The emergence of Gene-based medicine is closely related to the development of genetic engineering technology, which is the main body of modern biotechnology. Mainly used in molecular genetics, biology, medicine, pharmacy and other disciplines. It has high selectivity, a gene drug is not suitable for all races, and there are many differences in the genes of different races. With the development of genetic engineering technology, Gene-based medicine has roughly gone through three stages: bacterial genetic engineering, cellular genetic engineering, transgenic animals and synthetic biology. Due to the high efficiency of gene drugs, the use of gene technology to modify the human body is very risky, so the sports association has included gene doping on the prohibited list and strictly prohibited its use.
The selectivity of Gene-based medicine
Gene drugs are highly selective. A gene drug is not suitable for all races, and there are many differences in the genes of different races. For example, sickle-cell disease is rarely found in yellow people, but it has a high incidence in whites and blacks. The reason is that whites and blacks have a parasite in their bodies. Drugs to treat sickle-cell anemia can make an antibody in the patient’s body. , thus warding off parasites. Therefore, this genetic drug for sickle cell anemia can only be given to whites and blacks.
In addition, different living environments also require different gene drugs. For example, the cancer that people are most eager to use gene therapy also has environmental characteristics: liver cancer has a high incidence in Asia, lung cancer, stomach cancer, esophageal cancer, and liver cancer are the most common chronic diseases in China, and rectal cancer is the highest incidence of cancer in the United States. Therefore, the environment is also one of the most important contents in the development of Gene-based medicines.
The birth of Gene-based medicine
The emergence of Gene-based medicine is closely related to the development of genetic engineering technology, which is the main body of modern biotechnology. Genetic engineering is to achieve the recombination of genetic material through the insertion, splicing and recombination of nucleic acid molecules, and then transfer the target gene to a new host cell with the help of virus, bacteria, plasmid or other vectors, and make the target gene in the new host cell. Techniques for internal replication and expression. Gene is a specific segment of DNA molecule, so genetic engineering is also called biological engineering at the level of DNA molecule.
Modern geneticists believe that a gene is a general term for specific nucleotide sequences with genetic effects on the DNA (deoxyribonucleic acid) molecule, and is a DNA molecule segment with genetic effects. Genes are located on chromosomes and are arranged linearly on chromosomes. Genes can not only pass genetic information to the next generation through replication, but also make genetic information expressed. Differences in hair, skin color, eyes, nose, etc. between different races are caused by genetic differences.
Humans have only one genome, with about 50,000 to 100,000 genes. The Human Genome Project was first proposed by American scientists in 1985, aiming to elucidate the sequence of 3 billion base pairs of the human genome, discover all human genes and find out their location on the chromosome, decipher all human genetic information, and make the human first. A complete understanding of self at the molecular level at a time. Officially launched in 1990, the goal of the $3 billion effort is to precisely sequence the 3 billion base-pair human genome, ultimately figuring out what protein each gene makes and what it does.
As the human genome is gradually deciphered, a map of life will be drawn, and people’s lives will change dramatically. Gene medicine has entered people’s life, and using gene to treat more diseases is no longer an extravagant hope. Because as our understanding of human beings advances to a new level, the causes of many diseases will be uncovered, drugs will be better designed, and treatment plans will be able to “prescribe drugs to the cause”, and living and eating habits may be based on By adjusting the genetic situation, the overall health of human beings will be improved, and the medical foundation of the 21st century will be laid.
Its main tasks are the separation, synthesis, cutting, recombination, transfer and expression of genes. In the past 20 years, DNA recombination technology and gene therapy technology have developed very rapidly and have entered the stage of practical application. The progress of DNA recombination technology has greatly improved people’s understanding of the nature of life, including the understanding of the genetic basis of diseases. In the future, we will gain a further understanding of the pathogenesis of cancer, the genetic characteristics of the disease, the function of the immune system, the etiology of metabolic exhaustion diseases, and the physical and chemical mechanism of brain function, thus giving birth to new ways of treating hereditary diseases and major difficult diseases. Gene-based medicine is the product of the development of genetic engineering technology. Its appearance will revolutionize the existing medical practice and make all diseases conquerable for people. People yearn to stay away from disease, and the era of having a healthy body is coming to us.
