Blackwell Talks began the semester with an exploration in biology, and that's how they ended as well. On Monday, Dr. Amorette Barber, assistant professor of biology, presented on "Immune Cells: New soldiers in the war against cancer. " Barber is in her first year with the biology department and came to Longwood from Dartmouth Medical School.
Barber focused on the use of immune cells to fight cancer cells aside from better known treatments. Cancer is the second most common cause of death in America. It is a close second behind only heart disease and accounts for one in four deaths. By the end of 2011, it estimated that more than 570,000 people will have died due to cancer.
Current treatments to fight cancer include surgery, radiation and chemotherapy. "These treatments can't really target all the cancer cells in your body," said Barber.
One new treatment method in the fight against cancer is known as immunotherapy, the use of immune cells in destroying the cancerous cells. The immune system protects against disease and identifies bad pathogens in the body, which include tumor cells that can cause cancer. Therefore, it would make sense for immune cells to take over the role of cancer killers.
These immune cells are able to identify which cells are otherwise healthy and can leave them alone. Two different types of immune cells are being used in the therapy — T-cells and natural killer (NK) cells.
The process, as Barber explained, looks relatively simple. The tumor cell is removed from the patient, and T-cells and NK cells are put in isolation. In the clinical lab, NK cells and T-Cells are then cultured and activated to expand. Then, cells are re-infused intravenously into the patient. This process takes anywhere from a few weeks to a month or more.
Barber discussed the pros and cons of using both NK cells and T-cells with immunotherapy. For NK cells, they easily recognize tumors and target numerous tumor types. However, they have a short lifespan — only five to six days — and are unable to penetrate the tumor well while in the body, even though results in the lab are very satisfactory.
For the T-cells, they have a longer lifespan, which can last the patient's entire existence. In addition, they are able to penetrate the tumors within the body with satisfactory progress. However, T-cells only target one tumor type. "The feasibility of these T-cells is really hard," said Barber.
Concerning the research, Barber said the idea was to combine the pros of the NK cells and the T-cells being used. A specific receptor was created, called the chimeric NKG2D (chNKG2D) receptor. The research found that NKG2D ligands were found in the lung, breast, colon and kidney cancer cells, among others. In fact, about 80 percent of all cancers might express the ligands for this particular receptor. In humans, these ligands are not found in normal tissues. "We think our treatment will leave the healthy tissues alone," Barber commented.
Barber also said the addition of receptors could target and kill ovarian cancer cells thanks to proven research in the clinic. During one particular study, cells after a patient's surgery were actually used as test material.
One of the questions was if the chNKG2D receptor could eliminate an established tumor burden and increase the survival rate. Using the receptor on mice cancer cells, they found with ovarian and melanoma cells that the survival rate was 100 percent, and the mice remained tumor free.
In humans, cancer can easily recur because some cells are not removed during treatment. Just like before, through more research, they found the chNKG2D receptor was able to keep cancer from recurring with a 100 percent achievement rate in mice.
Next semester, Barber said she will be working with students to further understand what downstream signaling pathways are structured and how this affects the functionality of the T-Cells.
Monday's Blackwell Talk was the last one of the semester.
Dr. Baber discusses one of the slides detailing her research on fighting cancer
