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Category Archives: Stem Cells

Text of Klein’s Comments Supporting Rejected Applications

Posted: August 26, 2012 at 3:55 pm


Robert Klein, who served 6 ½ years as the first chairman
of the $3 billion California stem cell agency,  testified before the agency's board for the first time on July 26, 2012. Klein, a real
estate investment banker and attorney, spoke on behalf of two applicants whose
grants had been rejected by the agency's reviewers. The appearance
has raised questions about the propriety of Klein's actions.

Here is a link to an item on his appearance. Here is the text of
his comments as reported in the transcript of the meeting.

“As the board knows, I've never addressed any grant from the
floor. It is critical here to understand that we have here
StemCells, Inc., which is the only company in North America
and, for that matter, maybe in the world, that has had two stem cell
therapies in the brain with these specific neural stem cells. They
have a huge body of experience here. 

“Secondly, one of the fundamental issues here that it (the
company's grant application) was downgraded on was the issue of the
fundamental concept, the platform concept, of injecting two focal
injections in the brain, in the hippocampus of the brain. It's
important to note that I've sat on three (CIRM)peer reviews where the
scientists really affirmed this specific approach with extremely high
scores, three different views. All right.

“So it's very important to realize we have a standard deviation
here of 12 (on the review scores). These scientists were completely
split. With some recusals on that panel, if you have 12 or 13 that
can really vote, three or four very low scores can bring it out of
the funding category all the way down. It is in the region where
this board is looking where the other three peer reviews, right,
early translation, the one before that was the planning grant review,
that the hippocampus was a good platform.

“Then they said the key weakness was you can't show migration.
Dr. Laferla (a co-PI on the application) has told me that
today the Journal of Neuroscience accepted the publication of
the data demonstrating migration. It was stated previously in the
application, but it wasn't accepted for publication. It now is.
That is the fundamental weakness that they identified in this
approach.  

“So we have a reaffirmed approach to the hippocampus by three
different peer review groups and a substantial portion of these
reviewers along with data dealing with the weak point. I'm sorry it
happened today. The data was out there, accepted for publication
today, means that it should definitely fall into this category. And,
of course, Dr. (Alan) Trounson (president of CIRM) wouldn't
have been able to review that in process because he was recused from
this grant by his own voluntary recusal. So the progress of this
data being accepted for publication is new information today. 

“If I look at the entire history of CIRM, as Leeza (Gibbons,
a CIRM director) says, building up to this point, we have reaffirmed
this approach from the very beginning with Dr. Laferla, with multiple
scientific approvals, and board approval, and we have the best
company in North America with the greatest experience with these
neural stem cells, with the best researcher we have for the potential
to address this disease, and we have brand-new data that demonstrates
and totally contradicts the key weakness on which it was downgraded.”

Here is the text of Klein's remarks on
behalf of a second application, also rejected by CIRM reviewers.

“This is the only other disease team grant I will address. Very
specifically, this was a disease team grant that I was on the peer
review in the planning grant stage. There are some fundamental
issues here. Is the international company on which the one antibody
that's not coming from Stanford, the two for sorting are
coming from Stanford, is the other antibody coming from this
international company a commitment that you can rely on? 

“The reviewers said this was a showstopper. That's the word they
used. They made a decision this was a showstopper because they did
not believe the company because they thought that the documentation
was inadequate. You now have a letter that goes into great
proprietary depth about the depth of this company's commitments
written by the head of development and translation internationally
for the company. 

“If we cannot depend on company commitments of this type, and
you will review the letter in executive session, if you have one, I
will not understand how we'll be able to collaborate with companies
with proprietary products and processes where they're making
commitments to academic institutions of the highest standard. I
believe this company is going to perform. I was on an hour call to
confirm with eight members of that company their level of commitment,
and I am completely convinced by that point. 

“The review is completely factually wrong on this issue about
the other two antibodies for sorting this. Dr. (Irv) Weissman
has just said they have not only been developed, they have been used
in clinical trials. There's data on them. And they are, in fact,
being thawed under FDA direction to reuse in this trial. 

“So I believe there's a major factual difference. Remember with
Karen Aboody there was a major factual error that was pivotal
in elevating that, and we found tremendous performance on that grant
by Karen Aboody of City of Hope

“So you have a decision to make. As a risk issue, do we believe
this company? Finally, this is broader than SCID. 

