The center cluster of cells, colored blue, shows a colony of human embryonic stem cells. These cells, which arise at the earliest stages of development, are capable of differentiating into any of the 220 types of cells in the human body
Image Credit: Clay Glennon, University of Wisconsin-Madison
Most adult cells can replicate or divide a specific number of times before they die. Current thinking is that telomeres within the cell's nucleus keep count of the number of divisions and are ultimately responsible for the cell's death. But cells apparently have overriding mechanisms for controlling the replication of cells.
Stem cells are different. They have the ability to keep producing new cells. Embryonic or induced pluripotent cells are called undifferentiated cells because with the right stimulus, they can develop into any type of cell. Adult stem cells are generally more specialized - a muscle stem cell can only produce muscle cells, not neurons. But adult stem cells are very important to the body, because that is how the body refreshes it organs and tissue.
Researchers have long known there is a link between cancer and unregulated division. When the telomeres are prevented from counting, the cell frequently initiates a tumor. Researchers Attack Stem Cells That Cause Colon Cancer explains that only a few cells within a tumor are only capable of forming the tumor. Also, traditional cancer treatments such as chemotherapy kill tumor cells successfully, but not the cancer stem cells. This probably explains cancer recurrence and researchers are attempting to discover ways to kill the cancer stem cells.
The Medical News Today article explains it is difficult to kill only the cancer stem cells and not the necessary adult stem cells in a treatment. For colon cancer, they have identified an insulin-like growth factor receptor (IGF-1R) that distinguishes between adult stem cells and cancerous stem cells.
More generally, Embryonic stem cells reveal oncogene's secret growth formula tells that researchers have discovered a gene expression, c-Myc, that is related to the transcription, or replication of the cell's DNA. A normal cell has some enzyme processes that will halt or pause the transcription process. c-Myc somehow overrides the pause, and enables transcription, and ultimately, cell division. Researchers are now attempting to discover drugs that can regulate c-Myc and thus prevent cells from producing tumors.
Sheesh - I know from the number of hits searching on older blogs about the Gulf oil fields, that many are interested in how the government is attempting to control the oil spill. The Department of the Interior has a website, Gulf of Mexico - Transocean Drilling Incident. The graphic on the left shows the current location of the sheen. See the website for additional information and resources.
Deepwater Update tells that on the 28th, the unified command initiated a successful burn of the petroleum on top of the surface and other burns would be considered.
We are where we are. It is not President Obama's fault, nor Secretary Chu's fault that we need to drill in the Gulf of Mexico. Accidents are going to happen. We need to responsively clean up this mess, and attempt to send 'clear signals' to consumers and industry that the U.S. needs alternative energy.