Characteristics of Cancer

What is Cancer?

Cancer is an abnormal, uncontrolled growth of cells, antagonistic to the body's natural tissues and cells. Many different forms of the cell-function cause cancer. There is a process of cell growth and reproduction in the human body. Unfortunately or accidentally, cells that are unable to respond to this process may result in the production of tumor growth and become a cause for cancer. Every tissue is responsible for the diversity in the steps that are involved in the regulation of cell growth and division. Different kinds of cancer that can be found in the human body include retinoblastoma cancer, breast cancer, prostate cancer, melanoma cancer, ovarian cancer, and so forth.

Figure 1a: Various kind of Cancer

Figure 1b: breast cell and cancer cell

Cancer is a genetic disease and the cell's genes play an important role in the diversity of the cell cycle. Therefore, it is necessary to understand how genes work. Cells are the basic structure unit of life. Each gene that is located one of 23 pairs of chromosomes consists of an organized series of nucleotide bases: adenine, thymine, cytosine, and guanine and made of 100 to more than million base pairs. Every one of the approximately 100,000 genes in the human genome carries the instructions for the production of a protein. DNA consists of the chromosomes in the nucleus of the cell. Genes are the part of DNA, which encode the genetic information, about cell growth, division and function of a cell, that is passed from one generation of a cell to another. However, the most important point is how the cells of our body replicate their contents and then divide. The different functions of cell, which are involved in cancer, are the growth of the cell cycle, the variation in DNA structure, and chromosome distribution.

Figure 2: Cell cycle and DNA

The cell cycle, which plays an important role in cancer, is divided in to four phases. Cell begins to increase in size and prepare to duplicate its DNA during the first G1 phase. During the S phase, cell creates the DNA with the exact repetition of chromosomes. Later on, there is a quiet period for the preparation of final phase, which is G2 phase. The last phase of the cell cycle is mitosis during which the cell divides in two daughter cells. Mitosis is the most important phase and fundamental process of the life, which means that the development of a baby is a series of mitosis. During this phase, inaccurate distribution of chromosomes can be resulted in a chance for cancer in the next generation. This cell cycle, which makes the link with genes that are related to DNA and chromosomes, is the main source of cancer. DNA made of two complementary strands that bind with weak hydrogen bonds between A-T and C-G. Suppose one base pair has a nucleotide series - CGATG. So, the other base pair must have a nucleotide series-GCTAC.

Reference: www.cancergenetics.org