Development of Gene Medicine
With the development of genetic engineering technology, Gene-based medicine has roughly gone through three stages:
bacterial genetic engineering
It expresses the target gene through prokaryotic cells (usually E. coli). This project is quite complicated, and there are many problems in cost and process.
Cell genetic engineering
Cell genetic engineering also has shortcomings, because the conditions for human or mammalian cell culture are quite harsh and the cost is too high, which limits the development of cell genetic engineering.
That is, a certain gene of a human or mammal is introduced into the fertilized egg of a mammal, and each cell has the introduced gene, which can be stably passed on to the next generation. Such a new individual is called a transgenic animal. The advent of transgenic animals has opened up a new way for the use of new genetic engineering methods to obtain low-cost and high-activity Gene-based medicines.
The secondary metabolic reaction chain is optimized through computer-aided design, and the gene regulatory network is artificially synthesized, so as to realize the metabolic engineering of exogenous medicinal biomolecules expressed in engineered bacteria or yeast cells, especially the secondary metabolic drug molecules of natural drugs, for example, in 2003 Beckley University in the United States successfully expressed the plant drug molecule fenugreek in yeast cells.
Scientists have found that many human congenital diseases are caused by the lack of corresponding genes, and it is difficult to cure with ordinary drugs. After expression, the active gene drug can be extracted from the milk or other tissues secreted by the animal to treat the disease caused by the gene defect. This method of obtaining drugs from genetically modified animals is called animal pharmacy.
Animal pharmaceutical companies have changed people’s impression of pharmaceutical companies. It looks more like a ranch. Here, herds of genetically modified cattle and sheep graze on the green grass. On the surface, they are no different from ordinary cattle and sheep. However, the milk they secrete is a medicine that can cure human diseases. Animals are equivalent to a large drug factory. With their cheap milk, they provide human beings with a lot of precious drugs they need.
Experts predict that gene therapy for diseases will move from testing to clinical applications on a large scale in the next century. By then, a large number of drugs produced by biotechnology will come out, and the biopharmaceutical industry will become one of the fastest growing high-tech industries in the 21st century. Although the bio-high-tech pharmaceutical industry has the characteristics of strong investment, long cycle and high risk, once industrialized, it will bring high profits. Compared with the traditional pharmaceutical industry, animal pharmaceutical factories have less investment, high efficiency and no pollution. Etc.
It generally takes 20 to 30 years to develop a new drug. Even if technology develops further, it is difficult to be less than 10 to 15 years. The cycle of genetically modified sheep is generally 18 weeks, and it only takes 2 to 3 years for cattle. And the benefits are amazing. For example, a kind of lactoferrin produced by the Golden Horse Company of the Netherlands using genetically modified cows is made into milk powder with functions such as iron transfer and antibacterial. It is estimated that the annual sales of this nutritional milk powder is 5 billion US dollars.
The “blood coagulation factor” expressed by the transgenic goat successfully tested by the Shanghai Institute of Medical Genetics in February 1998 will have an amazing output value if it enters industrial production. According to statistics from the United States, in the past, coagulation factor VII was extracted from the blood source of donated blood. The annual demand of patients in this area in the United States is about 120g. This 120g must be extracted from 1.2 million liters of plasma. For 200ml, 6 million blood donors are needed to provide plasma. If we use genetically modified cows for production, only 1.2 cows of milk will be enough.
The biomedical revolution brought about by genetically modified animals has not only produced huge economic benefits, but also changed people’s traditional medical methods. People can drink delicious milk while achieving the purpose of curing diseases. Change can not but be exciting.
