Research Paper Volume 12, Issue 14 pp 15104—15120

Figure 7. Pro-MMP-9 protein expression secondary to STAT5a overexpression and 17-β-Estradiol treatment suggest a hormonal regulation of DCIS progression with this transcription factor. (A) MCF10DCIS.com empty vector and STAT5a overexpressor cells were treated with vehicle (DMSO) or 1nM estradiol for 24 hours. Whole cell lysates (75μg) were used to assess the protein expression of MMP-9. GAPDH was used as a loading control. Western blotting was performed in triplicate on cells derived from 3 independent passages. (B) Using the LI-COR imager, densitometry was used to determine the protein expression of MMP-9 upon normalizing to the loading control. Data are reported as % empty vector. Quantitatively, no significant difference in MMP-9 expression was observed between vehicle-treated empty vector and STAT5a overexpressor cells (NS, p=0.382, n=3). Upon treatment with estrogen, a significant increase in MMP-9 protein expression was observed in STAT5a overexpressor cells compared to empty vector cells (39.1-fold, p<0.001, n=3).