GENETICS OF CANCER

Cancer tissues are made up rapidly dividing cells that can no longer be controlled by the body mechanism in cell cycle.

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These cells undergo such erratic proliferation unlike other normal divisions, growth and expire at the end of their lifespan, they do this as a result of Apotosis (cell death or cell limitation). These cells contain heritable mutants, they induce angiogenesis so as to get hold of the nutrients of the body.

ORIGIN OF CANCER CELLS
Cancer cells begin from growth of abnormal body cells which must have undergone mutation of their chromosomes causing them to grow uncontrollably after the eratic division of such cells and the resultant cells of such division are abnormal cells of the body which are called Tumors.
Mutations can happen in the somatic cells of the body or in the germ cells of the gonads. Some of these cancer cells can grow rapidly within days while others can take years to grow to a disturbing level.

CHROMOSOMAL NUMBER
A normal human somatic cell has 46 chromosomes (23 pairs of chromosome), while a normal gamete be it the ovum or sperm cell has 23 chromosomes instead of 23 pairs of chromosomes.
A normal human somatic cell is diploid in nature, while the normal gamete is haploid in nature.
In case of Polyploidy or Euploidy, which is a known multiple of n-chromosome and these multiples could be;
(a) Diploid
(b) Triploid

On the other hand Aneuploid refers to the chromosome number that is not polyploidy or euploidy. This is especially indicating the presence of either chromosomes. For example XX in female and XY in male. In the case of trisomy, we have an additional X or Y added. It could also indicate a missing chromosome.

Cancers are caused by Mutations and these mutations of chromosomes may be caused by the following conditions;

(i) Pathogenic conditions
May be caused due viral particle, bacteria, parasites and other microscopic agents which can be very detrimental for the well-being of the individual.

(ii) Chemical conditions
They include toxins of counter drugs and alcohol of different rates

(iii) Physical conditions
A lot of radiation from various sources examples include X-rays, Y-rays and Ultraviolet rays.

All these actors can lead to the mutation of chromosomes which could lead to the abnormal growth of cells and cause cancer.

Carcinogens are the substances which are responsible for causing cancer by production of toxic substances which may cause mutation of chromosomes especially DNA.

The study of cancer genetics is known as ONCOGENESIS.

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