Development of an in vitro model by CRISPR-Cas9 for the study of metastatic-promoting properties of mutated TP53 and RB1 in triple-negative breast cancer

Cancer is a complex disease, requiring specific treatments for each type. Triple-negative breast cancer (TNBC) is the most aggressive form of human breast cancer; however, it lacks specialized treatments, leaving patients with poor prognoses. The underlying molecular mechanisms responsible for the aggressive traits of TNBC remain elusive; however, one crucial clue is that TP53 and RB1, important tumour suppressor genes, are commonly mutated together in TNBC patients. Evidence suggests mutations of these genes could collectively promote metastasis. To better understand the effects TP53 and RB1 mutations have on metastatic characteristics of TNBC, we generated a cell line model by successfully knocking out TP53 and RB1 from a TNBC cell line, utilizing CRISPR-Cas9. Validation assays monitoring cell cycle phase distribution, metastasis-promoting gene expression, and cell migration revealed the intricacy of developing a TNBC cell line model and that further modifications are essential. Once established, the model could prove essential for identifying TNBC therapeutic targets.