Kontaktinhibisjon

Kontaktinhibisjon, also known as contact inhibition or anchorage dependence, is a cellular phenomenon observed in animal cells. It refers to the cessation of cell division when a cell encounters another cell, effectively preventing overcrowding. This process is mediated by cell-to-cell contact, which triggers intracellular signaling pathways that inhibit proliferation. When cells are plated at a low density, they divide freely. However, as they grow and divide, they eventually come into contact with neighboring cells. This contact initiates a signal that causes the cells to stop dividing, forming a confluent monolayer. This mechanism is crucial for normal tissue development and maintenance, ensuring that tissues do not grow uncontrollably.

The molecular mechanisms underlying kontaktinhibisjon involve various cell surface proteins and adhesion molecules. Cadherins, for example, play a significant role in cell-cell adhesion and signaling. Upon contact, these molecules can activate signaling cascades, such as those involving protein kinases and phosphatases, ultimately leading to the arrest of the cell cycle. This regulated cell growth is a hallmark of healthy tissues.

Disruption of kontaktinhibisjon is a key characteristic of cancer cells. Cancer cells often lose their ability to respond to contact inhibition signals, allowing them to proliferate uncontrollably and form tumors. This loss of normal growth regulation contributes to the invasive and metastatic nature of many cancers. Research into the mechanisms of kontaktinhibisjon has provided valuable insights into understanding and potentially treating cancer.