Apoptosis Induction in Primary Human Colorectal Cancer Cell Lines and Retarded Tumor Growth in SCID Mice by Sulforaphane
Figure 1
(a) Sulforaphane mediates the survival of five human primary colorectal cancer (CRC) cell lines (five groups, per group) and thus inhibits their proliferation. In vitro study was initiated by treating each of the cell lines to the increasing doses of SFN (0, 6.25, 12.5, 25, and 50 μM) for 24 hours. Statistical analysis used the t-test, with the significant differences determined at the level of versus control group (SFN 0 μM), while the symbol on the bar denotes the difference which is statistically significant at as compared to the 12.5 (#) or 25 μM (&). (b) Reversibility of the growth inhibitory effect of SFN. The CRC cell lines were each first treated with SFN 12.5 μM for 24 hours. After the treatment was terminated by washing off SFN, the cultures were reincubated for 24–72 hours to check the extent of recovery of cancer cells. The survival of these SFN-treated CRC cells was then measured by MTT method. (c) Effect of SFN on colony formation. CRC cells were treated with SFN, and number of colonies was counted. Results were expressed as a percentage of control, which was considered as 100%. All data were reported as the means (±SEM) of at least three separate experiments. Statistical analysis used the t-test, with the significant differences determined at the level of versus time 0 group, while the symbol on the bar denotes the difference which is statistically significant at as compared to the time 24 (#) or 48 (&) of the recovery study.