Donald Kohn has written a letter that's in the public
domain that I suggest you read. It makes it very clear that opening
the niche for repopulating the immune system without chemotherapy and
radiation is a key contribution to every form of genetically modified
stem cells for an entire range of childhood diseases and other
genetic diseases in addition to therapies like sickle cell or aids. 

“I suggest that that profound contribution that can be made to
the field is a risk that is worth taking early on because of his
contribution to so many other areas. You have 12 other letters from
North America's leading pediatric geneticists that fundamentally
provide extraordinary support for this position and this approach.”

Source:
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CIRM Board Member Prieto Defends Klein's Right to Appear Before Board

Posted: August 26, 2012 at 3:54 pm


A member of the governing board of the
California stem cell agency, Francisco Prieto, has commented
in an email about the “unseemly performance” item concerning the
agency's former chairman, Robert Klein. Prieto is a
Sacramento physician who serves as a patient advocate member of the
board. He has been on the board since its inception. Here are his
remarks.

“I wanted to comment on this piece
from the perspective of another patient advocate.  While I think
you know that I did not always agree with Bob Klein during his tenure
on the ICOC(the agency's governing board), I would strongly defend
his right to appear and give his opinions to the Board.  He is a
private citizen now, albeit one with considerable experience and
expertise, and I think his greatest vested interest in this case
stems (you should pardon the expression) from being the child of a
parent with Alzheimers.  As you point out, some eyebrows may be
raised, and I can imagine that some board members might be swayed in
either direction by his testimony, but  he is a passionate and
committed advocate, and he has the right to advocate before us.”

Source:
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An Unseemly Performance: Former Chair of Stem Cell Agency Promotes $20 Million Research Proposal

Posted: August 26, 2012 at 3:54 pm


Bob Klein is nearly an icon in the
history of the $3 billion California stem cell. And when he appeared
before its governing board last month and aggressively touted a $20
million grant proposal already rejected by agency reviewers, his
actions raised eyebrows.

Robert Klein
Elie Dolgin/Nature photo
Klein's comments carried unusual
weight, given that they were supported by his unique and influential
relationship with the California Institute for Regenerative
Medicine(CIRM)
. He and his associates wrote the 10,000-word ballot
initiative that created the stem cell agency in 2004. He ran the $35
million electoral campaign that convinced voters to buy into the
idea. Klein raised millions on behalf of the effort. He personally
provided the campaign $3 million. And he was the first chairman of
the agency, leaving that office only 13 months ago, when he was
designated chairman emeritus.
The meeting last month marked Klein's
first public appearance before the board on behalf of a specific
application.. He heralded the applicant, StemCells, Inc., as unique
and the “best” in United States with a “huge body of
experience.”

(The full text of his testimony can be found here.)
Irv Weissman
Stanford Photo
StemCells Inc. is a publicly traded company based in Newark, Ca., that was founded by renown Stanford
scientist Irv Weissman, who sits on its board. Weissman also played
an important role in the Prop. 71 ballot campaign that created the
stem cell agency. StemCells, Inc.'s application was turned down by
CIRM reviewers who gave it a score of 61, but the company appealed the action to the agency's governing board. Following the appearance by Klein, Weissman and others, the CIRM board sent the application back for more review.
The board will reconsider it next month or in October.
One California stem cell researcher,
who requested anonymity, said it is “highly inappropriate for Bob
Klein to be advocating for any grant application from a public
company.”
The scientist said,

 “He has
considerable influence with the ICOC(the CIRM governing board), and
is closely associated with biotech in the Bay Area. Even if he
doesn't make a lot of money himself from this, then he certainly has
friends who will.  Irv Weissman would be one of those friends."

In response to questions asked on Aug. 7 by the
California Stem Cell Report, Klein today defended his actions.  He was asked if he had “any sort of
financial ties” to firms or individuals that would benefit from
approval of the award. Klein, who is a real estate investment banker and also an attorney, said he has
“no financial interest” in the firm or individuals that might
benefit.
Klein also indicated his appearance was
entirely appropriate. He defined his role as a patient advocate –
not as a lobbyist who is paid for advocating on behalf of a company.
Klein said he had “a particular responsibility to contribute my
background knowledge and experience.”
Klein said he hoped other former board
members would follow his example. He said,

“(I)t would be a tragedy if the
expertise of board members built up over six or more years is lost.”

