Spring Break
Cancerous tissue derived from a single cell
Issue date: 4/30/09
Recently, researchers at the Hopkins Kimmel Cancer Center have discovered that prostate cancers that have spread to other parts of the body all come from a single cancer cell in the prostate.
Cancer is caused by mutations in an individual's DNA, and these mutations come in many varieties, such as deletions or additions of DNA bases. Cancer-causing mutations can also take the form of "copy number changes," where the individual has more or less than the normal two copies of each gene. Cells with copy number variations have the potential to grow and divide uncontrollably, cancer's trademark.
If cancerous tissue is left unchecked, it has the tendency to spread to other parts of the body in a process known as metastasis. Cancer cells from the original cancer site break off, travel through the bloodstream and arrive in new areas in the body where they take root, forming new cancerous sites.
The Hopkins researchers took samples from 94 different cancerous sites in 30 men who had died of metastatic prostate cancer. This study took place over the span of 14 years, as researchers dissected every single piece of cancerous tissue and analyzed it, in both the original site in the prostate and the metastatic sites, totaling around 30,000 blocks of tissue.
Researchers compared the DNA of metastatic cells to that of the original cancerous cells, looking for differences in copy number and individual nucleotides.
The metastatic cells had a shared pattern of copy number defects, meaning that all of the tissue samples had the same variations from the normal two copies of each gene. From this, the researchers were able to conclude that most, if not all, of the metastatic cancer cells are clones of a single cell in the prostate.
When the copy number variations were compared between different subjects, they found that there were many common gains and losses in several parts of their genomes. Although the exact region in which DNA was gained or lost varied between individuals, all of these variations were found in the same general region.
Scientists hope to use these findings to be able to eventually determine the specific genomic features of primary cancer cells that have already proven to be lethal.
A database of the various genetic features of cancer cells in different individuals and groups could potentially allow physicians to tailor cancer treatments specifically to each patient, based on the genetic signatures and diversity of their cancer cells.
Although the single-cell origins are not the only contributing factor to metastatic cancers, additional research in this field may eventually lead to a more effective targeting mechanism for treating existing cancerous tumors.
Cancer is caused by mutations in an individual's DNA, and these mutations come in many varieties, such as deletions or additions of DNA bases. Cancer-causing mutations can also take the form of "copy number changes," where the individual has more or less than the normal two copies of each gene. Cells with copy number variations have the potential to grow and divide uncontrollably, cancer's trademark.
If cancerous tissue is left unchecked, it has the tendency to spread to other parts of the body in a process known as metastasis. Cancer cells from the original cancer site break off, travel through the bloodstream and arrive in new areas in the body where they take root, forming new cancerous sites.
The Hopkins researchers took samples from 94 different cancerous sites in 30 men who had died of metastatic prostate cancer. This study took place over the span of 14 years, as researchers dissected every single piece of cancerous tissue and analyzed it, in both the original site in the prostate and the metastatic sites, totaling around 30,000 blocks of tissue.
Researchers compared the DNA of metastatic cells to that of the original cancerous cells, looking for differences in copy number and individual nucleotides.
The metastatic cells had a shared pattern of copy number defects, meaning that all of the tissue samples had the same variations from the normal two copies of each gene. From this, the researchers were able to conclude that most, if not all, of the metastatic cancer cells are clones of a single cell in the prostate.
When the copy number variations were compared between different subjects, they found that there were many common gains and losses in several parts of their genomes. Although the exact region in which DNA was gained or lost varied between individuals, all of these variations were found in the same general region.
Scientists hope to use these findings to be able to eventually determine the specific genomic features of primary cancer cells that have already proven to be lethal.
A database of the various genetic features of cancer cells in different individuals and groups could potentially allow physicians to tailor cancer treatments specifically to each patient, based on the genetic signatures and diversity of their cancer cells.
Although the single-cell origins are not the only contributing factor to metastatic cancers, additional research in this field may eventually lead to a more effective targeting mechanism for treating existing cancerous tumors.
Be the first to comment on this story