The Wnt-mediated proliferation and self-renewal of mammary stem cells (MaSCs) requires Gpr177.

<p>(A) Statistical analysis shows the percentage of mitotic cells positive for immunostaining of Ki67 in the control, MMTV-Wnt1, MMTV-Wnt1; Gpr177^MMTV mammary gland. <i>P</i> values indicate significance of the study (n = 3). (B) Mammosphere analysis examines the self-renewing and proliferation abilities of MaSCs in primary (1⁰) and secondary (2⁰) cultures of control, MMTV-Wnt1 and MMTV-Wnt1; Gpr177^MMTV. The effect of IWP-2 on the Wnt-mediated stem cell self-renewal and proliferation is also investigated. Data represent the mean ± SEM in three independent experiments. Asterisks indicate the <i>p</i> value (1⁰: *, <0.0062, **, <0.0022, ***, <0.0283 and 2⁰: *, <0.0004, **, <0.0024, ***, <0.0076). (C) Diagram illustrates the average size of spheres is not significantly different in the control (131.9±6.9), MMTV-Wnt1 (124.8±3.2), MMTV-Wnt1; Gpr177^MMTV (124.2±4.3), MMTV-Wnt1+IWP-2 (151.5±6.4) cultures. (D) Diagram illustrates the limiting dilution transplantation and calculation of the success ratio showing the frequency of mammary stem cells in MMTV-Wnt1 and MMTV-Wnt1; Gpr177^MMTV mice.