(The full text of his response can be found here.)
Klein's appearance came at a propitious
time for financially strapped StemCells, Inc. The company's
financial information shows that it is losing $5.4 million a quarter
as of the end of June and had only $9 million in cash on hand. It
also had liabilities of $11.6 million, up substantially from $8.5
million in September of last year.
The researcher who criticized Klein's efforts as inappropriate also said,

"StemCells Inc has been on the
stock market for 20 years, without producing anything of value for
the investors.  The stock price has been sinking fast:  it
was 60 cents this June; last year at this time, it was around $5 a
share.   

“On July 17, when the CIRM Disease
Team Award review results became available, the stock rose from 87
cents to $1.80 – a person who could anticipate the outcome of the
CIRM applications could have made considerable money in that 24 hour
period.”

Weissman's role
with the StemCells, Inc., is more than scientific. According to the
company's financial statements, he holds 88,612 shares. His wife,
Ann Tsukamoto
, is executive vice president of the firm. She holds
185,209 shares in the firm.
Weissman played a significant role in
the Prop. 71 campaign. He did the “billionaire circuit,” raising
money for the initiative, according to an article by Diana Kapp in
San Francisco magazine. Among other things, Weissman worked the
exclusive Bohemian Grove in Northern California and “pitched”
Bill Bowes, a co-founder of Amgen, who, along with his wife, gave
$1.3 million to the campaign. Weissman was the key to securing a
$400,000 contribution from Microsoft's Bill Gates. Weissman also plumped for Prop. 71 in a TV campaign ad.
In addition to StemCells, Inc., Klein
and Weissman supported a successful attempt last month to overturn
reviewers' rejection of another $20 million application by Judith Shizuru
of Stanford. The application received a score of 53 from reviewers.
One of the application's problems cited
by reviewers was the availability of antibodies for the study. The
antibodies were developed by Systemix, a company founded by Weissman.
Systemix was acquired by Novartis in 1997 for about $70 million.
Weissman said he has “negotiated back” rights to key antibodies,
which he said are now held by Stanford.
Klein said that reviewers believed the
research was “a showstopper” but did not think the documentation
was adequate. He told the CIRM directors that they now have a letter
with proprietary information that supports the grant application.
Our take: The stem cell agency has long
labored under the perception that it is something of an insiders'
club. Even the prestigious journal Nature warned in 2008 about what
it called “cronyism” at CIRM. If anything, the situation is worse today,  four years later. Enterprises associated with persons on the CIRM board of directors have received more than 90 percent of the funds handed out by the agency. Klein's efforts last month
reinforce the not-so-pleasant image of the stem cell agency as an
old boy's club and create an impression – at the very least – of
unseemly insider influence.

Source:
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Text of Klein's Response to Questions Concerning His Advocacy on Rejected Grant Applications

Posted: August 26, 2012 at 3:54 pm


Here is the text of Robert Klein's response today to the California Stem Cell Report concerning his appearance before the governing board of the California stem cell agency July 26, 2012. Klein, former chairman of the agency, real estate investment banker and attorney, promoted two applications seeking $20 million each from the agency. Both applications had been rejected by the agency's reviewers. Here is a link to an item on the subject.

"Dear David,
"You have posed two
questions related to my continuing role as a Patient Advocate in
contributing information to the Board of the California Institute for
Regenerative Medicine
, in an effort to optimize decisions on medical
and scientific grants and loans for research that could mitigate
and/or cure chronic diseases or injuries. 

"Q: Do you have any sort
of financial ties to StemCells Inc. or any of the individuals or
firms that would benefit from approval of those awards by the ICOC(the CIRM governing board)?
"A: I have no financial
interest in StemCells Inc. or any of the individuals or firms that
would benefit from approval of those awards by the ICOC. In fact, I
have no financial interest in any biomedical research company.

"Q: Do you think it is
appropriate for the former chairman of the ICOC to lobby that body on
behalf of awards to specific companies or individuals?
"A: First, it is
fundamental that the terms be defined to properly respond to your
question. A “Patient Advocate” is a member of a patient family or
a medical/scientific care /support group who advocates for medical
and scientific advances that might potentially mitigate and/or cure a
patient’s chronic disease or injury. A “Patient Advocate” is
not paid for his/her advocacy, unless they are staff members of a
non-profit institution dedicated to a specific disease or group of
diseases or injuries. 

"Second, a “lobbyist”
is a paid representative of a company or a for-profit institution(s)
with a financial interest in the outcome of a governmental decision. 

