Click here to download the HSCI Cancer Program Overview.

Most existing cancer therapies are designed to shrink a tumor mass, but do not eradicate the tumor. Following tumor mass reduction therapy, in 80% of cases the tumor will return and either the cancer or the toxicity of the treatment will be fatal. The HSCI Cancer Program's research is aimed at developing new cancer-eradicating, rather than tumor-shrinking, therapies designed to destroy cancer stem cells, which are believed to be responsible for the growth and propagation of tumors.

There is evidence that cancer stem cells exist in central nervous system, colon, pancreatic, and ovarian cancers, however these stem cells cannot yet be positively identified nor can they be purified for therapeutic research. Thus, the program's first goal is to meet this challenge by identifying and purifying colon and ovarian cancer stem cells. The team chose to focus on these two cancers first because the experiments require large tumor tissue samples, which exist in these cancers. HSCI's clinical presence is critical because obtaining the tissue samples for researchers requires access to specialized surgical facilities that treat patients with these diseases.

Collaborating with World-Class Hospitals

Working in collaboration with HSCI-affiliated surgical oncology hospitals—the Massachusetts General Hospital for ovarian cancer and the Brigham and Women's Hospital for colon cancer—has made the complicated and multi-step process of sample acquisition feasible and has allowed HSCI researchers to identify primary tumor cells in human colon and ovarian cancer. From these primary cells the team has narrowed down the possible cancer stem cell populations to a few candidates in each case.

Screening for Cures

The program is also working with purified leukemia cells and has designed a method for efficiently and effectively purifying the stem cells and screening for drugs that could target and destroy leukemia cells without affecting normal cells. There are approximately 200 types of leukemia (the complexity of solid tumors is even greater), and each may have a unique stem cell. However, this technique specifically targets the stem cell properties shared by all leukemia cells, thus avoiding the need to uniquely identify individual stem cell types.

Once the team has successfully identified colon and ovarian cancer stem cells, they will use the method developed for purifying and screening leukemia stem cells to search for treatments for colon and ovarian cancer. This year, HSCI also funded a seed grant that will focus on developing screens for the genes that regulate breast cancer stem cells.

Initiating a Broad Discussion

Moderating this year's Malkin Symposium, which focused on cancer stem cells, were Gary Gilliland, Director of HSCI's Cancer Program, and Jerome Ritz, an HSCI Faculty Executive Committee member. Speakers at the event included Owen N. Witte, MD, of the University of California at Los Angeles; John Dick, PhD, of the University of Toronto; Scott Armstrong, MD, PhD, an HSCI Principal Faculty member at Children's Hospital Boston; Kornelia Polyak, MD, PhD, of the Dana Farber Cancer Institute; and Peter Dirks, MD, PhD, of the University of Toronto, Hospital for Sick Children.