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Interviews: Dr Susanna Penco on the use of human cell lines


Dr Susanna Penco is a biologist who specialises in general pathology and is a researcher in the department of experimental medicine at the University of Genoa in Italy. She teaches at the school for medical science and pharmacology. Her main research interest lies in the use of human cell lines for application to the study of cancer and also for testing cosmetic products. In addition, Dr Penco has co-authored several articles published in the international scientific literature and has written books and education manuals. She was the recipient of the 2013 DNA prize, awarded by the Order of National Biologists, and also received the Pietro Croce prize in 2007 for “the best project for the abolition of animal experimentation and the promotion of non animal methods”.
Antidote Europe (AE) : At what stage during your studies did you decide to use in vitro methods to replace the use of living animals ? And for what reasons?
Susanna Penco (SP) : I decided to stop using animals in the early 1980s, well before obtaining my degree during the laboratory work I undertook as part of my thesis. I was very fortunate to work with people who allowed me to pursue my career by respecting my moral principles to not use animals, which was well before the introduction in Italy in 1993 of a law permitting conscientious objection.

Sadly, this situation is the exception, rather than the rule: the law on conscientious objection has remained largely a paper tiger since animal experimentation is an obligatory requirement in most research institutes.
My personal decision not to use living animals was motivated by ethics and science. However, in the course of my career, the scientific aspect played an ever more important role. Today, in light of  emerging technology, I am convinced more than ever that animal experimentation is not only unnecessary but actually holds back medical, biological and scientific progress, because it is based on out-dated methods. In this third millennia, my hope is that modern medicine will be able to cure and prevent disease, especially in view of the current uncertain economic future of social health care. Chronic diseases now weigh heavily upon the economy and as a consequence, on the quality of life of patients and their families and society as a whole. In my view, modern medicine will not be able to make progress as long as we continue to apply a band aid to fix a problem that requires a major overhaul. It is imperative to change mindsets and to allocate significant funding to innovative non animal research methods, to replace out of date methods that were never scientifically validated in the first place.

AE : Your research team succeeded in transforming human fat cells into other types of cells, for example nerve cells. Could you briefly explain – in non-scientific terms – how you achieved this remarkable result?
SP : Our research team has very few paid staff. We therefore work principally in collaboration with young graduates, who we remunerate for their valuable help. In the laboratory in the department of experimental medicine at the University of Genoa, some researchers employ in vitro as well as in vivo methods, while others, including myself, avoid animal studies completely. Our current research project uses stem cells, which are quite a popular news item in the media. Stem cells behave like young children in the sense that they do not yet possess a definite character. They have enormous potential, which they will put to use when required. In simple terms, their development needs to be guided (as parents would guide a child) in order to obtain a useful result and avoid getting a bad result (stem cells can potentially become « bad » by becoming cancerous, for example). Our goal to transform undifferentiated human fat cells into nerve cells has already produced some good results. The secret to the technique lies in selecting the right kinds of stem cells (those with good characteristics) and to then carefully “groom” them to specifically become nerve cells, rather than any other kind of cell.

AE : Is it possible to use these manufactured nerve cells to test pharmaceutical drugs such as antidepressants, or are these cells limited to testing chemical substances such as industrial pollutants?
SP : It would be possible to test various substances, simply by using the appropriate culture medium in order to guide cell development from fat cell to nerve cell. Once the nerve cells have been formed, they can be used for various toxicity tests, including environmental pollutants. These cells can also be used to study the effect of psychiatric drugs. We are currently working to refine these cells even further.

Human fat cells, which are found in our body fat, represent an important store of stem cells and are available to be transformed into other cell types as and when needed by our body. This unique capability can be put to good use in the laboratory. We are able to obtain these human stem cells from cosmetic surgeons who remove excess adipose tissue from patients for aesthetic reasons (for example during liposuction or breast reduction). Any human tissue collection always requires  informed consent on the part of the patient, in order to allow us to use their cells for laboratory study, rather than throwing them in the bin.
AE : Are there other ways in which to manufacture nerve cells from human stem cells?

SP : Cells of mensenchymal origin (e.g. the umbilical cord) can be groomed to become nerve cells for research purposes. There are currently more than 150 published studies describing the use of these cells to produce nerve cells. The main aim of producing these cells is to discover new therapeutic molecules, including psychiatric drugs. This project is ambitious and if properly financed would be very helpful in the neurosciences. One idea would be to create a human disease model to replace the animal model, which has clearly failed to produce a result, as in the case of Alzheimer‘s and other neurodegenerative diseases.
AE : We sincerely thank you for giving up the time to take part in this interview and we congratulate you on your awards. Would you care to share something about your future research plans with our readers?

SP : I thank you for the interview, which I find a great honor. The DNA prize, shared with my colleague Michela Kuan, is a wonderful and unexpected surprise. It is hopefully a sign that attitudes within the scientific establishment are beginning to change for the better.
There are many thoughts that come to mind but I would like to share the most pressing ones. Researchers who use animals such as rats and mice justify their use of rodents on the basis that they are the lowest on the scale of mammalian brain development. Even if this was true, what does that say about the relevance to humans of using animals that are so different to us? Based on this logic, we should only use anthropoid apes, the primates that most closely resemble humans, together with the enormous costs associated with keeping such animals in captivity, in addition to the serious ethical objections. The real reason that mice are used is that they are a lot cheaper to buy, to feed and to house, in addition to being less liked by society. But what has all this got to do with scientific progress?

As someone afflicted by multiple sclerosis and knowing many young researchers who have worked on animal models of my disease, I have shared my doubts with these scientists on the lack of efficacy of using animal models for drug testing and I am disappointed by the fact that such poor models are still in use today. Why are funds not being urgently allocated to research methods that are more ethical and more reliable, with for example greater emphasis on studying the brains of deceased patients? With the help of innovative thinking, we could begin to discover the unknown causes of many diseases and provide cures, rather than just treatments (that are often very expensive), for the benefit of all concerned.