The apoptosis-inducing agent gemcitabine has a direct effect on B16 tumors in vitro and in vivo.

<p>(A) The relative in vitro sensitivity of B16 parental, B16.Nuc, B16.Cyto, and B16.Sec tumor cells to gemcitabine was assessed by MTT assay, after a 48 hr incubation with drug. With relevent concentrations of gemcitabine that kill 50% of respective tumors shown. (B) <i>In vivo</i> growth of B16 parental only, and B16 parental mixed with 10% (194 nmols) of B16.Sec-, Cyto-, or Nuc-CL4 antigen-containing tumors, after subcutaneous inoculation of F1 mice on day 0, and intraperitoneal administration of a single dose of gemcitabine (240 µg/g) or saline on day 6. Bar graph shows tumor sizes on day 11. For simplicity, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0107894#pone-0107894-g003" target="_blank">Figure 3B</a> only shows data from the 10% antigen concentration experiment as this was similar to that of 1 and 5%. Mean ± SEM. Six mice per group from two independent experiments. One-way ANOVA followed by a Bonferroni post test against all groups.