Stem Cells Provide Niche for Growth of Human Ovarian Cancer Cells in Mice

Cancer researchers have developed an in vivo model system that promotes growth of certain types of tumors that fail to grow in the traditional mouse xenograft format. The xenograft procedure of transplanting human cancer cells into immunocompromised mice has become an important tool for the development of anti-cancer drugs.

As some types of tumors fail to grow as classical mouse xenografts, investigators at the Technion-Israel Institute of Technology (Haifa, Israel) sought to develop an alternate methodology. To this end, they extended previous studies carried out with human embryonic stem cells (hESCs). In the current work, they injected hESCs into mice in order to establish human-based teratomas. They then transplanted human ovarian cancer cells, either directly from a patient or after being cultured as subpopulations, into teratomas in different mice. Immunocompromised mice without teratomas served as the control group.

Results published in the January 2009 online edition of the journal Clinical Cancer Research revealed that certain subpopulations that did not develop into tumors in the conventional mouse xenograft model did generate tumors in the hESC-derived teratomas. The hESC-derived teratomas provided a microenvironment that promoted growth of certain tumor cell subpopulations. Examination of the tumors revealed the presence of "master cells" - the progenitors responsible for the recurrence and regrowth of cancer, even after derivative "daughter" cells are killed off by chemotherapy.

"Growing cancer stem cells from the patient in a way that mirrors their growth in the human body could allow clinicians to check the sensitivity of a particular tumor to different treatments," explained senior author Dr. Maty Tzukerman, professor of medicine at the Technion. "This ability could provide clinicians with ways to customize cancer treatments for each individual patient."

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Technion-Israel Institute of Technology