Contributor: Camilla Czulada
Cancer is contagious……. THAT IS JUST WRONG!
Cancer is not contagious! Cancer is a disease that begins at a cellular level due to an overgrowth of cells. It begins with just one single cell! Naturally, cells in our body divide and multiply. This process of cell division called Mitosis is usually regulated by a series of stop and go signals. We have oncogenes, which promote cell growth, and tumor suppressor genes, which code for proteins that check cells through the process of mitosis for errors and stop cell growth. In a normal body, these two genes work together to create a balance. As cells die, new cells are created proportionally. Tumor Suppressor Genes, stop pairing mistakes and tell the body to slow down when something isn’t right, such as a mutation. However mutagens, which are physical or chemical influences from heredity and the environment, can cause mutations to occur at the level of the DNA. In a normal DNA sequence, Adenine and Thymine pair up and Cytosine and Guanine pair up to create a double helix structure. When a mutation, or change to the normal DNA sequence of A&T pairs and C&G occurs, this process can get “out of whack.” A mutagen can cause an extra base to be inserted or removed, which throws off the entire process causing a frame shift in the structure. Oncogenes get stuck in the “on” position and cells begin to multiply at a faster rate than they die. This overgrowth of cells creates a tumor.
But unfortunately it doesn’t end there! Cancer cells can spread throughout the body by a process called metastasis. Cancer cells are abnormal cells. The cell itself and the nucleus have an irregular shape; they’re dark in color and contain less cytoplasm. More importantly, cancer cells do not stick to each other like normal cells do. This free movement allows metastasis to occur. During this process, cells are carried through the bloodstream or the lymphatic system to other areas of the body. Cells can either be stopped in the bloodstream or in the lymph nodes. Once they are stopped they are either killed off or begin to form another tumor. Cells that do not stop cling onto other areas and begin to multiply in this secondary location, creating even more tumors!
You may be wondering- If cancer isn’t contagious then how do these mutations come about? Mutations occur in everyone’s bodies, and they occur fairly frequently! Certain factors, which we will talk about later, cause cells to divide so quickly that the mutations cannot be fixed as they usually are by the tumor suppressor genes. So, if in the DNA sequence A pairs with C instead of T and the cells are dividing too quickly, the tumor suppressor genes can’t say STOP something isn’t right here. The oncogenes take over and continue to duplicate these mutated cells. Once there are many irregular cancer cells together a tumor is formed. The tumor eventually gets too big the tumor suppressor genes become totally dysfunctional.
But you don’t ‘catch’ a mutation by shaking someone’s hand or drinking out of a friend’s cup. Mutations are caused by either heredity or carcinogens. Sometimes people are simply born with genes that are more likely to have mutations, or one can be born with a mutated gene such as the BRCA1 gene. When our coding-DNA is producing proteins, a mutation in BRCA1 & 2 genes, which produce tumor suppressor proteins, does not allow our body to produce correct proteins, or does not produce them at all. Since proteins have a major influence on cell division, a mutation of these genes is responsible for up to 25% of hereditary breast cancer. Mutations can also be caused by environmental factors called carcinogens. Carcinogens are things like tobacco, UV rays and coal, which cause an increased rate of cell division, which allows changes in DNA to occur over time. One example is a mutation of the p53 gene, the most common, acquired cancer-causing mutation. The P53 gene, located on chromosome number 17, is a tumor suppressor gene. So, when this gene is mutated there is nothing to stop cell division. Acquired mutations from carcinogens cause frame-shifts like we talked about above. For example, too much exposure to sunlight can cause Thymine and Cytosine to break away from the double helix structure, causing a lesion
One reason for this misconception could be that certain infectious organisms have been proven to cause cancer. For example, a virus such as the Human Papilloma Virus, which is contagious, has been shown to have caused virtually all cases of cervical cancer. Viruses, which are typically taken care of by the immune system, sometimes live in the body for years and eventually their presence causes a mutation of cells.
So, even though viruses, and bacteria, which can lead to cancer, are contagious cancer itself is not contagious. It is not necessary to take measures to protect yourself from a person who has cancer!