Karsinogeneesiin

Karsinogeneesiin is the biological process by which normal cells are transformed into cancer cells. This transformation is a multi-step process that involves the accumulation of genetic and epigenetic alterations. These changes can disrupt normal cell growth, division, and death, leading to uncontrolled proliferation.

The process typically begins with an initial exposure to a carcinogen, which is an agent that can cause cancer. Carcinogens can be physical, such as radiation or certain chemicals, or biological, such as viruses. These agents can damage DNA, leading to mutations. While cells have repair mechanisms, some damage may persist.

Following DNA damage, a series of mutations can occur in key genes that regulate cell growth and division, known as oncogenes and tumor suppressor genes. Activation of oncogenes promotes cell growth, while inactivation of tumor suppressor genes removes critical brakes on cell division.

These genetic changes are often complemented by epigenetic modifications, which alter gene expression without changing the underlying DNA sequence. Epigenetic changes can silence tumor suppressor genes or activate oncogenes, further contributing to the development of cancer.

Over time, these accumulated alterations can lead to a population of cells that are no longer responsive to normal regulatory signals. This uncontrolled growth and division is the hallmark of cancer, allowing for the formation of tumors and potential metastasis to other parts of the body.