A gene-editing record in pigs, a Nobel for DNA repair and the rising placebo effect in painkiller studies. This week in Abstract Science.
(Nature, 10/6/2015, Sara Reardon)
Using CRISPR technology, scientists modified more than 60 genes in pig embryos–enough, they think, to a produce a suitable, non-human organ donor. The work was presented this week by Harvard Geneticist George Church at a meeting of the US National Academy of Sciences (NAS) in Washington, DC on human gene editing. Researchers have long thought of growing organs suitable for human transplantation in pigs, but concerns over organ rejection stymied efforts. The gene-editing tool known as CRISPR may have enabled them to overcome this obstacle, however. Church said they were able to inactivate 62 porcine endogenous retroviruses embedded in all pigs’ genomes that cannot be treated or neutralized and can potentially cause humans harm.
(Wall Street Journal, 10/7/15, Gautam Naik and Anna Molin)
The Nobel Prize for Chemistry, awarded this week to a trio of scientists from Europe and the US who were the first to describe the mechanisms that human cells rely upon to repair DNA, is especially important in drug development, particularly in cancer. Tomas Lindahl of Sweden, Paul Modrich of the U.S., and Aziz Sancar, a dual American and Turkish citizen, shared the award for their separate research discoveries elucidating into how living cells function and the mechanisms behind cancer development and aging. Beginning with his 1974 discovery of a bacterial enzyme that aids in DNA repair, Lindahl spent 35 years examining many of the proteins in the cell’s toolbox. Modrich was recognized for demonstrating how cells use a mechanism called “mismatch repair” to fix errors that occur when DNA is replicating during cell division. And Sancar won for mapping a process that enables cells to repair UV damage to DNA.
(New York Times, 10/5/15, Lawrence K. Altman )
Another trio of scientists were awarded the Nobel Prize for Physiology or Medicine this week for discoveries that helped revolutionize the treatment of some parasitic diseases, including malaria. William C. Campbell and Satoshi Omura won for developing Avermectin, the parent of Ivermectin, a medicine that has nearly eradicated river blindness and radically reduced the incidence of filariasis, which can cause elephantiasis. Inspired by Chinese traditional medicine Tu Youyou, the third recipient, discovered Artemisinin that is now part of standard anti-malarial regimens that have reduced death rates from the disease.
(Nature, 10/6/2015, Jo Marchant)
It’s no secret how hard it’s becoming to develop new painkillers that pass muster. What is surprising is one of the reasons why. An analysis conducted by McGill University pain researcher Jeff Mogil found that responses to sham treatments have become stronger over time, making it harder to prove a drug’s advantage over placebo. More surprising, though, is that this placebo effect seemed to only exist in US clinical trials. Why is unclear; Mogil thinks that as US trials get longer, larger and more expensive, they may be enhancing participants’ expectations of their effectiveness.
—Compiled by Senior Scientific Writer Regina McEnery