Spring 2009 Newsletter

Dr Luminita Paraoan and Dr Lyndsay Davies (post-doctoral researcher funded by The Humane Research Trust) in the Ocular Molecular Biology Laboratory at the University of Liverpool.

Novel effector of cell death studied in an eye cancer experimental model

Dr Luminita Paraoan, University of Liverpool

Funding from The Humane Research Trust is enabling a new line of research into mechanisms controlling the fine balance between cell death and survival. The research is undertaken in the Ophthalmology Research Unit, University of Liverpool making use of specific eye cells as an experimental model of a cell death pathway that plays a role in cancer development.

Cells have an in-built mechanism, called programmed cell death or apoptosis, which dictates their own death. This method of self-destruction safely removes cells from the body and is critical for reducing the number of cells when needed, for removing worn-out or aged cells or for eliminating damaged cells and thus preventing cells with defects from multiplying and limiting further damage that can lead to uncontrolled cell growth and the development of cancer. In cancer, the mechanism of apoptosis is often faulty, frequently due to mutations or loss of genes that normally function to promote cell death. This also makes cancer cells more difficult to destroy, since many anti-cancer drugs and treatments work by promoting the diseased cells to undergo cell death. Consequently, cancer cells which cannot engage in this process are often resistant to these drugs.

Apoptosis is a highly organised and tightly controlled method of cell death that involves the interaction and association of many different proteins and molecules. Removal or modification of just one of these components can lead to disruption of this complex process. We are investigating the role played by a gene called PERP (abbreviated from p53-apoptosis effector related to PMP-22) recently shown by us to control the death of cells in a type of eye cancer. Specifically, PERP occurs at much lower levels in the aggressive (compared with the less aggressive) type of uveal melanoma (UM) that spreads to other parts of the body, leading to a high mortality rate. In addition, PERP is also involved in maintaining contacts between cells. Loss of such cell-cell contacts is implicated in the spread of cancer cells to other parts of the body. Consequently, the lack of PERP may cause the inability of abnormal cells to be removed, as well as possibly mobilising them, thus contributing to the progression of the cancer.

We have identified five established and well characterized HUMAN UM cell lines, originally derived from primary UM tumours, that represent a reliable experimental model for investigating the activation, mechanism of action and regulation of PERP in both cell death and cell adhesion. These cell lines also display distinct features allowing vitally important questions regarding the role of PERP in cancer formation and progression to be addressed in cells with different levels of aggressiveness. To date, the involvement of PERP in such processes has relied heavily on the use of animal models and animal-derived tissues. Our in vitro experimental model is highly amenable to the experimental manipulation that is required for dissecting such complex biological mechanisms. We are particularly interested in studying the effect that different levels of PERP have on the ability of cells to undergo cell death and on their response to inducers of apoptosis, some of which are considered potential therapeutic agents. In addition, whereas animal models have been used extensively for investigating the capacity of UM cells to invade other tissues, we will use an in vitro approach to study the effect of PERP on the invasive properties of UM cells and establish whether low PERP levels contribute to their levels of aggressiveness. These findings may have implications for other cancer types which have reported an association between low PERP levels and aggressive tumours.   

In the long term, we believe that our investigations into the role and regulation of PERP will provide further understanding of how the decision between the life and death of a cell is made, and so lead to the development of better treatments. .

 A new era for human stem cell research

Dr Mark Williams

In recent years stem cells have become an intense focus of biomedical research and an area of ethical debate.  Controversies in the melting-pot of stem cell research include cloning animal embryos (e.g. Dolly the sheep), unsubstantiated reports of cloning human embryos, the use of human embryos (surplus to requirements for in vitro fertilisation procedures) to generate human embryonic cell lines, and, to overcome the shortage of human donor eggs and technical difficulties, generation of human/animal hybrid embryos.  These developments raise new ethical and legal concerns and have played a prominent role in shaping the political landscape.  For example, one of President Obama’s major acts to date has been to overturn his predecessor’s ban on funding human embryonic stem cell research.  At a recent meeting of the UK National Stem Cell Network (Oxford, April 2009), emerging techniques such as the advent of induced pluripotent stem cells and advances in adult stem cell culture herald an increase in the use of non-embryonic human stem cells for biomedical research (see below).  It is hoped that these developments will ease the controversy and expedite the translation of stem cell research into clinical application.

