The Future of Cell Biology

Kevin Daugherty, Director of Marketing for Greiner Bio-One, and Dr. David Kirk, Technical Director of MDS Pharma Services, sit down to discuss molecular and cell biology, improved tissue devices and the biggest potential for cell culture.

NGP. What are the recent advancements in molecular and cell biology?
DK. The major advance in molecular biology in the last decade is unquestionably the sequencing of the human genome, as well as the sequencing of many other animal and plant genomes. The availability of the human gene sequences provides unprecedented access to large numbers of potential new drug targets. Validation of these new targets has proven difficult and it is a major bottleneck in early drug discovery. However, new genetic technologies such as siRNA and gene knock-out animals are now proving useful in validating new targets.

The universal recognition of the need for better in vitro and in vivo models systems for predicting drug response in humans has lead to several important developments in cell biology. Most notably, primary cell lines derived from a wide range of normal human tissues are now being used as more relevant models for drug evaluation.  Another recently developed in vitro human model system currently used for toxicity assessment in early discovery, is the human adult stem cell.

The Systems Biology approach is gaining traction in drug discovery and numerous cell-based technology platforms are available that can simultaneously evaluate multiple assay parameters.

KD. Our industry and business has witnessed numerous advancements in molecular and cell biology. Among them: developments in the capacity to turn off the expression of genes through gene silencing coupled with the timing of gene expression and the control of transcription; the understanding cell signalling and communication among intra- and extra-cellular receptors and the multiple effect of signalling molecules; developments in cancer biology in how cancer develops and can be suppressed; work being done on the mechanisms of infectious diseases and how to block infections on the cellular level; and embryonic and stem cell development and differentiation.

NGP. What requirements for improved cell and tissue culture devices have developed as a result of this?
KD. Consumable devices used in cell and tissue culture research have improved to provide increased sensitivity affording the researchers the tool to more easily, in time and effectiveness, uncover information they are looking for. This sensitivity has focused on materials that do not have extraneous substances, purity of the raw materials used in production that do not auto fluoresce during research, consumables supplied with customer specified coatings, and consumables that are DNA/RNA/DNase/RNase free. The challenge is of course to demonstrate to the researcher who may have become accustom to certain consumables based on previous success and discoveries that the new consumables can provide him or her with reliable results and added value in time and effectiveness in conducting their research. Developments and requirements for consumables that are customized and/or designed to handle specialized assays and equipment automation have also been significant in contributing to advancements in molecular and cell biology.

DK. The current acceptance of cellular systems as providing superior quality data to biochemical methods has resulted in the development of a broad spectrum of enabling technologies for cell-based assays. Typically, this new generation of robotic cell handlers is programmable and can automatically support all the routine labor-intensive culture procedures. Together with automated cell counters and cell dispensing equipment, cell biology has been pushed to a new level of reproducibility and efficiency not possible with the traditional manual approach.

The significant improvements in the development of nutrient culture media to retain specific cellular function/growth has been critical for the continual development of more relevant cellular models for the different therapeutic areas…especially for the development of stem cells which can be differentiated into multiple cell lineages at will (e.g. liver, kidney, skin).

Increasing numbers of cell reagents (recombinant cells, antibodies, fluorescent probes, siRNA reagents etc) combined with cell-based assay platforms configured for 96, 384 well(or higher) plate readers and using a range of detection modes (imaging, fluorescence, calcium mobilisation, electrophysical, cell dielectrics etc) provides for  an automated and comprehensive cellular analysis.

NGP. How can drug compounds be identified even faster and more effective?
DK. In early drug discovery, several approaches are currently adopted to identify higher quality lead compounds faster and more cost effectively. The first is the automation and miniaturization of the screening process. Using 1536 well plates with compatible robotic liquid handlers significantly reduces both the amount of sample required and the cost of assay reagents. However, working with vanishingly small liquid volumes presents significant technical challenges.

Supplementary approaches focus on the early prediction of compound toxicity, which is still a major cause of drug failures (around 30 percent). Predictive tools are commercially available and using quantitative structure-activity relationships (QSAR) they can help identify structural alerts for various toxicities (Cardiotox, genotox etc). This bioinformatics approach can be a useful preliminary screen prior to a cell-based screen. Cell-based screens are designed to measure off target (toxicity) effects simultaneously with the “on target” effects using a high content multiplexed assay approach. Hit compounds can be evaluated quickly and toxicity issues associated with potent “lead” compounds can be optimised in subsequent medicinal chemistry cycles prior to testing in animals or humans.

