The Cross-Border Biotech Blog

Biotechnology, Health and Business in Canada, the United States and Worldwide

Tag Archives: DNA

Friday Science Review: May 7, 2010

Amazing!  Three Nature papers this week…

Cracking the Code: The human body is much more complex than the 20,000 or so genes that are encoded in our DNA.  This multiplicity of genetic messages is enhanced by alternative gene splicing, a process where different segments of DNA exons are spliced together to create a different gene message.  It is possible to create hundreds of new messages from a single gene.  The so called “splicing code” or rules that determines how and where a particular part of a gene is spliced with another segment was deciphered by researchers at the University of Toronto.  They can now accurately predict how genetic messages are rearranged on a large scale.  Hundreds of different RNA features are taken into account including certain factors in specific tissues to give rise to tissue specific expression.  This is an amazing discovery by Drs. Brendan Frey and Benjamin Blencowe that garnered the cover story in this week’s Nature journal.

Stem Cells on Hormones: The ovarian hormone, progesterone, stimulates breast stem cells as its levels peak during the natural reproductive cycle.  Researchers observed up to a 14-fold expansion of breast stem cells at peak progesterone levels in a mouse model.  This is the first evidence of a direct link between hormones and breast stem cells.  Since cancers are thought to initiate from stem cells, if there are other oncogenic factors pushing the system this may be a critical point that ultimately drives the start of a cancer.  There are implications of this study to further understanding how reproductive history is a strong risk factor for breast cancer and may lead to therapeutic intervention.  The research team at Princess Margaret Hospital, University Health Network was led by Dr. Rama Khokha and describes their work in Nature.

Reversing HER2 Breast Cancer: Through genomic studies of HER2 positive breast cancer, it was noted that the 14-3-3sigma gene was frequently missing.  After several years of hard work focusing on this gene, researchers have demonstrated that the 14-3-3sigma gene does indeed play a specific role in the development and function of breast epithelial tissue.  In the absence of 14-3-3sigma, the normally organized and polarized sheets of epithelial cells clump together and lose polarity.  It is this loss of organization without 14-3-3sigma that likely contributes to breast cancer progression.  From a therapeutic standpoint, the reintroduction of 14-3-3sigma into HER2 positive breast cancer cells resulted in the restoration of cell polarity and opens a window for further studies as a pathway to target.  Dr. William Muller (my former mentor) and his team at McGill University describe their research in the early edition of Genes and Development.

Bionic Muscle: Artificial proteins were assembled together in a fashion that mimics the molecular spring structure of a muscle protein called Titin, which is a very large protein that gives muscle tissue its unique properties of strength, extensibility and resilience.  This is why muscle has superior elasticity.  The biomaterial looks like a string of beads and although it exhibits only some of the mechanical characteristics of muscle tissue, its structure can be adjusted to provide specific properties of different types of muscle.  There are obvious future applications of this technology in regenerative medicine and tissue engineering.  Drs. Hongbin Li and John Gosline at the University of British Columbia present their work in this week’s Nature journal.

Friday Science Review: August 14, 2009

Great stuff this week in Canadian science news…

A GIFT for MS patients:  An experimental treatment tested in mice with multiple sclerosis was able to reverse the disorder with few side effects.   The new compound is called GIFT15 – a hybrid protein between GSM-CSF and Interleukin-15.  Surprisingly, it produces results that you would not expect from the action of the individual proteins.  GIFT15 causes B-cells to switch from immune responsive into immune-suppressive regulatory cells and this forces MS into remission.  The treatment method takes B-cells from the individual and exposes them in vitro to GIFT15 to convert them to regulatory B-cells before they are injected back into the patient – a form of personalized medicine.

As always, one should be cautious as these experiments were tested in mice and it is unknown how humans would respond .  It does, however, present a new approach to finding a treatment regime for MS and may also lead to similar therapies for other autoimmune disorders.

Dr. Jacques Galipeau led the study at the Lady Davis Institute for Medical Research, McGill University and it is presented in the early on-line edition of Nature Medicine.

An Epilepsy gene discovery:  A mouse that experiences seizures was identified in a mutagenesis screen that led to the discovery of an inactivating mutation in the Atp1a3 gene encoding the Na(+),K(+)-ATPase alpha3 isoform protein.  It is a sodium-potassium transporter protein having important roles in maintaining the electrochemical gradient across cell membranes.  When the mutant gene was augmented with a wild type Atp1a3 gene by breeding the mutant mouse with a transgenic mouse expressing normal Atp1a3, the protein function was rescued and more importantly, the seizures subsided completely.  The human ATP1A3 is almost identical to the mouse protein and studies are underway to try to find a similar mutation in patients.

Dr. Roder’s group at the Samuel Lunenfeld Research Institute at Mount Sinai Hospital in Toronto published these results in PNAS this week.

New forensic DNA extraction tool:  High quality nucleic acids can now be extracted from the smallest sample size or from highly contaminated samples.  The technology is based on the electrical properties of nucleic acids rather than on the chemical properties that traditional purification methods are based on.  It uses a novel electrophoresis technology called SCODA (Synchronous Coefficient of Drag Alteration), a fancy name for a type of rotating electrical field that selectively acts on long, charged polymers (e.g. DNA).  This electrical field will concentrate DNA while separating it from contaminants.

The research was performed by the biophysics team led by Dr. Andre Marziali at the University of British Columbia.  They have already teamed up with UBC spin-off company, Boreal Genomics to package the technology into a cool-looking device called the Aurora.  It is not surprising that it has garnered a lot of interest from law enforcement groups in Canada and the U.S.   Of course, there are a number of other applications for this technology such as in clinical research for the early detection of diseases or infections.

The research is described in a PNAS paper that will be coming out very soon but here is the UBC press release.  A great example of “Today’s Canadian science = tomorrow’s Canadian start-ups” (…if you caught the tweet last week).

Wow!  Canadians are on a roll… more research published in Proceedings of the National Academy of Sciences. Here are the headlines:

Dr. Jeffery Wrana’s team (Samuel Lunenfeld Research Institute) describes how this signaling pathway is involved in breast cancer metastasis.

Dr. Uzonna (University of Manitoba) reports on why in some cases, vaccination against Leishmaniasis (a parasitic disease) can actually make them more susceptible to future infections.

Dr. Brisson (Université de Montréal) studies the Whirly protein – need I say more?

Dr. Barry Honda (Simon Fraser University) uses Drosophila to help us better understand O-linked N-acetylglucosamine transferase (OGT), which has been implicated in a number of processes including insulin signaling, neurodegenerative disease and cellular stress response.

Dr. Zatorre (Université de Montréal) breaks down how our brain processes sound and suggests that it is similar to the visual system of our brain.

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