Proto-oncogenes are genes that help cells grow frequently. When a proto-oncogene mutates or there are too many copies of it, it becomes a “bad” gene that can become permanently turned on or activated when it is not supposed to be. This creates the cell to grow out of control, which can lead to cancer. This gene is called an oncogene. Normal genes that slow down the division of cells, repair DNA mistakes, or tell cells when to die (apoptosis or programmed cell death) are known as tumor suppressor genes. Cancer can be led by the tumor suppressor genes not working properly and cells growing out of control.
An important difference between oncogenes and tumor suppressor genes is that oncogenes result from the activation (turning on) of proto-oncogenes, but tumor suppressor genes cause cancer when they are not activated (turned off).
Tumor is an abnormal growth of cells that serves no purpose. A benign tumor is not a deadly tumor that could cause many damages to an individual, which is known as cancer. A benign tumor doesn’t invade nearby tissues or spread to other parts of the body the way cancer can. The benign tumors tend to remain localized and usually do not pose a threat to one’s health or causing death. On the other hand, a malignant tumor consists of renegade cells that do not respond to the body’s genetic controls on growth and division. It can migrate from their site of origin and attack or invade surrounding body tissue. This tumor can sadly lead to death.
Tumor heterogeneity illustrates the observation that different tumor cells can show separate morphological and phenotypic profiles, including cellular morphology, gene expression, metabolism, motility, proliferation, and metastatic potential. This phenomenon occurs both between tumors known as inter-tumor heterogeneity and within tumors or better known as intra-tumor heterogeneity. A minimal level of intra-tumor heterogeneity is a simple consequence of the imperfection of DNA replication. Whenever a cell (it can be healthy or cancerous) divides, a few mutations are acquired, leading to a diverse population of cancer cells.
The heterogeneity of cancer cells remarkably introduces challenges in designing successful treatment strategies. However, research into understanding and characterizing heterogeneity can allow for a better comprehension of the causes and development of the diseases. Ultimately, it gives a possible guide to the creation of more refined treatment strategies that incorporate knowledge of heterogeneity to create higher efficacy.