Figure 2.

E2-dependent xenograft tumors induced by MCF-7 cells are blocked by the expression of TRβ. A: Two clones each of MCF-7-Neo and MCF-7-TRβ were inoculated into athymic mice without or with E2 as described in Materials and Methods. No tumors were induced by MCF-7 cells in the absence of E2 treatment. B: Tumor weight was determined at the endpoint for the MCF-7-Neo (clones #1 and #12) and MCF-7-TRβ (clones #18 and #19). ★represents no tumors. The data are expressed as mean ± SE (n=3). The p values are indicated.