The Growing GE (Genetic Engineering) Sector - Part II - A BUDDING INDUSTRY

(Note: This article is the 2nd in a 3 part series on Genetic Engineering. To read the 1st part, please click here. )

Written by Paul Melamud - Validation Manager, QPharma

Introduction

When we refer to organisms that are “transgenic”, this means that DNA from one species has been inserted into another species for expression.  Gene transfer between organisms of the same species is often called “intragenic”, and that between species that are sexually compatible is called “cisgenic”. These latter types are widely known; for example, Gregor Mendel selectively mated pea plants to study genetics in the 1800s, and for another, dog breeders continually attempt to create dogs that perfectly match the personality and stature conformation standards set forth by the Americal Kennel Club. These also comprise the basics behind the theory of evolution.

The first transgenic products were plants, made primarily to create disease-resistant and higher-nutrition foodstuffs (refer, for example, to Hope, a traditionally-produced (non-recombinant) hybrid that saved American wheat crops in the 1930s).  In the 1980s, the first true Genetically Engineered or "GE" plants (tobacco) were made with inherent insecticidal and herbicide-resistant properties.  These days, there are many bright prospects for products being dubbed “plantigens” and “plantibodies” that will contribute to public health at large, if introduced into standard crops.  What may be surprising to learn, then, is that there are not yet any FDA-approved, plant-biopharmed pharmaceutical products. 

Processes

There are two main processes that are used to genetically engineer plants for traits such as herbicide resistance.  Similar techniques would be employed to cause the plant to express phenotypes with human therapeutic use.  The first process, bacteria-mediated transformation, is accomplished with a bacterial vector, most commonly Agrobacterium tumefaciens, a plant parasite that can cause tumors by injecting DNA into host cells.  It is this unique mechanism that scientists have harnessed to deliver DNA of their choosing for expression in plants.  The second process, biolistic transformation, involves coating pellets of metal, such as tungsten or gold, with DNA and literally firing them into plant cells so that they lodge in the nuclei.  Once there, the DNA separates from the metal and becomes integrated with the host DNA for expression.

These two processes are illustrated below, one diagram from McGraw-Hill Higher Education and the other from BBC News (see links below image for references).

http://www.mhhe.com/biosci/pae/botany/botany_map/articles/article_03.html

http://news.bbc.co.uk/2/shared/spl/hi/pop_ups/03/sci_nat_how_a_plant_is_genetically_modified/html/3.stm

 There are a few other, less common methods that are used, including electroporation (electrically inducing transient holes through cell walls and membranes through which DNA can be introduced) and viral transduction (analogous to the bacterial vector transformation method). Electroporation is illustrated below.

http://www.inovio.com/images/IMG_how_ep_delivers.gif

Any of these methods can be used to attempt to transform millions or billions of cells – and that’s a good thing, because successes may occur as rarely as one in a billion.  Scientists can’t look at every cell, so they have developed techniques (as illustrated above) that can easily distinguish the successes and allow for their isolation.  The above method illustrates the use of a “selective agent” or “selectable marker,” which means that only the successfully transformed cells will survive exposure to the negative stimulus (i.e. the herbicide against which the genetic change would protect).  Another method is coupling the desired gene with a second one that will provide a “screening marker”, which can be observed by a scientist; an example would be a gene that causes a cell to fluoresce under UV light, which would indicate successful integration of the DNA that was introduced. 

Regulation

We can all appreciate how relatively new such products are, and that the process of development, testing, and eventually clinical trials and/or field studies to bring these products to the market would still be underway.  There are a few other reasons, though, that I think explains why we don’t see such products on the market yet.

 One reason behind this is that... 

The Growing GE (Genetic Engineering) Sector - Part I - Of Course I've Heard of Cows!

For the next few weeks, we’re going to try something a little different. One of our Validation Managers has picked a “hot topic” that hasn’t been talked about much anywhere else, and would like to present it in the manner of an open discussion forum so that all of our blog readers, as well as our other blog writers, can learn from each other. The topic for the next couple of weeks highlights drugs that are the result of genetic engineering. We hope you find this to be a really cool and unique opportunity, and will gladly do it again with another topic if our readers enjoy this.

