By Tracy Joo
Cancer is considered one of the leading causes of deaths worldwide. While there is currently no exact cure for cancer, for years scientists have been testing various tactics on ways to purely eliminate, or at least, slow down the progression of cancer. Today, common cancer treatments may range from chemotherapy, radiation therapy, stem cell transplant, surgery, and interferon therapy (Dority). The type of cancer determines the treatment options and it depends on how much the cancer has spread and where exactly it is located. A recent study performed by researchers from the University of Pennsylvania Abramson Cancer Center and Perelman School of Medicine has shown promising outlooks on treating patients with advanced chronic lymphocytic leukemia (CLL) by altering their own immune systems to fight against cancerous cells (Penn Medicine News). Because of its promising outlooks this new mechanism of cell therapy for the treatment of leukemia may in fact be the foundation to the cure for cancer as a whole.
Leukemia is a type of cancer dealing with the blood. It includes the blood-forming tissues, the lymphatic system and the bone marrow (Mayo Clinic). In most cases of individuals who have leukemia, it begins in their white blood cells or “leukocytes”; however, leukemia can also develop in red blood cells as well. Leukocytes are blood cells that fight off infection and their main function is in protection. Individuals who do not have leukemia have leukocytes that develop and divide in a normal fashion when their body requires them. Conversely, people diagnosed with leukemia have irregular bone marrows that produce abnormal amounts of uncharacteristic white blood cells (Mayo Clinic). These abnormal white blood cells will then spread through the blood stream causing infection to other tissues and organs. For example, many times it will spread in the central nervous system, liver, lymph nodes, and the spleen (Leukemia Research Foundation).
The researchers of this study had discovered a way to genetically modify CLL patients’ immune systems, specifically by reengineering their own T cells. A T cell is a specific type of lymphocyte and its primary function is to fight against infection. CLL is one of the most common types of leukemia and about 15,000 people in the United States (mostly adults) have been diagnosed and approximately 4,300 deaths occur from the particular disease (Bazell). The study involved the removal of the patient’s cells, making alterations to them, and then infusing the modified cells back into them, following chemotherapy. Three adult chronic lymphocytic leukemia (CLL) patients participated in this experimental study and all showed early successful results. In fact, two of the patients are in remission following their treatment and have been cancer free for more than 2 ½ years (Science Daily). The cell therapy involved genetically programming T cells to rapidly replicate and eradicate leukemia cells. Carl June. MD, director of Translational Research and a professor of Pathology and Laboratory Medicine in the Abramson Cancer Center who led the work, stated, “Within three weeks, the tumors had been blown away, in a way that was much more violent than we have ever expected” (Penn Medicine).
Another study by the same researchers was performed on two children with an aggressive or high-risk form of leukemia that withstand conventional treatments. After treatment, the two children showed complete remission, or in other words, showed absolutely no evidence of cancer cells present in their bodies. The Children’s Hospital of Philadelphia and the University of Pennsylvania published this report in The New England Journal of Medicine on March 25, 2013 and will appear in the print issue on April 18. 7-year old Emily Whitehead, who was one of the pediatric patients, is presently free of cancer just 11 months from receiving her body’s own T cells that were bioengineered. Just last spring, Emily was desperately battling cancer and at near death from the disease. This incredible cell therapy treatment unexpectedly had an outcome of completely reversing her condition. The altered T cells were able to direct its mode of action to a specific target existing in the particular leukemia she had called acute lymphoblastic leukemia (ALL) (Science Daily). ALL is also the most common type of childhood cancer. Emily is just among 12 other patient with advanced leukemia to be given the experimental treatment (Grady), which was originated at the University of Pennsylvania. The other patient, who was 10 years of age, responded almost exactly the same to Emily Whitehead. Co-first author Stephan A. Grupp, M.D., PH.D., of The Children’s Hospital of Philadelphia, stated that, “This study described how these cells have a potent anticancer effect in children; however, we also learned that in some patients with ALL, we will need to further modify the treatment to target other molecules on the surface of leukemia cells,” (Science Daily). Grupp is a professor of Pediatrics at the Perelman School of Medicine at the University of Pennsylvania and the director of the Translational Research for the Center for Childhood Cancer Research at The Children’s Hospital of Philadelphia. This study elaborates on Grupp’s continued group effort with the researchers and scientist at who initially created the adjusted T cells at Penn Medicine (Science Daily.)
Furthermore, this study is considered to be a type of immunotherapy, since the process involves the manipulation of the immune system to advance its cancer-destroying abilities. Looking into more detail on a molecular level, the experiment, again involved changing the patient’s own T cells to target another type of immune cell in their body that had become cancerous, called B cells. The scientists genetically transformed their T cells in the laboratory and created a new type of cell called, CAR (chimeric antigen receptor), which was also named a CTL019 cell. These new bioengineered cells are constructed to dismantle and attack CD19, which is a specific protein that transpires on the surface of distinct B cells. When the modified cells are injected back into the bodies of the patients, the CTL019 cells rapidly replicate thousands of times and spread throughout their bloodstreams. This incredible mechanism carries on for months afterward, serving as a protection against the possible regeneration of acute lymphoblastic leukemia (Science Daily). Although there are mixed reviews on this method of treating cancer, experts in cancer who have not taken part in this study believe it to have an outstanding promise. Dr. Ivan Borrello, an associate professor of medicine at the Johns Hopkins University School of Medicine and cancer expert stated that, “I think this is a major breakthrough,” (Grady). Moreover, the researchers continue to improve their methods and are looking into new ways of approaching this procedure to overall benefit the patients.
In addition, Novartis, a major drug company, has already dedicated $20 million to the Pennsylvania research team on developing a new research center at the university in order to allow the treatment to be available to the market. “Hervé Hoppenot, the president of Novatis Oncology, called the research “fantastic” and said it had the potential – if the early results held up – to revolutionize the treatment of leukemia and related blood cancers; researchers say the same approach, reprogramming the patient’s immune system, may also eventually be used against tumors like breast and prostate cancer” (Grady).
It is evident that there are still many questions that remain on this new approach to cancer treatment. Since the research is in its early stages, questions such as, how exactly the treatment works in some patients effectively and not in others still remains a medical mystery. There is no straightforward explanation of the in-depth molecular cascades that take place during the treatment procedure. Further experimentations must be performed to conclude specific causations.
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