Murine mammary gland: PRA transgenics vs. wild-type. Murine mammary gland: PRA transgenics vs. wild-type

Progesterone receptor (PR) is expressed from a single gene as two isoforms, PRA and PRB. In normal breast human tissue, PRA and PRB are expressed in equimolar ratios, but isoform ratio is altered during malignant progression, usually leading to high PRA:PRB ratios. We took advantage of a transgenic mouse model where PRA isoform is predominant (PRA transgenics) and identified the key transcriptional events and associated pathways underlying the preneoplastic phenotype in mammary glands of PRA transgenics as compared with normal wild-type littermates. Overall design: Reference-based 2-color microarray design. Two-condition experiment, PRA transgenics vs. wild-type. Biological replicates: 3 wild-type, 4 PRA transgenics.

孕酮受体（Progesterone receptor，PR）由单基因转录表达，产生PRA与PRB两种同工型。在正常人类乳腺组织中，PRA与PRB以等摩尔比表达，但在恶性进展过程中，该同工型比例会发生改变，通常会导致PRA:PRB比值升高。我们采用PRA同工型占优的转基因小鼠模型（PRA transgenics），对比正常野生型同窝仔鼠，鉴定出PRA转基因小鼠乳腺组织癌前表型背后的关键转录事件及相关通路。实验整体设计：采用基于参考序列的双色微阵列（microarray）实验设计，为双条件对照实验：PRA转基因小鼠与野生型小鼠。生物学重复设置为：野生型3例，PRA转基因小鼠4例。