The Immortal Cell: The Story of HeLa and the Evolution of Cancer Treatment
Cancer is a disease deeply embedded in our lives. In the past, it was a mysterious realm, but thanks to scientific advancements, our understanding and treatment of cancer have evolved remarkably. Today, let's explore the history of cancer treatment, starting with the discovery of the 'HeLa cells' in the 1950s, all the way to the cutting-edge 'next-generation cancer drugs' of today, explained in an easy and engaging way.
The Immortal Cells: The Story of HeLa
About 70 years ago, in 1951, racial segregation against Black people was still rampant in the United States. At that time, there was only one hospital in Maryland that treated Black impoverished individuals without discrimination: Johns Hopkins University Hospital.
One day, a 31-year-old Black woman named Henrietta Lacks visited this hospital. The doctor found a tumor in her uterus and took a tissue sample for examination. Unfortunately, the tumor was identified as aggressive cervical cancer, and she passed away just three months after the diagnosis.
But something astonishing happened. The cancer cells taken from her body didn't die; they continued to multiply. While cancer cells typically die within 3-4 days in a test tube, Henrietta's cancer cells have survived for over 70 years, and an astonishing 50 million tons have been cultured worldwide, showcasing incredible vitality.
Johns Hopkins Hospital named these miraculous cells 'HeLa cells' and began to freely distribute them to other hospitals and research institutes for research purposes. Thanks to these HeLa cells, over 11,000 patents and 70,000 research papers have been published, and they even led to two Nobel Prize in Medicine winners. The polio vaccine, which many of us received as children, was also made possible by these very HeLa cells. Although Henrietta Lacks lived a short life, her cells have made a profound contribution to the advancement of human medicine.
Cancer, Like Zombies? Unraveling the Characteristics of Cancer Cells
Cancer cells can be likened to zombies from a movie. Cells that should die don't, and instead, they continue to survive, transforming surrounding normal cells into cancer cells. Just like a few zombies can be contained, but if they overrun a whole village and spread to others, there's no stopping them.
Cancer cells require a tremendous amount of nutrients for rapid growth. They primarily get nutrients through blood vessels. For cancer cells to grow larger, surrounding blood vessels must also expand. This is why cancer cells even create new blood vessels to aggressively absorb nutrients.
Cancer can occur in any part of our body where there are cells, but it tends to grow faster in areas with rapid growth. For example, the brain mostly develops during childhood, which is why brain tumors are often seen in children. Conversely, in older adults, whose growth rate is slower, cancer also grows more slowly, allowing them to live longer even with cancer.
Because cancer cells consume so many nutrients, rapid, unexplained weight loss can be one of the early symptoms of cancer. If you suddenly lose a lot of weight for no reason, it's a good idea to see a doctor for a check-up.
Surprisingly, back in the 1900s, cancer wasn't even among the top causes of death. At that time, people often died earlier from infectious diseases like influenza and tuberculosis, so fewer people died from cancer. However, with modern medical advancements extending human lifespans, cancer has now become the overwhelming leading cause of death in South Korea.
Evolving Cancer Treatment: From First to Fourth-Generation Cancer Drugs
Cancer treatment broadly involves surgery and cancer drugs. Cancer drugs, in particular, have undergone remarkable advancements over the past few decades. Currently, first to third-generation cancer drugs are commercialized, and fourth-generation cancer drugs are actively being researched.
1st Generation Cancer Drugs (Chemotherapy)
First-generation cancer drugs are what we commonly think of as chemotherapy. They target rapidly dividing cells, exploiting the characteristic of cancer cells. The problem is that they attack not only cancer cells but also rapidly growing normal cells like hair follicles. This often leads to severe side effects such as hair loss, vomiting, infertility, and malnutrition during chemotherapy.
2nd Generation Cancer Drugs (Targeted Therapy)
Second-generation cancer drugs, or targeted therapy, selectively attack specific cancer cells. For example, leukemia drugs are effective only against leukemia cells, significantly reducing side effects compared to first-generation drugs. However, their limitation was that they were only effective for specific types of cancer.
3rd Generation Cancer Drugs (Immunotherapy)
The third-generation cancer drugs, immunotherapy, are gaining significant attention recently. Cancer cells sometimes disguise themselves as normal cells to evade our immune system. Immunotherapy unmasks these disguised cancer cells, allowing our body's immune system to directly attack them. They offer the advantage of being effective against most cancers, similar to first-generation drugs, but with far fewer side effects.
New Hope: Next-Generation Cancer Drugs (Metabolic & 4th Generation)
While first to third-generation cancer drugs are commercialized, even more advanced next-generation cancer drugs are under development.
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Metabolic Anticancer Drugs: These drugs target the unique metabolic process of cancer cells. While normal cells use oxygen to produce energy, cancer cells consume 20-30 times more glucose for energy production. Metabolic anticancer drugs exploit this abnormal energy consumption of cancer cells by blocking their energy supply, essentially starving them to death. Since the energy production method of most cancer cells is similar, these drugs have the advantage of being applicable to a wide range of cancers, and research is ongoing to maximize their effect when used in combination with existing immunotherapy drugs.
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4th Generation Cancer Drugs (CAR-T Cell Therapy): Fourth-generation cancer drugs enable the patient's own cells to directly attack cancer cells. CAR-T (Chimeric Antigen Receptor T-cell) cell therapy, often called the "serial killer of cancer cells," is a prime example. This treatment involves extracting T-cells from the patient's blood, genetically modifying them to recognize and attack cancer cells, and then re-injecting them into the patient's body. These modified T-cells intelligently seek out and attack only cancer cells, and their detection ability is passed on genetically, continuing the fight.
CAR-T cell therapy showed groundbreaking treatment effects for blood cancers that previously had no cure, earning it recognition as 'Research Breakthrough of the Year' by Science magazine in 2013. However, a significant drawback has been its exorbitant cost, often hundreds of thousands of dollars per treatment.
Efforts to Revolutionize CAR-T Treatment Costs
The high cost of CAR-T treatment has been a major burden for patients. Therefore, scientists are actively researching ways to dramatically reduce this cost. Traditionally, T-cells were extracted from the body, genetically modified, and then re-injected. However, recent developments involve modifying T-cells directly inside the body.
Companies like Interius and Umoja Biopharma in the U.S., and EsoBiotec in Belgium, are conducting clinical trials with specialized viral vectors (delivery vehicles) that bind only to proteins on the surface of T-cells. Interius showed remarkable results in a lymphoma patient trial, where cancer cells completely disappeared within 6 days in a patient who received a high dose. EsoBiotec's success in a multiple myeloma patient trial, where cancer cells vanished in a month, led to its acquisition by AstraZeneca for $1 billion.
Of course, in-vivo genetic modification carries the risk that the gene targeting cancer cells might be delivered to unintended cells. To address this risk, U.S. companies Capstan Therapeutics and Ona Therapeutics are researching a new method using mRNA technology, famously known from COVID-19 vaccines. This involves delivering mRNA that synthesizes a protein binding to cancer cells into T-cells. The mRNA then produces the protein and degrades, essentially creating "single-use CAR-T cells." Both companies plan to enter clinical trials this year.
The Unyielding Quest to Conquer Cancer
Cancer remains one of humanity's greatest threats, but as we've seen, the pace of advancement in cancer drugs is incredibly rapid. From Henrietta Lacks' miraculous cell discovery to now utilizing a patient's own cells and creating treatments within the body, we've come a long way. This kind of groundbreaking cancer drug development can have a profound impact not just on disease treatment but on society as a whole. Let's hope for the day when cancer is finally conquered.
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