Microorganisms grow rapidly and are easy to control, which is suitable for large-scale industrial production. If the genes that biosynthesize the corresponding drug components are introduced into microbial cells to produce the corresponding drugs, not only the yield problem can be solved, but also the production cost can be greatly reduced.
Insulin is a specific drug for treating diabetes. For a long time, it can only be extracted from the pancreas of pigs, cattle and other animals. 100Kg pancreas can only extract 4-5g insulin, and its low yield and high price can be imagined. When the synthetic insulin gene is introduced into E.coli, 100g insulin can be produced per 2000L culture medium. Large-scale industrial production has not only solved the problem of drug output that is more expensive than gold, but also reduced its price by 30%-50%.
Interferon is a panacea for viral infection. Previously, it was extracted from human blood, and only 300L of blood was used to extract 1mg. Needless to say, its "precious" degree. Genetically engineered human interferon α-2b (Andafen) is the first industrialized genetically engineered human interferon α-2b in China. Has antiviral, tumor cell proliferation inhibiting, and immune function regulating effects. Widely used in the treatment of viral diseases and various tumors, it is currently recognized as the first choice for the treatment of viral diseases and the main drug for tumor biotherapy. The industrial production of artificial blood, interleukin and hepatitis B vaccine through genetic engineering has played an important role in alleviating human suffering and improving human health.
Gene diagnosis and gene therapy. Using the "DNA probe" designed and manufactured by genetic engineering to detect viral infections and genetic defects such as hepatitis virus is not only accurate, but also rapid. By introducing normal genes into patients with genetic diseases through genetic engineering, the pain of patients can be relieved at one time. Patients with severe combined immunodeficiency lack normal human immune function and will die as long as they are slightly infected by bacteria or viruses. The mechanism of this disease is the mutation of the gene encoding adenosine deaminase (ADA) on the cell autosome, which can be treated by genetic engineering.
Genetic engineering will bring Chinese medicine into a new era.
At the international symposium on "Traditional Chinese Medicine and Natural Medicine", experts in China believed that the research on transgenic medicinal plants or organs, the cloning of key enzyme genes of effective secondary metabolism pathway, the research on DNA molecular markers of traditional Chinese medicine and the research on gene chip of traditional Chinese medicine have become hot spots in the research of traditional Chinese medicine, which will bring traditional Chinese medicine into a brand-new era. According to Guo De 'an, deputy director of the State Key Laboratory of Natural Medicine and Biomimetic Medicine in Peking University, the research on transgenic medicinal plants or organs and tissues is one of the more active fields in biotechnology of traditional Chinese medicine in recent years.
In the research of transgenic medicinal plants, the Institute of Medicinal Plants of China Academy of Medical Sciences used Agrobacterium rhizogenes and Agrobacterium tumefaciens to induce Salvia miltiorrhiza to form hairy roots and crown gall, and then differentiated into plants. They made a comparative study on the morphology and chemical composition between them and cultivated salvia miltiorrhiza. The results showed that the leaves of plants regenerated from hairy roots were shriveled, internodes were shortened, plants were dwarfed and fibrous roots were developed. The plants regenerated from crown gall tissue have tall plants, developed roots and high yield. The content of tanshinone is high, which is of great significance for salvia miltiorrhiza breeding and improving the quality of medicinal materials.
Guo Dean said that studying the biosynthetic pathway of chemical components of traditional Chinese medicine is not only conducive to the bionic synthesis of these chemical components, but also can artificially regulate the synthesis of these chemical components, which is conducive to the directional synthesis of the required chemical components. Domestic research in this field has begun. It is understood that the application research of biotechnology in Chinese medicine research is gradually emerging. Some aspects, such as tissue and cell culture of medicinal plants, have accumulated 20 or 30 years of experience, and the theory and technology are quite mature, which has formed a certain scale in the country. Among them, the research on cell engineering of Chinese herbal medicine is in its heyday.
Guo Dean said that in the face of the problem that many wild plants are on the verge of extinction and it is difficult to introduce in some special environments, Chinese scientists have begun to explore the production of useful secondary metabolites by cultivating a large number of higher plant cells and organs. The research contents include the screening of high-yield tissues or cell lines, the optimization of culture conditions and the regulation of biosynthesis pathway of secondary metabolites in order to reduce costs and improve the yield of secondary metabolites.
In addition, the research on biotransformation of exogenous chemical components by using plant suspension cultured cells or adventitious roots and hairy roots has also quietly emerged in recent years, and has made some progress.
Moreover, scientists pay more attention to the regulation of biosynthesis pathway of secondary metabolites. These studies have achieved exciting results, indicating that the cell culture of medicinal plants in China has entered a new era.
