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| Tuesday, 10 August 2004 |
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Pharm crop stalled for now by Joe Cummins Rice genetically modified to produce two human proteins moved a step closer to commercial approval, but was stalled at the eleventh hour, for now. The following article warns of the potential hazards of the GM rice. The California Rice Commission recently approved Ventria BioScience's request to grow the state's first crop genetically modified to produce pharmaceuticals. The transgenic rice produces two human proteins - lactoferrin and lysozyme - found in breast milk, tears and saliva, which the company hopes will kill bacteria that cause severe diarrhoea. Ventria proposed to grow up to 120 acres of transgenic rice in 10 Californian counties, which it claimed were sufficiently far away from the state's main rice fields. The Commission recommended that the California Department of Food and Agriculture (CDFA) approve the request as quickly as possible, giving it only a limited time to decide on the proposal. As the planting season lasts from April to July, and a proper review process takes time, Ventria opted for a fast-track process. In a victory for science and sanity, the CDFA denied Ventria's applications to grow the transgenic rice, as the company had yet to obtain the necessary approval from federal regulators. It also did not see any reason for a hurried review of the proposal by treating it as an emergency under state law and wanted to give the public more time to comment on the issue. However, the CDFA decision leaves open the possibility the proposal could resurface, in time for next year's growing season in California, or in other places outside California. The United States Department of Agriculture (USDA) also refused to renew Ventria's permit for field trials, which it has had since 1997, saying the company planned to grow its experimental rice too close to crops intended for human consumption. In 2002, Greenpeace disclosed the location of a site in northern California where rice plants modified with the human genes lactoferrin and lysozyme were being tested. Lactoferrin acts against bacterial pathogens by preventing them from taking up iron needed for their growth, while lysozyme breaks down the cell wall material of the bacterial pathogens. The biopharmaceutical rice crop was being tested by a Californian biotechnology company, Applied Phytologics. The Greenpeace disclosure created an avalanche of concern from the public and from both conventional and organic rice farmers fearing that contamination of their crops would lead to economic disaster. Washington State University field-tested barley altered with human genes for lactoferrin, lysozyme, antitrypsin and antithrombin without any comment from the public, even though this posed an obvious threat to both conventional and organic beer production and animal feed, not to mention the hazards to health. Maize modified with human lactoferrin was field-tested by Biochem SA company and by Meristem Therapeutics company in France, again with no comment from the public even though such tests threaten both conventional and organic maize production in Europe. Most of the field-testing of genetically modified (GM) biopharmaceutical crops appears to have been carried out in the United States, France and Canada. The US completed 315 such tests between 1991 and 2002, including GM maize, rice, soya and Tobacco Mosaic Virus. The majority of tests were done in Nebraska, Hawaii, Wisconsin and Puerto Rico. Canada completed 53 field tests of pharm crops between 1995 and 2003 while France completed 24 such field tests between 1995 and 1998. In the US and Canada, field trials of pharm crops are veiled in secrecy under the 'confidential business information (CBI)' designation, which hides the details of the gene constructs as well as the exact locations of the field tests. Thus, people living near the field trials have no means of relating any illness or discomfort experienced from exposure to polluted plant debris or pollen, or to contaminated ground or surface water escaping from the test sites. The GM rice pharm crop, like other crops that produce pharmaceuticals in seed, has a gene construct that includes the human genes for the biopharmaceutical protein driven by a seed-specific promoter, and the protein is expressed with a fusion polypeptide (the signal peptide) that causes the fusion protein to accumulate in a cell compartment such as a vacuole or seed endosperm. Human lactoferrin produced in plants has been described in a US patent granted in 2003. Human lysozyme incorporated in plants was patented in 1994 as a biopesticide to protect plants against fungal and animal pests, and its localisation to the endosperm of transgenic rice has been reported more recently. Expression of human milk proteins in plants was discussed by nutrition experts who said such products should be tested in rats and then in human volunteers; but they have totally ignored the problem of inadvertent exposure to the products by consuming crops contaminated by the product resulting from the inevitable, 'accidental' spread of pollen or seed. Chickens were fed GM rice with human lysozyme and lactoferrin, and the rice was reported to have antibiotic-like properties. Lactoferrin participates in the regulation of immune functions and controls pathogens by binding iron required for bacterial growth. Lactoferrin has been implicated in asthma with fatal consequences. Lactoferrin variants have been associated with localised juvenile periodontitis. It has been suggested that milk lactoferrin possesses allergenic sites. Lactoferrin is a protein modified by glycosylation, a modification that contributes to enzyme activity and to allergenicity of the protein. Human lactoferrin was found to be glycosylated differently from the human transgene protein produced in tobacco. The different patterns of glycosylation observed in human and the tobacco transgene product should not be considered insignificant until full studies of allergenicity of the transgenic protein are completed. Chicken egg lysozyme is a well-known potent food allergen while human lysozyme is clearly not allergenic. Like lactoferrin, lysozyme is a glycosylated enzyme and variants of human lysozyme have been characterised. The glycosylation patterns of the transgenic enzyme produced in plants appear to have been neglected even though that pattern will influence allergenicity of the product. Clearly, both transgenic lactoferrin and transgenic lysozyme are potentially hazardous to human health, and such concerns should be made clear to those exposed at or near the field-test sites. Transgenic rice crops may spread pollen or seed to adjacent fields, thus contaminating those crops. Rice is known to be somewhat self-fertilising, but clearly capable of spreading both pollen and seeds to nearby fields. Studies on gene flow between commercial rice and weedy red rice suggest that transgenes may spread to non-transgenic rice. Once established, the transgenes may be difficult if not impossible to eliminate. Organic and conventional rice producers have a legitimate concern over the secrecy surrounding the field-testing of the transgenic rice. Transgenic glufosinate-resistant rice (Liberty Link) was deregulated in the US during 1999; USDA/APHIS (the Animal Plant Food Inspection Service) thought that the transgenic rice would not pollinate weedy red rice, and even if it did, the weed could be eliminated using herbicides other than glufosinate. I have outlined the concerns over the threat of transgenic rice to organic and conventional producers and the probable instability of transgenic rice some years ago. Recently, recombinant biopharmaceutical production in transgenic crops has been actively promoted, in spite of incidents of contamination of food production uncovered during field tests of such crops. Production of the biopharmaceutical crops in confined greenhouses was deemed un-economic even though such production provides the barest essentials for isolating the pharm crops from contaminating our food crops as well as the atmosphere and groundwater. Once released, the modified crops cannot be recalled, and the polluting effects may persist for generations to come. Transgenic crops producing human milk proteins are promoted because 'mother's' milk is presumed safe for all, but the transgenic 'mother's milk' proteins are far from identical to the real thing. In the case of the transgenic rice, it does not contain the native human genes and proteins. Instead, it contains synthetic copies of the native genes that are modified for high-level production in plants. This involves changes in codons and amino acids as well as in the sugar molecules added to the final protein. The products are essentially untested for potential allergenicity and toxicity to humans, livestock and wild life. The transgenic milk-protein crops are just the start (or ripples on the surface of a deep ocean). Other transgenic crops will follow, producing anti-coagulants, human growth hormone, antibodies and a range of other biopharmaceutical products all potentially significantly different from the natural products. The biopharmaceutical dam may soon burst leaving the human population with an array of hidden non-prescribed medications in their food, plus a host of side effects to boot. - Third World Network Features |
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