Related Experiment Video
Updated: May 25, 2026
A Doxorubicin-induced Cardiomyopathy Model in Adult Zebrafish
Published on: June 7, 2018
Continual low-level MEK inhibition ameliorates cardio-facio-cutaneous phenotypes in zebrafish
Corina Anastasaki1, Katherine A Rauen, E Elizabeth Patton
1The Institute for Genetics and Molecular Medicine, Medical Research Council, Human Genetics Unit and Edinburgh University, Crewe Road South, Western General Hospital Campus, EH4 2XR, UK.
Abstract:
Cardio-facio-cutaneous (CFC) syndrome is caused by germline mutations in KRAS, BRAF and MEK1/2. The highly selective and potent MEK inhibitors that have been developed as anti-cancer agents hold potential as therapeutics for CFC syndrome. We have previously shown that the effects of CFC mutations on zebrafish gastrulation can be prevented by a 1-hour treatment with MEK inhibitors within a specific developmental time-window. However, MEK activity is essential for normal development and PD0325901 treatment outside this treatment window leads to additional developmental defects in MEK-dependent tissues. We now test ten different doses of PD0325901 at six developmental time points and assess the effects on body axis length, heart development and craniofacial structures in zebrafish embryos. Notably, we find that a continuous low-level dose of PD0325901 that has only minor inhibition of MEK activity can prevent the action of both the common CFC BRAF(Q257R) kinase-active allele and the BRAF(G596V) kinase-impaired mutant allele through the first 5 days of development. These results provide a detailed study of the effects of PD0325901 in development and show that, unlike in cancer, which requires robust inhibition of MAPK signalling, a partial reduction in phospho-ERK1/2 activity is sufficient to moderate the developmental effects of BRAF(CFC) mutations.
Insights
Cardio-facio-cutaneous (CFC) syndrome treatments may benefit from MEK inhibitors. Low-dose PD0325901 effectively mitigated developmental defects caused by CFC mutations in zebrafish, suggesting a new therapeutic approach.
Area of Science:
- Developmental Biology
- Genetics
- Pharmacology
Background:
- Cardio-facio-cutaneous (CFC) syndrome results from germline mutations in KRAS, BRAF, and MEK1/2.
- MEK inhibitors, developed for cancer, show therapeutic potential for CFC syndrome.
- Previous studies indicated MEK inhibitor effectiveness within a specific zebrafish developmental window.
Purpose of the Study:
- To investigate the effects of varying doses and developmental time points of PD0325901 on zebrafish embryos.
- To determine the optimal MEK inhibition level for mitigating CFC syndrome-related developmental defects.
- To assess the impact of PD0325901 on body axis length, heart development, and craniofacial structures.
Main Methods:
- Zebrafish embryos were treated with ten different doses of PD0325901 across six developmental time points.
- Effects on body axis length, heart development, and craniofacial structures were evaluated.
- Inhibition of MEK activity and phospho-ERK1/2 levels were assessed.
Main Results:
- A continuous low-level dose of PD0325901 prevented developmental defects caused by common CFC BRAF mutations (BRAF(Q257R) and BRAF(G596V)).
- Partial reduction in phospho-ERK1/2 activity was sufficient to moderate developmental effects.
- Unlike cancer therapy requiring robust inhibition, CFC syndrome may benefit from milder MEK pathway modulation.
Conclusions:
- Continuous low-dose PD0325901 is effective in preventing CFC syndrome-related developmental abnormalities in zebrafish.
- Partial MEK pathway inhibition offers a potential therapeutic strategy for CFC syndrome.
- This study provides detailed insights into PD0325901's developmental effects and its differential application in cancer versus genetic disorders.