"I am serving as a
Patient Advocate in my presentations to the Board of the California
Institute for Regenerative Medicine. As the former Chairman of the
Board, I have a particular responsibility to contribute my background
knowledge and experience for the Board to consider, along with all
new information, in reaching their best decision. I hope other former
Board members, who possess a wealth of scientific, medical, and
institutional knowledge that can benefit the Board, would consider
the value they can contribute to future decisions. As Board terms
expire, it will be important not to lose that institutional knowledge
and medical/scientific expertise that has been built up over the last
seven plus years of the Agency’s existence. 

"In an outline format,
I would suggest the following areas where the knowledge of former
Board members can be especially valuable in optimizing the input for
Board decisions in the future. 

"A number of Board
members have participated in up to 20 or more Peer Review meetings,
some of which cover multiple days. Current grant or loan requests
represent the result of scientific and medical advancement that has
been intensely vetted in prior peer reviews; the information gained
in those peer reviews should not be lost, when a subsequent grant or
loan request – built on the earlier research outcomes – is
considered. Each peer review session has the benefit of different
specialists and scientists and/or biotech representatives with
unique backgrounds and areas of expertise. The value of the prior
contributions may be pivotal, in considering a later application,
developed from the earlier medical or research advances funded
through CIRM’s grants or loans. The current peer review,
scientific staff presentation, and Board expertise, is not the limit
of the Board’s information, in reaching the best current decision.
To the extent the Board can draw from prior peer reviews (unique
insights), prior scientific staff presentations, and prior Board
expertise, additional information that can enhance a potential
decision, the Board has the opportunity to optimize its decision
making process. This is particularly valuable, when there is a high
standard deviation – a substantial split – in the scoring
positions from the current peer review. 

"Beyond peer review
participation, Board members have intensely engaged in another 35
plus Working Group sessions on Facilities and Standards, in addition
to more than 70 Board meetings and over 125 Subcommittee meetings,
as of August 2012. Retiring Board members possess a treasury of
information on policy development, process, federal and state laws
and regulations, and the regulations of the agency, as well as in
depth information on research facilities and capabilities throughout
California, the nation, and the world. It takes a substantial length
of time for a new Board member to gain a comprehensive knowledge in
all of these areas and each Board member will develop unique
insights, which it would be a tragedy to lose. As Chairman, I
frequently reached back to consult with former Board members on
areas of their special expertise and I would hope that all current
and future Board members utilize the significant asset in developed
knowledge of the prior Board members. To the extent prior members
can be available for public meetings, this would be a substantial
benefit to the agency to broadly inform the Board, the scientific
staff, and the public. 

"The Board has a
unique contribution to make on programmatic resource allocations and
risk management of the research and clinical investments in each
disease area. The opportunities in some disease areas for major
advancement are numerous, whereas there are major diseases and/or
critical research areas where the potential, high-value advancement
options are relatively limited. For Board members who have
participated in over 20 peer reviews and 70 Board meetings, the
programmatic perspective on the opportunities in each disease area
has been highly developed. Concurrently, those Board members or
former Board members have substantial knowledge that is of critical
value in reaching programmatic decisions on the number of
opportunities for advancement in any specific disease area and the
relative risk that needs to be taken to accomplish meaningful
breakthroughs in advancing the research and clinical opportunities
in a disease and/or injury area. 

"I hope these examples
of how former Board members can contribute to the current Board’s
information in reaching decisions on the best medical/scientific
grants and loans are helpful. As I stated earlier, it would be a
tragedy if the expertise of Board members built up over six or more
years is lost. The field is extremely complicated and the Board needs
the opportunity to consider all of the information available. The
Board can choose to accept or reject any past advice or opinions
gained from prior peer review sessions or Board meetings, but the
Board should have access to the full spectrum of information and the
treasury of scientific and medical advice the agency has received
since its inception.

"There are areas that I
have not addresses in this short response, such as the institutional
value of applicants being able to rely upon prior scientific and/or
policy direction, in their current applications. From a historical
perspective, prior Board members and/or the Chairman can have
significant information that is relevant to these evaluations,
especially if the individual Board member served on a special Task
Force , Subcommittee or peer review. These more complicated areas of
individual contribution by former Board members I can address in a
future communication; but, this specific subject – alone – could
comprise several pages and I would like to obtain critical advice and
perspective from other former Board members and the scientific
community before discussing this area in greater detail.
"Bob Klein
"Chair Emeritus
"California Institute
for Regenerative Medicine"

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Text of Klein's Comments Supporting Rejected Applications

Posted: August 26, 2012 at 3:54 pm


Robert Klein, who served 6 ½ years as the first chairman
of the $3 billion California stem cell agency,  testified before the agency's board for the first time on July 26, 2012. Klein, a real
estate investment banker and attorney, spoke on behalf of two applicants whose
grants had been rejected by the agency's reviewers. The appearance
has raised questions about the propriety of Klein's actions.

