Genetically Engineered models - Cancer Science

What are Genetically Engineered Models?

Genetically engineered models (GEMs) are organisms whose genomes have been altered using genetic engineering techniques. These models are instrumental in studying various biological processes and diseases, including cancer. GEMs can include transgenic animals, where new genes are introduced, or knockout models, where specific genes are disrupted.

How are GEMs Created?

GEMs are created using technologies such as CRISPR/Cas9, which allows precise editing of the genome. Other methods include zinc finger nucleases and TALENs. These techniques enable scientists to either introduce mutations that mimic those found in human cancers or to delete genes to study their function in tumor development.

Why are GEMs Important in Cancer Research?

GEMs offer a controlled environment to study cancer biology. They help in understanding the role of specific oncogenes and tumor suppressor genes in tumor initiation, progression, and metastasis. GEMs can also be used to test new cancer therapies and to study the mechanisms of drug resistance.

What Types of GEMs are Commonly Used?

Common GEMs include:

Transgenic models: These models have additional genes inserted into their genome. For example, the Myc transgenic mouse model is widely used to study lymphomas.
Knockout models: Specific genes are inactivated in these models. The p53 knockout mouse is used to study the role of p53 in various cancers.
Conditional models: These models allow gene activation or inactivation at specific times or in specific tissues, providing insights into the temporal and spatial roles of genes in cancer.

What are the Limitations of GEMs?

While GEMs are invaluable, they have limitations. The genetic background of the model organism can influence the experimental outcomes. Additionally, some human cancer traits may not be fully replicated in GEMs. Ethical considerations and the time and cost associated with developing GEMs are also significant challenges.

How are GEMs Used in Drug Development?

GEMs play a crucial role in preclinical drug testing. They help in identifying potential drug targets and in understanding the efficacy and toxicity of new drugs. For instance, xenograft models, where human tumor cells are implanted in immunocompromised mice, are often used to test new cancer therapies.

What is the Future of GEMs in Cancer Research?

The future of GEMs in cancer research looks promising with advancements in genomic technologies. The development of more sophisticated models that better mimic human cancers will enhance our understanding of cancer biology and improve the discovery and testing of new treatments. Innovations like organoids and humanized mice are also expected to complement GEMs in cancer research.