Altered miR-7 expression regulates breast tumor cell proliferation and migration.

<p>Mir-7 expression was stably suppressed in the MCF-7 cell line to generate the MCF-7/miR-7KD cell line and a miR-7 expression plasmid was stably introduced into the MCF-7/HER2Δ16H cell line to generate the MCF-7/HER2Δ16H/miR-7 cell line. (A) Western blot analysis of the MCF-7 vector control, MCF-7/pcDNA and the HER2Δ16 expressing MCF-7/HER2Δ16H and MCF-7/HER2Δ16M1 and cell lines with altered miR-7 expression. Relative miR-7 expression levels are indicated below each lane as determined by qRT-PCR. (B) Colony formation assay where colony number and diameter were calculated using a ColCount Colony Counter with supplied statistical software. Asterisk indicates cell lines significantly greater than MCF-7/pcDNA and MCF-7/HER2Δ16/miR-7 as determined by paired Student's <i>t</i> test (<i>p</i><0.006). (C) Cell cycle analysis was performed in a Guava Easy Cyte Mini Base System with supplied statistical software. Asterisk indicates cell cycle phase significantly different from parental cell line as determined by paired Student's <i>t</i> test (<i>p</i><0.01). (D) Cell migration was determined in an xCELLigence CIM-Plate 16 with the RTCA DP Instrument for 48 hrs. Cell Index (referred to here as Migration Index) was calculated using the supplied RTCA Software. Asterisk indicates that MCF-7/HER2Δ16H is significantly greater than the other tested cell lines as determined by paired Student's <i>t</i> test (<i>p</i><0.005). (B–D) The data represents the mean +/− SE of at least three independent experiments.