Posts Tagged ‘cancer stem cell’

Frozen blood a source of stem cells, study finds

Friday, July 2nd, 2010

(Reuters) – Frozen blood from stored samples can be used to make cells resembling stem cells, researchers said on Thursday — opening a potential new and easier source for the valued cells.

They used cells from blood to make induced pluripotent stem cells or iPS cells — lab-made cells that closely resemble human embryonic stem cells but are made from ordinary tissue.

These iPS cells have in the past been made from plugs of skin, but blood is much easier to take from people and to store, the researchers reported in the journal Cell Stem Cell.

“Blood is the easiest, most accessible source of cells, because you’d rather have 20 milliliters of blood drawn than have a punch biopsy taken to get skin cells,” Judith Staerk of the Whitehead Institute for Biomedical Research in Massachusetts, who worked on the study, said in a statement.

Stem cells are the body’s master cells, the source of renewed blood and tissue. So-called adult stem cells exist through life but they are partially developed.

Embryonic stem cells from days-old embryos have the ability to become all the cell types in the body and also can proliferate in the lab for years.

IPS cells are made by activating three or four genes that distinguish embryonic stem cells.

Whitehead’s Rudolf Jaenisch, who directed the work, said being able to use blood will open opportunities for researchers who want to use iPS cells to study how diseases develop.

“There are enormous resources — blood banks with samples from patients that may hold the only viable cells from patients who may not be alive any more, or from the early stage of their diseases,” Jaenisch said.

“Using this method, we can now resurrect those cells as induced pluripotent stem cells. If the patient had a neurodegenerative disease, you can use the iPS cells to study that disease.”

(Reporting by Maggie Fox; Editing by Julie Steenhuysen)

Cancer Stem Cells | Human Cell Research | Drug Discovery | Conversant

Monday, August 31st, 2009

Most chemotherapeutic drugs today are targeting mature cancer cells…  are these cancer drugs targeted at the wrong kinds of cells?

This is a pretty tough problem.  While we know that currently available cancer drugs dramatically reduce the size of tumors, we also know that MOST cancers will eventually recur.  There is some amazing, pioneering work being done in universities, non-profits (like HudsonAlpha), and biopharma to address this issue.  Some research we’ve reviewed points toward small populations of cells — “cancer stem cells” or “CSC”s  — that are ultimately responsible for the growth of tumors and are resistant to current therapies.

Most of our existing cancer treatments have been developed based on animal models, where therapies that can show ability to promote tumor shrinkage were considered effective.  Most mice do not live beyond 1-2 years so using that model to assess relapse is not practical.

Also, the efficacy of cancer treatments is, in the initial stages of testing, often measured by the ablation fraction of tumor mass (fractional kill).  Since the theory is that CSCs form a very small proportion of a given tumor, this may not necessarily select for drugs that act specifically on the cancer stem cells.  Since conventional chemotherapies kill differentiated or differentiating cells – which form the bulk of the tumor but are unable to generate new cells – a population of CSCs, which gave rise to it, could remain untouched and cause a relapse of the disease.

More next time…