Figure 8.

T-oligo increases survival of mice injected intravenously with MCF-7 cells. (a) MCF-7 cells received fresh serum-containing medium supplemented with increasing concentrations (10 to 40 μM) of the 11mer or 16mer T-oligos or diluent alone and were harvested at 96 hours. At 10 μM and 20 μM, the 16mer inhibited MCF-7 yield substantially more than the 11mer, and 20 μM 16mer reduced cell yields comparably to 40 μM 11mer. (b) MCF-7 cells were supplemented with 11mer or 16mer T-oligos (20 μM) or diluent (Dil) alone. Within 48 hours both T-oligos induced H2AX and p53 phosphorylation, but this occurred to a greater extent with the 16-base T-oligo. (c) SCID mice inoculated intravenously with MCF-7 cells received intravenous T-oligo or diluent injections as per the Materials and methods. Doses giving comparable growth inhibition at 96 hours were used: 20 μM 16mer versus 40 μM 11mer, equivalent to 60 versus 120 nmoles injected into the estimated murine 1.5 ml peripheral blood volume. Both T-oligos increased survival of the mice, with the 16mer having a greater effect.