Cancer is a disease that affects people of all nationalities and age groups and all cancers start with mutations in one cell.
Cancer is a disease that affects people of all nationalities and age groups. There are many different types of cancers affecting different parts of the body. A cancer, or tumor, can occur in any organ or tissue of the human body. Solid tumors form lumps, while liquid tumors flow freely in the blood. (Labels identify location of: brain cancer, lung cancer, liver cancer, stomach cancer, skin cancer, prostate cancer, breast cancer and ovarian cancer.) All cancers start with mutations in one cell. The mutations are in the cell's DNA and may be inherited. Less than 10% of all cancer mutations are inherited. Usually, the mutation arises as a result of environmental factors. The DNA mutation may be a single nucleotide change as shown below, or a deletion or duplication of DNA sequence. A change in the genetic sequence can then lead to the production of a mutant protein. Although in rare cases one mutation is enough, it is usually an accumulation of mutations that irreversibly transforms a normal cell into a cancerous one. As we age, we accumulate more and more mutations; this explains why cancer incidence increases with age. These mutations can disrupt the cell's life cycle of growth, proliferation, and death. This leads to the accumulation of more "rogue" cancer cells and the development of a tumor mass. In 2000, Douglas Hanahan (shown below) and Robert Weinberg published a paper in Cell, "The Hallmarks of Cancer," which identified some organizing principles of cancer cell development. "We believe that cancer acquires capabilities and that these capabilities are all, to some approximation, necessary to produce a successful tumor. And these may not be a complete description of a tumor but they, probably just in the same way as you describe a car as having a motor and some wheels and tires and a gas tank and some brakes you haven't completely described the car, but you've described a lot of the capabilities that allow it to do what it does. So I think the same issue here is that tumors have a set, a minimal set, of capabilities, that we think are necessary, and so we call these the hallmarks of cancer."
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- ID: 935
- Source: DNALC.IC
Conventional cancer drugs are cellular poisons that block replication or some other aspect of cell growth. These drugs affect all cells – healthy or cancerous.
Professor Robert Weinberg discusses how cancer cells have to learn how to avoid the process of programmed cell death known as apoptosis carried out in normal cells.
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Matt Ridley talks about chromosome 13, BRCA2 gene for breast cancer susceptibility.
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Mary-Claire King speaks about how much was yet to be understood about the genetic mechanisms of cancer when she began her hunt for genes associated with breast cancer.
This section explains that lung cancer is the leading cause of cancer deaths in the United States and it is almost entirely preventable, since the vast majority of cases are due to cigarette smoking.
Familial colon cancer was long thought to be inherited; however a complete understanding of its causes awaited the discovery that specific genetic mutations confer a large increase in susceptibility to these types of cancers.
In this section, hear what experts have to say about drugs that disrupt the function of receptors on a cell's surface.
This section identifies that a cancer gene alters the normal functioning of a protein, and there are three major categories of cancer genes.