Friday, March 20, 2009

Advances in Cancer.... Linking the Pieces

As part of the Darwin Bicentennial Lecture Series at Appalachian State University, Dr. Paul Ewald, author of Plague Time: The New Germ Theory of Disease, recently gave a presentation on the genetic basis of cancer. During the lecture, Dr Ewald spent a considerable amount of time discussing the role of infectious agents, specifically viruses, as the causative agents of cancer. Specifically, Dr Ewald talked about the human papillomavirus (HPV), and how screening of seemingly unrelated cancers, such as breast cancer and cancers of the head and neck, are linking this virus as a potentially more important agent in cancer formation than previously thought.

If infectious agents are responsible for priming cells to enter into a tumor-forming stage, as Dr Ewald's work strongly suggests, then the use of vaccines against these agents could be a major advance in the evolution of preventative strategies against cancer. HPV vaccines are already recommended for young women to prevent against cervical cancer later in life. Now it appears that these vaccines may have potential benefits in other areas as well.

Interestingly, a recent article in Science Daily (Genetic Markers for Aggressive Head and Neck Cancers) presents data from a study at the Albert Einstein College of Medicine that a specific type of genetic markers, called microRNAs, may be used to identify individuals who are highly susceptible to forms of head and neck cancer. The researchers in this study propose that genetic screening may be useful in the development of new treatments for these cancers.

Is is possible that the microRNA markers identified by the team at the Albert Einstein College of Medicine are actually indicating susceptibility to the HPV virus? We know that everyone who carries HPV does not necessarily develop cancer, but the reason why is not yet clear. It could be that a genetic susceptibility is the key. Certain genetic combinations could promote HPV influence, and result in the formation of the cancer phenotype. If this is the case, then trials of using the HPV vaccine on individuals who have these specific microRNA markers are definitely in order. This could provide some very useful insights on new treatments of specific types of cancers, specifically those that have been identified to be associated with an infectious agent.

Sunday, March 15, 2009

RicochetScience Goes Twittering

The sign of a true geek is their desire to try out new tech - after all, new e-toys are like crack to a geek... and I am no exception. Although I have been a little slow in seeing the benefits of Twitter, I am beginning to come around. At first I thought that it might just be the next generation of social text messages, but now I am starting to see it in a new light - a new form of scientific communication.

Although I will always be a geneticist at heart, my research interests now focus on how to effectively communicate information quickly to students and interest groups. Obviously blogs are a component of that communication, but I also am experimenting with eBooks, Kindle, Nings, and Wiggios (these are for textbook development mostly). RicochetScience is already on Facebook.... and I am sure that there is more to come.

So if you have an interest in following some of the latest developments in science, with a strong focus on genetics, then go ahead and subscribe to my twitter post, RicochetScience. At least once a week I will send out posts about some of the more interesting stories in the news, and maybe a few links back to this site as well. Please feel free to email me at any time about your comments, good or bad - feedback is important!

And I promise you... you won't have to read any posts about what I am doing right now...

Tuesday, March 10, 2009

Jumping Genes and Stem Cells

I have always held a fascination for transposons, or jumping genes as they are sometimes called. Part of this interest may be due to my background in Drosophila genetics, where a transposon called a P element has been used extensively for genetic manipulation of flies for years. But also there is the fact that P elements appears to have made the jump into Drosophila melanogaster only recently (with in the past 50 years). From an evolutionary perspective this is fascinating as it allows us to study how a genome (in this case Drosophila) responds to the introduction of a new transposon.

However, On another front, the study of transposons joined forces with the study of stem cells this week. Even though President Obama has reversed the ban on using embryonic stem (ES) cells in research, scientists are still actively pursuing methods of generation stem cell lines. of particular interest are the induced pluripotent stem cells (iPS cells - see "This Isn't Science Fiction Anymore"). iPS cells are adult stem cells that have been convinced to revert back to a more generalized (less specialized) state. Although iPS cells have only been around for a few years, they have created a definite interest in the scientific community. If a method of making iPS cells was simplified - then it may be possible to make stem cells out of almost any human cell type. This would practically eliminate the need for embryonic (ES) stem cells and open up new avenues for genetic research.

One of the main problems with the generation of iPS lines has been the genetic vector used to alter the cells. For the past few years this has focused almost exclusively on the use of viruses. The main problem with viruses has been the fact that they are very disruptive to genomes. When a virus integrates itself into the genome it has the potential to disrupt important genes or their regulatory regions. But there is now another way and it involves the use of transposons. Once of the benefits of the transposon is that it carries a gene called transposase, which is what promotes the movement of the transposon in the genome. It also means that the location of the transposon is transient - it can move in and then move back out again. Like viruses, transposons can be genetically engineered to contain other genes, in this case the genes to make a cell pluripotent. One of the transposons that has been selected to do this is appropriately named piggyBac. piggyBac is a rather large transposon (around 2,400 base pairs in length) that has been used in the past to perform genetic transformation in fruit flies and other insects.

What is now possible, at least in mouse trials, is to deliver a genetically engineered transposon containing genes for pluripotency into a cell. Then, once the genes have been expressed, and the cell has undergone a transformation into a stem cell, the transposon can be activated and the genes removed. Thus, if the transposon inadvertently inactivated a gene of importance, it may be removed from the gene with very little consequence. By doing this geneticists hope to greatly increase the potential of using iPS cells in research.