Name the group of genes that have been identified and normal cells that could lead to cancer. How do these genes cause cancer?

Dear student,
The group of genes that have been identified in which the normal cells act as cancerous cells are called as proto-oncogenes. These genes cause cancer when a mutation occurs in these genes. A dominant type of mutation occurs in the proto-oncogene which is called as the oncogene. These oncogenes than produce a protein in large quantities that lead to increase in cell division and a decrease in the differentiation in cell and inhibit and stop the process of the cell death. All these lead to the production of the cancer cells. These mutations in the normal functioning of the gene can be caused by the exposure of the cells to the carcinogenic compounds or substances like tobacco smoke, ultraviolet rays or can be inherited from parents.
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Cancer is a genetic disease—that is, cancer is caused by certain changes to genes that control the way our cells function, especially how they grow and divide. Genes carry the instructions to make proteins, which do much of the work in our cells. Certain gene changes can cause cells to evade normal growth controls and become cancer. For example, some cancer-causing gene changes increase production of a protein that makes cells grow. Others result in the production of a misshapen, and therefore nonfunctional, form of a protein that normally repairs cellular damage. Genetic changes that promote cancer can be inherited from our parents if the changes are present in germ cells, which are the reproductive cells of the body (eggs and sperm). Such changes, called germline changes, are found in every cell of the offspring. Cancer-causing genetic changes can also be acquired during one’s lifetime, as the result of errors that occur as cells divide or from exposure to carcinogenic substances that damage DNA, such as certain chemicals in tobacco smoke, and radiation, such as ultraviolet rays from the sun. Genetic changes that occur after conception are called somatic (or acquired) changes. There are many different kinds of DNA changes. Some changes affect just one unit of DNA, called a nucleotide. One nucleotide may be replaced by another, or it may be missing entirely. Other changes involve larger stretches of DNA and may include rearrangements, deletions, or duplications of long stretches of DNA. Sometimes the changes are not in the actual sequence of DNA. For example, the addition or removal of chemical marks, called epigenetic modifications, on DNA can influence whether the gene is “expressed”—that is, whether and how much messenger RNA is produced. (Messenger RNA in turn is translated to produce the proteins encoded by the DNA.) In general, cancer cells have more genetic changes than normal cells. But each person’s cancer has a unique combination of genetic alterations. Some of these changes may be the result of cancer, rather than the cause. As the cancer continues to grow, additional changes will occur. Even within the same tumor, cancer cells may have different genetic changes.