Sejtfüggség

Sejtfüggőség, often translated as cell dependency or cellular dependence, refers to a phenomenon in cell biology where a cell's survival or proliferation is reliant on specific external signals or conditions. This dependency can manifest in various ways, but it fundamentally means that without the sustaining factor, the cell will undergo programmed cell death (apoptosis) or cease to divide.

One common form of sejtfüggőség is anchorage dependence. Most normal mammalian cells require a solid surface to adhere to before they can divide. This attachment to the extracellular matrix or other cells provides crucial signals that promote survival and cell cycle progression. Cancer cells, in contrast, often lose this anchorage dependence, a characteristic that contributes to their ability to metastasize.

Another significant aspect is growth factor dependence. Many cells require specific growth factors, which are signaling proteins, to stimulate their division and survival. These factors bind to receptors on the cell surface, triggering intracellular pathways that promote cell proliferation and inhibit apoptosis. Without these growth factors, the cells undergo programmed cell death.

Sejtfüggőség plays a critical role in normal tissue development and maintenance, ensuring that cells only survive and divide when and where they are needed. It also serves as a crucial mechanism for preventing uncontrolled cell growth. The loss or alteration of sejtfüggőség is a hallmark of many diseases, particularly cancer, where cells acquire the ability to bypass these regulatory mechanisms and grow independently of external cues. Understanding sejtfüggőség is therefore vital for developing targeted therapies for various diseases.