Tag Archives: bone-marrow

Research shows cell’s inactive state is critical for effectiveness of cancer treatment

by Esther Napolitano, napolite@mskcc.org
Memorial Sloan-Kettering Cancer Center

A new study sheds light on a little understood biological process called quiescence, which enables blood-forming stem cells to exist in a dormant or inactive state in which they are not growing or dividing. According to the study’s findings, researchers identified the genetic pathway used to maintain a cell’s quiescence, a state that allows bone marrow cells to escape the lethal effects of standard cancer treatments.

Researchers at Memorial Sloan-Kettering Cancer Center (MSKCC) found elevated levels of the tumor suppressor protein p53 in hematopoietic stem cells (HSCs) immature cells in the bone marrow that have the capacity to differentiate into all types of mature blood cells. They showed that when chemotherapy or radiation is delivered to a cell that lacks both p53 and a gene called MEF, the cell not only becomes less quiescent, but also becomes more susceptible to being killed. These findings are published in the January 9, 2009, issue of Cell Stem Cell.

“This is the first time that anyone has established that p53 has a role in defining a cell’s state of quiescence. Furthermore, it is surprising that some cells that lose p53 can actually be killed more readily than those that have p53 intact,” said the study’s senior author, Stephen Nimer, MD, Chief of the Hematology Service and Member of the Molecular Pharmacology and Chemistry Program at MSKCC. “Our findings have important implications for developing therapeutic strategies that could eliminate quiescent cancer stem cells.”

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Marrow-stem cell donor matching program does life-saving work

Dan Scheffers, of Kalamazoo is tested to possibly become a bone marrow donor.

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Stem Cells And Leukemia Battle For Marrow Microenvironment

From MedicalNewsToday.com

Learning how leukemia takes over privileged “niches” within the bone marrow is helping researchers develop treatment strategies that could protect healthy blood-forming stem cells and improve the outcomes of bone marrow transplantation for leukemia and other types of cancer.

In a paper in the journal Science, available early online Dec. 19, 2008, researchers from the University of Chicago Medical Center show that by blocking one of the chemical signals that leukemic cells release, they could help prevent the cells that mature to become red and white blood cells from being shut down by the cancerous invader.

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FDA Approves Drug that Boosts Stem Cell Yield for Bone Marrow Transplants

From FDA.gov

The U.S. Food and Drug Administration today approved Mozobil (plerixafor), a drug that helps increase the number of blood stem cells for bone marrow transplantation in patients with certain forms of blood cancer.

Mozobil is intended to be used in combination with the growth factor granulocyte-colony stimulating factor (G-CSF), for treatment of adults with multiple myeloma or non-Hodgkin’s lymphomas. Multiple myeloma is cancer of the plasma cell, a cell in the bone marrow that produces antibodies to help fight infection and disease. Non-Hodgkin lymphomas are a diverse group of blood cell cancers derived from lymphocytes, a type of white blood cell.

Prior to receiving high-dose chemotherapy or radiation therapy, patients with these forms of cancer sometimes undergo a procedure known as apheresis in which blood stem cells are collected and stored for reinfusion after therapy. G-CSF is commonly administered to help release and collect stem cells from the bone marrow. Mozobil is an injectable drug that, when used in combination with G-CSF, boosts the number of stem cells released from the bone marrow into the blood stream.

“Collecting the millions of cells needed for a bone marrow transplant can take hours or days,” said Richard Pazdur, M.D., director, Office of Oncology Drug Products, Center for Drug Evaluation and Research, FDA. “Mobozil provides a new therapeutic option for patients with certain types of blood cancers by increasing the number of stem cells collected in a given time period to be reinfused after therapy.”

In two randomized clinical trials – one in patients with non-Hodgkin’s lymphoma, the other with multiple myeloma – Mozobil combined with G-CSF increased the number of stem cells available for collection and transplantation compared with patients receiving G-CSF alone.

The most commonly reported adverse reactions in these trials and other smaller studies were diarrhea, nausea, fatigue, injection site reactions, headaches, joint pain, dizziness and vomiting.

Mozobil is manufactured by Genzyme Corp., Cambridge, Mass.