In 1951, a sample of cancer cells taken from a patient in Baltimore changed the course of modern medicine. Those cells, now known as HeLa cells, became the first human cell line to survive and multiply indefinitely in a laboratory setting. Decades later, they remain one of the most widely used tools in biological and medical research worldwide.
But behind the science lies a story that raises serious ethical questions, questions that the scientific community is still working through today.
What Are HeLa Cells?
HeLa cells are an immortal human cell line derived from cervical cancer tissue. Unlike normal human cells, which stop dividing after a set number of cycles, HeLa cells divide continuously under standard laboratory conditions. This makes them extremely useful for scientific experiments that require a stable, consistent supply of living human cells.
The name HeLa comes from the first two letters of the donor's first and last name: Henrietta Lacks. They belong to the broader category of tumor cell lines, which are used widely across oncology and biomedical research.
The Origin: Henrietta Lacks and Johns Hopkins
Henrietta Lacks was a 31 year old African American woman diagnosed with an aggressive form of cervical cancer at Johns Hopkins Hospital in January 1951. During her treatment, a tissue sample was collected from her tumor without her knowledge or consent, which was standard practice at the time.
Researcher George Otto Gey noticed something unusual about her cells. While samples from other patients would die within days in the lab, Henrietta's cells kept growing. They doubled roughly every 24 hours, making them unlike anything scientists had seen before.
Henrietta Lacks passed away on October 4, 1951. Her cells, however, lived on and were soon distributed to research labs across the world. Today, authenticated cervical cancer cell lines including HeLa remain essential tools for studying HPV, tumor behavior, and treatment response.
Why Are HeLa Cells Immortal?
Normal human cells have a built-in division limit controlled by structures called telomeres, the protective caps at the ends of chromosomes. Each time a cell divides, telomeres shorten slightly. Once they become too short, the cell stops dividing and eventually dies.
HeLa cells produce an enzyme called telomerase at abnormally high levels. Telomerase rebuilds the telomeres after each division, allowing the cells to bypass the usual limit and keep dividing indefinitely. This is a trait common to many cancer cells but was especially pronounced in Henrietta's tumor.
Additionally, HeLa cells carry an abnormal number of chromosomes, typically between 76 and 80 instead of the standard 46. This genetic instability is part of what makes them so aggressive and so resilient.
Major Scientific Contributions of HeLa Cells
The impact of HeLa cells on medicine and research is difficult to overstate. Some of the most significant breakthroughs they contributed to include:
Polio Vaccine Development
In the early 1950s, HeLa cells were used to grow and test the poliovirus in large quantities. This was a critical step in developing Jonas Salk's polio vaccine, which went on to eradicate polio across much of the world.
Cancer Research
Scientists have used HeLa cells to study how cancer cells grow, spread, and respond to treatment. They serve as a baseline model across many areas of cancer research, from breast and lung cancer to leukemia and cervical tumors.
Virology and Vaccine Testing
HeLa cells are susceptible to a wide range of viruses, making them ideal for virology research. They have been used in HIV research, HPV studies, and more recently, in research related to COVID-19.
Drug Development and Toxicology
Before new drugs reach human trials, researchers often test their effects on cell cultures. HeLa cells provide a human cell model for early stage screening of potential therapies, helping identify toxicity or efficacy.
Gene Mapping and Cloning Research
HeLa cells played an important role in early gene mapping efforts and continue to be used in studies involving gene expression, CRISPR editing, and transfection protocols.
The Controversy: Ethics, Consent, and Family
The story of HeLa cells is not just about scientific achievement. It is also about a major ethical failure.
Henrietta Lacks never consented to her cells being taken for research. Her family was not informed until the 1970s, decades after the cells had been commercialized and distributed worldwide. While companies profited from products developed using HeLa cells, the Lacks family had no access to basic healthcare and received no compensation.
The racial dimension of the case is also significant. Henrietta was a Black woman at a time of deep racial inequality in American medicine. Her story reflects a broader history of Black patients being exploited in medical research without proper consent or recognition.
In 2013, the National Institutes of Health reached an agreement with the Lacks family to control access to the HeLa genome sequence. In 2023, the family secured a legal settlement with Thermo Fisher Scientific, one of the companies that had commercialized HeLa derived products. Further lawsuits against other companies remain ongoing.
The case of Henrietta Lacks directly influenced the development of modern informed consent regulations, including the Common Rule introduced in the United States in 1991, which requires that patients be fully informed before their biological materials are used in research.
Are HeLa Cells Still Used Today?
Yes, HeLa cells are still widely used in laboratories around the world. They appear in tens of thousands of published research papers. Their availability, consistency, and well-documented behavior make them a practical choice for many types of experiments.
However, their use is not without criticism. Contamination is a known issue: HeLa cells are notoriously aggressive and have been found to overrun other cell cultures in labs, compromising research results. Scientists today are required to authenticate their cell lines using methods like STR profiling before publishing data.
For researchers who need reliable, well-characterized cell models, AstralCell offers a broad range of authenticated tumor cell lines including cervical cancer models produced in-house with quality control verification.
Frequently Asked Questions
What are HeLa cells used for?
HeLa cells are used in cancer research, drug testing, vaccine development, virology, gene editing studies, and toxicology. They provide a consistent human cell model for laboratory experiments.
Why are HeLa cells immortal?
They overexpress telomerase, an enzyme that prevents telomere shortening. This allows the cells to divide indefinitely without dying, unlike normal human cells.
Are HeLa cells cancer cells?
Yes. HeLa cells originated from a cervical cancer tumor. They carry abnormal chromosomes and exhibit aggressive division, both characteristics of malignant cells.
Why are HeLa cells controversial?
They were taken without Henrietta Lacks' consent and later commercialized, while her family received no benefits. The case exposed serious ethical gaps in medical research and contributed to the development of modern consent laws.
Can you buy HeLa cells?
Yes. Authenticated HeLa cell lines are available through licensed cell line suppliers and biorepositories for use in certified research facilities.
How many chromosomes do HeLa cells have?
HeLa cells typically have between 76 and 80 chromosomes, compared to the standard 46 in normal human cells.
Were HeLa cells used in COVID-19 research?
Yes. HeLa cells were used in some early studies related to COVID-19, particularly in experiments exploring how the virus interacts with human cell receptors.