Expression of deregulated MYC with activated NeuNT in mammary gland developed mammary tumors with molecular heterogeneity

The goal of this study is to investigate the role of deregulated c-MYC in cooperation with activated NeuNT (mutated rat HER2) in mammary tumor molecular heterogeneity. We monitored female mice through two cycles of pregnancy/lactation in order to activate Blg-Cre expression in mammary gland after the second cycle. MYC-NeuNT mice develop tumors between 4 and 12 weeks post Blg-Cre activation, H&E images from these tumors showed histologic heterogeneity. NeuNT mice developed tumors between 28 to 44 weeks post Blg-Cre activation that also showed histologic heterogeneity. Overall design: ROSA-LSL-MYC mice were crossed with LSL-NeuNT and Blg-Cre mice to get mice that express both MYC and NeuNT in response to Cre-mediated recombination in the mammary gland. We monitored the female mice through two cycles of pregnancy/lactation then activated and waited for tumors to reach 20mm in diameter (end point). We collected 14 tumors from MYC-NeuNT mice, 4 tumors from NeuNT mice , and 3 normal mammary gland samples from control Myc mice without Blg-Cre. One piece of tissue from each sample was used to extact total RNA with Trizol according to manufactuer's protocol.