The Study of the Human Embryonic Stem Cells - Essay Example

Embryonic Stem Cell Research The study of the Human Embryonic Stem cells has been the center of discussion in the scientific arena. It alsocreated widespread debates all over the world not just because of how it is done but also of the moral issues surrounding it. Embryonic stem cells are pluripotent cells that could be obtained from a week old fertilized egg. Under viable conditions, these 50-150 young cells can continuously divide and eventually differentiate to become any cell type. Upon its discovery, scientists became very enthusiastic in pursuing stem cell researches most especially because it shows potentials for treating several diseases. On the other hand, hopeful patients wait for concrete results from different laboratory tests to confirm that it is indeed an answer to their ailment. The purpose of this paper is to give a brief background on some facts about the human embryonic stem cells. Particularly it will explore answers to the following questions: 1. When and how did the embryonic stem cell research begin 2. How are embryonic stem cells obtained and cultured in the laboratory 3. What are the benefits that would be derived from this research 4. What are the issues and negative feedbacks against the embryonic stem cell research 5. What is the government's position with regard to the advancement of this research in the United States Introduction Each of us started as a single living cell that resulted from the union between a sperm and an egg. From this single cell, certain chronological events took place that eventually led to the development of different body parts. Cells increase in number and differentiated to many cell types until we reached and assumed a human form. Many doctors agree that this is a miracle of Science. On the other hand, some started to try and make this miracle happen in a petri dish for purposes of helping fertilization occur between couples wanting to have babies. Eventually, this simple experiment led to the discovery of another potential wonder that these dividing young cells could give. Thus, embryonic stem cells became a word of mouth in all scientific publications and journals. These cells are found in a 4-5 day old embryo. They have a unique capability to continuously divide that enables them to self-renew. Embryonic stem cells are also capable of differentiating and developing into many cell types such as brain, heart, liver, skin cells, etc upon instructions of biological signals (NIC 2006). Hence, they are also called pluripotent cells. History of Embryonic Stem Cell Research Embryonic Stem Cell Research began through the efforts of Gail Martin, Matthew Kaufman and Martin Evans when they derived mouse embryonic stem cells way back in 1981 (The White House 2001). However, the breakthrough happened in February 1998 when James A. Thomson of the University of Wisconsin and his team announced that they had successfully isolated and cultured the first human stem cell line derived from blastocytes. The team obtained these blastocytes left over from successful in-vitro fertilization procedures (Stem Cells Portal 2008). Thomson revealed that the obtained cells transformed into different types when it was injected under the mice's skin. Furthermore, there were also remnants of the fundamental mammalian embryo layers proving that these cells are also flexible during the course of their development. The results obtained from the study shed hope gearing towards finding a medical treatment for some diseases (Pedersen 1999). Just about the same time that year, another group of scientists were conducting experiments similar to that of Thomson. John D. Gearhart of Johns Hopkins University in Baltimore was also extracting and culturing the same cell types from human fetal ovaries and testes (Pedersen 1999). Other developments and laboratory experiments soon followed with the same aim of developing their own embryonic stem cell line. One major scientific development took place in May of 2003 when researchers announced that they have successfully created human egg cells from embryonic stem cells. These eggs could again be recycled to produce stem cells. If continues experiments prove that such artificial egg cells can be suppliers of embryonic stem cells, then there won't be a need to destroy blastocysts in the future and thus allowing resolutions to the controversy. Just this year, another similar study immersed this time by a group of European scientists claiming that they have derived human embryonic stem cells from a 4-cell stage embryo called the blastomere. Dr. Hilde Van de Velde reported that their research would affirm that ES cells can be obtained without destroying the embryo. The team led by Velde utilized mature eggs taken from two couples who were subjected for treatment in an IVF center. They were able to successfully create and extract three 4-cell stage embryos which were separated to become 12 single blastomeres. These blastomeres were cultured to divide further producing 12 morulas. One was determined to be a potential human embryonic stem cell