Systematic genome-wide RNAi screen to identify novel synthetic lethal interactions in human breast cancer cell lines: implications for the development of therapeutic molecular targets.

癌症是一种异质性疾病，由遗传和表观遗传改变的积累引起，导致细胞不能正确响应各种信号，如增殖、分化、粘附和凋亡的控制。大多数化疗都是基于非特异性地影响快速生长的肿瘤细胞和各种正常细胞的药物，因此产生严重的副作用。新的抗癌疗法集中在选择性杀死癌细胞的同时保留正常细胞，因此毒性较小。应用RNAi技术发现肿瘤细胞特异性脆弱性是一种新的策略，将有助于在癌症治疗中开发更合理的治疗方法。在这个项目中，我将进行基因沉默策略，引入特定的扰动，在不影响正常细胞的情况下破坏乳腺癌细胞的稳态。为此，将使用含有70,000个短发夹rna的第二代shRNA文库作为扰动方法，在整个基因组中搜索维持不同乳腺癌细胞（基底、腔和非转化细胞系）活力所需的基因。该项目利用RNAi技术来识别基因，这些基因在沉默时，只会降低携带预先存在的遗传改变的乳腺癌细胞的生存能力，而不会影响正常细胞。因此，这项研究计划的成功完成将为更有效、更低危害的乳腺癌治疗提供新的靶点。

Cancer is a heterogeneous disease that arises from an accumulation of genetic and epigenetic alterations resulting in a failure of cells to respond correctly to diverse signals, such as control of proliferation, differentiation, adhesion and apoptosis. Most chemotherapeutic treatments are based on drugs that affect unspecifically the rapidly growing tumor cells and a variety of normal cells producing, therefore, severe side effects. Novel anticancer therapies are focused on treatments that selective kill cancer cells while sparing normal cells and therefore are less toxic. The application of the RNAi technology for discovering of tumor cell specific vulnerabilities is a novel strategy that will help to the development of more rational therapies in cancer treatments. In this project, I will conduct a gene silencing strategy to introduce specific perturbations to compromise the homeostasis of breast cancer cells without affecting normal ones. For this purpose, a second-generation of shRNA library of 70,000 short hairpin RNAs will be used as a perturbation method to search the entire genome for genes that are required to maintain the viability of different breast cancer cells (basal, luminal, and non-transformed cell lines).This project exploits the RNAi technology to identify genes that, when silenced, exclusively reduce the viability of breast cancer cells that carry preexistent genetic alterations without affecting normal cells. Thus, the successful completion of this research plan will provide novel targets for more efficient and less harmful breast cancer therapies.