Prof J.P. Martinez-Barbera
Professor of Developmental Biology and Cancer
Developmental Biology & Cancer Dept
UCL GOS Institute of Child Health
- Joined UCL
- 1st Feb 2003
My research program aims to understand normal development and pathology of the brain and associated structures, such as the pituitary gland and eyes. Developmental disorders of the brain have an overall significant prevalence in humans and include congenital defects as well as childhood brain tumours. For the last several years my group has provided important insights into normal brain and pituitary development. In addition, we have contributed significantly to the understanding of the aetiology and pathogenesis of human congenital hypopituitarism and pituitary tumours (eg craniophryngioma). Our aim is to reveal the aetiology and pathogenesis of these human disorders using a multidisciplinary approach. The Institute of Child Health is perfectly placed to carry out this research due to its strong links to Great Ormond Street Hospital for Children (GOSH). My group collaborates with several clinicians from GOSH, including endocrinologists, neuropathologists and oncologists.
Specific aims of my research are: (1) To identify the genetic basis and to determine the mechanisms underlying developmental disorders of the brain and pituitary gland, as a means of understanding the corresponding human defects and to establish new diagnostic and prognostic methods in humans; (2) To develop new methods to treat pituitary tumours (eg craniopharyngioma) using our unique genetic tools with the ultimate goal of translating the findings into the clinic for the benefit of the patients.
Current ongoing research:
1.Identification of the genetic basis of developmental brain and pituitary disorders. We have identified a large number of genes that when mutated result in brain defects in mice and proven that some of them are relevant for human conditions. However, the genetic causes are still missing for the majority of the cases.
2. Determining the mechanisms that lead from genes to brain and pituitary disorders. We need to understand gene function during normal development if we aim to reveal how mutant genes lead to human disease. This knowledge can be translated into improved management of the patients. We use a multidisciplinary approach to understand gene function in normal and abnormal embryonic development.
3. Understanding a novel model involved in pituitary oncogenesis. We have recently revealed a paracrine model whereby mutated pituitary stem cells induce tumours. We are studying the molecular and cellular mechanisms of this model, which may have broader implications in the field of oncogenesis.
4. Development of new methods to treat pituitary tumours: There is a real clinical need to improve treatments for human tumours such as childhood craniopharyngioma. Our research has identified several pathways that are elevated in these tumours, suggesting that the inhibition using specific inhibitors could lead to novel treatments. We are using unique genetic tools that we have developed to perform pre-clinical studies. Specific inhibitors against several pathways are being tested in our models for childhood craniopharyngioma.
1993-1999. Part-time lecturer (90 hours/year) at the University of Cadiz (Spain). I
was solely responsible for two of the courses taught in the Department of Biochemistry
and Molecular Biology: (i) ”Molecular Biology and Biotechnology (1993-1995);
(ii) Biochemistry (1996-1999). This teaching activity involved both practical
and theoretical courses. From 1996, during my post-doctoral training in Sweden,
until 1998, I went back to Spain for eight weeks each year to deliver my
lectures. Eventually, I resigned from this position in Spain in 1999, since I
was fully committed to research in UK.
Every January, I have
delivered a two-hour lecture entitled:” Axis formation in the mouse” in the BSc
course organised by Prof. Claudio Stern (Mechanisms of Development).
- University of Cadiz,Spain
- PhD, Biochemistry and Molecular Biology | 1995
- University of Cordoba, Spain
- BSc, Medical and Veterinary Genetics | 1989
I obtained my PhD at the University of Cadiz (Spain). There, I cloned and characterized several pituitary hormone genes from farmed fish species. Later, I moved to the University of Lund (Sweden) as a postdoctoral scientist in the laboratory of Stefan Krauss, where I changed field to work in developmental biology. In March 1997 I joined the laboratory of Dr. Rosa Beddington to pursue the analysis of the Hesx1 null mutant mouse I had engineered. The characterization of these mutants was instrumental for the identification of mutations in the human gene HESX1 in patients with septo-optic dysplasia. I also characterized the Hex mutants, which revealed the importance of Hex in forebrain, liver and pancreas development. Finally, I joined Prof. Antonio Simeone’ s laboratory at KCL, determined to continue my research in the field of brain development. I analyzed the brain defects in double Otx2;Gbx2 deficient mice, which demonstrated an essential role of these two transcription factors in the positioning of the mid-hindbrain boundary.
I started my own laboratory at the UCL-Institute of Child Health funded by a Research Career Development Fellowship from the Wellcome Trust in 2003. Initially, I focused my research on the cellular analysis of the forebrain defects observed in the Hesx1-deficient embryos. We generated a Hesx1-Cre mouse line to carry out detailed genetic fate mapping of Hesx1-expressing cells in the forebrain. Using this tool, we demonstrated that the absence of Hesx1 leads to a cell fate transformation of anterior to posterior forebrain. In addition, we expanded our scientific horizons by performing a thorough analysis of the pituitary defects in Hesx1 mutants.
In 2008, I was awarded a University Award from The Wellcome Trust to characterize the molecular mechanism underlying the forebrain defects observed in Hesx1-deficient mice. This award has helped to consolidate my laboratory in the field of forebrain and pituitary development. The main goal of my lab is to understand normal development of the forebrain and pituitary gland through mouse models and to apply this knowledge to reveal insights of pathological conditions affecting these structures in children. In addition, we have demonstrated an essential role for this signaling pathway during normal pituitary development and shown that its deregulation leads to an enlargement of the pituitary progenitor/stem cell (PSC) pool and subsequently tumorigenesis. This research has revealed the molecular and cellular origin of human adamantinomatous craniopharyngioma, a devastating tumour mainly affecting children. This latter research has allowed us to generate new hypotheses regarding the biology of these elusive PSCs and discovered novel signaling pathways likely to play a role in normal pituitary development and in disease.
Another important aspect of my research at the ICH and UCL has been the establishment of UCL Transgenics, which was not previously available.