A and B. MCF10AT1 cells. Cells were transduced with either with pLenti-GRM1, pLenti-LacZ, shGRM1, or NS control vector and stably selected before plating in soft agar. GRM1 overexpression significantly increased number of colonies on soft agar compared to the control LacZ cells (A), an effect reversed by shGRM1 (B). C. MCF10CA1d cells. Silencing GRM1 significantly decreased colony formation compared to the non-silencing (NS) vector control in MCF10CA1d cells. Finally, colony formation is inhibited by BAY in both MCF10DCIS.com cells (D) and MCF10CA1d cells (E). For all assays 1×105 cells were suspended in 0.4% agarose and colonies formed on the soft agar were counted after three weeks on Gel Count machine. Results are recorded as the mean ± SEM of three experiments, where *p<0.05 compared to control. F. Live cell imaging of 4 day MAME cultures of MCF10AT1-
LacZ
and MCF10AT1-
GRM1
cells illustrate increases in proliferative and invasive phenotype in cells expressing
GRM1
. 15,000 cells were seeded per coverslip on reconstituted basement membrane. Differential Interference Contrast images from 16 contiguous fields were obtained with a Zeiss LSM-510 META confocal microscope. Tiled images allow one to see the relative sizes of the structures formed over a 4-day period. Bar, 100 µm. Legend: LacZ = pLenti-LacZ; GRM1 = pLenti-GRM1.