Figure 1.

GH potentiates E2-stimulated proliferation in T47D human breast cancer cells. A, GHR mRNA expression was examined in a panel of ER+ human breast cancer cell lines by QPCR using the ΔΔcycle threshold method with 36B4 as an internal control. B, T47D cells were treated with 500 ng/mL GH, 10 nM E2, or both for 5 days. Cell numbers were determined using the methylene blue assay and are presented as percent of untreated cells on day 0. C, BrdU incorporation was assessed in T47D cells after 72 hours of treatment with GH, E2, or both. D, T47D cells were treated for 5 days as described in B in the absence or presence of 1 μM of the ER antagonist ICI 182,780. Data points or bars with different letters are significantly different (P < .05).