HeLa term is used in conjunction with the word cell and used in the literature of the biological and medical topics. This line of cells that are derived from cancer cells taken from the patient named Henrietta Lacks, died from cancer in 1951. HeLa cell line are today used to study cancer.

HeLa cells are called immortal, they can share an infinite number of times, unlike the conventional cell, with a Heyflik limit. The current population is still inherited from HeLa cell samples, extracted from Henrietta Lacks. These cells are proliferating unusually fast, even compared to other cancer cells. Sometimes these cells infect cultures of other cells.

At the moment there are several cell lines of HeLa, all of which are descended from a common ancestor, these cells are used as model cancer cells and are used in the study of mechanisms of signal transmission between cells.

Hayflick limit is the border dividing somatic cells, named after its discoverer Leonard Heyflika. In 1965, Heyflik observed as cells Rights dividing in cell culture, dying after approximately 50 divisions, and show signs of aging when approaching this boundary.

This border has been found in cultures of fully differentiated cells as a human, and other multicellular organisms. The maximum number of points varies depending on the type of cells and the more differs depending on the organism. For most of human cells Heyflika limit is 52 divisions.

Heyflika associated with the reduction of telomeres, sections of DNA at the ends of chromosomes. If the cell does not have active telomerase, as the majority somatichnyh cells with each cell division telomeres are reduced, because DNA polymerase is not able to replicate the ends of DNA molecules (possibly telomere sometimes reduced under the influence of other factors). When after a certain number of divisions of telomeres disappear completely, the cell usually becomes arrested at a certain stage of the cell cycle or starts a program of apoptosis, i.e. cell suicide.