DEVELOPMENT OF METHODS TO VALIDATE SYNTHETIC LETHALITY INDUCTION IN VITRO AND IN VIVO

CASTELLARO A; NIGRA AD; CARBAJOSA S; M, RODRIGUEZ-BAILI MC

Buenos Aires

Congreso; Reunio conjunta de Sociedades de Biociencias de Argentina; 2017

SAIB

One of the current challenges in the development of anticancer therapies lies in the identification of drugs that selectively kill cancer cells with minor impact on normal cells. A strategy of selective cytotoxicity that has yielded promising results is the induction of synthetic lethality (SL). SL induction involves tumor-acquired mutations that sensitize cells to a given treatment when they are in combination. We are focused in the study of drugs that cause SL in BRCA1/2-deficient cancer cells (Bd-cells). Herein we show the validation of potential drugs which have been previously identified as SL-inducers using a cell-based high-throughput screening platform based on flow cytometry. Three validation methods were developed to assess the performance of these drugs on a Bd-cell model in comparison to the wild type cell line (Bw-cells). The first method evaluates the clonogenic potential of Bd-cells and Bw-cells after the treatment with the drugs, using an adaptation of the colony formation assay. The second method involves the use of 3D chimeric spheroids constituted by an equal proportion of Bd-cells and Bw-cells. Both cell populations are tagged with different fluorescent proteins and can therefore be quantified by flow cytometry after the treatments with the drugs. The third model is a double tumor xenograft approach in Nude mice. This model consists in the generation of flanking tumors in a single mouse, one from Bd-cells and the other from Bw-cells. Mice are then treated with potential SL-inducers or vehicle and the progression of each tumor-type is assessed in order to expose the SL phenomena in vivo.