Effect of RB1 status on response to radiation or doxorubicin of CD44⁺/CD24^−/low/ESA⁺ cancer stem cell (CSC)-enriched fraction in human TNBC lines.

<p>Treatment with 5 Gy radiation or IC₅₀ doses of CDDP or doxorubicin. (<b>A</b>) Viable cell population of 7-AAD control MDA-MB-231 cells. (<b>B</b>) ESA positive cell fraction of untreated MDA-MB-231 cells. (<b>C–D</b>) MDA-MB-231 CSC fraction in untreated and irradiated cells. (<b>E–F</b>) HCC1937 CSC fraction in untreated and irradiated cells. (<b>G</b>) Relative change in the CSC fraction for each line treated with CDDP, doxorubicin or radiation. (<b>H</b>) Average relative ratio of the CSC fraction for RB⁺ and RB⁻ TNBC cell lines treated as indicated. RB⁺ lines (red): MDA-MB-231, MDA-MB-157 and HCC38. RB⁻ lines (blue): MDA-MB-436, MDA-MB-468, and HCC1937. p-value calculated using a two-tailed t-test. n.s. = not significant.