“Latest Stem Cells News”

Researchers at Queen Mary, University of London, studied equivalent cells taken from mouse brains. Principal investigator Silvia Marino, Professor of Neuropathology at Queen Mary, University of London, and her team showed that medulloblastomas can grow from a type of brain stem cell and that these cancers are a distinct form of the disease which may require a completely different approach to treatment.

Like a Hole in the Head: Living with a Brain Tumour

An experimental drug is on the way, which might be effective to fight brain cancer (glioblastoma) and prostate cancer.
The researchers are experimenting on this drug at the University of Texas Southwestern Medical Centre (UTSMC).
According to Jerry Shay, professor of cell biology, the drugs are promisisng because they attack not only the tumour cells but also the rare cancer stem cells in the body. So, it would be effective to root out cancer from the body.
“Because it attacks a mechanism that’s active in most cancers, it might prove to be widely useful, especially when combined with other therapies,” said Shay.

An experimental drug currently being tested against breast and lung cancer shows promise in fighting the brain cancer glioblastoma and prostate cancer, researchers at UT Southwestern Medical Center have found in two preclinical studies.

The drug’s actions, observed in isolated human cells in one trial and in rodents in the other, are especially encouraging because they attacked not only the bulk of the tumor cells but also the rare cancer stem cells that are believed to be responsible for most of a cancer’s growth, said Dr. Jerry Shay, professor of cell biology and a senior co-author of both papers. The glioblastoma study appears in the January issue of Clinical Cancer Research. The prostate cancer study is available online in the International Journal of Cancer.

Warnings are being issued by experts of the dangers of medical tourism saying that unproven stem cell therapy overseas could leave patients worse off.

Signing up for stem cell therapy is worth the risk for many people who are suffering with conditions like spinal injury, multiple sclerosis, motor neuron or Parkinson’s disease.

A medical journal reported earlier this year that an Israeli teenager developed brain tumors after experimental injections at a Russian clinic.

There are alternate reports also of patients contracting meningitis after treatments in China.

A handbook will be released by the Australian Stem Cell Centre to help patients analyze radial stem cell treatments abroad.

Experts, however, are warning patients against taking the risk with radical treatments abroad.

The Australian Stem Cell Centre Clinical adviser Dr Kirsten Herbert says that three patients contracted meningitis after stem cell treatment in China because of spinal cord injuries.

He also adds that cancer too is a possible side-effect although the likelihood is very rare.

It is important to not demoralize people who are seeking these cures but they must be helped in finding the right advice.

from http://topnews.us/content/28514-warning-issued-against-stem-cell-tourism-experts

CD133 (Prominin) is widely used as a marker for the identification and isolation of neural precursor cells from normal brain or tumor tissue. However, the assumption that CD133 is expressed constitutively in neural precursor cells has not been examined.

Methodology/Principal Findings

In this study, we demonstrate that CD133 and a second marker CD15 are expressed heterogeneously in uniformly undifferentiated human neural stem (NS) cell cultures. After fractionation by flow cytometry, clonogenic tripotent cells are found in populations negative or positive for either marker. We further show that CD133 is down-regulated at the mRNA level in cells lacking CD133 immunoreactivity. Cell cycle profiling reveals that CD133 negative cells largely reside in G1/G0, while CD133 positive cells are predominantly in S, G2, or M phase. A similar pattern is apparent in mouse NS cell lines. Compared to mouse NS cells, however, human NS cell cultures harbour an increased proportion of CD133 negative cells and display a longer doubling time. This may in part reflect a sub-population of slow- or non-cycling cells amongst human NS cells because we find that around 5% of cells do not take up BrdU over a 14-day labelling period. Non-proliferating NS cells remain undifferentiated and at least some of them are capable of re-entry into the cell cycle and subsequent continuous expansion.

Conclusions

The finding that a significant fraction of clonogenic neural stem cells lack the established markers CD133 and CD15, and that some of these cells may be dormant or slow-cycling, has implications for approaches to identify and isolate neural stem cells and brain cancer stem cells. Our data also suggest the possibility that CD133 may be specifically down-regulated during G0/G1, and this should be considered when this marker is used to identify and isolate other tissue and cancer stem cells.

from Elites TV

A new drug combination tested in mice may target the cells responsible for driving some pancreatic tumors. The combination of gemcitabine and the experimental drug tigatuzumab eliminated populations of cancer stem cells and reduced tumor growth in a mouse model of pancreatic cancer, researchers from the Johns Hopkins Sidney Kimmel Cancer Center reported at the AACR annual meeting.

The results provide a rationale for testing the promising combination in patients with this deadly disease, Dr. Rajesh Kumar NV and his colleagues concluded.

Cancer stem cells are thought to self renew while giving rise to tumors, and they may resist conventional treatments. The researchers found that human pancreatic cancer stem cells overexpress a protein called death receptor-5 (DR-5), which is involved in programmed cell death (apoptosis). The protein is also the target of tigatuzumab, a humanized monoclonal antibody also known as CS-1008.

To evaluate the drug’s effects on these important cells, mice were given tigatuzumab alone, gemcitabine alone, or a combination. Although gemcitabine reduced tumor size, it increased levels of pancreatic cancer stem cells (as defined by the protein markers ALDH, CD24, and CD44), and all of the tumors recurred. The combination treatment, however, led to long-term remissions in half of the treated mice.