Here is a link to an item on his appearance. Here is the text of
his comments as reported in the transcript of the meeting.

“As the board knows, I've never addressed any grant from the
floor. It is critical here to understand that we have here
StemCells, Inc., which is the only company in North America
and, for that matter, maybe in the world, that has had two stem cell
therapies in the brain with these specific neural stem cells. They
have a huge body of experience here. 

“Secondly, one of the fundamental issues here that it (the
company's grant application) was downgraded on was the issue of the
fundamental concept, the platform concept, of injecting two focal
injections in the brain, in the hippocampus of the brain. It's
important to note that I've sat on three (CIRM)peer reviews where the
scientists really affirmed this specific approach with extremely high
scores, three different views. All right.

“So it's very important to realize we have a standard deviation
here of 12 (on the review scores). These scientists were completely
split. With some recusals on that panel, if you have 12 or 13 that
can really vote, three or four very low scores can bring it out of
the funding category all the way down. It is in the region where
this board is looking where the other three peer reviews, right,
early translation, the one before that was the planning grant review,
that the hippocampus was a good platform.

“Then they said the key weakness was you can't show migration.
Dr. Laferla (a co-PI on the application) has told me that
today the Journal of Neuroscience accepted the publication of
the data demonstrating migration. It was stated previously in the
application, but it wasn't accepted for publication. It now is.
That is the fundamental weakness that they identified in this
approach.  

“So we have a reaffirmed approach to the hippocampus by three
different peer review groups and a substantial portion of these
reviewers along with data dealing with the weak point. I'm sorry it
happened today. The data was out there, accepted for publication
today, means that it should definitely fall into this category. And,
of course, Dr. (Alan) Trounson (president of CIRM) wouldn't
have been able to review that in process because he was recused from
this grant by his own voluntary recusal. So the progress of this
data being accepted for publication is new information today. 

“If I look at the entire history of CIRM, as Leeza (Gibbons,
a CIRM director) says, building up to this point, we have reaffirmed
this approach from the very beginning with Dr. Laferla, with multiple
scientific approvals, and board approval, and we have the best
company in North America with the greatest experience with these
neural stem cells, with the best researcher we have for the potential
to address this disease, and we have brand-new data that demonstrates
and totally contradicts the key weakness on which it was downgraded.”

Here is the text of Klein's remarks on
behalf of a second application, also rejected by CIRM reviewers.

“This is the only other disease team grant I will address. Very
specifically, this was a disease team grant that I was on the peer
review in the planning grant stage. There are some fundamental
issues here. Is the international company on which the one antibody
that's not coming from Stanford, the two for sorting are
coming from Stanford, is the other antibody coming from this
international company a commitment that you can rely on? 

“The reviewers said this was a showstopper. That's the word they
used. They made a decision this was a showstopper because they did
not believe the company because they thought that the documentation
was inadequate. You now have a letter that goes into great
proprietary depth about the depth of this company's commitments
written by the head of development and translation internationally
for the company. 

“If we cannot depend on company commitments of this type, and
you will review the letter in executive session, if you have one, I
will not understand how we'll be able to collaborate with companies
with proprietary products and processes where they're making
commitments to academic institutions of the highest standard. I
believe this company is going to perform. I was on an hour call to
confirm with eight members of that company their level of commitment,
and I am completely convinced by that point. 

“The review is completely factually wrong on this issue about
the other two antibodies for sorting this. Dr. (Irv) Weissman
has just said they have not only been developed, they have been used
in clinical trials. There's data on them. And they are, in fact,
being thawed under FDA direction to reuse in this trial. 

“So I believe there's a major factual difference. Remember with
Karen Aboody there was a major factual error that was pivotal
in elevating that, and we found tremendous performance on that grant
by Karen Aboody of City of Hope

“So you have a decision to make. As a risk issue, do we believe
this company? Finally, this is broader than SCID. 

Donald Kohn has written a letter that's in the public
domain that I suggest you read. It makes it very clear that opening
the niche for repopulating the immune system without chemotherapy and
radiation is a key contribution to every form of genetically modified
stem cells for an entire range of childhood diseases and other
genetic diseases in addition to therapies like sickle cell or aids. 

