Some students I was teaching thought that this might be possible: to engineer the insulin-producing cells with a correctly functioning gene, a type of gene therapy.  While this has been a goal for researchers, and they have successfully made insulin-producing cells in the lab from embryonic stem cells, they are not appropriate for transplant because they do not release the insulin in response to glucose levels.  Plus, the immune system might still recognize these cells as foreign and destroy them.

So a new study is looking at transforming cells of the gut that don’t have a specific job yet.  These cells receive signals throughout the life of an individual to become many different types of cells that are used for normal gut function.  So could they engineer these cells to receive the signals to become insulin-producing cells?  Also, would the cells only release the insulin in response to blood glucose levels?

Two Columbia University researchers have started finding possible answers to these questions.  Once they turned off a gene that normally plays a key role in the fate of a cell, insulin-producing cells were generated.  Having cells in the gut that make insulin can be dangerous if they did not release insulin in response to blood glucose levels, but these “new” gut cells have glucose-sensing receptors to allow them to do just that. Another remarkable feature was that the gene could be turned off either early on in development, or later on in adulthood, so it wouldn’t matter how old the patient was.

The next step is to take the research that has been done on mice so far, and see if they can mimic this in humans with the use of a drug or chemical.  This method will also need to prove to be safe and more effective than current methods of treatment, not just to avoid the burden of daily injections.

This has recently been reported for patients with Hemophilia B.  Hemophilia B, also known as Christmas disease, is due to a deficiency of the clotting factor IX (FIX).  The first reported case of Hemophilia B due to a decrease in FIX was in 1952, and was called “Christmas Disease” after the first patient diagnosed was named Stephen Christmas.  Without this clotting factor, the blood does not form clots and results in severe bleeding episodes, especially in the joints and muscles.

Bettert reatment for this disorder began back in the 1960’s where they would inject FIX concentrates into the blood of patients with hemophilia B.  This increased the average age of death of 24 to a median lifespan of 63 years of age.  So with the success of the protein therapy, why try to fix the genes?  With each treatment costing $150,000 to $300,000, a patient needing clotting factors for hemophilia could incur a lifetime cost of $20 million.

So there needs to be a way that a patient can have a more effective treatment option that will cost less.  This new treatment option offers some hope.  Using a new virus for the administration of the gene, patients have seen an increased production of FIX protein for longer periods of time, and were able to stop or decrease the amount of concentrate injections they would need.  With one injection of the virus only costing about $30,000, dramatic cost savings have already been seen.  While this does offer new hope for the treatment of clotting disorders, follow-up with a larger number of patients and for longer periods of time will be needed to fully weigh the benefits and risks of this technique.  Once this has been done, hopefully we will see gene therapy used more in practice and maybe even for more than just clotting disorders.

Ponder, Katherine P.  Merry Christmas for Patients with Hemophilia B. The New England Journal of Medicine 10.1056; December 10, 2011.  Nathwani A.C., Tuddenham E.G.D., Rangarajan S., et al.

When we think of a detective the first thing that comes to mind is an investigator, either a member of a police agency or a private entity.  However there are unique detectives within the multifaceted arena of medicine.  All though we might already think of most doctors as detectives there are special doctors, units, working at the National Institute of Health’s (NIH) undiagnosed disease program.  Doctors such as William A. Gahl at the NIH are disease detectives that try to elucidate the causes and genetic basis involved in the hundreds of unsolved and mysterious diseases that arise each year.  Dr. Gahl who was interviewed for an article in scientific American explained that his group has accepted 400 out of 1700 special cases of unsolved disease.  The selection process of these cases is tough, determining which cases are new diseases and if there is a possibility of determining the genetic and biochemical basis of the disease.   As each case is worked mutations are identified that are associated with each disease.  But Dr. Gahl States that this is only the beginning of the puzzle.  The challenge becomes to identify the genetics with the pathology.

Dr. Gahls’ group has been working on a case in which a patient has endured pain for approximately twenty years and muscles of their legs have turned as hard as bricks limiting mobility.  It was determined that the patient had a rare condition in which their blood vessels bore a thick coat of calcium that restricted blood flow.  One of the first steps taken in the study was to examine the parents of the patient.  The parents after examination were healthy, which lead the group to believe that the patients’ disposition might be due to a recessive mutation.  Meaning that each parent had only one copy of a unique mutation but upon having children probability lead to the patient receiving two copies of the mutation.  After an in depth study Dr. Gahls’ group identified the location of the mutation and the error prone gene associated.  The gene that was identified is NT5E.  NT5E is involved in the production of the nucleoside adenosine (which is involved in a number of biochemical processes).  To examine this gene closely doctors cultured the patients skin cells and inserted the normal gene of NT5E and even introduced adenosine alone into the cells and miraculously they observed a reduction in calcification.  Through this analysis a better understanding of adenosine in the regulation of calcium has been brought to light.  However Dr. Gahl explains that there are a number of reasons why patients cannot just receive adenosine, but there is a class of osteoporosis drugs that pose as good candidates for treatment and they are waiting to see how these drugs perform.

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Research carried out by Dr Yang Li and colleagues at Harvard Medical School, the Technical University of Denmark, and the Université Libre de Bruxelles, have highlighted two genes – LAPTM4B and YWHAZ – that may inhibit the response of anthracycline-based adjuvant chemotherapy for breast cancer. The group found that patients who have a high expression of the genes show a reduced sensitivity to anthracycline-based adjuvant chemotherapy (though they remain somewhat susceptible). Conversely, patients with these genes switched off, showed a heightened sensitivity to the chemotherapy.

This breakthrough will allow doctors to take our clinical treatments to next level – personalized medicine. Genetic profiles of patients and of specific cancers will enable doctors to selectively determine chemotherapy regimes with the most potential for preventing relapse. A continued effort will have to be made to decipher how these two genes block the action of anthracycline-based adjuvant chemotherapy.

Reference:
1. http://www.nhs.uk/news/2010/01January/Pages/Genes-affect-cancer-treatment.aspx