April 21, 2003
Gene Therapy Cures Type I Diabetes In Mice

Scientists at Baylor College of Medicine have developed a gene therapy that causes liver cells to convert into insulin producing beta cells which normally are found only in Islets of Langerham in the Pancreas.

HOUSTON (April 21, 2003) A gene therapy developed by researchers at Baylor College of Medicine has apparently cured diabetes in mice by inducing cells in the liver to become beta cells that produce insulin and three other hormones.

"It's a proof of principle," said Dr. Lawrence Chan, professor of medicine and molecular and cellular biology as well as chief of the division of diabetes, endocrinology and metabolism at the College. "The exciting part of it is that mice with diabetes are 'cured.' "

In the research, which is described in a report in Nature Medicine's online edition today, Chan and his colleagues used the NeuroD gene, a transcription factor that induces the liver to produce cells that make insulin and the three hormones associated with the pancreas' endocrine system.

The gene was attached to a so-called "gutless" adenovirus from which all toxic genes had been removed. This viral vector is a very efficient way to introduce genes into liver cells. Alone, NeuroD partially corrected the disease in the diabetic mice. Combined with a beta cell growth factor called Btc, the gene therapy complete cured the mice's diabetes for at least four months.

An added benefit is that the cells in the liver also produce glucagon, somostatin and pancreatic polypeptide, which may play a role in controlling insulin production and release.

"Until now it has not been possible to induce the formation of islets by any gene therapy approach," said Chan.

It does not mean that the treatment can be used in people immediately.

"It's farther from people than I would like," he said. He knows of no stumbling blocks to its effectiveness in people.

The main stumbling block is the vector or virus used to take the gene into the cells. Chan and his colleagues used the safest viral vector available today, but he expects even safer ones to be available within the decade.

"We want to use the safest vector possible," he said.

The treatment has advantages over transplant of islet cells, the insulin producers in the pancreas, because it avoids the lifelong use of powerful immunosuppressive drugs and eliminates the need to find a compatible donor.

Chan credits one of his postdoctoral students, Dr. Hideto Kojima, with much of the work in developing this protocol.

A UPI article about this report says this treatment does not permanently cure diabetes.

However, this "cure" is temporary and would require repeated injections, researchers point out. Also, just because this worked very well in mice does not guarantee such effects in people. "Unfortunately, it will probably take years," before such a treatment would be available to diabetes patients, Chan said. "Like any other gene therapy, the major concern is safety. People are quite different than mice.

The UPI article is the only article on this story that makes this claim that treatment does not last indefinitely. It seems odd. If cells are induced to differentiate into a different cell type I'd expect the new cell type state to be stable. Also, this treatment has already worked for 4 months in these mice. How long does it take for the treatment to wear off? It is possible that the NeuroD genes added to cells gradually break down and when they stop being expressed then all the downstream effects they cause in the cells stop happening.

Even if the injections had to be periodically repeated they'd still be an enormous boon for sufferers of Type I diabetes. Not only would diabetics be freed from daily injections, blood tests, and carefully regimented diets but they'd also live longer and healthier lives.

In the longer run gene therapies will improve to allow genes to be added to cells in ways that cause those genes to stay around permanently. Ways will be developed to deliver stable plasmids into cells and those stable plasmids will carry the desired genes.

My guess is that within 10 to 15 years type I diabetes will be a curable disease. If the genes used in this latest work have the same effect on human liver cells then the biggest remaining obstacle will be the development of better gene therapy vectors to deliver genes safely into cells. That's a topic that is seeing a great deal of work and it seems reasonable to expect better and safer gene therapy delivery methods will be developed within several years.

Share |      Randall Parker, 2003 April 21 10:55 AM  Biotech Therapies


Comments
Thomas said at April 28, 2003 8:11 AM:

The treatment may not be permanent because the modified liver cells may not be able to reproduce copies of themselves with the (new) active insulin producing genes. Basically the treatment would last as long as the 'infected' cells survived.

There may also be the potential for auto-immune responses that work to kill off the 'insulin infected' liver cells if the adenovirus leaves any protein fragments of itself attached to the cell.

Patrick Walsh said at December 12, 2003 6:15 PM:

Please add me to you newsletter.

Thanks, pcw

Sea`a Garrett said at February 23, 2004 7:10 PM:

I am a 18 year old girl from washington. i got diabetes when i was 10... let me tell you {it sucks} well anyways i heard about this treatment and i would love to be one of the people that they try it on... i would take a chance of anything happeing to me becasue i hate diabetes sooooo much... i want it gone .. i cant take the fact that my body never feels right or in the long run have something cuz off.... i want to be able to have healthy kids when i grow up and not worry about me not having a leg or something to go out and play with them...

i really want to try this.. -Sea`a Garrett

C said at March 11, 2004 8:23 AM:

I say keep up the good work, i support your efforts. Also to everyone out there, yes diabetes does "suck" but you can control it. It's all about your mind set. I've been diabetic for half my life now and have mild kidney damage.....and I'm ONLY 26. So until a "cure" is discovered do not give up on yourself. It's never to late to get in the right frame of mind. Life is short, so make it last as long as possible.

diabetic said at September 13, 2004 12:04 AM:

I'm a type 2 diabetic, so this is not much use for me, but it is good news just the same.

The soooner diabetes is eradicated the better.

s.nilofer.rahi said at September 16, 2004 9:38 PM:


Respected sir;

i would like to know whether the liver cells which were tranformed to beta cells had been taken from sufferer?

is it not possible to remake those beta cells which are not secreting the required hormones to work as the normal cells by introducing the neuro d gene; in them only?

it is believed that the human & mice genome r similar then what is the reason behind to carry out the same in man?

pls send reply for this query as early as possible because i am making some exhibits for our university exhibition .

thanking u

S.NILOFER.RAHI
M.sc. BIOTECHNOLOGY {STUDENT}
GULBARGA UNIVERSITY;
GULBARGA; INDIA

Randy said at October 10, 2004 9:59 PM:

I know this article is over a year old, but its exciting to read none the less. Has everyone read the updated article that came from the MA General Hospital. I think the bottle neck to finding a cure for type 1 is federal funding and finding away to reeducate the persons immune system not to attack insulin producing cells. If doctors can reeducate the immune cells by removing the bad ones and using the patients own cells, maybe from the liver, to reeducate the new immune cells and be able to do this on a mass scale, then everyone with type 1 will have a fighting chance. I believe the beta cells will start to multiply and produce insulin again once they aren't being killed off.

Eugene Swanepoel said at December 20, 2004 1:16 AM:

It seems that South Africa is far behind in finding a cure for diabetes. I am 37 and was only diagnosed 5 years ago. I find it difficult to control my sugar and sometimes have readings of up to 25. I understand that a cure is still experimental. I am willing to try anything to cure my diabetes. Anyone need a body to experiment on? I am game.

Joe said at May 13, 2010 7:38 PM:

I agree with those of you who want to use your bodies as testing pods. I too have been a type 1 diabetic for ten years and would gladly volunteer.

Saahil said at January 10, 2011 4:53 AM:

I am just 15 and is suffering from type 1 diabetes ......I too need a cure for it ...and i don't want to undergo any surgery

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