Experimental Therapeutics Programme

Biology Section

Head of Section:  Carmen Blanco
Research highlights

During 2017, our Section was involved in several projects:

Cyclin-dependent kinase 8 (CDK8)

We characterised ETP-93, a second improved dual lead compound, and ETP-18, a nanomolar selective CDK8/CDK19 inhibitor, as it was described in the Medicinal Chemistry Section.

Microtubule-associated serine/threonine protein kinase-like (MASTL) and HASPIN

These projects are undertaken in collaboration with the CNIO Cell Division and Cancer Group. For MASTL, we tested 98 new compounds in our biochemical assay with active human full length MASTL protein. We identified low nanomolar inhibitors that were profiled in a small internal kinase panel, revealing off-targets that were removed. The more potent and selective inhibitors are under cellular characterisation. For HASPIN, we tested in a biochemical assay 90 compounds belonging to 3 different chemical series. Active compounds were also profiled in the small internal kinase panel. Cellular inhibition of phosphorylation of H3T3 was evaluated for those inhibitors with a biochemical IC50 below 100nM. We identified nanomolar biochemical and cellular HASPIN inhibitors and representative molecules for two chemical series that have been profiled in a panel of 468 kinases (KinomeScan), thereby obtaining a high level of selectivity for both of them (S(35) of 0.025 and 0.007). These compounds are under further cellular evaluation and in vivo PK.

Telomeric repeat binding factor 1 (TRF1)

This project is carried out in collaboration with the CNIO Telomeres and Telomerase Group. A phenotypic assay to measure the association of TRF1 to telomeres was used to test 44 compounds, which include ETP-946 analogues and its corresponding chemical probes. Moreover, we used one of these chemical probes, ETP-455, to perform cellular localisation assays of the putative target of ETP-946. This information has been used to design pull-down experiments that are currently ongoing. Furthermore, we have tested the ETP-antitumour library to identify new signalling pathways that modulate TRF1. We are validating these new pathways by using a chemical-biology approach that we previously applied to uncover that the PI3K/ AKT pathway regulates TRF1.

Cancer stem cells (CSC) and screening to identify new senolytic drugs

These projects are carried out in collaboration with the CNIO Tumour Suppression Group. For the CSC project, we collaborated on the pharmacokinetic characterisation of the most interesting identified hit, as well as in the in vivo validation studies. For the new senolytics screening project, ETP-Biology provided support for testing and analysing the ETP-antitumour and ETP-5K libraries in an assay that compares the viability of tumour cells and senescent cells. After validation of the hits identified by single point and the testing of analogues, four hits were selected for further characterisation.

Brain metastasis screening
The CNIO Brain Metastasis Group developed an ex vivo assay to search for drugs that kill human brain metastasis in mice. One class of drugs identified in the screening was further characterised; we contributed to the experimental design and the analysis of tumour levels in PK/PD experiments in order to help design the administration schedule for the efficacy study performed by our collaborators.
Screening to identify new Ras modulators

The CNIO Genomic Instability Group has developed an assay to search for drugs that modulate the Ras pathway. ETP-Biology has provided support in running the experiments with both the ETP-800 and ETP-5K libraries and by testing the analogues. Two interesting hits were identified and we performed their ADME profiles ; they are currently under pharmacokinetic characterisation and will eventually progress to in vivo PoC studies.

Screening to identify New mTOR modulators

The CNIO Metabolism and Cell Signalling Group developed an innovative assay to search for drugs that modulate the mTOR pathway. ETP-Biology provided support in running the experiments with both the ETP-800 and ETP-5K libraries. The identified hits are under further characterisation.

Collaborations with other CNIO Groups

ETP-Biology has provided support by testing and analysing the ETP-antitumour library, either alone or in combination, in order to identify: i) novel treatments or combinations in MPNST cell lines in collaboration with the Microenvironment and Metastasis Group; ii) novel treatments or combinations in bladder cancer cell lines in collaboration with the Epithelial Carcinogenesis Group; iii) novel treatments or combinations in brain cancer cell lines in collaboration with the Brain Tumour Group; and iv) novel treatments of KRas mutant NSCLC mouse cell lines with and without EGFR in collaboration with the Experimental Oncology Group.