What is the difference between a normal somatic human cell and a HeLa cell?
The human body contains more than one hundred thousand billion cells, which can be divided in two categories, if we look at it in a simplified way. One of them is somatic (derived from the greek “soma”, meaning body) cells, which are the kind of cells forming the body of an organism, such as skin, blood, or muscle cells – apart from germ cells, the second category.
One characteristic of these somatic cells is their ability to divide a few times before they die. Sometimes, mutations (i.e. modifications of their DNA, the carrier of the genetic information) can happen and lead to a cascade of events that may lead the cell to a cancerous state. Henrietta Lacks, an African-American born in 1920, developed cervical cancer in 1951. During her illness, a researcher collected (without her consent) some of these cells and managed to grow them outside of the body in a petri dish. Indeed, compared to somatic cells, these cancerous cells have more DNA (over 30 additional chromosomes) which have been rearranged and mutated, allowing them to acquire new abilities such as “immortality” (i.e. capacity of dividing many many times).
This first human cell line was called HeLa (an acronym for HEnrietta LAcks) and is now widely used in laboratories as they represent a human cell model that can be kept in culture for a long time. However, as HeLa cells possess a lot of specific properties, any hypothesis tested with these cells may need to be further confirmed using other cell lines closer to the somatic cells, such as primary lines, in order to better understand and fight diseases such as cancer.
Answered by: David Sitbon, Ph.D. Student, Unit “Nuclear Dynamics” UMR3664 CNRS/Institut Curie