Cell proliferation is a biological process in which the cell grows on the one hand and divides on the other. Cell division is also called cytokinesis and completes the preceding mitosis, nuclear division. This process is used for the reproduction of cells in the human body.
What is cell proliferation?
Cell proliferation is a biological process in which the cell grows on the one hand and divides on the other. Cell proliferation is divided into different phases. First, mitosis takes place. This is the replication of the genetic material in the form of chromosomes, which are located in the nucleus of the cell. They consist of DNA and histones. Replication of DNA occurs, so that subsequently a double set of chromosomes is present in the cell. The chromosomes consist of two strands each. They then form a kind of X-shape with identical sister chromatids held together by a centromere. Histones are protein complexes involved in the shaping of chromosomes. The replication of DNA and formation of the double set of chromosomes is called interphase. During prophase, the formation of two centrosomes occurs, which are located at the opposite poles of the cell. These centrosomes regulate the microtubules, which play an important role in the division of chromosomes. The microtubules form from the centrosomes toward the chromosomes. During the prometaphase, the nucleus loses its surrounding membrane. The spindle apparatus is formed, which consists of the microtubules. They bind chromosomes so that they can be transported through the cell. In metaphase, the sister chromatids of chromosomes, which have accumulated in a certain area of the cell, are separated from each other. Prior to this, condensation of the chromosomes occurs. The chromosomes are then aligned in the equatorial region of the cell. This area is also called the metaphase plate. The kinetochores, the areas of the chromosomes that bind the microtubules, are all occupied by microtubules. During anaphase, the sister chromatids are separated from each other. This occurs in the two directions of the centrosomes at both poles of the cell. An accumulation of the same set of chromosomes then occurs at each pole. Finally, in telophase, the microtubule strands, which are attached to the kinetochores of the chromosomes, form back. The nucleus with its surrounding membrane is rebuilt around the chromosomes. There are now two cell nuclei. Subsequently, cytokinesis, the cell division, takes place. In this process, the mother cell laces itself to produce two cells, each with a nucleus.
Function and task
Cell division possesses an important role in human development. It is significantly involved in human growth. Even during development in the womb, cell division is important for the formation of all organs and tissues. Through cell division, genetic information is also passed on to other cells. In addition, cell division also serves to renew certain tissues. An example of this is the skin, which regenerates itself again and again. The epidermis, which is the outermost layer of the skin, consists of keratinocytes, which multiply by cell division and form the protective callus by dying and keratinizing. The continuous cell division of these cells ensures that the protective covering can be maintained. However, there are also cell types which are no longer able to divide in adulthood. These are the muscle and nerve cells. They are differentiated and no longer divide.
Diseases and disorders
When the regulation of cell division is disturbed, cell proliferation may increase. This results in the formation of tumors. These are ulcers, which can occur in all tissues. They can also be benign. In this case, they are merely cell types that show disturbed cell division, but do not cause any further damage to the body. Tumors of this type must nevertheless be partially removed, as they can impair the affected person’s freedom of movement, for example. Malignant tumors, on the other hand, severely affect the body of the affected person. These malignant tumors can spread in the body and even lead to death.This disease is also commonly referred to as cancer. The cells with a disorder of proliferation displace healthy cells and tissue, resulting in loss of function. This disease can have several causes. Often it is due to mutations, which can be inherited. These mutations then affect genes that play an essential role in the regulation of cell division. Other causes are environmental influences. Excessive UV radiation can lead to skin cancer. Viruses are also capable of causing cancer. Examples are so-called oncoviruses such as the hepatitis B virus or retroviruses. Cancer is usually treated with radiation therapy or chemotherapy, as well as with the attempt to surgically remove malignant tumors as far as possible. The goal is to remove and permanently destroy all cells that have a disorder of cell division to prevent further outbreak of the disease. This must be reviewed at regular intervals after any of the therapy.