Guo Dean believes that the main research direction in the future should focus on tissue cell culture of precious and endangered medicinal plants; Regulating the production of secondary metabolites; Biotransformation of some important chemical components in traditional Chinese medicine. In addition, the biotechnology research of animal medicine should be strengthened.
Transgenic animals that produce the most effective drugs
Transgenic animals are an individual expression response system, which represents the latest achievements in drug production in the present era and is also the most complex and promising biological response system. As far as gene drugs are produced by transgenic animals and livestock, the ideal expression site is mammary gland. Because mammary gland is an exocrine organ, milk does not enter the internal circulation, which will not affect the physiological and metabolic reaction of transgenic animals themselves. The gene product obtained from transgenic animal milk is not only high in yield and easy to purify, but also the expressed protein has been fully modified and has stable biological activity, so it is also called "animal mammary gland bioreactor". 1994 China academy of sciences published the transgenic poultry oviduct bioreactor and constructed the expression vector by using the flanking sequence of egg white protein gene. 1997 The first international symposium on transgenic animals was held in Beijing on 1996. In 2007, China's National 863 Program was included in the guide. Using mammary glands of transgenic cattle, sheep and other livestock to express the protein gene needed by human beings is equivalent to building a large pharmaceutical factory. This pharmaceutical factory obviously has the advantages of less investment, high efficiency and no pollution.
From the biological point of view, the utilization and conversion efficiency of energy by living organisms is beyond the reach of any mechanical device in the world today. Therefore, it is the most effective and advanced method that people can imagine to produce drugs through transgenic animals.
Mammary gland of transgenic animals can continuously provide the production of target gene (drug protein), which not only has high yield, but also has stable biological activity after full modification and processing. As a bioreactor, transgenic movement can reproduce indefinitely, so it has the advantages of low cost, short cycle and good benefit. Some drug proteins isolated from the milk of genetically modified livestock are being used in clinical trials.
At present, China has obtained transgenic mice, rabbits, fish, pigs, sheep and cattle in the field of transgenic animal research.
Although the drugs produced by transgenic animals (livestock)-mammary gland bioreactor or precious protein have not yet formed an industry, according to foreign economists, the drugs produced by transgenic animals will stand on the world market in about ten years. At that time, the annual sales of drugs alone exceeded $25 billion (excluding nutritional proteins and other products), making the transgenic animal (livestock)-breast bioreactor industry the most profitable new industry.
From June 5438 to February 25, 2000, the appearance of three transgenic sheep in Beijing and various transgenic vegetables, rice and cotton before that made people pay more attention to transgenic technology. So what kind of mysterious technology is transgenic technology?
Academician of China Academy of Engineering and Director of Shanghai Institute of Medical Genetics, Shanghai Children's Hospital believe that transgenic animals refer to artificially introducing animal or human genes that people want to study, or protein genes with economic value, usually called exogenous genes, into fertilized eggs (or early embryonic cells) of animals through experimental methods, so as to integrate them with their own genomes. In this way, foreign genes can proliferate with cell division and can be stably passed on to the next generation of animals.
Mr. Guan Tian, chief animal husbandry officer of Beijing Xingluyuan Biotechnology Center, the third high-tech agricultural experimental demonstration zone in Shunyi District, Beijing, said that the significance of transgenic animals and transgenic sheep lies not in the sheep itself, but in the fact that the goat milk they produce can extract α antitrypsin, and each of them can be called a natural gene pharmaceutical factory with great value.
According to Mr. Tian, the preparation of transgenic sheep is to inject human α antitrypsin gene into the male nucleus of ewe fertilized egg through micro-operation, and integrate it with sheep's own gene to form an inseparable whole. This new genome can be stably passed on to the born lamb. Goats have also become a new strain created artificially, which is different from female goats, and their offspring will also carry this α-antitrypsin gene. This process is somewhat similar to plant grafting.
Preparing transgenic animals is a complex task. At present, in the development of transgenic animals, the integration rate of foreign genes with the animal's own genome is low, and their expression is often not ideal, and the inherent characteristics of foreign genes can not be fully expressed or expressed. The integration rate of experimental animals such as cattle, sheep and pigs is generally around 1%. There may be many reasons for this. The first is the problem of target gene. The expression level of different foreign genes is different and varies from person to person. Secondly, whether the combination and connection of the internal parts of the foreign gene expression vector are reasonable; More importantly, whether it is reasonable for foreign genes to reach the integration position in the animal genome. Scientists still don't know where integration is highly expressed and where it is poorly expressed. People can't control the position of foreign gene integration, so they can only integrate randomly. Therefore, the low integration rate is inevitable.
Although there are still some technologies that need to be solved urgently, the great progress in the research of transgenic animals, especially its wide application in various fields, has had a far-reaching impact on biomedicine, animal husbandry and pharmaceutical industry.