Cancer is a disease that involves uncontrolled cell divisions that infiltrate and subsequently damage the normal body tissue. These uncontrolled cell divisions occur due to acquired or inherited mutation or damage to the DNA within the cells.
DNA controls normal cell growths and divisions. DNA mutations are common in normal cells, however, these cells can easily repair majority of these mutations. The cells that are unable to repair themselves die. If these mutated cells, neither repair themselves nor die, they can grow abnormally and become cancerous. Additionally, DNA mutations can increase the life of cancer cells causing them to accumulate in the affected part of the body.
Over the years a large number of different treatments such as radiation therapy and surgical processes have been developed to treat different types of cancers. Chemotherapy is the field of medicine that involves using different types of medication to treat a large number of cancers. It is often combined with other cancer treatments to make cancer treatment more effective.
The main objective of all chemotherapy agents and drugs is to destroy the cancerous cells while minimizing any damage to the healthy cells. To achieve this, various studies have been done to identify the characteristics that are unique in cancerous cells and non existent in normal cells. Therefore, one of the main features that chemotherapy agents usually target is the fast growing nature of the cancer cells.
Understanding the Cell Cycle
For better understanding of how chemotherapy works, it is important to have a basic idea of the cell cycle. Cell cycle basically involves a sequence of events that occur when a cell duplicates itself and divides into two new cells. The cycle occurs in fours phases- G1, S (Synthesis), G2, and M (Mitosis).
DNA replication occurs during the S phase. RNA and small amount of protein is developed during the G2 phase. Actual nuclear and cytoplasmic cell division occurs during the M phase. Most of the protein synthesis occurs during the G1 phase and because during this phase DNA is coiled tightly, it is not actively transcribed or copied.