Figure 1. Estrogen is not sufficient to initiate a growth advantage in NSCLC xenograft tumor models or cell lines.

Average tumor growth rate of tumors starting at (200–400 mm³) in mice xenografts of A549 (A) and HCC827 (B), in presence or absence of estrogen. N =20 mice per group and experiment was repeated twice. The log-rank (Mantel-Cox) test was used to compare the statistical differences among the groups. Mice were sacrificed when the tumor reached 1000mm³. NSCLC xenograft tumors were sectioned and stained by immunohistochemistry for Ki-67 to measure tumor proliferation between vehicle and estrogen-treated NSCLC tumors (C). Cells were serum starved for 24 hours. 10⁻⁹M of estrogen (E2) and 10⁻⁸ M of pure anti-estrogen fulvestrant (F) was added. MTT assay was performed after 96 hours of incubation (D). Results are presented as a fold change of vehicle-treated proliferation. Calu6 and A549 were serum starved and transfected with ERα or ERβ cDNA. Luciferase activity was measured, and results are expressed as fold change of control (E). Results are presented as mean of biological triplicates ± SEM and experiment was repeated three times.