line. De Velde admitted that further testing needs to be done in order to address the morality of using embryos in its 4-cell stage as compared to embryos in its 8-cell stage. The team also specified that they are highly considering people's negative reception of the study. De Velde believes that by interfering in the earlier stages, further destruction of the embryo will not happen. (Science Daily 2008). Recently, researchers from California placed embryonic stem cells into mice as they grow in the womb. It was found out that as these cells developed some embryonic stem cells survived and assumed the characteristics of mouse cells. This study further established the capabilities of embryonic stem cells to differentiate in many forms (Stem Cell Portal 2008). Obtaining and Culturing Embryonic Stem Cells - a difficult task All the eggs and sperms used for experimental studies should have written consent from the donors. Upon approval, these cells are brought to different laboratories for further examination. The first thing to do is to produce the needed embryo where the stem cells will be acquired. Special laboratory technique is done to enable a sperm fertilize an egg in vitro. Several tests are needed before a successful implantation is achieved. A single cell called embryo results from this fertilization. A four to five day old embryo is called a blastocyte (NIH 2008). A microscopic blastocyte is composed of three parts: trophoblast, blastoel and the Inner Cell Mass. The outer trophoblast is a concaved shaped structure made of cells and will eventually develop to become the placenta and the umbilical cord. Just beneath the trophoblast is a hollow space called the blastocoel. At one part of the blastocoel, the Inner Cell Mass (ICM) develops. It is composed of a clump of approximately 30 actively dividing cells (NIH 2008). The ICM eventually develop to become the baby and sac-like amnion yolk. It is also the source of pluripotent cells (Kimball 2007) which will be obtained for stem cell researches (Pillai 2008). Culturing a blastocyte needs constant monitoring and careful incubation. Several days are needed in order to produce viable stem cells. After in-vitro fertilization, the blastocyte is placed in a culture well. The trophoblast cells are removed from the blastocyte leaving only the ICM (Federsen 1999). The ICM will be inoculated in a medium. The culture dish is composed of mice embryonic skin cells that have designed beforehand not to divide. This is commonly used because of its stickiness which enables it to hold the dividing human embryonic stem cells. It also provides sufficient nutrients for the culture. After several days, clumping of the ICM occurs in some parts of the dish. Researchers will then start sub-culturing the ICM by separating and placing it in other culture feeders. This process (scientifically known as passage) could be done as many times as needed. The separated culture cells are then placed in other culture wells and are allowed to develop and become colonies. At this stage, the embryonic cells are pluripotent because they are undergoing mitotic cell division without differentiating. The sub-cultures can be subjected to freezing for preservation purposes. Embryonic stem cells that have been kept frozen for six or more months are considered embryonic stem cell lines. These lines are made available for further studies that other institutions will conduct (NIH 2008). At the course of culturing and sub-culturing of stem cell lines, scientists must be consistently checking if the cells have the characteristics of true embryonic stem cells. Several laboratory tests are needed although scientists claim that there is no standards set in identifying such cells. The procedures include the following: a) waiting for ample months to cultivate and subculture the stem cells. This will confirm if the cells are able to self-renew for longer periods of time. Scientists continuously check for their activity through a powerful microscope. b) administering procedures that will check for some specific protein markers present only in cells that did not yet differentiate. Specifically, they would search for the Oct-4 protein, a transcription factor, that controls the cell differentiation at the appropriate time. c) examining the chromosomes to check if there are damages that incurred during the process. As we all know chromosomes carry the genes responsible for cell characteristics. If chromosomes have been altered, mutation might happen affecting the results of the experiment. d) testing if the cells are still viable even after they have been frozen and melted. e) injecting the cells to a immunosuppressed mouse and observe if a tumor called teratoma would occur. This will confirm if the embryonic stem cells still has the pluripotent characteristic because teratoma contains combinations of numerous differentiated and semi-differentiated stem cells (NIH 2008). When the embryonic stem cells are tested to have pluripotency characteristics, the differentiation process begins. Scientists try to control the kind of culture where they will inoculate the clumps