What is the Difference Between Oncogenes and Proto Oncogenes?

🆚 Go to Comparative Table 🆚

The main difference between oncogenes and proto-oncogenes lies in their function and the presence of mutations. Here are the key differences:

  • Proto-oncogenes are genes that normally help cells grow and divide to make new cells, or to help cells stay alive. They play important roles in regulating normal cellular growth, division, and apoptosis, which is programmed or controlled cell death. Proto-oncogenes are often compared to the gas pedal on a car, helping the cell grow and divide.
  • Oncogenes are mutated genes that have the potential to cause cancer. When a proto-oncogene mutates or there are too many copies of it, it can become turned on (activated) when it is not supposed to be, at which point it's now called an oncogene. Oncogenes can lead to uncontrolled cell growth and division, which may result in cancer development. They are often compared to a gas pedal that is stuck down, causing the cell to divide out of control.

Oncogenes can be activated in cells in different ways, such as gene variants/mutations, which can be inherited from a parent or occur during a person's life when a mistake is made when copying the gene during cell division. Other ways oncogenes can be activated include epigenetic changes, where different chemical groups can be attached to genetic material (DNA or RNA) that affect whether a gene is turned on or off.

Comparative Table: Oncogenes vs Proto Oncogenes

The difference between oncogenes and proto-oncogenes is that oncogenes are mutated or defective versions of proto-oncogenes, which can lead to cancer development. Here is a table summarizing their differences:

Feature Proto-oncogenes Oncogenes
Function Regulate cell division and cell cycles, encoding for cell cycle regulator proteins Promote uncontrollable cell division, producing different proteins
Formation Normal genes Result from mutations or overexpression of proto-oncogenes
DNA Sequence Unaltered Mutated or defective
Protein Production Encodes for positive cell cycle regulators Encodes for different proteins, leading to uncontrollable cell division
Genetic Modifications None Gene amplification, chromosomal translocations, point mutations, insertions or deletions

When DNA sequences of proto-oncogenes are mutated and converted into oncogenes, they can lead to cancerous growth due to uncontrolled cell division.