Phenotype-based approach to find gene interactions underlying breast cancer risk

描述（由申请人提供）：鉴定导致常见（非孟德尔）形式乳腺癌的基因将能够早期识别有风险的个体，并制定预防和治疗方案。这是一个非常困难的问题，因为常见形式的乳腺癌的遗传风险是多个基因-基因相互作用的结果，每个单独的基因对风险的贡献很小。标准方法（例如遗传关联研究）在检测潜在风险的许多基因-基因相互作用方面能力不足。我们提出了一种基于表型的方法来预测常见形式的乳腺癌的潜在风险的基因-基因相互作用。该方法基于细胞DNA损伤反应（乳腺癌易感性的中间表型）中的缺陷是可遗传的这一观察结果，从而有可能绘制导致该表型的基因-基因相互作用。我们假设，基因-基因相互作用的敏感性，DNA损伤酵母和人类之间是保守的。我们的方法将是：i）使用酵母S。酿酒酵母进行全基因组筛选，以筛选与人乳腺癌肿瘤抑制基因的同源物协同作用的突变，从而赋予对DNA损伤的敏感性，以及ii）在这些鉴定的合成相互作用中筛选在人乳腺上皮细胞中保守的那些。 具体目标1：在S.酿酒酵母，以鉴定与人乳腺癌肿瘤抑制基因的酵母同源物协同产生对DNA损伤的敏感性的突变。 具体目标二：利用RNA干扰技术，建立稳定敲除乳腺癌抑制基因的人乳腺上皮细胞系。 具体目标3：确定在酵母中发现的遗传相互作用在人类乳腺上皮细胞中是否保守。 项目叙述：确定一个人患癌症的风险可能会在几个方面对公共卫生产生巨大的影响：i）识别乳腺癌的风险等位基因将有助于根据个人的风险状况制定具有成本效益的癌症筛查计划; ii）识别风险等位基因将允许识别将从预防策略中获益最多的女性; iii）鉴定风险等位基因将阐明疾病的病理生理学，从而产生靶向治疗剂或化学预防剂，例如现有的靶向激素和抗体疗法。

DESCRIPTION (provided by applicant): Identification of genes contributing to common (non-Mendelian) forms of breast cancer would enable early identification of individuals at risk and tailoring of prevention and treatment regimens. This is an extremely difficult problem since heritable risk for common forms of breast cancer is a result of multiple gene-gene interactions, with each individual gene making only a minor contribution to risk. Standard approaches (e.g. genetic association studies) are underpowered to detect the many gene-gene interactions underlying risk. We propose a phenotype-based approach to predict gene-gene interactions underlying risk for common forms of breast cancer. The approach is based on the observation that defects in the cellular DNA damage response (an intermediate phenotype for breast cancer susceptibility) are heritable, making it possible to map gene-gene interactions responsible for this phenotype. We hypothesize that gene-gene interactions governing sensitivity to DNA damage are conserved between yeast and humans. Our approach will be to: i) use the yeast S. cerevisiae to perform genome-wide screens for mutations that synergize with homologs of human breast cancer tumor suppressor genes to confer sensitivity to DNA damage, and ii) to screen amongst these identified synthetic interactions for those that are conserved in human mammary epithelial cells. Specific Aim 1: Perform genome-wide screens in S. cerevisiae to identify mutations that synergize with yeast homologs of human breast cancer tumor suppressor genes to produce sensitivity to DNA damage. Specific Aim 2: Using RNA interference, build human mammary epithelial cell lines that have stable knock- down of breast tumor suppressor genes. Specific Aim 3: Determine if genetic interactions discovered in yeast are conserved in human breast epithelial cells. PROJECT NARRATIVE: Determination of an individual's risk for developing cancer could have tremendous public health impact in several ways: i) identifying risk alleles for breast cancer will facilitate cost-effective cancer screening programs tailored to an individual's risk profile; ii) identifying risk alleles will allow identification of women who will most benefit from prevention strategies; iii) identifying risk alleles will elucidate the pathophysiology of the disease, leading to targeted therapeutics or chemoprevention agents such as existing targeted hormonal and antibody therapies.