of separated ICM and make it suitable for the differentiation to any cell type like cardiac, muscular or skin cells. They can either alter the chemical make-up of the culture or perform other procedures directly in the genes to make necessary changes. Scientists already have available procedures to perform such experimentation. For example, if they would want the embryonic stem cells to develop into a neuron or a pancreatic cell, they should culture embryonic bodies in an Insulin/transferrin/fibronectin/selenium culture. Then they would choose which of these embryonic bodies have Nestin-positive cells for neuronal precursor and pancreatic progenitor. Each will be cultured in different media. A certain chemical named bFGF will be removed from both cultures with the addition of nicotamide, a protein molecule, in the medium where the pancreatic progenitor cells are being cultured. The cells will differentiate according to the signals given to them (NIH 2008). Advantages of the Embryonic Stem Cell Research - a promise foretold Supporters of the embryonic stem cell study raise positive statements regarding the benefits that humans can reap if it will be allowed to continue. One potential importance of the human stem cell lines is its promise for cell-replacement therapies. This means the human embryonic stem cells can heal damage tissues in some major organs. Since it has pluripotency characteristics, these cells can replace worn-out tissues to young and renewable ones. For example, damages in cardiac tissues might happen due to a severe heart attack. The heart could no longer function properly than it used to. Through human embryonic stem cells, it may become possible to create healthy cardiac cells and transplant them to the patient's heart. Such experiment was successfully done in mice when bone marrow stem cells were introduced to a damaged heart. The heart showed positive signs of cell regeneration which eventually lead to its healing. Some of such diseases that could be treated using embryonic stem cells are degenerative diseases such as Parkinson's disease, Alzheimer's disease, spinal cord injury, stroke, heart disease, diabetes, osteoarthritis and rheumatoid arthiritis (NIH 2008). Scientists will also not experience difficulty in its supply because embryonic stem cells can be easily cultured in laboratories wherein numerous cells can be obtained (vescell 2007). Another importance of this study is that it would help enlighten the minds and provide opportunities to study the mechanism of human embryonic development and the factors that control it. In a way, it will help unravel the secrecy of cell division (vescell 2007). The entire process of studying how undifferentiated cells become specific and specialized will be realized. In normal conditions, scientists are aware that certain genes control the signaling process of the human development. However, in some abnormal medical cases wherein cancer and birth defects occur, scientists still cannot exactly pinpoint the culprit that led to abnormal mitosis. Using stem cells could provide significant knowledge regarding the genetic, molecular and chemical controls of such process. In turn, scientist could create specific medicines in treating these diseases (NIH 2008). Another advantage of determining signals is to effectively control the differentiation process thus allowing success in culturing specific cell type. It would be possible to determine specific channels that scientists would create directing the cells develop to the desired type. For example, in order to produce insulin secreting beta cells for the pancreas, embryonic stem cells might be incorporated with the gene needed to become beta cells which are lacking in the recipient (vescell 2008). Human stem cell lines could be also used to experiment the effectiveness of newly discovered drugs. Examples include studying the safety and hazards that a new medication can bring to differentiating cells. Another is through using cancer stem cell lines to test the effectiveness of anti-tumor drugs. Existing scientific knowledge is still very limited in this area (NIH 2008). Pillai (2008) also reported that Stem Cell research could find treatments on how aging could be slowed down. Continuing studies could also help treat complications related to aging. Negative Impact of the Human Stem Cell Research - a fallback There are always two sides of the coin. Despite of its promises, many people disagree and express strong resistance against the continuance of the Embryonic Stem Cell Research. Primarily, they oppose the study because it uses embryos. Many believe that life starts the moment fertilization takes place. With such notion, blastocytes are already considered as living things. It is very immoral and unethical to destroy embryos in expense for the advancement of scientific knowledge. Such a move is socially unacceptable since it is also liken to forced abortion (Pillai 2008). Scientists also claim that embryonic stem cells could treat different diseases. However, there is also the possibility that the recipient might biologically reject the implanted