KD. Automation. The ability to provide real-time testing of compounds where materials are taken from a library, modified and real-time information is provided to the researcher so further modifications can be made and real-time testing of in-vitro models to get immediate information on cell cultures.

Focused research on targeted pathways before looking at compounds where the identification of genes predisposed to disease will be related to the disease in patients. Combining genomics and genetics can bring focus and speed to target identification bringing us faster to new, safer and more effective drugs.

NGP. What are the challenges involved in future progress involved in molecular and cell biology?
KD. Competition, costs, funding and political environment all play key and interrelated roles to future developments in molecular and cell biology. A competitive-related challenge to cell biology is the production of biopharmaceuticals in transgenic animals and plants. Transgenic domestic animals and plants have the potential to improve scalability and yield of cell culture reducing the cost in development and production of biopharmaceuticals.

Cost and funding go hand-in-hand where private investments/funding made in life sciences need to demonstrate a return that is competitive with other industries. Cost thus plays an important role in that return.

Political environment and funding also are interrelated in that the former has direct impact on the funding made available. Reducing the availability of research grants will have negative consequences not only to the scientific community and our countries’ ability to make rapid advancements in potential disease treatments and cure through molecular and cell biology, but also on the industries supporting scientific research.

DK. Target validation is a major bottleneck for drug discovery due to the poorly characterised targets emerging from the genomics project. RNA interference is a popular approach for both in vitro and in vivo target validation studies. Knock-out (genetically modified) mice are also used. Failure to correlate the gene function with the specific disease will ultimately cause drug failure further down drug development…at a considerable cost!

Like toxicity, lack of efficacy is also a major cause of drug failure (around 30 percent). More relevant models, perhaps using human stem cells, are needed to help improve predictability in human populations.

One obstacle hampering drug development is the increasingly complex Intellectual Property landscape. A recent GAO report (Nov 2006) cites IP issues as one of several factors in Pharma’s inability to keep NDA submissions on a par with the increase in their R&D expenditures.

NGP. Where do you see cell culture’s biggest potential?
DK. I see the role of cell culture playing an increasing important role at several closely related points in early drug discovery. First, as mentioned above, cell-based assays will be used more and more in primary and secondary compound screens as multiplexed assays. Cellular assays will also be increasingly used in target validation studies.

I anticipate that cell-based safety assays mimicking the required regulatory assays (genotox, hERG, drug-drug interactions, and target organ toxicity) will be used increasingly at earlier points in discovery as multiplexed screens.

One major advantage of cell-based assays is their utility in determining the mechanism of compound toxicity as well as helping elucidate their mechanism of action. Oncology is indeed a fertile area for using cell-based assays to evaluate new oncology targets. The availability of a large number of human tumor cell lines that contain well characterised mutations in a wide spectrum of growth related genes greatly assists in target validation and compound screening.

KD. The biggest potential in cell culture is with stem cells because of self-renewing properties and ability to become any type of tissue or organ in the human body as well as the potential for the treatment of illnesses where current disease management or treatment is not as safe and effective or does not exist.

Cell culture could also have a large potential in the production of pandemic vaccines such as the case with influenza, which is produced using egg-based technology, which can be very labour and time intensive. Cell culture has the potential to be more economical and can bring vaccines to market faster by moving into higher yielding cell or bacterial based production.

Kevin Daugherty is the Director of Marketing for Greiner Bio-One, Inc. (Monroe, North Carolina) BioScience and Preanalytic businesses in North America. Daugherty has been in the medical/laboratory device industry for 15 years in various marketing and sales management positions and joined Greiner Bio-One in January 2005. Prior to joining Greiner Bio-One, Daugherty was at Beiersdorf AG’s (Hamburg, Germany) US operation (Charlotte, North Carolina) in their professional medical business unit. Daugherty is a graduate of Miami University (Oxford, Ohio) and began his career in the semiconductor industry before moving to medical/laboratory device industry.

David Kirk has 15 years experience working in many areas of early drug discovery at MDS Pharma Services (previously Panlabs). Prior to assuming his current role of Technical Director, Kirk was, Associate Director of Bioanalytical Services, Director of In Vitro Metabolism and Director of Cell Biology at MDS Pharma Services. He also has regulatory GLP experience. He developed and ran GLP-compliant In Vitro Metabolism client services and has represented a client at their FDA Advisory committee by presenting their in vitro drug-drug interaction data.

Kirk also has 19 years experience in studying the cell biology of urological cancers and was Director of the Prostate Cancer Research Program at the Huntington Medical Research Institutes (Pasadena,CA) where he was Principle Investigator on an NIH funded grant (NIDDK) to study Benign Prostatic Hyperplasia.