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Genetics: How Genes play a Role in Cancer

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Overview

Genes are a basic physical and functional unit of heredity. Genes are made up of DNA (Deoxyribonucleic acid). Some genes act as an instruction to make proteins but most genes don’t have instructions. According to research, each cells compromises of 30,000 different genes. In this article, we will discuss the role of genes in cancer. Genes are basically located on chromosomes within each cell. They have the responsibility to cell the functionality of the cell. Some responsibilities are listed below:

  • Control the growth of cell
  • Division of cell
  • The decision of life of the cell

What is Chromosomes?

A chromosome is a DNA molecule with part or all part of genetic material in an organism. they are thread-like structures in cells that contain genes. There are two sets of chromosomes, each set contains twenty-three. A human inherits one set of the chromosome from the father and one from the mother.

Chromosomes are the thread-like structures in cells that contain genes. There are 46 chromosomes, arranged in 2 sets of 23. There is one chromosome responsible for determining your gender.  The remaining chromosomes pair determine other physical characteristics. These chromosome pairs are known as autosomes.

Working of Genes

One important question that arises in the mind is “How genes working in the human body?”. Genes control the working of cells by making proteins. These proteins act as a messenger in the cell. Each gene must have the correct information for making the gene. Correct information lead to allow the protein to perform the correct function for the cells. Information can be lost or incorrect due to the damaging of genes in the proteins. One of the fatal diseases arises in the human body due to this damaging of the informational gene known as Cancer.  An abnormal protein provides different information to the protein than a normal protein. In this result, cells multiply uncontrollably and lead to be cancerous.

What is Genetic Mutation?

Gene mutation is a permanent alteration in the sequence of DNA that makes up a gene. Hence, the alteration can be different from the sequence of normal person DNA. There are two types of genetic mutations.

Acquired Mutations

The most common cause of cancer and they occur from the damage to genes in a particular cell during a human life. This could be a breast cell or a colon cell when then multiply to many times and form a tumor. Cancer that occurs due to the acquired mutation known as Sporadic Cancer.  An important thing to be noted that Acquired Mutation is not passed from parent to child and not found In every cell of the body.

Factors of Acquired Mutation

Some factors are listed below:

  • Tobacco
  • Ultraviolet radiations (UV)
  • Viruses
  • Age

Germline Mutations

This type of mutation occurs in the sperm cells or egg cells and very less common. It passes directly from a parent to a child at the time of conception. Initial sperm or egg cells to be copied into every cell in the body as the embryo grows into a baby. It can pass to the generation due to the mutation affects the reproductive cell of parents. Cancer caused by Germline Mutation is commonly known as  Inherited cancer. According to the study, it is about 5-20% of all cancers.

Mutation and its role in Cancer

Mutations often happen in the human body. It can be beneficial, harmful or no can be effortless. The action of mutation depends on where the mutation occurs in the body. Most of the time, the body corrects most of the mutation. The most important to know that the single mutation will not cause cancer according to different case studies. Most of the time, cancer occurs due to multiple mutations over a lifetime. This is the reason, most of the cancer cases found in older people. They have had more opportunities for mutations.

How Genes Responsible for Cancer?

There are broad categories of genes that contribute to cancer development. Some categories are listed below:

Tumor Suppressor Genes:

These are protective genes. In general, try to limit the growth of cells by monitoring how quickly cells divide into new cells. These genes also contribute in repairing mismatched DNA and controlling when cells die. When tumor suppressor genes mutate, cell growth becomes uncontrollable. As a result, tumors produce in the body. Tumor Suppressor genes include BRCA1, BRCA2, and TP53. These genes are also called DNA Repair Genes.

Germline mutations in BRCA1 or BRCA2 genes increase a risk of developing Heredity Breast or Ovarian Cancers in women. In men, a mutation in these genes can be responsible for Heredity prostate or Breast Cancer. The most commonly mutated gene in reported cancer patients is TP53. More than 50% of cases involve missing or damaged TP53 gene. The mutation in this gene is rare but can be the cause of developing high risk of developing many different types of cancer.

Oncogenes:

These turn a healthy cell into a cancerous cell. Mutations in these genes are not known to be inherited. Two common oncogenes are:

  • HER2, a specialized protein that controls cancer growth and spread. It is found in some cancer cells like breast and ovarian cancer cells.
  • The RAS family of genes, which makes proteins involved in cell communication pathways, cell growth, and cell death.

 

Challenges in Understanding Cancer Genetics

We have already discussed about the working of genes and how cancer gene evolve but according to the researchers, many types of cancers are not directly link with specific gene. Cancer may involve multiple gene mutation. Genes also interact with the environment according to the latest research and it make more complicated to understand the role of genes in Cancer. Due to research on how the changes in genes can affect cancer development, there is a lot of improvement in the care of cancer, early detection of cancer, risk deduction, the use of targeted therapy and the survival rate of cancer patients. Moreover, study on the role genes changes in the development of cancer help doctors to find better ways to:

  • Predict the risk of cancer in a person
  • Cancer diagnosing
  • Treatment of cancer

 

How Genes Play their Role in Hereditary Cancer Syndromes?

About 5-10 percent of all cancer due to the inherited gene mutation. According to latest research, more than 50 hereditary cancer syndromes is the cause of specific gene mutation. Gene mutation responsible for the disorders in cells and predispose individual to developing certain cancers in the body. A test named “Genetic tests for hereditary cancer syndromes” helps the doctors to identify,

Whether a person of a family have syndrome that cause the gene mutation. This test also shows whether family members without obvious disease have inherited the same mutation as a family member who carries a cancer-associated mutation.

Many types of genes that can play a role in hereditary cancer syndromes. Some mutated genes are listed below:

  • One of the most common mutated gene in all cancer is TP53, that suppressed the tumors growth due to the production of its protein.
  • Inherited mutations in the BRCA1and BRCA2 genes are associated with hereditary breast and ovarian cancer syndrome.
  • PTEN is another gene that produce protein, assist in the suppression of tumor growth. Mutation in this gene, results Cowden Syndrome, an inherited disorder that increase the risk of breast, thyroid, endometrial, and other types of cancer.

 

For more genes that can play a role in hereditary cancer syndromes, see Genetic Testing for Inherited Cancer Susceptibility Syndromes.

 

 

 

 

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