“I suggest that that profound contribution that can be made to
the field is a risk that is worth taking early on because of his
contribution to so many other areas. You have 12 other letters from
North America's leading pediatric geneticists that fundamentally
provide extraordinary support for this position and this approach.”

Source:
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Human melanoma stem cells identified

Posted: August 24, 2012 at 9:13 am

ScienceDaily (Aug. 23, 2012) Cancer stem cells are defined by three abilities: differentiation, self-renewal and their ability to seed a tumor. These stem cells resist chemotherapy and many researchers posit their role in relapse. A University of Colorado Cancer Center study recently published in the journal Stem Cells, shows that melanoma cells with these abilities are marked by the enzyme ALDH, and imagines new therapies to target high-ALDH cells, potentially weeding the body of these most dangerous cancer creators.

"We've seen ALDH as a stem cell marker in other cancer types, but not in melanoma, and until now its function has been largely unknown," says the paper's senior author, Mayumi Fujita, MD, PhD, investigator at the CU Cancer Center and associate professor in the Department of Dermatology at the CU School of Medicine.

Fujita's group transplanted ALDH+ and ALDH- melanoma cells into animal models, showing the ALDH+ cells were much more powerfully tumorigenic. In the same ALDH+ cells, the group then silenced the gene that creates this protein, finding that with ALDH knocked down, melanoma cells died in cultures and lost their ability to form tumors in animal models. In cell cultures, silencing this ALDH gene also sensitized melanoma cells to existing chemotherapies. When the group explored human tumor samples, they found distinct subpopulations of these ALDH+ cells, which made up about 0.1-0.2 percent of patients' primary tumors. In samples of metastatic melanoma -- the most aggressive form of the disease -- the percentage of ALDH+ cells was greater, even over 10 percent in some tumors, further implying the powerful danger of these cells.

"In these same ALDH+ cells, we find the markers of stem cells are upregulated and those of cell differentiation are downregulated. In addition to these clues, ALDH+ cells generate the heterogeneous cell types seen in the original tumor," says Fujita, meaning that in addition to self-renewal and tumorigenesis, ALDH+ cells fulfill the third criteria for a cancer stem cell: the ability to differentiate.

The study also shows how the ALDH gene and its protein act to create a cell's stem-like properties.

"One way ALDH makes a cancer stem cell is through the retinoic acid signaling pathway," Fujita says. The protein ALDH leads to the overproduction of retinoic acid, which in turn binds to a cell's nuclear receptors and influences the expression of many of the cell's genes -- for example, genes involved in regulating cell survival, repair, and proliferation, all of which combine to confer chemoresistance. Target cells with high ALDH and you target all the downstream effects, including the retinoic acid signaling pathway.

"Our hope is that we can intervene in this signaling, either at the level of ALDH or elsewhere in the pathway, especially to re-sensitize cells to chemotherapy. Using a new drug to take away a melanoma stem cell's chemoresistance could boost the effectiveness of existing drugs," Fujita says.

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Astrocytes control the generation of new neurons from neural stem cells

Posted: August 24, 2012 at 9:13 am

24.08.2012 - (idw) University of Gothenburg

Researchers from the Laboratory of astrocyte biology and CNS regeneration headed by Prof. Milos Pekny just published a research article in a prestigious journal Stem Cells on the molecular mechanism that controls generation of new neurons in the brain. Astrocytes are cells that have many functions in the central nervous system, such as the control of neuronal synapses, blood flow, or the brains response to neurotrauma or stroke. Reduces brain tissue damage

Prof. Peknys laboratory together with collaborators have earlier demonstrated that astrocytes reduce the brain tissue damage after stroke and that the integration of transplanted neural stem cells can be largely improved by modulating the activity of astrocytes. Generation of new neurons

In their current study, the Sahlgrenska Academy researchers show how astrocytes control the generation of new neurons in the brain. An important contribution to this project came from bo Academy, one of Sahlgrenskas traditional collaborative partners.

