HeLa cell
HeLa cell, type of cancer cell belonging to the first continuously cultured human cell line, established in 1951 from a tumor removed from Henrietta Lacks, a patient undergoing treatment for cervical carcinoma at Johns Hopkins Hospital in Baltimore, Maryland. The designation HeLa is derived from the first two letters of Lacks’s first and last names. Unlike most normal human cells, which divide only a limited number of times before entering senescence (a state in which cells no longer divide), HeLa cells continue to divide indefinitely under appropriate laboratory conditions. This property has made them one of the most widely used cell lines in biomedical research.
HeLa cells were the first human cell line to be successfully established and maintained in continuous culture, making it possible for scientists to grow large numbers of genetically similar human cells for laboratory study. Since their introduction, HeLa cells have been used extensively in research in fields such as cell biology, cancer, virology, genetics, and immunology, as well as in the development of new drugs and vaccines. They played an important role in the development and testing of the polio vaccine in the 1950s and in the decades following have contributed to advances in the understanding of cell division, chromosome structure, gene expression, viral infection, and the effects of radiation and drugs on human cells.
HeLa cells are a common source of cross-contamination of other cell lines and have been responsible for the accidental replacement or contamination of numerous laboratory cultures, contributing to instances of cell line misidentification. The HeLa cell genome has also been shown to be highly unstable, housing numerous genomic rearrangements and abnormal numbers of chromosomes, in a phenomenon known as chromothripsis. These genetic changes reflect the cancerous origin of the cells and distinguish them from normal human cells. Consequently, results obtained with HeLa cells must be interpreted with an understanding of their unusual genetic characteristics and may not always be representative of normal human tissues.
The collection and subsequent widespread use of Lacks’s cells occurred without her knowledge or informed consent, a practice that reflected prevailing medical standards of the time but later prompted significant ethical discussion. Her case contributed to broader public and scientific debates about patient privacy, informed consent, ownership of biological specimens, and the responsible sharing of genetic information. In 2013, an agreement between the Lacks family and the U.S. National Institutes of Health established controlled access to the HeLa genome sequence for many federally funded researchers.