Kasvainprosessi

Kasvainprosessi, also known as tumorigenesis or oncogenesis, refers to the biological process by which normal cells transform into cancer cells. This transformation is a multi-step phenomenon involving the accumulation of genetic and epigenetic alterations that disrupt normal cellular regulation. These alterations can arise from various sources, including DNA damage caused by carcinogens, errors in DNA replication, or inherited mutations.

The process typically begins with a mutation in a gene that controls cell growth and division, such as a proto-oncogene or a tumor suppressor gene. Proto-oncogenes, when mutated, can become oncogenes, promoting uncontrolled cell proliferation. Tumor suppressor genes normally inhibit cell growth, but mutations inactivate them, removing this crucial brake. As more mutations accumulate, cells gain new abilities, such as evading cell death (apoptosis), uncontrolled replication, and the capacity to invade surrounding tissues and spread to distant sites (metastasis).

Key hallmarks of cancer development include sustained proliferative signaling, evasion of growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis (the formation of new blood vessels to supply the tumor), and activating invasion and metastasis. The progression from a single mutated cell to a clinically detectable tumor is a complex journey influenced by both the genetic landscape of the tumor cells and the surrounding tumor microenvironment. Understanding the kasvainprosessi is fundamental to developing effective cancer prevention, diagnosis, and treatment strategies.