n e w s of
tH^§^KKm
seems to agree. Holmes, whose own group has been synthesizing PPV derivatives substituted at the "unconventional" 2,3-positions on the benzene ring, calls the Xerox-led work "a significant breakthrough in widening the scope of the synthesis of these materials." Ron Dagani
Human cells Immortalized' by telomerase Human cells that normally lack the ability to make telomerase seem to live forever when genetically engineered to produce the enzyme, researchers have found. The study, reported in last week's Science [279, 349 (1998)], provides the first direct, conclusive evidence that telomerase plays a major role in the control of cell senescence—the process by which cells become old and die. It was conducted by Serge Lichtsteiner of Geron Corp., Menlo Park, Calif.; cell biology and neuroscience professor Woodring E. Wright of the University of Texas Southwestern Medical Center, Dallas; and coworkers. The work does not necessarily demonstrate that a person—or even just sets of cells inside a person's body—could be immortalized safely by inducing telomerase expression. But the work could have near-term applications in the production of long-lived in vitro human cell lines for research purposes, and it may have longterm therapeutic implications as well. Most body cells don't express telomerase. In these cells, telomeres (the ends of chromosomes) shorten a little bit with each cell division. And when telomeres become too short, chromosomes signal the cell to stop dividing or, in some cases, to die. Hence, progressive shortening of telomeres appears to act like a biological clock, limiting the number of times a cell can replicate. Telomerase, which is expressed in cancer cells and reproductive cells, maintains telomere length by catalyzing the addition of repetitive DNA sequences to chromosome ends. Lichtsteiner, Wright, and coworkers have now found that inducing telomerase expression in body cells that don't normally make the enzyme results in telomere lengthening and a major increase in cell life span—in fact, it makes the cells potentially immortal. "There's no question that this is of tremendous scientific significance," says mi10 JANUARY 19, 1998 C&EN
crobiology and immunology professor Ronald A. DePinho of Albert Einstein College of Medicine, New York City, whose research interests include cell cycle checkpoint control and the role of telomerase in cancer and senescence. "The most striking observation is how dominant telomerase is in commandeering the behavior of cells around the transition into senescence. It's surprising that one molecule would have such a significant impact on a process that most would think would be multifactorial. This puts us in a position to understand the process much better." In the near term, the work should make it possible to grow normal human cells in culture for research and therapeutic applications. Until now, cultured cells had to be transformed with oncogenes or oncoproteins to make them capable of di-
viding repeatedly. "We had to make the cells abnormal to use them in the biological processes we want to study," says DePinho. "To be able to take normal cells and expand them significantly is really fantastic. It's the type of discovery where, once it is made, one is stimulated to brainstorm about all sorts of new experiments and applications." Potential long-range therapeutic applications, DePinho suggests, include enhancing the replicative capacity of aged cells, thereby facilitating wound healing, and expanding immune system cells to fight infection. However, he says, it may be necessary to regulate the induced telomerase expression carefully to prevent the modified cells from becoming cancerous. Stu Borman
Quebec chemical industry weathering the storm
substation on dedicated industrial lines, was granted permission to restart operations on Sunday. Plant employees and contractors spent the next 36 hours deicing equipment to ensure safety. "One-quarter of our employees are out taking care of personal situations," says Louis A. Rail, Petromont secretary and general counsel. Deciding when to return to work is based on their own judgment, he says, "no questions asked. It's a disaster area." Petromont is a Canadian limited partnership of Quebec provincial-governmentowned entities and Union Carbide. Carbide sent scores of tanker trucks full of aircraft deicing and anti-icing fluid from its Carteret, N.J., terminal to the area. The plants are operating at a slower pace, with rail transportation service limited and electrical supplies on allocation.
