GreatWall International Cancer Certer
Cancer Stem Cells Target Therapy    

What are cancer stem cells?

The cancer cells in a tumor are arranged in a hierarchy and contain a minority population of
cancer stem cells that drive tumor growth while the majority of the cancer cells are unable to
do so. These small populations of self-renewing cells that give rise to all of the cells in the
tumor are called cancer stem cells. Though cancer stem cells make up less than 5 percent of a
tumor, they may underlie the cancer and be resistant to conventional treatments.

Therapeutic implications of cancer stem cells

Characters of cancer stem cell

A defining characteristic of human cancer stem cells is the ability to grow new tumors. As few
as 100 cancer stem cells could regenerate copies of the original tumor when transplanted into
mice. Some tumors rapidly spread to other organs, as often happens in patients.
Cancer stem cells have originally been identified in leukemia and later in several solid tumor
types. They have very different properties from the bulk of the tumor, as they divide much
more slowly and have very efficient drug- resistance mechanisms. Current treatments might
largely spare cancer stem cells, thus leading to tumor recurrence and metastasis. The recent
identification of growth and differentiation pathways responsible for cancer stem cell
proliferation and survival will help in the discovery identification of novel therapeutic targets.
Developing selective drugs against cancer stem cells offers not only further understanding of
mechanism of tumorigenesis but also provides for great therapeutic opportunities.
Cancer stem cells in solid tumors are the main reason for chemotherapy and radiation therapy
failure. Cancer stem cells are dormant and have pumps to pump out chemotherapy drugs,
resulting in chemotherapy failure and cancer metastasis as well as recurrence. According to
this current recognized theory, chemotherapy itself only has effects on fast proliferating cancer
cells and causes tumor shrinking, but has no effects on cancer stem cells which lead to later
cancer recurrence and metastasis. Until now, no drugs that target cancer stem cell effectively
are in commercial use.

Our treatment targeting at cancer stem cells

Cancer stem cells have been isolated in various solid tumors including breast, pancreas,
ovary, colon and rectum cancers. In China, research into the PI3K-AKT-mTOR signaling
pathway (a recently discovered mechanism by which cancerous stem cells transmit signals)
with regards to targeting cancer stem cells and overcoming their resistance to chemotherapy
has proved rewarding. By targeting cancer stem cells in breast, pancreas and colorectum
cancer with the novel agents identified by researchers and physicians in China, positive results
in controlling cancer progression and extending survival time have been obtained.

Last Updated ( Wednesday, 13 February 2008 16:18 )  

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