In the brain, astrocytes control how many new neurons are formed from neural stem cells and survive to integrate into the existing neuronal networks. Astrocytes do this by secreting specific molecules but also by much less understood direct cell-cell interactions with stem cells, says Prof. Milos Pekny. Important regulator

Astrocytes are in physical contact with neural stem cells and we have shown that they signal through the Notch pathway to stem cells to keep the birth rate of new neurons low. We have also shown that the intermediate filament system of astrocytes is an important regulator of this process. It seems that astrocyte intermediate filaments can be used as a target to increase the birthrate of new neurons. Target for future therapies

The article Astrocytes Negatively Regulate Neurogenesis through the Jagged1-Mediated Notch Pathway is published in Stem Cells. function fbs_click() {u=location.href;t=document.title;window.open('http://www.facebook.com/sharer.php?u='+encodeURIComponent(u)+'&t='+encodeURIComponent(t),'sharer','toolbar=0,status=0,width=626,height=436');return false;} html .fb_share_link { padding:2px 0 0 20px; height:16px; background:url(http://static.ak.facebook.com/images/share/facebook_share_icon.gif?6:26981) no-repeat top left; } Share on Facebook Weitere Informationen: http://bit.ly/NCJEdI - article

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Repairing cartilage with fat: Problems and potential solutions

Posted: August 24, 2012 at 9:13 am

Public release date: 23-Aug-2012 [ | E-mail | Share ]

Contact: Hilary Glover hilary.glover@biomedcentral.com 44-020-319-22370 BioMed Central

Stem cells isolated from fat are being considered as an option for treating tissue damage and diseases because of their accessibility and lack of rejection. New research published in BioMed Central's open access journal Stem Cell Research & Therapy shows that this is not as straightforward as previously believed, and that fat-derived stem cells secrete VEGF and other factors, which can inhibit cartilage regeneration. However pre-treating the cells with antibodies against VEGF and growing them in nutrients specifically designed to promote chondrocytes can neutralize these effects.

Chondrocytes make and maintain healthy cartilage but damage and disease including osteoarthritis can destroy cartilage resulting in pain and lack of mobility. Stem cell therapy using cells isolated from adult tissue (such as fat) are being investigated as a way of repairing this damage. Stem cells have the ability to become many different types of tissue so the real trick is persuading them to become cartilage rather than bone, or blood vessels, for example.

Researchers from the Georgia Institute of Technology found that adipose (fat) stem cells (ASCs) secrete large amounts of factors, especially the growth factor VEGF, which prevent cartilage regeneration and actually causes the death (apoptosis) of chondrocytes along with the formation of blood vessels. Treating ASCs with medium designed to encourage their differentiation into cartilage cells was able to reduce the amount of these secreted factors and also prevented the growth of blood vessels. Specifically, an antibody designed to neutralize VEGF prevented chondrocyte apoptosis.

Prof Barbara Boyan, who led this research, explained, "Non-treated ASCs actually impeded healing of hyaline cartilage defects, and although treating ASCs improved the situation they added no benefit to compared to cartilage allowed to heal on its own. However we only looked at cartilage repair for a week after treatment, and other people have shown that two to six weeks is required before the positive effect of ASCs on influence cartilage regeneration is seen."

So while stem cells from fat may be able to help repair damaged cartilage, careful handling and pre-treatment may be required to ensure a positive result.

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Dr Hilary Glover Scientific Press Officer, BioMed Central Tel: +44 (0) 20 3192 2370 Mob: +44 (0) 778 698 1967 Email: hilary.glover@biomedcentral.com

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Study Identifies Human Melanoma Stem Cells

Posted: August 24, 2012 at 9:13 am

Cancer stem cells are defined by three abilities: differentiation, self-renewal and their ability to seed a tumor. These stem cells resist chemotherapy and many researchers posit their role in relapse. A University of Colorado Cancer Center study recently published in the journal Stem Cells, shows that melanoma cells with these abilities are marked by the enzyme ALDH, and imagines new therapies to target high-ALDH cells, potentially weeding the body of these most dangerous cancer creators.

Weve seen ALDH as a stem cell marker in other cancer types, but not in melanoma, and until now its function has been largely unknown, says the papers senior author, Mayumi Fujita, MD, PhD, investigator at the CU Cancer Center and associate professor in the Department of Dermatology at the CU School of Medicine.

KEY POINTS:

Fujitas group transplanted ALDH+ and ALDH- melanoma cells into animal models, showing the ALDH+ cells were much more powerfully tumorigenic. In the same ALDH+ cells, the group then silenced the gene that creates this protein, finding that with ALDH knocked down, melanoma cells died in cultures and lost their ability to form tumors in animal models. In cell cultures, silencing this ALDH gene also sensitized melanoma cells to existing chemotherapies. When the group explored human tumor samples, they found distinct subpopulations of these ALDH+ cells, which made up about 0.1-0.2 percent of patients primary tumors. In samples of metastatic melanoma the most aggressive form of the disease the percentage of ALDH+ cells was greater, even over 10 percent in some tumors, further implying the powerful danger of these cells.

