NEWS OF THE W EEK
ZU M A P R ESS/N EWSCO M
RULING SOUGHT ON RARE EARTHS
A worker in China processes yttria, a rare-earth oxide.
TRADE: The U.S., Europe, and Japan
want WTO to settle a dispute on China’s export restrictions
T
HE U.S., JAPAN, and the European Union have
asked the World Trade Organization (WTO) to establish a dispute settlement panel to investigate and issue a ruling on claims that China is unfairly restricting exports of rare-earth materials, as well as tungsten and molybdenum. The action follows a complaint the three economic powers brought to the Geneva-based trade arbiter in March. The three charge that China’s use of export duties, quotas, and other restraints on these materials violates WTO rules (C&EN, March 19, page 8). China accounts for 97% of the world’s production of rare-earth minerals, a group of 17 chemical elements essential for making a wide array of high-tech products, including hybrid car batteries, wind turbines, cell phones, and other advanced electronics. China also accounts for 91% of global output of tung-
ZINC FINGER AGENTS ENTER CELLS SOLO
COURTESY OF THOMAS GAJ
Zinc finger nucleases enter cells, where they bind adjacent sequences on specific genes (such as the gene for the CCR5 HIV receptor) and induce gene modification.
MOLECULAR BIOLOGY: The genemodifying proteins can be delivered without viral packaging of their genes
A
NEW METHOD to bring the gene-modifying
proteins called zinc finger nucleases (ZFNs) inside cells could make it possible to minimize the side effects of gene therapy. In ZFN-based gene therapy, genes for ZFNs are packaged inside viral vectors to be introduced into cells. The cells then express the proteins, which modify target genes. Two vector-delivered ZFNs are currently in clinical trials—one of them modifies the gene for CCR5, a receptor HIV uses to infect immune cells. But viral vectors often lead to overproduction of the introduced genes WWW.CEN-ONLIN E .ORG
6
sten, a metal used in electrical and military applications, and 36% of world production of molybdenum, a metal mainly used in the steel industry. “It is vital that U.S. workers and manufacturers obtain the fair and equal access to raw materials like rare earths that China specifically agreed to when it joined the WTO” in 2001, says U.S. Trade Representative Ron Kirk. The parties held formal talks in late April but were unable to agree on a solution. “We regret that we are left with no other choice but to solve this through litigation,” says EU Trade Commissioner Karel De Gucht. WTO officials have scheduled a July 10 meeting to consider the request for a dispute settlement panel. A final decision could take up to two years. Critics say that limiting export of the materials gives China the ability to boost prices by curtailing the global supply. Kirk calls the restraints “part of a troubling industrial policy aimed at providing substantial competitive advantages for Chinese manufacturers at the expense of foreign manufacturers.” China counters that the export restrictions are necessary to protect its environment from excessive mining and conserve an exhaustible natural resource. “We have no intention of protecting our domestic industry through trade-distorting measures,” says Ministry of Commerce spokesman Shen Danyang. China, he adds, has always abided by WTO rules.—GLENN HESS
and DNA modifications at “off-target” sites, both of which can cause side effects. No one thought ZFN proteins could penetrate cells directly. But a team of researchers noticed that ZFNs exhibit some characteristics of cell-permeating peptides, and now they find that ZFNs can enter cells by themselves (Nat. Methods, DOI: 10.1038/nmeth.2030). However, using the proteins directly does not yet modify target genes as efficiently as some viral-vectorbased techniques. “We show we can directly knock out the human CCR5 receptor used in HIV entry by simply adding a purified protein to cells,” says ZFN specialist Carlos F. Barbas III of Scripps Research Institute, whose group carried out the study. “My lab intends to develop this as a gene-free gene therapy for HIV. The existing method, now in Phase II trials, uses viral delivery methods that are more dangerous than our new approach.” “This is an important technical step forward” that could improve the safety of current protocols, comments gene therapy researcher Mark A. Kay of Stanford University School of Medicine. “The fact that ZFNs work by themselves is quite unexpected,” says virus, stem cell, and gene therapy expert Paula Cannon of the University of Southern California Keck School of Medicine. “This protein delivery method will definitely give an extra level of safety because there are no viral vectors involved. The challenge will be to see if the method is as effective as the viral-vector approach.”—STU BORMAN
J ULY 9, 20 12
