What are characteristic of cancer cells?
Cancer cells are characterized by a number of distinctive features, including:
- Uncontrolled growth and proliferation: Cancer cells divide and multiply rapidly and uncontrollably, forming tumors. This growth is not regulated by normal cell cycle controls, and cancer cells can continue to divide even when there is no need for new cells.
- Invasion and metastasis: Cancer cells have the ability to invade and spread to other parts of the body, a process known as metastasis. This occurs when cancer cells break away from the primary tumor and enter the bloodstream or lymphatic system, traveling to other organs and tissues where they can form new tumors.
- Angiogenesis: Cancer cells promote the formation of new blood vessels, a process called angiogenesis, which provides the tumor with oxygen and nutrients necessary for its growth and survival.
- Reprogrammed metabolism: Cancer cells exhibit altered metabolism, often relying on glycolysis (fermentation of glucose) for energy production, even in the presence of oxygen. This metabolic shift is known as the Warburg effect.
- Evasion of apoptosis: Apoptosis, also known as programmed cell death, is a normal process by which cells that are damaged or no longer needed are eliminated from the body. Cancer cells, however, often develop mechanisms to evade apoptosis and continue to survive.
- Genomic instability and mutations: Cancer cells often have genetic alterations and mutations in various genes, which can lead to the dysregulation of cell cycle, growth, apoptosis, and other key cellular processes. These genetic changes can be acquired over time or inherited from parents.
- Sustained proliferative signaling: Cancer cells have defects in the pathways that control cell growth and division. These pathways, such as the PI3K/Akt/mTOR and RAS/MAPK pathways, are constitutively activated in cancer cells, promoting cell growth, proliferation, and survival.
- Dysregulated immune response: Cancer cells can evade detection and destruction by the immune system, which normally plays a role in recognizing and eliminating abnormal cells. This immune evasion can occur through various mechanisms, such as the expression of immunosuppressive molecules or downregulation of immune recognition molecules.
- Tumor microenvironment: Cancer cells interact with surrounding stromal cells, immune cells, and the extracellular matrix to form a complex tumor microenvironment. This microenvironment can influence tumor growth, progression, and metastasis.
- Reprogrammed cellular identity: Cancer cells often undergo changes in their cellular identity, acquiring characteristics of stem cells or embryonic cells. This plasticity allows cancer cells to adapt to different environments and resist therapies.
- Aneuploidy: Cancer cells frequently exhibit aneuploidy, a condition in which the number of chromosomes is not a multiple of the normal diploid number. Aneuploidy can contribute to genomic instability and facilitate the acquisition of additional mutations.