In these same ALDH+ cells, we find the markers of stem cells are upregulated and those of cell differentiation are downregulated. In addition to these clues, ALDH+ cells generate the heterogeneous cell types seen in the original tumor, says Fujita, meaning that in addition to self-renewal and tumorigenesis, ALDH+ cells fulfill the third criteria for a cancer stem cell: the ability to differentiate.

The study also shows how the ALDH gene and its protein act to create a cells stem-like properties.

One way ALDH makes a cancer stem cell is through the retinoic acid signaling pathway, Fujita says. The protein ALDH leads to the overproduction of retinoic acid, which in turn binds to a cells nuclear receptors and influences the expression of many of the cells genes for example, genes involved in regulating cell survival, repair, and proliferation, all of which combine to confer chemoresistance. Target cells with high ALDH and you target all the downstream effects, including the retinoic acid signaling pathway.

Our hope is that we can intervene in this signaling, either at the level of ALDH or elsewhere in the pathway, especially to re-sensitize cells to chemotherapy. Using a new drug to take away a melanoma stem cells chemoresistance could boost the effectiveness of existing drugs, Fujita says.

SOURCE: University of Colorado Denver

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Study Identifies Human Melanoma Stem Cells

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New Partnership to Drive Mass Production of Life-Saving Stem Cells

Posted: August 23, 2012 at 12:11 pm

TORONTO, ONTARIO--(Marketwire -08/23/12)- Stem cells hold great promise for treating and curing numerous diseases; however, a major challenge facing scientists is how to produce stem cells in the massive quantities required for clinical use. The McEwen Centre for Regenerative Medicine (McEwen Centre) and the Centre for Commercialization of Regenerative Medicine (CCRM) are partnering to establish a fund that will drive research in this area.

The McEwen Centre-CCRM Commercialization Impact Prize launches today, and will solicit innovative ideas from regenerative medicine scientists working in labs throughout the McEwen Centre. The winning team(s) will be awarded up to $600,000 to pursue research that will determine how to manufacture stem cells for clinical use and drug screening.

"This private-public funding partnership is an important step forward to accelerating the advance of a discovery from a lab bench to the patient and onto the global market. Scientists at the McEwen Centre are making significant progress towards finding a cure for diseases such as Type 1 diabetes and heart disease. Collaborative partnerships are the key to discovering the cures sooner!" says Rob McEwen, co-founder of the McEwen Centre, and Chief Owner, McEwen Mining.

Deadline for submissions is October 15, 2012. The Prize will fund up to two, 2-year projects that address the following challenges:

"Overcoming the scale-up and manufacturing challenge of stem cells would be a huge advancement for the regenerative medicine (RM) industry and this initiative fits in perfectly with our mandate to bridge the RM commercialization gap," explains Dr. Michael May, CEO of the Centre for Commercialization of Regenerative Medicine. "We're very pleased to be working with the McEwen Centre, already a partner of ours, to make this happen."

The Commercialization Impact Prize budget template and application form can be found here: http://ccrm.ca/Commercialization-Impact-Prize or http://mcewencentre.com/ccrm.

About McEwen Centre for Regenerative Medicine

The McEwen Centre for Regenerative Medicine was founded by Rob and Cheryl McEwen in 2003 and opened its doors in 2006. The McEwen Centre for Regenerative Medicine, part of Toronto-based University Health Network, is a world leading centre for stem cell research, facilitating collaboration between renowned scientists from 5 major hospitals in Toronto, the University of Toronto and around the world. Supported by philanthropic contributions and research grants, McEwen Centre scientists strive to introduce novel regenerative therapies for debilitating and life threatening illnesses including heart disease, spinal cord injury, diabetes, diseases of the blood, liver and arthritis.

About Centre for Commercialization of Regenerative Medicine (CCRM)

CCRM, a Canadian not-for-profit organization funded by the Government of Canada's Networks of Centres of Excellence program and six institutional partners, supports the development of technologies that accelerate the commercialization of stem cell- and biomaterials-based technologies and therapies. A network of academics, industry and entrepreneurs, CCRM translates scientific discoveries into marketable products for patients. CCRM launched in Toronto's Discovery District on June 14, 2011.

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New Partnership to Drive Mass Production of Life-Saving Stem Cells

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