The ice storms that lashed eastern Canada earlier this month closed down Montreal and cut power to hundreds of thousands of people for more than a week during brutally cold weather, as electricity transmission towers toppled under the weight of the ice. Chemical plants in the area were shut temporarily and brought back up at reduced capacity, with supplies and rail shipments limited by frozen tracks and switches. Petromont's ethylene plant in Varennes, Quebec, for example, was down from Friday, Jan. 9, through Monday, Jan. 12. The plant, which is connected to an electrical
However, Rail says, "we never had to call force majeure." And despite five-inchthick ice coating everything, "we have had no major accidents." Sterling Pulp Chemicals' Buckingham, Quebec, facility has been running at about two-thirds capacity, suffering several blackouts. The process for making sodium chlorate and sodium chlorite is "extremely dependent on electricity," points out Paul Timmons, vice president of operations. But the plant's biggest problem, he says, is shipments. Railcars that normally transport about 95% of the plant's raw materials are now hampered by iced tracks. The office building and maintenance shop at the facility have been kept open to house employees who lost power at home. In Montreal, "most of the head offices were closed until Thursday," says Jules Lauzon, the Canadian Chemical Producers Association's regional manager for Quebec, who worked by candlelight at home. "It is incredible, the number of things we cannot do anymore." Elisabeth Kirschner
Are signs of martian life contaminants? In the latest volley in the debate over the martian meteorite ALH84001, two groups of scientists report evidence they say shows that the putative traces of ancient microbial life on Mars are most likely terrestrial contaminants. Jeffrey L. Bada, marine chemistry professor at Scripps Institution of Oceanography, La Jolla, Calif., and colleagues say amino acids found in carbonate globules—the primary site in the meteorite for evidence of martian life—are similar to those occurring naturally in the Antarctic environment where the meteorite was discovered [Science, 279, 362 (1998)]. In another study, A. J. Timothy Jull, research scientist in the geosciences department at the University of Arizona, Tucson, reports that l4C levels in organics taken from the meteorite indicate a terrestrial origin and that carbonate-related material in the meteorite appears to be extraterrestrial—an indication that the two meteorite components are unrelated, Jull says [Science, 279, 366 (1998)]. Members of the original team that proposed the martian life hypothesis, however, say the studies are flawed and
don't provide conclusive evidence one way or another. "We were not surprised—all Antarctic meteorites show some contamination," says Everett K. Gibson Jr., of the National Aeronautics & Space Administration's Johnson Space Center in Houston. The San Diego study, Bada explains, focused on amino acids because they presumably would be important in the chemistry of life. The mix of amino acids—including alanine, glycine, and serine—found in ALH84001 is similar to University of Arizona's Jull examines radiocarbon data that found in another mete- from the mass spectrometer. orite, EETA79001, which the Scripps group says is known to be con- son notes. "Everybody wants to have an taminated. It is also similar to the mix answer very quickly, and they're not gofound in the Antarctic ice that surrounded ing to be getting it, because it's such a complex sample," he says. both meteorites. Elizabeth Wilson However, Gibson and Stanford chemistry professor Richard N. Zare, another of the original paper's authors, take issue with the fact that Bada's group did not examine polycyclic aromatic hydrocarbons, or PAHs—compounds associated with the carbonate globules that they say are one of the key lines of evidence for past martian life. They note that, unlike amino acids, PAHs are relatively insolu- The employment outlook for chemists ble in water. and chemical engineers over the next The Arizona researchers looked at ra- decade is a bright one. According to the dioactive 14C levels in portions of the me- Department of Labor's just-released bienteorite. Carbon-containing compounds as- nial "Employment Outlook: 1996-2006," sociated with living things contain charac- job opportunities for chemists and chemteristically high levels of l4C. Because the ical engineers will grow more rapidly meteorite is many millions of years old, than total chemical industry employment any elevated 14C levels in compounds or industrial employment as a whole. Overall, the report projects that the stemming from a martian biosphere would have long since dropped, Jull ex- manufacturing sector will lose 349,000 plains. Consequently, low l4C levels in car- jobs, primarily to increased automation, bon-containing compounds would indi- between 1996 and 2006. However, chemists and chemical engineers are likely to cate an extraterrestrial origin. The group heated meteorite samples see job gains, as they often provide the reto temperatures where most organics search and engineering muscle behind combust and analyzed the released car- manufacturing productivity gains and new bon with a mass spectrometer. They labor-saving product introductions. The number of chemists employed in found this carbon contained large percentages of l4C, indicating that much of the all sectors of the economy will increase organic material stemmed from Earth's 19%—from 91,000 to 108,000—between biosphere. However, at the higher tem- 1996 and 2006, according to the report. peratures at which carbonates generally Factoring in the number of people who break down, the group found lower lev- will retire or take other jobs—such as exels of 14C, suggesting the carbonates ecutive, administrative, or managerial positions—the Labor Department Bureau of came from Mars. Such back-and-forthing is just an indi- Labor Statistics (BLS) sees 36,000 jobs for cation of the scientific process working chemists opening up over the decade. Chemical engineers will fare nearly as on an extremely difficult problem, Gib-
Bright job prospects for chemists, chemical engineers
JANUARY 19, 1998 C&EN 11
