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，它是由于遗传和表观遗传改变的积累导致细胞无法对不同的信号做出正确的反应，如控制增殖、分化、黏附和凋亡。大多数化疗药物都是基于对快速生长的肿瘤细胞和各种产生严重副作用的正常细胞产生非特异性影响的药物。新的抗癌疗法专注于选择性杀死癌细胞，同时保留正常细胞的治疗，因此毒性较低。应用RNAi技术发现肿瘤细胞特异性易损性是一种新的策略，将有助于开发更合理的癌症治疗方法。在这个项目中，我将实施基因沉默策略，引入特定的扰动，在不影响正常乳腺癌细胞的情况下，破坏乳腺癌细胞的动态平衡。为此，包含70,000个短发夹状RNA的第二代shRNA文库将被用作扰动方法来搜索整个基因组，以寻找维持不同乳腺癌细胞(基础、腔和未转化的细胞系)活性所需的基因。该项目利用RNAi技术来识别当沉默时，携带先前存在的基因变化的乳腺癌细胞的活性完全降低而不影响正常细胞的基因。因此，这项研究计划的成功完成将为更有效和更少伤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.