17beta-hydroxysteroid dehydrogenase type 1 (17β-HSD1) is a positive regulator of MCF7 cell migration. (A) and (B) Comparison of cell migration between wild type (WT) MCF7 and MCF7 cells stably transfected with 17β-HSD1 (MCF7-17βHSD1). A scratch was applied to WT MCF7 and MCF7-17βHSD1 cells confluent in dishes (3.5 cm diameter) and the ability to invade the scratch was measured. (A) The relative migration of WT MCF7 and MCF7-17βHSD1 cells at 24 and 36 hours post-scratch was quantified. The scratch widths, two near the border and three in the middle of the scratch (as shown in B) were measured at the indicated time points using the NIH ImageJ software and data were used to calculate the percentage of migration. (B) Results showed that WT MCF7 cells have less ability to invade the scratch than the MCF7-17βHSD1 cells. Lines represent measurements made to assess modifications in scratch widths. (C) 17β-HSD1 knockdown by siRNA in MCF7-17βHSD1 cells. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was performed using 17β-HSD1 and β-actin primers and total RNA extracted from MCF7-17βHSD1 cells transfected with 17β-HSD1-specific siRNAs or control siRNA. (D) and (E) Effect of 17β-HSD1 knockdown on MCF7-17βHSD1 cell migration. MCF7-17βHSD1 cells were transfected with 17β-HSD1-specific siRNAs or control siRNA for 48 hours before creating a wound by scraping the cell monolayer. Cells transfected with 17β-HSD1 siRNA have less ability to invade the scratch than cells transfected with control siRNA. All experiments were done in quadruplicate, and representative images of cell progression in the scratch are shown. Error bars represent standard deviation. *P <0.05 analyzed by Student's t-test.