__________________________________________________

 OF COURSE I’VE HEARD OF COWS…

Written by Paul Melamud - Validation Manager, QPharma

…but have you ever heard the buzzwords “pharming” or “biopharming” before? The terms refer to a growing sector of FDA-regulated industry that uses recombinant DNA technologies to genetically engineer (GE) animals (pharming) or plants (biopharming) to generate proteins and protein metabolites that they would not otherwise be capable of creating.

Such products might be delivered to a patient in a variety of ways:

• Through ingestion, perhaps as an "edible vaccine"; such was conducted as "proof of concept" by the University of Maryland's School of Medicine ('98) www.niaid.nih.gov/news/newsreleases/1998/pages/ediblevacc.aspx

• Through injection, as with the first FDA-approved transgenic animal product, which is produced in the milk of goats genetically modified to produce the anti-clotting drug Atryn (FDA-approved in 2009, approved in 2006 by EMEA) www.transgenics.com/pressreleases/pr020609.html

• Through body contact, perhaps through patches, lotions, or even clothing articles

Pharming has an innovative (and to this author, fascinating) approach to mass-production of drug products, with obvious advantages compared to more traditional processes, including cheaper facilities (e.g. farms), flexible scale-up and scale-down capabilities (e.g. breeding programs), and, to a degree, renewable/reusable bioreactors (e.g. plants or animals). 

And the potential lucrativeness of these ventures is no joke! Case in point: a fairly recent Scientific American article (see: http://www.scientificamerican.com/article.cfm?id=atryn-pharming-goats-transgenic) estimated start-up for a standard mammalian cell bioreactor facility producing 100kg/year of a drug to cost hundreds of millions of dollars, while an equivalent-volume farm could be put into service for only tens of millions of dollars, and with far cheaper operating costs – “at literally chicken feed with our chickens,” as one manufacturer put it.

While DNA was discovered as early as 1869 and its genetic ties identified in the early 1950s, and despite the fact that human drug manufacturers using transgenic recombinant DNA techniques have been around since the 1970s, regulations remain largely unspecific toward this type of process. As you can surely imagine, the relative novelty and complexity of the products and their production processes place pharmed proteins in what often seem like “uncharted waters” for development and regulatory approval.

In fact (confirmable through the below-referenced website), the U.S. government has not issued any new legislation (Acts) specific to GE products, instead relying on predicate health and safety laws to regulate them. However, regulatory agencies have issued some interesting and helpful guidelines that help manufacturers to address the special needs for these types of products. These are managed through a tripartite arrangement between government agencies, called the Coordinated Framework for Regulation of Biotechnology, which is responsible for jointly overseeing all such products. This framework was authorized in 1986 (51 FR 23302; also refer to http://usbiotechreg.nbii.gov/). It is noted that the European Union has gone a bit further than the U.S., with an official Directive (2001/18/EC) and numerous derivative regulations and guidances specific to transgenic organisms ( see http://www.biotethics.org/downloads/articles/EU%20Legislation%20GMOs.pdf for a comprehensive list, as of 2006, with hyperlinks).

Of course, where the genetic enhancement of a living organism is concerned, there is always political and humane-interest controversy. We will take a closer look at the controversy next week as we explore the current world of transgenic plants, and the week after with transgenic animals.

More on this topic next week...stay tuned!

Questions To Our Readers:

1) Have you ever heard of or been involved with (as a manufacturer or a user) any really cool products created through genetic engineering?

2) Given that the technology has been around for nearly 40 years, do you have any thoughts as to why there are few of these products yet on the market?

3) There’s been quite a bit of controversy, public opinion, and even fear out there regarding therapeutic products like these. Are there any risks and benefits about this biotechnology or the products that either scare you or thrill you? Do you think genetic engineering products, either or both from plants and/or animals, is a good idea?

Let's get a discussion started!
Please share your answers in the comment section below!