Mutations and Cancer in Australia - Report Example

Summary

The process of DNA replication involves the use of various enzymes to split the strands, bind primers elongate the new strands and add telomeres. The process can lead to mistakes that DNA repair system should eliminate. However, some defects during the DNA replication process may remain uncorrected leading to a gene mutation. These gene mutations in the cells are responsible for the formation of the tumours. However, not all mutations can lead to the development of cancer cells. In most cases, tumours develop after mutation of the tumour suppressor genes and proto-oncogenes. Both the tumour suppressor genes and proto-oncogenes play significant roles in the regulation of cell division and apoptosis. Therefore, alteration in the functions of proteins from these genes can cause increased cell division and development of tumours. The treatments for various types of cancer aim at eliminating cancer cells. Nonetheless, new types of treatments are increasing specificity and efficiency to eliminate cancer cells while leaving normal cells.

Cases of newly diagnosed cancer in Australia have been on the rise since 1982. Some of the possible reasons for such increase in diagnosis cases are due to new technologies and interventions to detect cancer early. Men and women in Australia show the varying risk of diagnosis with different types of cancers. Women show great risks of being diagnosed with breast cancer. However, men in Australia have great diagnosis risk of prostate cancer. Nonetheless, there are types of cancer that great prevalence in both men and women. Age also seems to play a role in the variation in newly diagnosed cancer cases. The number of people diagnosed with cancer seems to rise with ages of people. Australian societies need to take preventive actions such as change of lifestyles and elimination of carcinogens to minimise cancer cases.

Mutations and Cancer in Australia

Cancer results from uncontrolled growth of cells leading to the development of tumours. Mutation refers to an alteration in the DNA that may or may not affect the functions of the cells. The cell growth and apoptosis are regulated by some proteins produced in the cells. Mutations affecting one of these proteins could cause loss of cell growth regulations that can cause tumours. Development of new treatments focus increasing specificity and eliminate cancer cells. Most of these treatments aim at acting at the molecular level to treat various types of cancer.

DNA Replication

During cell division, the helical doubled stranded DNA has to replicate to maintain the genetic makeup of all cells. The replication process starts with the fork formation that separates the double strands of DNA. DNA helicase is the enzyme responsible for unzipping of DNA double strands leading to the formation of leading and lagging strands. The next step in the process is binding of the primers that are short pieces of RNA generated by the enzyme DNA primase. The DNA polymerases carry out the elongation process (Craig, Cohen-Fix, Green, Greider, Storz & Wolberger, 2014, 203). Elongating of the leading strand is continuous while that of lagging strand requires binding of multiple primers forming Okazaki fragments.

After complete formation of the new DNA strands, exonucleases removes the RNA primers that are replaced with appropriate bases. The exonuclease enzyme is also responsible for proofreading the strands and eliminating any error (Kelley, 2012, 82). DNA ligase enzyme carries out the process of joining the Okazaki fragments and the telomerase adds the telomere sequences at the ends of DNA strands.

Defects in Replication Process

The process of DNA replication often leads to some errors in the sequence of the DNA strands. The defects in replication process are the initial step in the development of cancer (Gauthier, Herrick and Bechhoefer, 2010, 1). Normal cells have mechanisms using the exonucleases enzymes to repair the DNA sequence. However, there are cases where the replication process results in an alteration in DNA sequence that persists. If the changes affect genes regulating cells growth and division, then it can result in the development of tumours.

Differences between Normal Cells and Cancer Cells

The cancer cells divide rapidly and do not go through differentiation process. However, the normal cells divide at a slower rate and differentiate to carry out specific functions in the body. In some cases, the cancer cells lose the molecules that make them stick together. Therefore, the cancer cells can easily relocate from one point to another. However, the normal cells stick together with the help of adhesive molecules. The cancer cells also lose their ability to repair genes and die. One of the genes for repairing damages in the cells that are often damaged in cells is p53 gene. Apoptosis process in normal cells ensures that cells do not accumulate to levels that lead tumours. Moreover, normal can repair their DNA. The appearance of the cancer cells also differs from the normal cells when viewed under a microscope. The cancer cells are either larger or smaller than normal cells. Besides, the cancer cells show abnormal shapes.

