What happens to cells when proto-oncogenes are mutated to oncogenes?

When proto-oncogenes are mutated to become oncogenes, the primary effect is that cell growth is overstimulated. Proto-oncogenes usually play vital roles in normal cell growth and division by encoding proteins that facilitate these processes. When mutations occur in these genes, they can lead to the production of altered proteins that promote excessive or uncontrolled cell proliferation.

This overstimulation of growth often results in the evasion of regulatory mechanisms that normally keep cell division in check, contributing to the formation of tumors. The key distinction here is that while proto-oncogenes help regulate the normal cycle of cell growth, mutated oncogenes can push cells towards hyperproliferation. Thus, the change from a proto-oncogene to an oncogene is crucial in cancer development, as it shifts the balance from normal regulation to unchecked cell division.