Normal cells follow a proper life cycle and respond to different cellular signals that control their behaviours. In contrast, cancer cells exhibit uncontrolled division and growth and ignore these signals.
Here is a detailed breakdown of the major differences between normal and cancer cells.
Cell Characteristics | Normal Cells | Cancer Cells |
Shapes | Normal cells are regular in shape. | Cancer or tumour cells are irregular in shape. |
Nucleus | They possess a visible nucleus with a proportionate size. | These cells have a large and darker nucleus. |
Maturation | Normal cells are mortal and do not grow after a certain stage (cell senescence). | Cancer cells are immature and immortal. They can survive in anoxic conditions. |
Growth | These cells follow the entire life cycle in a systematic process. Additionally, they exhibit all the cellular functions normally. | Exhibits uncontrolled growth and enhanced metabolic processes. Do not follow the cellular mechanisms. |
Visibility | They are visible to the immune cells due to their communicative nature. | Evades immune detection through mechanisms like PD-L1 expression, therefore, the immune system fails to detect them in the early stages. |
Blood Supply | Promotes angiogenesis only during the repair mechanism processes. | Continuously exhibits angiogenesis and forms tumours. It later spreads to other parts of the body. |
Oxygen Availability | Requires oxygen during cellular respiration and other molecular processes. Normal cells cannot survive without the proper supply of oxygen. | Cancer cells adapt to hypoxia (low oxygen) via HIF-1α but still require oxygen for survival. |
Cellular Environment | Normal cell cytoplasm maintains pH ~7.2 (neutral) to maintain the overall pH of the cytoplasm. | Cancer cells export lactate to create an extracellular acidic microenvironment, but maintain near-neutral intracellular pH. Mutations enable the cellular organs to perform optimally in acidic environments. |
Energy efficiency | These cells possess a very high energy efficiency due to several metabolic functions. | Cancer cells exhibit controlled production and breakdown of glucose, making it less energy-efficient. |
Nutrient Preferences | Normal cells thrive not only on glucose, but also on different fats and ketones to produce energy. | Cancer cells metabolize glutamine, fatty acids, and ketones in addition to glucose to perform all their functions. They are extremely sensitive to other biomolecules. |
Mutations in the DNA of the cancer cells interfere with the normal functional processes. It instigates these cells to grow uncontrollably and crosses the phase of ageing and dormancy.
Cancer cells develop due to certain genetic mutations; these include:
The body's defence mechanism (immune system) normally eliminates these damaged or mutated cells before we age, but it typically loses this ability with age. This is one of the key reasons why the cancer develops in the later stages.
There are mainly three types of genes that trigger the formation of cancer cells. These are as follows:
Proper diagnosis is important to identify any kind of mutation, and checking family history can confirm it.