Metasizing Cancer Cells Essay -- Biology

The human body encompasses some thirty trillion cells. The cells which comprise normal, healthy tissues in the body live in an interdependent relationship with surrounding cells. These tissues are intricately arranged into a marvelous array of cell to cell adhesions and extracellular matrixes. Healthy cells reproduce in a coordinated manner which insures that a particular body tissue maintains its appropriate size, form, and function. Cells which have lost the ability to reproduce in a controlled fashion are termed cancerous cells. Cancer cells proliferate uncontrollably forming tumors causing disruption in the normal form and function of body tissues. The most dangerous of the cancer cells are those that can metastasize, which is the ability of the cell to migrate from the original or primary tumor site to a distant site where they establish secondary tumors. This is what makes metastasizing cancer cells so lethal and distinguishes a malignant cancer from a non-malignant cancer. Migrating Cancer Cell in vitro In order to accomplish such a migration, the malignant cells need to proceed through a series of steps which include: 1. detachment from the primary tumor mass 2. degradation of the basement membrane 3. migration to and invasion of a nearby blood or lymphatic vessel 4. survival within the blood or lymph system 5. attachment to the wall of the vessel at some distant site 6. penetration of the vessel wall and exiting of the vessel 7. migration to a site where a secondary tumor is established. The Role of Anchorage Dependence in Metastasis The mechanisms involved in the survival of a cell detached from the extracellular matrix are of great interest. Normal cells are anchorage dependent and... ...f mitastasis. This is primarily due the circulatory system's architecture. After cancer cells from the skin or other tissues find their way to the blood stream, they migrate downstream to the first capillary bed. For most organs, the lungs contain the first capillary bed downstream which enables the cancer to lodge in small blood vessels proliferate there. Prostate Cancer and its Effects Prostate Cancer often spreads to the bones. But unlike melanoma which becomes physically traped in the blood vessels, prostate cancer also seeks out a definitive adhesion molecule located on the stromal cell of the bone. The prostate cancer has a receptor which only recognizes this molecule, so will only adhere to this particular one. Colorectal Cancer and its Effects Colorectal cancer typically metastasize to the liver due to the intestines sending their blood here first.