Mutating E-cadherin in rats to model lobular breast cancer

本申请是为了响应特别利益通知（NOSI）而提交的，该通知被确定为 NOT-CA-23-045。”父母奖R 01 CA 271498专注于研究导管乳腺癌的大鼠模型， 但它没有研究浸润性小叶乳腺癌（ILC），在美国， 我们ILC主要是雌激素受体阳性（ER+）。E-钙粘蛋白（由CDH 1基因编码）缺失 是ILC在超过95%的病例中在蛋白质水平上丢失的特异性特征，而 CDH 1发生在65%的病例中。CDH 1的遗传缺失尚未被工程化到大鼠乳腺细胞中， 研究ILC，但我们现在有技术能力将CDH 1突变工程化到大鼠乳腺癌中， 腺体我们预测，CDH 1的损失将使大鼠乳腺ER+ ILC。在这个补充奖， 我们将与奥斯特赖希-李实验室合作，该实验室在研究ILC方面具有广泛的专业知识， 人类标本、细胞培养物和致癌物诱导的大鼠肿瘤的类器官。目标是开发一个 ER+ ILC的临床相关大鼠模型。两个具体目标是追求：目标1：检查体细胞的影响， CDH 1缺失对大鼠乳腺发育和功能的影响这种体细胞CDH 1 KO将在 使用我们最近公布的方法，使用导管内注射病毒用于高效体内CRISPR- 基因组编辑目的2：测试体细胞CDH 1缺失和PIK 3CA激活或PIK 3CA激活的组合是否是细胞凋亡的主要原因。 DMBA处理导致大鼠ER+乳腺肿瘤，其组织病理学和基因表达与 人ILC。我们选择CDH 1 KO和PIK 3CA激活的组合，因为单独的CDH 1 KO是 不太可能足以导致癌症，因为PIK 3CA是最常见的原癌基因突变， 人乳腺癌包括ILC。

This application is being submitted in response to the Notice of Special Interest (NOSI) identified as NOT-CA-23-045.”The parent award R01CA271498 is focused on studying rat models of ductal breast cancer, but it does not study invasive lobular breast cancer (ILC), which accounts for up to 40,000 cases yearly in the US. ILC is predominantly estrogen receptor-positive (ER+). Loss of E-cadherin (encoded by the CDH1 gene) is the pathognomonic feature of ILC being lost at the protein level in over 95% of cases, while mutations of CDH1 occur in 65% of cases. Genetic loss of CDH1 has not been engineered into rat mammary gland cells for studying ILC, but we now have the technical capabilities to engineer CDH1 mutations into rat mammary glands. We predict that CDH1 loss will predispose rat mammary glands for ER+ ILC. In this supplement award, we will team up with the Oesterreich-Lee laboratory, which has extensive expertise in studying ILC, using human specimens, cell culture, and organoids of carcinogen-induced rat tumors. The goal is to develop a clinically relevant rat model of ER+ ILC. Two specific aims are pursued: Aim 1: Examine the effect of somatic CDH1 deletion on rat mammary gland development and function. This somatic CDH1 KO will be achieved using our recently published method using intraductal injection of virus for high efficiency in vivo CRISPR- genome editing. Aim 2: Test whether the combination of somatic CDH1 deletion and PIK3CA activation or DMBA treatment results in rat ER+ mammary tumors with a histopathology and gene expression similar to human ILC. We select the combination of CDH1 KO and PIK3CA activation because CDH1 KO alone is unlikely to sufficient to cause cancer and because PIK3CA is the protooncogene most commonly mutated in human breast cancer including ILC.