<i>GRM1</i> and mGluR1 expression and activity in breast cancer.

<p><b>A. <i>GRM1</i> message is expressed at significantly higher levels in breast cancer versus normal breast.</b> GRM1 message was measured by qRT-PCR in 49 human breast cancers and 10 normal breast specimens. The whiskers in the box-and-whiskers plot represent a percentile range from 10 to 90. Cancer and control groups were compared using the unpaired t-Mann-Whitney test with Welch's correction (p = 0.0007, arbitrary units normalized to GAPDH ± SEM). <b>B. mGluR1 expression in human breast cancer.</b> Staining was patchy, with some breast cancer cells showing intense staining and others showing light staining, suggesting a mosaic of mGluR1-positive and mGluR1-negative cells in this specimen (magnification: 100×). C. mGluR1 expression in normal breast tissue. Little to no staining was observed in normal ductal and lobular epithelial cells. However, there was significant staining observed in the tissue vasculature, primarily the epithelial cells. (Magnification 40×) <b>D. mGluR1 expression in a breast cancer tissue microarray.</b> The CTMA4 breast cancer tissue array was subjected to mGluR1 IHC as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081126#s2" target="_blank">Materials and Methods</a> and the TMA examined by a breast pathologist (N. B.).