Henrietta Lacks was an African-American mother of five who sought treatment for cervical cancer at Johns Hopkins Hospital in 1951. During her treatment, a sample of her tumor cells was taken without her knowledge or consent. These cells, later named HeLa, possessed an unprecedented ability to survive and multiply indefinitely in a laboratory setting. This unique characteristic established the HeLa line as the first immortal human cell line, a foundational tool that accelerated biomedical research globally.
The Scale of HeLa in Scientific Literature
The number of scientific reports and publications involving HeLa cells demonstrates the cell line’s profound reach across all areas of biological study. An analysis conducted by the National Institutes of Health (NIH) found that over 110,000 scientific publications cited the use of HeLa cells between 1953 and 2018. This figure is a conservative estimate derived from database searches, as thousands of new papers utilizing the cells are published every year.
The volume of publications has shown a steady increase since the cells were first successfully cultured. While the number of papers was small in the 1950s, the annual publication count peaked at approximately 6,200 reports in 2015. This exponential growth illustrates how rapidly HeLa became the standard human cell model for labs worldwide, solidifying its place as arguably the most studied human cell line in history.
The Origin Story and Ethical Legacy
The scientific utility of HeLa cells is linked to the personal story of Henrietta Lacks and the ethical questions surrounding their origin. In February 1951, a doctor took a sample of Lacks’s cancerous tissue during her treatment without her consent, a common practice at the time. Researcher George Otto Gey cultured the cells, recognized their unique ability to flourish, and began distributing them freely to scientists worldwide.
Lacks passed away from cancer in October 1951, unaware that her cells were being commercialized. The family learned of the cell line’s existence in the 1970s when researchers contacted them seeking blood samples for genetic studies. This exposed a profound lapse in medical ethics, as a multi-million-dollar industry had developed around a biological specimen taken without the patient’s consent.
The controversy deepened when the HeLa genome was sequenced and published without the family’s permission. This event led to a historic 2013 agreement between the Lacks family and the NIH. Under this agreement, a working group that includes two Lacks family members reviews all applications for controlled access to the HeLa genome data. This arrangement established a precedent for managing access to the cell line’s genetic information, acknowledging the family’s moral ownership.
Why HeLa Cells Are Scientifically Unique
HeLa cells became the preferred research tool due to several unusual biological characteristics. Most human cells cease proliferation after a finite number of divisions, a phenomenon known as the Hayflick limit. HeLa cells bypass this limit because they express high levels of the enzyme telomerase, which rebuilds the protective caps on the ends of chromosomes. This allows for continuous division and grants the cells their laboratory “immortality.”
The cells are robust and adaptable, thriving in various culture conditions and easily propagated in large quantities. This hardiness made them an ideal, standardized platform for conducting repeatable experiments. HeLa cells also possess a highly abnormal number of chromosomes, a condition called aneuploidy, typically having between 76 and 80 chromosomes instead of 46. This genetic instability is linked to the original aggressive tumor and the integration of the Human Papillomavirus 18 (HPV18) genome.
Key Areas of Research and Discovery
The reliability and availability of HeLa cells enabled major scientific advances across numerous disciplines. One of the earliest and most profound applications was in the development of the polio vaccine during the 1950s. Jonas Salk’s team used HeLa cells to efficiently grow the poliovirus and test the vaccine’s effectiveness, accelerating its path to widespread use.
The cells were also instrumental in understanding fundamental processes related to cancer and genetics. Scientists used them to study the effects of radiation and toxins on human tissue, improving cancer treatments and safety protocols. Later work utilized HeLa cells for gene mapping, helping to assign specific genes to human chromosomes. The cells were even among the first human tissues sent into space to study the effects of zero gravity and cosmic radiation.