Table 1. K-H knockdown cells show specific DNA damage tolerance to 6-TG treatments.
| Cell Genotype | MSI Status | ∼LD50 valuesb | Reference | |
|---|---|---|---|---|
| IR (Gy) | 6-TG (μM, 48 h) | |||
| shScr 231a | - | 4.0 | 0.3 | (8) and this study |
| shk-h 231a | + | 2.8 | 1.2 | (8) and this study |
| MMR+ HCT116 3–6 | - | 4.0 | 3.0 | (18) |
| MMR- HCT116 | + | 3.8 | 30 | (18) |
a231, Human MDA-MB-231 triple-negative breast cancer cells.
bLD50, dose of agent leading to ∼50% kill.
A comparison of ∼LD50 values after 6-TG or IR treatment of shScr versus shk-h MDA-MB-231 (231) cells. Also included are sensitivity data against 6-TG and IR for known MMR-proficient (MMR+) HCT116 3–6 cells and -deficient (MMR-) HCT116 cells for comparison. Although, genetic background and treatment conditions differ between shScr/shk-h versus MMR-proficient/-deficient cells, the data highlight the unique phenotype of K-H-depleted cells, where they are simultaneously hypersensitive to IR, yet damage-tolerant to 6-TG.