Various Causes of Cancer

One of the causes of cancers is a mutation of the tumour suppressor genes. Mutation of tumour suppressor genes such as p53 gene results in deregulation of cell division, apoptosis and repair of the DNA. Thus, such mutation cause increased the rate of cell division that results in the formation of tumours. The presence of oncogenes in cells also cause cancer. Oncogenes form from mutations of proto-oncogenes and presence of many copies of proto-oncogenes. The presence of oncogenes causes cancer through increasing cell division and formation of tumours. Most mutations causing cancers involving actions of oncogenes are acquired. However, there are few cases where the cancer patients inherit mutations of the proto-oncogenes. Human epidermal growth factor receptor 2 (HER2) is one of the oncogenes that play a significant role in the regulation of cell growth, their survival and differentiation through various pathways (Iqbal and Iqbal, 2014, 1). Overexpression of HER2 is common in the breast and ovarian cancer cells (Lea, Cheek, Brazeau & Brazeau, 2015, 1).

Cancer can also result from mutation of the DNA repair gene can also result in cancer. Cells have mechanisms to ensure that damages to the DNA do not have adverse impacts on the body. However, there are cases where DNA of cells are not repaired and accumulation of these damages can cause cancer (Lahtz and Pfeifer, 2011, 51). Damage to the DNA repairing gene will lead to an ineffective system of repairing damaged DNA in the cells. Defective DNA repair system leaves the mistakes made during DNA replications.

Treatments

Treatments for cancer often use surgery, radiotherapy and chemotherapy to eliminate cancer cells (Kirita & Omura, 2015, 334). The latest treatments of cancer aim at eliminating cancerous cells from the body while leaving normal cells without any damage. One of the treatment for cancer is CAR-T cell immunotherapy. This kind of treatment focuses on the T cells in the body of patients and make them able to attack the cancer cells. The use of CAR-T cell immunotherapy is common in the treatment of haematological malignancies (Alonso-Camino, Harwood, Álvarez-Méndez and Alvarez-Vallina, 2016, 406). These new treatments are focusing on enhancing specificity.

Commonly Diagnosed Cancers in Australia

Australian statistics show that there is an increasing number of cancer cases since 1982. New cancer cases among males in Australia has shown fluctuation. The changes in cases of cancer among males greatly depends on prostate cancer from PSA testing. The statistics show that cancer cases among women have been on the steady rise. The changes in cases of female cancer significantly depend on the incidence rate of breast cancer. Development of new screening technologies, initiation of BreastScreen Australia (Bech, 2012, 8) and enhanced awareness about breast cancer are purported to be the cause of increased diagnosed cases of cancer among women.

Therefore, the most commonly diagnosed cancer in Australia is breast cancer (Australian Institute of Health and Welfare, 2017, 20). Colorectal, prostate, melanoma of the skin and lung cancers also contribute to large percentages of cancer diagnosis in Australia. Classification of cancer cases according to gender further shows how types of cancer affect males and females. Among men in Australia, prostate cancer is the most common with an estimated risk of diagnosis is one in seven before the age of 85 years. Among males, colorectal cancer shows diagnosis risk of one in eleven. Other types of cancers that are common among men in Australia include melanoma of the skin, lung cancer and head and neck cancers. Statistics on females in Australia show that breast cancer is the most common with one in eight risks of diagnosis. Other types of cancers common among women in Australia include colorectal cancer, melanoma of the skin, lung cancer and uterine cancer.

Cancer cases in Australia also seem to depend on the age of people in the society. The trend shows that cases of cancer diagnosis increase with age. Individuals between the age of zero and twenty-four years have the lowest rate of cancer diagnosis cases. Consequently, the data shows that individuals above the age of 65 years have the highest cancer cases. It is also worth noting that thyroid cancer has shown the greatest percentage increase.

The table 1 blow show the impact on age on newly diagnosed cancer cases

Age (Years)

Newly Diagnosed Cancer Cases Estimate In 2017 In Australia

0-24

1630

25-49

15989

50-64

37867

Over 65

78688

One of the possible reasons for the rise in cancer cases is foods that people consume. Most of the processed foods lead to the development of cancer through various pathways. Diet and nutrition can explain about 30% of colorectal cancer incidents (Vargas and Thompson, 2012, 613). Therefore, prevention of cancer should promote consumption of organic foods. Moreover, early diagnosis of cancer cases like prostate cancer plays a significant role in reducing cases of fatalities (Feletto, Bang, Cole-Clark, Chalasani, Rasiah and Smith, 2015, 1678). Therefore, promoting a change of lifestyle can play a crucial role in the prevention of cancer in Australia. There is also need to eliminate all carcinogens such as asbestos from the environment in Australia.

In conclusion, Cancer mostly originates from acquired mutations of the DNA. Carcinogens are the primary cause of DNA damages that lead to the development of cancer. Cases of cancer have been on the rise in Australia with breast cancer common in women and prostate cancer frequently diagnosed in men. Other types of cancers such as melanoma of the skin, lung cancer, and colorectal cancer are common in both men and women. Therefore, prevention strategies should consider eliminating origin of elements leading to the development of cancer.