Molecular Oncology and Targeted Therapies

Overview

Genome instability is one of the hallmarks of cancer, affecting the initiation, evolution, and treatment response of the majority of cancers. To limit the accumulation of genomic alterations, cells have evolved complex mechanisms that coordinate cellular responses altogether known as the DNA Damage Response (DDR). However, in many cases the DDR is not sufficient to protect our genomes from either exogenous or endogenous insults, which may lead to cancer.

The overall goal of our laboratory is to increase our knowledge on the mechanisms that regulate the DDR and to identify novel therapeutic opportunities to treat or prevent cancer.

With this purpose, we utilize a wide range of approaches to investigate genome instability from the underlying molecular mechanisms to its ultimate consequences on health. We use cellular-based systems to perform screens, gain mechanistic insight and analyze cellular phenotypes in different genetic backgrounds. Besides, we generate genetically modified mouse models to address the physiological impact of specific genetic alterations and their influence on cancer. For both, cellular and mouse models-based studies, we use CRISPR/Cas9 technology to efficiently manipulate the genome. In collaboration with groups at the University of Copenhagen, we perform proteomic studies to investigate novel regulatory networks and the interplay between different proteins involved in the DDR. We also employ high content microscopy (HCM) as a routine approach to quantify alterations in the DDR, and to perform genetic and drug screens to identify novel therapeutic targets or compounds with clinical interest. The most relevant findings are validated and further characterized using mouse models.

Research lines

1- Chromosomal Common Fragile Sites: Unravelling their biological functions and the basis of their instability. (ERC-Starting Grant-679068)

Within our genomes, some regions are particularly prone to break, and these are known as Common Fragile Sites (CFSs). CFSs are present in every person and are hotspots of oncogenic chromosomal rearrangements. Intriguingly, despite their fragility, many CFSs are well conserved through evolution, suggesting that these regions have important physiological functions that remain elusive. Most of the CFSs contain very large genes, which has made technically difficult to dissect whether the CFS role is due to the locus itself or to the encoded gene product. However, the emergence of the CRISPR/Cas9 technology has enabled an easier genetic manipulation of these loci. We have generated mouse models harboring large deletions at CFS loci to investigate their physiological functions at the cellular and organism levels. We have also developed proteomic approaches to identify the chromatin-bound proteome of CFSs and we are currently characterizing novel CFSs factors and their impact in tumorigenesis. Finally, and given that CFS fragility is influenced both by cell cycle checkpoints and dNTP availability, we use mouse models to study the impact of ATR/CHK1 pathway and dNTP levels on CFS instability and cancer.

2-Defining therapeutic targets and strategies for cancer prevention.

The majority of hereditary cancer syndromes are caused by mutations in genes involved in DNA repair or, more generally, in the DNA damage response (DDR), indicating the relevance of these pathways to prevent cancer. In this project, we aim to identify molecular targets in the DDR that could be exploited for cancer chemoprevention. We will evaluate which DDR-related tumor suppressor genes (TSGs) confer extra protection from DNA damage and malignant transformation using a CRISPR/dCas9-activation system to increase their endogenous expression in human cell lines. The most relevant TSGs identified will be investigated in vivo by developing genetically modified mouse models with specific activation of each TSG. This will allow us to investigate whether the potentiation of these DDR-related TSGs can prevent cancer development in carcinogen-induced and genetic cancer mouse models. We expect that the fundamental knowledge generated will be crucial to design cancer prevention strategies for individuals with increased cancer risk, and, ultimately, for the general population.

3- Identification of a novel therapeutic target for Myc-induced Lymphoma.

PICH is involved in the resolution of ultrafine anaphase DNA bridges (UFBs) and, therefore, is important to safeguard chromosome segregation and stability. We have recently generated a Pich knockout (KO) mouse model which allowed us to decipher that PICH is essential during embryonic development, and in RAS-induced transformation in vitro. We will take advantage of this model to investigate the role of PICH in adult animals, particularly as a potential therapeutic target for cancer treatment. We will also utilize our novel Pich conditional KO model in combination with different Cre-recombinase models, and cancer prone mice overexpressing Myc or null for p53. Finally, we will perform genetic and small molecule screens to identify modulators of PICH or related factors that compromise UFB resolution, aiming to identify novel anti-cancer therapeutic strategies.

Funding:

-ERC Starting Grant (ERC-StG-679068) from the European Research Council (2015-2022)

-Paula Aguilera and María Castejón are recipients of postdoctoral grants funded by the Junta de Andalucía with FEDER funds.

If you are interested in joining our group as master student, PhD student or Postdoc, please send us your CV and motivation letter to: andres.lopez@cabimer.es