Lung cancer is the second most common type of cancer and the main cause of cancer-related death worldwide. The high mortality is associated to late detection of the disease when most of patients already display distant metastases, reducing the overall 5-year survival to 20%.The main oncogenic pathway is MAPK with mutations in KRAS and EGFR, and high prevalence of inactivating mutations in TP53. In this context, the investigation of new molecular alterations could contribute to the understanding of the biology of this aggressive cancer. For example, the increase in PRC2/EZH2 complex activity has been reported in different types of cancer, especially in aggressive histotypes. EZH2/PRC2 is highly expressed during development, acting in the chromatin silencing through the trimethylation of histone H3 lysin 27 (H3K27Me3). The reactivation of EZH2/PRC2 in cancer could be associated to the acquisition of epithelial to mesenchymal (EMT) characteristics that drive cells to become more invasive and to form metastasis. Indeed, the loss of microRNAs of miR-200 family, small noncoding RNAs, is associated to the EMT process and metastasis in lung cancer. Thus, this project aims to understand the role of PRC2/EZH2 complex in aggressive lung cancer using gene editing methodology with CRISPR/Cas9 to induce the loss of function in the human EZH2 gene. Gene editing will be performed using the transfection of a plasmid to express sgRNAs that target EZH2 gene + Cas9 and selection with puromycin in lung cancer cell line. Next, functional in vitro (cell counting, cell viability, invasion and migration) and in vivo assays (xenotransplant in nude mice) will be performed to evaluate the effect of EZH2 silencing. In sum, we expect this study to contribute to a better understanding of the role of chromatin silencing by EZH2/PRC2 in lung cancer biology.
News published in Agência FAPESP Newsletter about the scholarship: