GENETICS OF CANCER
(Breast and Cervical cancer)
• BREAST CANCER:
Breast cancer is a cancer that arises in the tissues of the breasts. It is a leading cause of death in women in the western countries. A woman’s chance of developing breast cancer increases much more if the cancer runs in her family i.e., it is hereditary and hence can be inherited from our family. Breast cancer can also develop in males, but is very rare. About 1% breast cancer develop in males.
The two main genes that are mainly responsible for this catastrophe are “BRCA1 (Breast cancer 1)” and “BRCA2 (Breast cancer 2)”. These genes produce “tumor suppressor” proteins whose normal function is to inhibit cell division and repair the damaged DNA, hence keeping the cell’s genetic material healthy and stable. Hence it can be seen that the product of these two genes actually helps to keep our DNA stable.
Problem arises when these genes become altered i.e, it undergoes mutation. Mutation refers to the change in the DNA sequence which could result in a production of a protein of altered structure and function. BRCA mutations act in a dominant manner, which means that even though a person receives a single mutated version of the gene (the other copy being normal), they have a big chance of acquiring a second mutation and hence predispose them to breast cancer. (dominant expression of cancer)
Because they are inherited from the parents, they are known as “hereditary” or “germline mutations”, rather than “acquired” or “somatic mutation”. A harmful BRCA1 or BRCA2 mutation can be inherited from a person’s mother or father.
Apart from these two main genes, there are also other genes which are responsible for predisposition to breast cancer, but not so much as BRCA1 and BRCA2...
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...s and hence would not be able to evade the immune system.
• CONCLUSION :
Cancer is still a major threat to humanity. Every year it causes a large number of deaths. Breast cancer and cervical cancer are a leading cause of death in women in the western countries. Drugs prescribed for both of them are now being challenged. So if we could understand the genetics of both these cancers and understand the pattern of inheritance of the mutated allele’s one could prevent these cancers (especially breast cancer) before its onset. Understanding the functions of lncRNA is important for knowing and treating cervical cancer. Also, finding out the faulty genes in both the types of cancers could be helpful for knowing the genetic pathway. Taking all this together, cancer genetics is an important and will be a necessary tool in the future for treating and curing all types of cancers.
Women who inherit a mutation in one copy of BRCA1 or BRCA2 are at high risk of developing breast and ovarian cancers6. This could be due to the disruption in the pathway of BRCA proteins in the cell nucleus. If BRCA1 is defective, it loses its ability to fix damaged DNA and causes tumor. It is because once the defective BRCA1 raises, it allows the cells to develop and divide uncontrollably. Since defective in BRCA1 causes cancers, it is important to understanding the function of the protein by analyzing its sequence and structure.
At this point in time, scientists and doctors have yet to discover the specific causes for breast cancer. However, what is known are the different risk factors that may trigger or put women more at danger of acquiring this disease. Aged women who have experienced menopause are more vulnerable at containing this disease. Women are also more at risk if breast cancer is common within their family because it is hereditary. In addition, smoking and drinking are other factors that can put women at risk as well (Stephan, 2010). Obesity in particular is a huge risk factor. Women who are overweight, especially those who have a thicker upper body, are more likely to develop malignant cancers in the breast than a healthy woman (Vona-Davis and Rose, 2009).
Nikitina, E. G., Urazova, L. N., & Stegny, V. N. (2012). MicroRNAs and Human Cancer.Experimental Oncology, 34(1), 2-8. Retrieved from http://archive.nbuv.gov.ua/portal/chem_biol/eol/2012_1/002.pdf
A mutation in the BRCA1 or BRCA2 gene is associated with an increased risk of ovarian cancer
There are numerous risk factors for breast cancer. Genetics or family history of breast cancer in a one first-degree relative with breast cancer doubles a woman’s risk. Having two first degree relatives rises a woman’s risk by three times. A person’s personal history who have had one breast with cancer is three to four times as likely of developing a new cancer. White women are slightly more likely to develop breast cancer than are African-American women, but African-American women are more likely to die from this cancer. However in women under 45 years of age, breast cancer is more common in African-American women.
What is breast cancer? According to the National Cancer Institute at the National Institute of Health breast cancer is a, “cancer that forms in tissues of the breast" (cancer.gov). More specifically breast cancer is a malignant tumor that grows inside the breast tissue. What happens is one cell in the tissue does not get the stop signal and keeps dividing into this big mass. This big mass continues to grow and grow and could eventually taking over space that is meant for other tissue or getting into the blood stream taking the dividing cells elsewhere. Breast cancer normally starts in one of two places.
In the United States, starting from the first breast cancer case in 1930s to today, a woman's lifetime risk of breast cancer increases to one eighth (Gray et al.). Continuously increasing breast cancer rate has caused a lot of concerns among not only ordinary people but also scientists. For decades, scientists have been working on the causes of breast cancer in order to find the corresponding methods of treatment. However, only about 25% of the breast cancer cases got explained (Brody et al.); till today, heredity, lifetime exposure to environmental estrogen (the female sex hormone), and the dietary fat are the only major known causes (“Cover Story: Breast Cancer and Environment”). For the 75% unexplained breast cancers cases, scientists, through various of researches, have come up with several hypothetical breast cancer causes, in which synthetic chemicals and environmental radiations are the major ones.
Breast Cancer, as well as other forms of cancer, scientists do know how it occurs, but they do not know an exact cause. There are some genes in our body called oncogenes, genes that have potential to cause cancer, that increases the speed of cell division while other genes such as tumor suppressors, cause the cells to die at the correct time. Mutations that occur in the DNA, which “turn on” the oncogenes or “turn off” tumor suppressor genes, will cause some of the cells to be cancerous in the breast("American Cancer Society"). Also, Breast Cancer can be increased by inherited gene mutations and acquired gene mutations. The risk of Breast Cancer can be increased dramatically, through the inheritance from parent to offspring, if a mutation occurs. For example, if a suppressor gene, such as BRCA, forms a mutation, then it is likely to be passed to future generations. This gene no longer suppresses abnormal growth, therefore there is a higher chance of cancer being developed. Even though Breast Cancer can be inherited it is more likely to be acquired through one breast cell. The acquired mutations could be a result of of radiation or cancer-causing chemicals. ...
25% of the deaths h in 1991 and is the most common cause of death
The American Cancer Society publishes current advances made in cancer research on their website. Many of the exciting discoveries about how best to treat the disease focus on the genetic aspects associated with certain types of cancer. In addition, treatments aimed at genetic solutions to cancer may be more effective and may cause fewer adverse side effects than traditional cancer treatments (American Can...
Cancer develops when cells in a part of the body begin to grow out of
Breast Cancer As defined by Majure, breast cancer is an “uncontrolled growth of abnormal breast cells” (Majure: 110). It is also one of the cancers that women fear the most. Not only do women get diagnosed with breast cancer, men do too. However, it isn't as bad, or as common, in men as it is in women, so doctors don’t recommend screening for men.
A genetic mutation is a permanent change in the sequence of the DNA that makes up a gene. A mutation of these sorts can be caused by either inheritance from the parent or caused sometime during the life of someone. The mutation that has been inherited is called a germline mutation. Germline mutations affect virtually the entire body, and they seem to be present in every cell. A somatic mutation, or one that is caused in the DNA of a single cell sometime during the life, can be caused by an environmental factor or a wrong bonding in the DNA molecule. These cannot be passed down to the next generation of children because they occur in a specific cell as opposed to in a reproductive cell. Some mutations occur in the embryo as it is growing. These may occur during cell division, and some of the cells may or may not inherit this mutation. Some mutations are extremely rare, and others are incredibly common. Those that occur in more than one percent across a population are considered polymorphisms. Polymorphisms are considered normal variations in DNA, and they are known to cause simple changes such as variations in blood types and hair color. Although these are not typically fatal, they can influence the creation of some disorders (Lister Hill National Center for Biomedical Communications, U.S. National Library of Medicine, National Institutes of Health, Department of Health and Human Services, USA.gov, 2013).
Uterine cancer is an important women health problem developing rapidly, killing over 200,000 women each year. No one has discovered the actual cause, but there is a leading factor that has great suspicions to what is causing this cancer to grow rapidly.
In addition, limited data indicate that the prevalence of specific harmful BRCA1 and BRCA2 mutations may vary among individual racial and ethnic groups in the United States, including African Americans, Hispanics, Asian Americans, and non-Hispanic white.