Israel Medical Association Journal

Mesenchymal stem cells, or mesenchymal stromal cells, have emerged as a major new cell technology with a diverse spectrum of potential clinical applications. MSCs[1] were originally conceived as stem/progenitor cells to rebuild diseased or damaged tissues. Over the last 14 years, since the first report of MSC infusions in patients, the cells have been shown to suppress graft vs. host disease, stimulate linear growth in a genetic disorder of bone, and foster engraftment of haplo-identical hematopoietic stem cells. In all cases, few, if any, MSCs were identified at the site of clinical activity. This experience suggests a remarkable clinical potential, but a different general mechanism of action. Systemically infused MSCs seem to exert a therapeutic effect effect through the release of cytokines that act on local, or perhaps distant, target tissues. Rather than serving as stem cells to repair tissues, they serve as cellular factories that secrete mediators to stimulate the repair of tissues or other beneficial effects. Since both the tissue source of MSCs and the ex vivo expansion system may significantly impact the cytokine expression profile, these parameters may be critically important determinants of clinical activity. Furthermore, cell processing protocols may be developed to optimize the cell product for a specific clinical indication. For example, MSC-like cells isolated from placenta and expanded in a three-dimensional bioreactor have recently been shown to increase blood flow in critical limb ischemia. Future efforts to understand the cytokine expression profile will undoubtedly expand the range of MSC clinical applications.

Background: Metastatic melanoma is an aggressive and highly malignant cancer. The 5 year survival rate of patients with metastatic disease is less than 5% with a median survival of only 6–10 months. Drugs like dacarbazin (DTIC) as a single agent or in combination with other chemotherapy agents have a response rate of 15–30%, but the duration of response is usually short with no impact on survival. Interleukin-2-based immunotherapy has shown more promising results. The National Institutes of Health recently reported that lymphodepleting chemotherapy, followed by an adoptive transfer of large numbers of anti-tumor specific tumor-infiltrating lymphocytes, resulted in an objective regression in 51% of patients.

Objectives: To introduce the TIL[1] technology to advanced metastatic melanoma patients in Israel.

Methods: We generated TIL cultures from tumor tissue, choosing those with specific activity against melanoma and expanding them to large numbers.

Results: TIL cultures from nine patients were established and examined for their specific activity against the patients' autologous tumor cells. Twelve TIL cultures derived from 5 different patients showed the desired anti-tumor activity, making those 5 patients potential candidates for the therapy.

Conclusions: Pre-clinical studies of the TIL technology in a clinical laboratory set-up were performed successfully and this modality is ready for treating metastatic melanoma patients at the Sheba Medical Center's Ella Institute.

Regenerative medicine concerns the development of cells, tissues and organs for the purpose of restoring function through transplantation.

Stem cell research offers great hope to patients suffering from neuronal damage. Stem cell-based regenerative medicine holds huge potential to provide a true cure for patients affected by a neurodegenerative disease or who have suffered a stroke.