tissues. This could probably occur because the genes of the embryos where the pluripotent cells were obtained differ from the patient's genetic make-up. Some internal processes can occur that the body will not allow resulting to different kinds of malfunctions. Instead of being a cure, it has become a cause of abnormal functioning (bjmu 2008). The long term effects of the study pose another big question in the minds of its critics. For a while it may seem promising because it allows certain positive changes especially to targeted organs. However, in the future, there might be a far greater problem that may surface especially when the entire process has not been perfectly crafted. There are still some loop-holes which scientists are unable to determine. As such, embryonic stem cells may not be the solution to ailing problems and sacrifices are not worth it (Pillai 2008) Some people also raise the fact that pluripotent cells, if uncontrolled, can develop into tumors which will eventually lead to malignant cancers. Also they could transform into genetically altered tissues. For example, embryonic stem cells aimed to repair heart cells could develop bone cells in the process. However, supporters claim that such instances rarely happens (Weiss 2005). United States' position towards the advancement of Embryonic Stem Cell Research - an endless debate A recent survey reported that 66% of all Americans support the continuance of the Embryonic Stem Cell Research provided that stored embryos remaining after in vitro fertilization will be used. Americans believe that instead of being wastes materials, these embryos could be made useful by placing them in laboratories. However, even if there is a widespread support for this research, the government imposes a different guideline regarding this matter (Lyerly and Faden 2007). In the US alone, many laboratories are no longer pursuing the study due to lack of financial support both from the government and private sectors. We all know that in order to carry out such a research, a large amount of money must be utilized. In 2001, President Bush announced an executive order permitting the release of federal money to fund the continuous research on the 60 existing stem cell lines. However, it will not support and impose sanctions on further studies done using embryos. The president believes that it is not right to destroy another set of human embryos. In addition to this, the funds will only be used if a donor's consent is available, the embryos created are only left-overs from the existing study of reproductive health, and there are no financial accountabilities promised to the donors. The President also ordered a directive to the National Institute of Health in monitoring the existing stem cell lines and come up with a list of cell lines that followed the mentioned criteria. The President also created a Council on Bioethics headed by Dr. Leon Kass to further investigate the subsequent effects of studies to improve the Biomedical and Behavioral Science and Technology (The White House 2001). Such announcement crippled the independent researches about to take place. The laboratory funds were limited to the support of some few private sectors. Robert Lanza (cited in Begley 2007) said that there is no available funding to support the advancement of the research. Even pharmaceutical companies are not sustaining the study because it is too risky to get involve with. Lanza had real experience regarding this because his team started to isolate embryonic stem cells and allow them to differentiate to become retinal cells. The study ended up only in testing blind mice because they don't have sufficient amount of money for human clinical testing. Because of president's Bush's ban, many scientists alter from studying stem cells and only a small number of laboratories have the capacity of continuing stem cell line research (Begley 2008). Conclusion In any biotechnological advancement, sacrifices must be made. The full potentials of the Embryonic Stem cells will not be realized if no one will financially support the studies. Scientists must be given the chance to explore other ways on how to create embryonic stem cell lines that would not further destroy embryos but instead use what is available. As long as no concrete evidence proving that it can do whatever promises it makes, this study will always receive criticisms and endless debates from people. The question on whether or not embryonic stem cells are the answer to prolonging lives lies in the skeptic minds of the people. The future has its answers. BIBLIOGRAPHY: 1. (2006) Stem Cells Basics. National Institutes for Health. Retrieved on July 22, 2008 from http://stemcells.nih.gov/info/basics/basics1.asp 2. (2005) Q&A: Stem Cells. BBC News. Retrieved on July 22, 2008 from http://news.bbc.co.uk/2/hi/health/4562235.html 3. (2007) Information on Stem Cells and Stem Cell Therapy. Vescell. Retrieved on July 22, 2008 from http://www.vescell.com/stem-cell-information.php 4. (2001) Fact Sheet: Embryonic Stem Cell Research. The White House. 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