Oncogene Definition, History, and Mechanism of Activation – Cancer is one of the leading causes of death in the world. The incidence of cancer increases with age, so the longer a person’s life is the greater the chances of developing cancer. Cancer cells are autonomously transformed and growing body cells characterized by three characteristics, namely unlimited growth control, invasion of local tissues, and spread or metastasis to other parts of the body. Benign tumor cells also show a decrease in growth control, but do not invade or spread to other parts of the body.
In our body there are genes that have the potential to trigger cancer, which is called proto-oncogene. For some reason, for example, because of foods that are carcinogens (carcinogens that can cause cancer), pollution, or exposure to certain chemicals, or because of radiation, these proto-oncogenes can turn into oncogenes, which are cancer-triggering genes.
The Meaning of Oncogene
Oncogene is a cancer-causing gene.
What is Oncogene?
So, what exactly is the meaning of this word?
That’s right, as we’ve explained a little bit about the understanding above, this is a cancer-causing gene.
Oncogene Definition
Oncogene is an abnormal gene that is formed due to its mutation in proto-oncogene. Oncogene works to activate proteins. Increased oncogene is a pathology that causes the activation of proteins, especially proteins that play a role in cell division or cell cycles so that the oncogene causes malignant degeneration.
Oncogene is a modified gene that increases tumor cell malignancy. Oncogenes generally play a role in the early stages of tumor formation. Oncogenes increase the likelihood of normal cells becoming tumor cells, which can eventually lead to cancer. A study shows that carrying a short RNA (small RNA) along 21-25 nucleotide known as micro RNA (miRNA) can control oncogenes.
Oncogene is a mutant version of the normal gene, which triggers cell growth. Genes in normal cells that can turn into active oncogenes due to mutations, called proto-oncogenes. Mutations are able to convert proto-oncogene into active oncogenes.
The difference between oncogenes and normal genes is sometimes invisible. The mutant protein from which oncogene comes from can differ only by one single amino acid from a healthy version. So with just one single change, it has been able to change the function of proteins. When proto-oncogene has mutations (point mutations, translocations, amplifications, insertions or deletions) into oncogenes, then the physiological mechanism of the normal cell division process will be impaired and lead to gene lesions. This change will occur neoplastic cell division process.
Oncogene History
Oncogene was first discovered by Francis Peyton Rous in 1910 while observing tumors in poultry that could be transmitted to other creatures because they had sarcoma cells containing retroviruses, which were later called RSV.
In 1976 Dr. John Michael Bishop and Dr. Harold E. Varmus of the University of California, San Francisco proved that oncogenes are derived from damaged proto-oncogenes. Proto-oncogene has been found in many organisms, including humans. Since this important discovery, Dr. Bishop and Dr. Varmus was awarded the Nobel Prize in 1989.
Mechanism of activation of oncogenes
Proto-oncogene mutates into a gene referred to as an oncogene. Mutations can occur due to viral infections, radiation exposure, contamination of carcinogenic chemicals, either directly, or indirectly. Mutations that occur can be dot mutations, translocations, insertions, deletions, or amplifications. Cells that undergo mutations will be attempted to be repaired by various mechanisms and ways of correcting DNA mutations.
The protein produced by proto-oncogene is called wild type protein, while the protein produced by oncogene is called oncoprotein. Proto-oncogenes are polypeptides, oligopeptides, or steroid hormones. Proto-oncogene will be related to these receptors and bonds produce a transduction signal.
Oncogene is a gene that, when mutated or expressed at high levels, helps turn normal cells into tumor cells. Many abnormal cells usually undergo a programmatic form of death (apoptosis). Activated oncogenes can cause cells to survive and multiply instead. The oncogene most require additional steps, such as mutations in other genes, or environmental factors, such as viral infections, causing cancer.
Source:
- Image: Asw029, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons
- Video; Oncology for Medical Students
