from environmental factors

Additional file 2 Supplementary Table S1: Mass transitions of DNA adducts. Seven mass transitions that assume a neutral loss of 116 units of deoxyribose in DNA adducts of deoxyribonucleosides were monitored by mass spectrometry. Supplementary Table S2: Estimated molar ratios of DNA adducts in samples. As described in the Materials and Methods, the molar ratios of DNA adducts and three pairs of peak boundaries, namely, broad, best retention time (Best) and background (BG), were listed for each DNA adduct. A total of 341 samples were classified as GC (Case No. 1–59) and non-GC (Case No. 60–66). Samples from GC were also categorized as tumor or nontumor and are indicated in the Group Status column. Supplementary Table S3: Numbers of sampling sites. The number of samples per individual and its frequency are listed in the table of the nontumor portions of 59 GC cases. This is used to draw the histogram in Fig. 1b. Supplementary Table S4: Representative molar ratio of DNA adducts in individuals. Representative values of the molar ratio of DNA adducts in 59 cases of nontumor GC, 14 cases of tumor GC and 7 cases of non-GC were calculated. In addition to basic characteristics (age, sex, BMI, smoking, and alcohol), groups for comparison are indicated in Fig. 4 (Group Status) and Fig. 5 (Smoking Group, Alcohol Group and Smoking/Alcohol Group). To reduce redundancy, individual information for tumor samples was omitted, and the corresponding case number was indicated. Supplementary Table S5: Interindividual variance of DNA adducts. For the molar ratio of DNA adducts in 306 samples of nontumor gastric mucosae in 59 gastric cancer cases, the Kruskal-Wallis test was performed to compare individuals. Asymptotic significance calculated by SPSS software is displayed. The p-values less than 0.05 are marked in yellow. Supplementary Table S6: Normality test of the distribution of DNA adducts among individuals. The Shapiro-Wilk test was performed to determine the distribution of the representative molar ratio of DNA adducts in individuals. Cases with 0 values were excluded. The p-values less than 0.05 are marked in yellow. df: degrees of freedom. Supplementary Table S7: Accumulation of DNA adducts in tumor or nontumor sites of gastric mucosae. The Kruskal-Wallis test was performed to compare non-GC, GC nontumor and GC tumor samples. In the two DNA adducts showing p-values less than 0.05, Bonferroni-corrected pairwise Mann-Whitney U tests were also performed. The related box plots are drawn in Fig. 4. The p-values less than 0.05 are marked in yellow. Supplementary Table S8: Comparison of DNA adducts between sexes and among environmental exposure groups. The Mann-Whitney U test was performed to compare the molar ratio of DNA adducts in individuals with different characteristics, including sex, tobacco smoking, alcohol consumption and both habits. The data with p-values less than 0.05 are marked in yellow and are drawn as box plots in Fig. 5. Supplementary Table S9: Correlation analysis of age, BMI and 7 DNA adduct accumulations. Spearman’s rank correlation coefficient, rho and p-value were calculated pairwise among age, BMI and molar ratio of 7 DNA adducts. The p-values less than 0.05 are marked in yellow.