Stem cells hold immense regenerative potential that, in principle, could be harnessed to treat common conditions such as muscular dystrophy, Parkinson’s disease, spinal cord injuries, heart defects, diabetes, blindness, deafness, and inflammatory bowel disease.  A greater understanding of stem cell biology may also unlock the mysteries of cancer initiation and recurrence.  There are two main types of stem cell: (i) embryonic stem cells which develop into all the different cell types within the body; and (ii) tissue-specific adult stem cells which maintain the life-long structure and function of healthy adult tissues within which they are resident; for example, adult stem cells drive the production of ‘new’ cells required for the constant renewal of blood, skin and intestinal tissue, and for the repair of muscle, nerves and brain following injury (for further information see http://en.wikipedia.org/wiki/Stem_cell).  Two main strategies are being pursued to exploit these stem cell attributes in a therapeutic context: (i) regeneration of damaged or ageing tissues (e.g. heart or brain) by transplantation of embryonic stem cells, which replenish injured cells types (e.g. cardiac muscle fibres or neurons); or (ii) transplantation of adult stem cells, the most notable clinical example being the use of bone marrow derived stem cells in the treatment of leukaemia.  A related approach is to derive adult stem cells or entire tissues for transplantation from human embryonic stem cells cultured in the ‘test-tube’.  It is also anticipated that future treatments will be based on the factors that boost the function of tissue resident adult human stem cells to prevent age-related disease or following injury. 

A major hurdle to overcome for clinical application is the need for tissue matching/compatibility so as to avoid rejection of transplanted stem cells or tissues derived there from.  Until recently, the ‘best’ solution has been to generate embryonic stem cells from cloned human embryos (i.e. containing genetic material from the patient/recipient) so that the donor stem cells are a perfect tissue-match.  Notwithstanding ethical considerations and regional policies, the limited supply of embryonic stem cells and the technical challenges associated with cloning human embryonic stem cells have to date proved insurmountable.  However, a landmark discovery offers a ‘convenient’ solution to many of the above issues.  Switching on the expression of three or four selected genes in a human skin cell derived from a patient is sufficient to change it into an embryonic stem cell-like state.  In principle, these induced pluripotent stem (iPS) cells can be cultured and converted into a mature tissue cell type of choice (e.g. retina cells to cure blindness), as described above for embryonic stem cells, but which are a perfect tissue match for the recipient and can be used for therapeutic transplantation without fear of rejection.  iPS cells from disease affected patients can also be used for drug testing (e.g. on neurons generated from iPS cells derived from Parkinson’s sufferers).

Dramatic progress has also been made in developing systems to culture native human adult stem cells.  For example, intestinal tissue has been notoriously difficult to culture which has hampered the understanding of intestinal stem cells in health and disease. Work presented by our group described recent progress made in long-term culture of human colonic crypts and intestinal stem cell biology.  The human colonic crypt culture model previously funded by the Humane Research Trust maintains a population of intestinal stem cells that will facilitate progress in developing therapeutic strategies for tissue regeneration in inflammatory bowel disease and understanding stem cell behaviour in colon cancer.  A current project funded by the Trust aims to apply a similar approach to identifying adult stem cells in Barrett’s oesophagus, a precursor for oesophageal cancer.

In summary, remarkable advances have been made in human stem cell research. There is a growing synergism in the technologies, methodologies and biology of human stem cell research that will help the scientific community rise to the challenge of translating these findings into clinical application.

Scientists create living model of the basic units of the human brain

Researchers in the School of Life & Health Sciences at Aston University in Birmingham, UK are developing a novel new way to model how the human brain works by creating a living representation of the brain.

Professor Mike Coleman and his team

They are using cells originally from a tumour which have been ‘reprogrammed’ to stop multiplying. Using the same natural molecule the body does to stimulate cellular development, the cells are turned into a co-culture of nerve cells and astrocytes - the most basic units of the human brain.

These co-cultures can be developed into tiny, connected balls of cells called neurospheres, which can process information, which, at a very simple level, is the basis of thought. The research process does not require animal testing and since 2007 has been generously supported by the Humane Research Trust.

In the future, the tiny three-dimensional cell clusters, which are essentially very small models of the human nervous system, could be used to develop new treatments for diseases including Alzheimer’s, Motor Neurone and Parkinson’s Disease. These progressive and debilitating neurodegenerative conditions are becoming more common as the population of the UK ages.

Professor Michael Coleman, who is leading the research team, said: ‘We are aiming to be able to study the human brain at the most basic level, using an actual living human cellular system. Cells have to be alive and operating efficiently to enable us to really understand how the brain works.  In the longer term we hope that our procedure can be used to help us understand how conditions such as Alzheimer’s and other neurodegenerative diseases develop.  At the moment, most people are only too aware that current treatments for these conditions do not halt their progress and often have side-effects.  We hope that our technique will provide scientists with a new and highly relevant human experimental model to help us understand the brain better and develop new treatments to tackle neurodegenerative disease.

This is a press release issued by the University which was reported on by the BBC and Sky News.

