Frontlines

The proper diet for longevity may not be what is eaten, but what is not. University of California, Los Angeles, researchers have reported that the withdrawal of coenzyme Q (Q) from the diet of Caenorhabditis elegans extends the adult life span by almost 60% (P.L. Larsen, C.F. Clarke, "Extension of life-span in Caenorhabditis elegans by a diet lacking coenzyme Q," Science, 295:120-3, Jan. 4, 2002.) Q is found in the respiratory chains of mitochondria and can be obtained from eating anything that once was alive. Q functions as an electron carrier in aerobic respiration, creating a proton gradient across the mitochondrial membrane, which is coupled to ATP synthesis in the cell. Decreased Q levels accounted for the reduced generation of free oxygen radicals; these radicals cause oxidative damage to cells and decrease their lifespan. Pamela L. Larsen, a UCLA research associate of chemistry and biochemistry, says that researchers speculate that withholding Q would only benefit adults. "We know that we can get differences in phenotype from a change of diet, but there are different requirements for the body in development and during adulthood," says Larsen.

The National Science Foundation will distribute $7.7 million (US) during the next five years to eight women-in-leadership programs designed to help close the gap between the multitude of women entering science professions and the paucity promoted to management. "The data suggest that more and more women are entering science and engineering studies as undergraduate and graduate students," says Alice Hogan, director of the NSF program (www.nsf.gov/advance). "They have been earning doctorates for long enough for there to have been more change than what you see in the number of women at various levels of academic rank." According to 1997 NSF figures, women earn 27% of the doctorates in biological and agricultural sciences, yet they hold only 13% of full professorships. Men hold 72% of doctorates and 85% of full professorships. NSF's institutional transformation grants will finance programs to define the reasons for disparities and set up remedies. For example, at the University of California, Irvine, the grants will fund a mentor program for women faculty to develop skills crucial to advancing academically. The program also aims to establish models for other universities.

In a report that is certain to fuel the US national debate over human cloning and stem cells, a panel of the National Academy of Sciences has recommended that the use of somatic cell nuclear transfer (SCNT) be permitted to clone human cells for stem cell research. But the panel unanimously recommended that cloning for human reproductive purposes be outlawed because "it is dangerous and likely to fail." Members of the committee could not recall a previous instance when a NAS panel recommended making a scientific procedure illegal. The report (www.nap.edu/catalog/10285.html), released Jan. 18, noted that nuclear transplantation to produce human stem cells has "considerable potential for developing new medical therapies for life-threatening diseases and advancing fundamental knowledge." The panel based its findings on the scientific and medical aspects of cloning and not the ethical, societal, or religious elements. Those areas, however, were taken up during the first meeting of President George W. Bush's newly formed Council on Bioethics, which convened that same week. Bush charged the 18-member panel, chaired by Leon R. Kass of the University of Chicago, to "help be the conscience of the country." Bush supports legislation, passed last year by the US House of Representatives, that would outlaw human cloning both for reproductive and research purposes. The US Senate will consider similar legislation soon, but passage is considered doubtful. Meanwhile in the United Kingdom, an appeals court on Jan. 18 upheld regulations passed last year by Parliament that authorized cloning for research, overturning a lower court's ruling that had invalidated the rules.

The newly discovered molecular structure of two cancer-related proteins could provide the building blocks for therapeutic treatment. Using a synchotron light source to perform X-ray crystallography, researchers from Memorial Sloan-Kettering Cancer Center in New York City and the Brookhaven National Laboratory in Upton, NY, have photographed the tyrosine kinase receptor Eph, and its corresponding ligand, ephrin. (J-P. Himanen et al., "Crystal structure of an Eph receptor-ephrin complex," Nature, 414, 933-8, Dec. 12, 2001). The Eph receptor binds an ephrin ligand through a channel on its surface. The proteins are known to be involved in several cell-cell interactions, including the cell vascularization that surrounds tumors. "It has been shown that if you knock out Eph in time and prevent the formation of the vasculature around the tumor, then you may be able to cure the tumor," says Dimitar Nikolov, head of the structural biology and neuroscience laboratory at Sloan-Kettering. These proteins help propagate vascular endothelial cells and the specialized epithelial cells that are essential in cancer progression, notes Brookhaven's Kanagalaghatta Rajashankar. With this complex's structural detail, the framework exists to develop potential drugs that could block Eph signaling. Nikolov says the group is collaborating with companies that perform computational screenings to find small molecules that can bind to the binding pocket's three-dimensional structure. Nikolov explains, "We want to design a drug which can bind into the Eph channel and prevent the normal ligand from doing so."

"You can't always get what you want," Mick Jagger sings. Scientists are reporting that sometimes they can't even get what they need. A recent study on information sharing among geneticists shows that 47% of those who've requested post-publication information, data, or materials from other scientists were denied at least once in the preceding three years. (E.G. Campbell, "Data witholding in academic genetics," JAMA-Journal of the American Medical Association, 287[4]:473-81, Jan. 23, 2002.) The National Human Genome Research Institute funded this study, which determines that data withholding is no more prevalent among geneticists than among other life scientists, but also that scientists funded by the Human Genome Project were no less likely to deny requests. "I didn't find the overall conclusions surprising," says Francis S. Collins, NHGRI director. "Unfortunately it doesn't give enough information as to why these requests are being denied." Collins assures that NHGRI-funded researchers are upholding long-held data sharing principals, "DNA sequence information is being released not just after publication, but long before." The study's lead author, Eric G. Campbell, health care policy instructor at Harvard Medical School and Massachusetts General Hospital, lauds the NHGRI practice but states, "We were unable to detect a positive effect of this policy. It's likely that our methods were not sufficiently attuned to discovering such an effect." Requests for biomaterials were most likely to be denied (35%), followed by sequence information (28%). The most popular reason given for withholding data was the effort required to produce the materials or information followed by the need to protect a graduate student, postdoc, or junior faculty member looking to publish.