Dr. med. Sven Perner from Tübingen did not originally intend to become a pathologist nor did he intend to work in the USA. The fact that the physician nevertheless decided to get involved in both adventures led to rapid career progress in the scientific field. Perner was recently awarded the newly created “Württemberg Cancer Prize” for his work that has made decisive contributions to the understanding of prostate cancer development. In addition, the identification of a tumour-specific gene fusion might also be of great importance for other types of cancer.
"You do not became a pathologist, you are a pathologist," explained Dr. med. Sven Perner, 38, with a smile, well aware that this adage is a perfect description of his own career path. Perner, who was born in Ellwangen, originally planned to become a surgeon. However, towards the end of his studies at the University of Ulm, he had second thoughts and decided to become involved in an interdisciplinary subject. "I wanted to use the time in the Department of Pathology to change direction," said Perner who, despite his initial intentions, rapidly developed a fascination for pathology, and decided to continue working in the discipline.
Perner was recently awarded the newly created "Württemberg Cancer Prize" for his work on the "characterisation of gene translocations in prostate cancer", and he has never regretted his decision to remain in the field of pathology. "I know of no other discipline where it is possible to transfer knowledge gained in patient treatment into research and back again as directly as is the case with pathology," said Perner explaining his decision. Perner was particularly inspired by creative laboratory work and came to his current research area as a result of a collaborative project with urologists at the University Hospital of Ulm. Whilst working on this project, Perner came across the American pathologist and prostate cancer researcher Professor Dr. Mark Rubin who quickly offered him a position in his team at the Harvard Medical School in Boston.
“Actually, I never intended to go to the USA,” said Perner going on to add, “but in this case, I found I could not decline the offer.” Backed by a research grant from the German Research Foundation (DFG), Perner made his big move in December 2004: “I was able to convince my family to come with me, despite the many risks associated with the move,” said Perner who was married with a son, had not yet been approved as a medical specialist by the German authorities, nor was there any guarantee of being able to return to his workplace in Ulm. In Rubin’s laboratory, Perner focused on looking for molecular biomarkers that enabled the differentiation between prostate cancers that required treatment and those that did not. “The majority of prostate cancer patients have a good prognosis,” said Perner explaining that the majority of prostate cancers grow so slowly that they do not affect a man’s life expectancy. However, a small percentage of prostate cancers is very aggressive and has a deadly outcome. The diagnostic possibilities of differentiating these two subtypes very early are still limited. This is the great clinical dilemma: many patients undergo surgery or radiation even though they may not have required treatment, whilst the therapy of patients with aggressive tumours might not lead to the desired outcome.
For a long time, little had been known about the molecular mechanisms that lead to aggressive prostate cancer growth. This changed abruptly when in summer 2005, Rubin and his colleagues, including Perner, succeeded in identifying the TMPRSS2-ERG gene fusion, which results from the fusion of the oncogenic transcription factor ERG with the androgen-regulated promoter of the TMPRSS2 gene. So far, this event has only been shown in prostate cancer, which is why it is regarded as an organ- and cancer-specific alteration that is associated with aggressive tumour growth.
The TMPRSS2-ERG gene fusion is one of the most spectacular discoveries in the field of cancer research of the last years. Scientists long believed that such gene fusions only played a role in the development of leukaemias and other haematological malignomas. "As far as epithelial tumours were concerned, these chromosomal rearrangements were more or less regarded as unspecific phenomena of tumour cells," said Perner. Almost overnight, the identification of the TMPRSS2-ERG gene fusion in prostate cancer has triggered a comprehensive search for recurrent gene fusions in other cancers. "The fusion of an organ-specific promoter with an oncogen might quite possibly be a general principle of tumour development," said Perner. During his post-doc period, he did not immediately realise the groundbreaking importance of these results, quite in contrast to his experienced mentor. "Rubin was immediately aware of the large fish we had landed."
Following this discovery, Perner went through a very exciting and fertile phase of his scientific career. "The entire laboratory immediately changed direction to focus entirely on the further characterisation of this gene fusion event." The research has led to many outstanding publications. Thus, Perner's decision to go and work in Rubin's laboratory, very quickly came up trumps. However, Perner is well aware that such a research stay is by no means a guarantee of success. "I was at the right place at the right time," said Perner acknowledging that he was far luckier than many of his colleagues.
After four years, Perner finally decided to return to Germany, a decision that was made somewhat easier as he was awarded an Emmy Noether grant from the DFG. "The Emmy Noether programme gives me a lot of freedom," said Perner who has found the perfect environment for his work at the Institute of Pathology at the University Hospital of Tübingen. With his team of twelve international scientists, Perner now plans to further characterise the TMPRSS2-ERG gene fusion and establish it as an important biomarker in diagnostics. However, Perner is already thinking one step ahead: "This gene fusion, which leads to the overexpression of a growth factor, might turn out to be an ideal therapeutic target." In addition, Perner also hopes to close a small gap in his professional career. His research activities had previously prevented him from completing specialised pathology training that is necessary to obtain approval as an expert in pathology by the relevant German authorities. Perner will eventually become an approved expert in pathology, enabling him to look for new horizons with fewer risks than the ones he took several years ago when he moved to the USA.
Further information:PD Dr. med. Sven Perner University Hospital TübingenInstitute of Pathology Comprehensive Cancer Center Liebermeisterstr. 872076 Tübingen Tel.: +49 (7071) 29-84926 Fax: +49 (7071) 29-2258 E-mail: sven.perner1972[at]gmail.com