Academy of Pharmaceutical Sciences

Dr Lindsay Marshall, Aston University

PhD Student Anne Bielemeier with the poster she presented

Dr Lindsay Marshall and her HRT-funded PhD student, Anne Bielemeier, were invited to present their work at the Academy of Pharmaceutical Sciences focus group meeting in March (23rd to 25th).  The topic of the conference was "The changing face of Inhalation - fit for the future".  Lindsay was speaking in the session called "Technologies for the Future" about "Approaches to non-animal testing for current respiratory therapeutics" whilst Anne presented a poster of her work so far, entitled "Development of a multicellular co-culture model of normal and cystic fibrosis human airways in vitro" (a pretty impressive feat considering she only started in October!).
We are very pleased to report that the work was well received and attracted lots of interest from other like minded research groups.  We are all aware of the animal testing that occurs in pharmaceutical sciences and that any potential new drugs are first evaluated on laboratory animals. We are therefore very optimistic that our presence at the conference indicates that the pharmaceutical scientists are now starting to seriously consider the kind of cell culture alternatives to animal testing that Lindsay and Anne are developing.

Eyes, Kites and Sight: An Indian Adventure

Dr Michael Wormstone, University of East Anglia

In January, I visited India to meet with potential collaborators and give two invited talks. The first port of call was the Iladevi Cataract and IOL Research Centre in Ahmedabad. My presentation here was delivered to a packed 250 seat auditorium. The audience was a diverse mix of students, clinicians and senior scientists; however all seemed to take something from the work presented and a great deal of scientific discussion followed.  In my time in Ahmedabad, I also managed to pass on some of our human culture methods to Dr Kaid Johar, the Director of Research, and his team who would like to utilise these techniques in future research. I did however still manage to take in some culture and my experience was richer as a consequence. The food was great, poverty at times shocking and the driving utterly terrifying – I believe road signs in India are purely ornamental. However, the greatest aspect I will remember from my visit to Ahmedabad was the wonderful hospitality I received from all I met. On the day I flew to Hyderabad, the morning was spent atop a roof in the old city to celebrate the traditional kite festival. The skies were swarming with kites and people perched perilously on their roof top station while traditional snacks appeared with great regularity. This was real India and sharing this wonderful experience with locals was an honour and joy. I then arrived in Hyderabad for the 4 day ARVO-ASIA conference; this was intense, but rewarding. I discussed our work with a number of scientists based in India, wishing to learn some of our techniques and spent time discussing various points of interest with senior researchers within the eye field. My talk at the meeting was scheduled for the last session of the last day of the meeting. As delegates begin to disperse there are occasions when few people remain, but it was pleasing that many stayed, accompanied by their suitcase, to listen to my talk. Again the discussions that followed were interesting and the lab was commended on the quality of our science. I returned to England, tired and content.

New Team Member in Manchester

Drs Ian & Lynne Hampson, St Mary’s Hospital Manchester

We welcome the Kenyan clinician Dr Innocent Orora Maranga who has joined our group to study for a PhD in the Gynaecological Oncology Laboratories at St Mary’s in Manchester. Dr Maranga’s project is to evaluate the role of Human Immuno-deficiency Virus (HIV) and other viruses in both the cause and treatment of cervical cancer and he is being supported by Wellbeing of Women, The International Atomic Energy Agency and the Janice Cholerton Cancer and Postgraduate Studentship Fund.

With approximately 4 times the incidence found in the UK, cervical cancer is the most common women’s malignancy in Kenya and many other African countries. It is well known that this disease is caused by infection with the human papilloma virus (HPV) and that the use of chemical immuno-suppressants in transplant recipients can induce higher numbers of HPV related cervical abnormalities. Infection with HIV also compromises the immune system of those infected and it is endemic in Kenya and in other parts of Africa. Thus it would be predicted that Kenyan women who are HIV positive would develop higher numbers of cervical cancer yet this is not what is observed clinically. Although these women develop greater numbers of pre-cancerous cervical abnormalities, they do not show a corresponding increase in the numbers of invasive cervical cancers. Having spent most of his 1st year in Nairobi collecting clinical specimens, the first part of Dr Maranga’s research project will be to analyze normal and abnormal cervical smears taken from HIV positive and negative women for the presence of other viruses such as the human T-cell leukaemia virus (HTLV1) and adeno-associated virus (AAV). There is previous evidence to suggest that HTLV1 can augment and AAV can suppress the development of cervical cancer yet there is no information on how these two infections may contribute to the development of pre-cancerous or invasive cervical cancer in HIV positive women.

The second part of the project is concerned with the following questions:-

• Does a patient’s HIV status affect their response to radiotherapy for cervical cancer?
• Does anti HIV therapy influence the response of cervical cancer to radiotherapy?
• Are there biological markers of cervical cancer that can be used to predict the response of HIV positive and negative women to radiotherapy. 

To answer these questions Dr Maranga has secured more than 300 tumour samples from HIV positive and negative Kenyan women who have been treated with radiotherapy. Where possible, it is our intention to analyze the treatment response of these women with respect to their HIV status and whether they are receiving anti HIV therapy. Finally we are going to test these tumour samples for the presence of various protein markers to evaluate their potential as indicators of response to radiotherapy.   

This project is funded by a specific endowment administered by The Trust.