The achievement of Gene-based medicine
Gene recombination technology has achieved fruitful results one by one. In 1978, artificial insulin was synthesized. In 1979, the expression of growth hormone gene in Escherichia coli was realized. In 1982, artificial interferon was successfully developed. Since then, gene pharmacy has embarked on the road of industrialization. However, Gene-based medicines are manufactured by cultivating Escherichia coli and animal cells through genetic recombination technology, and it is impossible for low-level organisms such as Escherichia coli to produce drugs with complex structures, and the cost of animal cell culture is too high. Therefore, the use of genetic recombination and transplantation technology to cultivate transgenic animals to produce drugs came into being. British scientists are the first to use transgenic animals to extract drugs. At the end of 1997, the British PPL Therapeutics Company took the lead in using the “nuclear transformation” method used to clone “Dolly” to cultivate 200 sheep carrying human genes, and successfully extracted α-1 antitrypsin from milk. This is the first time scientists have extracted pharmaceutical ingredients that can be used to treat human diseases from the milk of genetically engineered sheep, laying the foundation for the establishment of an “animal pharmaceutical factory”. Subsequently, Finnish scientists implanted the human erythropoietin gene into the fertilized eggs of dairy cows to create a dairy cow that can produce erythropoietin. Theoretically, this dairy cow can extract 60-80 kg of erythropoietin a year, which is more than the amount used in the world.
Risks of Gene-based medicine
The use of genomic medicine will revolutionize medicine. Medicines will be specific to each individual, treatment will become more efficient and less expensive. “That’s what scientists tell us to understand DNA. But we’re still far from that day.
The journal Science recently reported that scientists optimistically estimate that genomic medicines won’t be available until 2053 (the 100th anniversary of the discovery of the DNA double helix), or at best 2020.
Scientists agree that we are not yet at the point where genetic information can be used to directly produce responsive drugs. In other words, we have not yet entered the real genetic era. Test Completion is Just the Beginning “We often have people asking, what will happen when the human genome sequence test is complete? The usual answer is: This will greatly facilitate drug development; the era of preventive medicine is coming; Human life expectancy will be extended. And we already know that the completion of the human genome sequence test is actually just the beginning.” said American scientist New Delhi Borina.
“When the genetic engineering of humans and some pathogens is partially completed, some people think that in 20 years, human medicine will be completely changed; some tenacious killers of human health will be effectively controlled. But when we celebrate the discovery of the molecular structure of the DNA double helix At the 50th anniversary, it became clear to us that such an understanding was premature,” said Professor David David of Oxford University’s School of Molecular Pharmacy.
If our knowledge of human physiology does not make decisive progress, DNA sequence testing will be meaningless. “We must understand what happens inside the human body when we are sick, and how we can intervene, treat and prevent it. For future medicines, we need solid knowledge and information to analyze the relationship between genes and various diseases , at least for some common diseases, we need to be able to figure out these relationships; in addition, we need to understand the influence of some external factors on the disease.”
Scientists believe that in the future, more obstacles will come from biological diversity, that is, the differences caused by different races.
About 30 years ago, doctors began treating children with leukemia with a powerful, cell-killing drug. The drug, called 6-mercaptopurine (6MP), has saved thousands of lives. However, this drug can have certain side effects. As early as more than 20 years ago, it has been found that its toxins can remain in the patient’s body and are inherited. The drug can build up quickly and then seep into the bone marrow, where it can lead to infection.
Different races have different percentages of people with this enzyme deficiency. For example, among the Caucasians, one in every 300 people, such a person cannot be treated with 6MP, otherwise it will be fatal.
This confusion will be a common problem encountered by future genomic medicines, and the risks of Gene-based medicines are certain.
Due to the high efficiency of gene drugs, it can be used to transform people into physical fitness, so some athletes and coaches who are desperate to achieve results have begun to take risks and come up with the idea of gene drugs. The use of genetic technology to modify the human body is very risky, so the sports association has included gene doping on the banned list and strictly prohibited its use.