Novel approaches to identify low-penetrance cancer susceptibility genes using mouse models

Molecular deconstruction, detection, and computational prediction of microenvironment-modulated cellular responses to cancer therapeutics

The field of bioengineering has pioneered the application of new precision fabrication technologies to model the different geometric, physical or molecular components of tissue microenvironments on solid-state substrata. Tissue engineering approaches building on these advances are used to assemble multicellular mimetic-tissues where cells reside within defined spatial contexts. The functional responses of cells in fabricated microenvironments have revealed a rich interplay between the genome and extracellular effectors in determining cellular phenotypes and in a number of cases have revealed the dominance of microenvironment over genotype. Precision bioengineered substrata are limited to a few aspects, whereas cell/tissue-derived microenvironments have many undefined components. Thus, introducing a computational module may serve to integrate these types of platforms to create reasonable models of drug responses in human tissues. This review discusses how combinatorial microenvironment microarrays and other biomimetic microenvironments have revealed emergent properties of cells in particular microenvironmental contexts, the platforms that can measure phenotypic changes within those contexts, and the computational tools that can unify the microenvironment-imposed functional phenotypes with underlying constellations of proteins and genes. Ultimately we propose that a merger of these technologies will enable more accurate pre-clinical drug discovery.

Mouse models of cancer: does the strain matter?

Mouse models are indispensible tools for understanding the molecular basis of cancer. However, despite the invaluable data provided regarding tumour biology, owing to inbreeding, current mouse models fail to accurately model human populations. Polymorphism is the essential characteristic that makes each of us unique humans, with different disease susceptibility, presentation and progression. Therefore, as we move closer towards designing clinical treatment that is based on an individual's unique biological makeup, it is imperative that we understand how inherited variability influences cancer phenotypes, how it can confound experiments and how it can be exploited to reveal new truths about cancer biology.

The human genome project and the discovery of genetic determinants of cancer susceptibility

The Human Genome Project has recently provided a great deal of information on the sequence that comprises the human genome. We are now in the process of structuring and deciphering the 3 x 10(9) base sequence in order to gain insights into its functional role. Several efforts are focusing on the search for DNA sequence variations underlying common/complex diseases that constitute a real burden in terms of public health measures. As expected, the genetic architecture of these complex traits, shows tremendous complexity, and the discovery and characterisation of susceptibility alleles constitute a real challenge for the geneticist. Conceptual and experimental genetic approaches aimed at dissecting the molecular features of susceptibility genes, in particular those predisposing to cancer, are outlined and discussed in this review.