DNA damage in cancer cells estimated with 24 h neutral comet assay: determination of DNA damage (double-strand breaks) induced by 0.5 × IC50, IC50, and 2 × IC50 concentrations of MM134, -6, -7, and -9 in cancer cell lines (BxPC-3 (A), PC-3 (B)) after 24 h incubation of cells with tested compounds. Data are represented as median tail DNA % with interquartile range and minimal and maximal values. The Kruskal–Wallis test was used to show a statistically significant difference between groups. Multiple comparisons using mean ranks for all groups module of Statistica software were used. In all groups, N > 200. * significant difference compared to the negative control; p < 0.05. # significant difference compared to the positive control (20 µM bleomycin); p < 0.05.