Questions continue to be asked after Dr Savio Woo, a gene therapist at the Mount Sinai School of Medicine in New York, was forced to retract two more of his papers last week. Dr Woo has retracted six papers this year after two of his post-docs, Li Chen and Zhiyu Li, were accused of scientific misconduct.
Dr Woo's group published four papers from 2005-2009 in three high impact journals. In 2005 a paper published in the Proceedings of the National Academy of Sciences suggested they had successfully cured mice suffering with a metabolic disease called Phenylketonuria by using a gene insertion technique, which utilised a viral enzyme phiBT1 intergrase. In 2008-9 the lab published three more times in Human Gene Therapy and The Journal of the National Institute detailing this technique in human cells and suggesting its application as a weapon against cancer. The most recent pair of retracted papers also covered this topic.
Professor Michele Calos, a geneticist at Stanford University, has reported his lab has been unable to reproduce the phiBT1 intergrase work and has found numerous factual errors in the publications. Dr Woo's group claimed that the intergrase enzyme allowed them to integrate the new gene sequences into a non-coding part of the genome therefore making it safer and less likely to affect the normal genes present in that stretch of DNA. Professor Calos has found this is not true.
A spokesman for Mount Sinai, Ian Michaels, told the Retraction Watch blog the institute mounted an independent investigation into Dr Savio Woo and his lab. He stated that Dr Woo is not believed to have committed any misconduct and confirmed that the two post-docs in question have been asked to leave. He said the medical school continues to be co-operative with the appropriate government agencies and it is committed to having the highest standards for research integrity.