Cancer research stories
1. First cancer-causing virus discovered:
It is well known now that some viruses can cause cancer. However, it was not known one hundred years ago. For the first time in 1911, a virus called Rous Sarcoma Virus (RSV) was discovered to cause cancer by Peyton Rous (the virus was named after him), who was working at Rockefeller University, by injecting cell free extract of chicken tumor into healthy Plymouth Rock chickens. The extract was found to induce a type of cancer called sarcoma. Peyton Rous was awarded Nobel Prize for his discovery in 1966.
In 1970’s, another breakthrough discovery was made in the University of California at San Francisco by two scientists, Michael Bishop and Harold Varmus, that the gene that can cause cancer can be found in normal mammalian cells. The gene that caused cancer in Rous Sarcoma Virus (RSV) was a gene called src. It turns out that the virus invaded the normal mammalian cells a long-time ago and hijacked the normal gene src from normal cells and mutated it to a cancer-causing gene. The cancer-causing gene is called oncogene. The normal gene is called proto-oncogene.
The viruses that can cause cancer include Human Papilloma Virus (HPV) that can cause cervical cancer and oropharyngeal cancer; Epstein-Barr virus (EBV) that can cause lymphoma and nasopharyngeal cancer; hepatitis B and C viruses that cause liver cancer; herpes simplex virus 8 (HSV8) that can cause Kaposi’s sarcoma, as well as others. These viruses contain proteins that can inactivate the tumor suppressor genes in human cells, hence cause cancer, or by making human cells grow out of control and cause cancer.
2. Can bacteria cause cancer?
Until H. Pylori was discovered to cause cancer, few would think bacteria could cause cancer. Below is a paragraph you can find from NCI website about H. Pylori and cancer:
In the 1980s, scientists began to notice the presence of curved bacteria, which later became known as H. pylori, in tissue samples taken from patients with ulcers of the stomach and upper small intestine. Believing that no bacteria could survive the harsh stomach environment, most scientists thought these mysterious bacteria were either due to contamination of tissue samples or just another harmless species of bacteria like many found in the gut. However, Australian researchers Barry J. Marshall, M.D., and J. Robin Warren, M.D., were convinced that the bacteria were actually the cause of ulcers. Marshall, frustrated with the lack of a good animal model of infection, infected himself with the curved bacteria. He became ill, developed inflammation of the stomach, and was able to culture the bacteria from his own ulcers, thereby proving the microbe to be the cause of stomach ulcers. For their discovery of H. pylori and its role in gastric ulcer formation, Marshall and Warren were awarded the 2005 Nobel Prize in Medicine.
3. Human genome project
Sequencing the whole human genome took 13 years to accomplish through US-led international efforts. In 2000, 3 years ahead of the plan, Francis Collins (the current NIH director) and Craig Venter stood by the side of President Clinton and made announcement that the human genome project was completed. Craig Venter led a private group to sequence the whole human genome.
4. A history of cancer
In addition to the viruses and the bacteria that can cause cancer, many other factors including radiation, chemicals, tobacco, alcohol, certain food and others are known to cause cancer. These factors cause cancer by causing mutations of some important genes in human cells.
This article from ACS (American Cancer Society) gives a nice summary on the history of cancer.
5. Double helix:
The era of molecular biology began when Watson and Crick discovered the structure of DNA in 1950’s. The significance of their discovery for biology is nearly equivalent to Einstein’s discovery of general relativity for physical science.
Double helix immediately explained how life replicates itself, what genes really are, and how genetics works.
6. First radiation therapy for cancer:
Dr. Henry Kaplan pioneered the first linear accelerator for treating cancer in 1955 while working at Stanford University. This link takes you to a 1984 article in New York Time on Dr. Kaplan’s life.
7. First chemotherapy:
The first chemotherapy drugs used for treating cancer were nitrogen mustards, a chemical agent used for warfare, discovered to be able to treat cancer by two pharmacologists, Louis S. Goodman and Alfred Gilman.
8. First antibody developed for treating cancer:
Rituxan (rituximab), an antibody against a protein on the surface of all B-cells, was found to be very effective in treating B-cell lymphoma. Rituxan is the first drug of monoclonal antibody class approved for treating cancer. Several other monoclonal antibody drugs are also being used for treating other cancers. Rituxan was developed at Stanford University by Professor Levy.
9. Protein phophorylation discovered by Edmond Fischer and Edwin Krebs:
In 1950’s, while studying how energy is released inside the cells they discovered a process called “Protein Phosphorylation”.
Protein phosphorylation is a process that one or more phosphate groups are added to a protein on a particular site of that protein. After the phosphorylation, the property of protein is altered in one of two ways: it gets activated or it gets inactivated. This process is reversible. The enzyme that adds a phosphate group on to a protein is called “Protein Kinase”; the enzyme that removes a phosphate from a protein is called “Protein Phosphatase”. It takes a while for scientists to realize this process is universal and is involved in all biological activities.
Many drugs that are used to treat cancer now are drugs that target on protein kinases.
In the 1992 presentation speech for their Nobel Prize, phosphorylation was quipped as a dance---
“one or several small phosphate groups are coupled to a protein, changing its properties. If the parallel with our human workers is pursued further, one could perhaps compare phosphorylation with ballet shoes. Despite their small size they have dramatic effects on their wearer! The shape of the foot is altered and after that, work is like a dance.”
10. The chromosome ends: Telemeres and telemerase:
Our human cells have 46 chromosomes that contain billions of DNA codes. However, unlike universe with no end in sight, each chromosome has two ends. What do these two ends look like and how are they protected so they don’t get chopped up? When the ends are chopped the chromosomes become unstable and can lead to cancer and other diseases.
In 1980’s, three scientists Elizabeth H. Blackburn, Carol Greider, and Jack W. Szostak, discovered the telemeres and the telemerase and explained how our chromosomes are protected.
The telemeres and the telemerase are present in all animal and plant cells. They are also related to the aging process, cancer, and stem cells.
Scientists are exploring ways to treat cancer by targeting telomerase.
