Cancer cells are cells gone wrong, in other words, they no longer respond to many of the signals that control cellular growth and death as described in the Krebs Cycle. Cancer cells originate within tissues and, as they grow and divide, they change even further from normalcy.
Over time, these cells become increasingly resistant to the controls that maintain normal tissue and as a result, they divide more rapidly than their progenitors and become less dependent on signals from other cells. Cancer cells even evade programmed cell death, despite the fact that their multiple abnormalities would normally make them prime targets for apoptosis. In the late stages of cancer, cells break through normal tissue boundaries and metastasize (spread) to new sites in the body.
The Cancer Stem Cell
Invasive cancer cells often secrete proteases that enable them to degrade the extracellular matrix at a tissue’s boundary. Proteases also give cancer cells the ability to create new passageways in tissues. For example, they can break down the junctions that join cells together, thereby gaining access to new territories, travel.
A Traveling Cancer Stem Cell – Metastasis
Metastasis means “new place” it is one considered one of the terminal stages of cancer. Abstract Metastases, rather than primary tumors, are responsible for most cancer deaths. In this stage, cancerous cells enter the bloodstream or the lymphatic system and travel to a new location(s) in the body, where they begin to feed and divide laying the foundation for secondary tumors. Not all cancer cells can metastasize. In order to spread in this way, the cells must have the ability to penetrate the normal barriers of the body so that they can both enter and exit the blood or lymph vessels, this is typically referred to as cancer stem cells.
Two University of Iowa studies offer key insights on how and why tumors form by recording in real time, and in 3-D, the movements of cancerous human breast tissue cells.
Cancer is unchecked cell growth, it has the will to live. Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls in the body, such as cell cycle arrest or programmed cell death. As a mass of cancerous cells grow, it can develop into a tumor. Cancer cells can also invade neighboring tissues and sometimes even break off and travel to other parts of the body, leading to the formation of new tumors at those sites. To prevent these deaths, improved ways to treat metastatic disease are needed, in other words killing the cancer stem cells is more important then the tumor itself.