A search for “Nature Target” can be misleading. The phrase combines the scientific publisher, Nature, with a concept in biomedical research known as a “target,” as there is no journal with this name. Instead, the term points to the groundbreaking discoveries published in top-tier journals, which often revolve around identifying scientific targets. This article will explain what a scientific target is, the different forms it takes, and how it serves as the foundation for developing new medicines.
Defining a Scientific Target
A biological target is a molecule or structure, most often a protein or nucleic acid, within an organism that a therapy is designed to interact with to produce a desired effect. The interaction between a drug and its target is often compared to a lock and key; the drug (the key) is designed to fit the target (the lock), altering its function to combat a disease.
The goal is to modify the target’s behavior, such as blocking an overactive target or activating an underperforming one. This physical binding initiates a chain of events leading to a therapeutic outcome. The precision of this interaction allows for the development of effective medicines while minimizing unintended effects on other parts of the body.
Common Types of Biological Targets
The most common biological targets are proteins. Among these, enzymes are a frequent focus as they speed up chemical reactions. In some diseases, a particular enzyme may be too active, so drugs are designed as inhibitors that bind to the enzyme to block its activity and slow the disease process.
Receptors are another class of protein targets on the cell surface that receive and transmit external signals. Therapies can activate these receptors by mimicking a natural signal or block them to prevent a signal from passing through. A large percentage of approved drugs work by interacting with a specific class known as G protein-coupled receptors.
Therapies can also interact with nucleic acids like DNA and RNA to prevent a harmful protein from being produced. Technologies like RNA interference (RNAi) use small RNA molecules to degrade specific messenger RNA (mRNA) sequences. This approach silences a gene before its protein is created, offering a way to treat conditions that were previously difficult to address with conventional drugs.
Sometimes the target is an entire signaling pathway, a series of interacting molecules that control a cell function. When this pathway is dysregulated in a disease, a drug can be developed to inhibit a component, disrupting the abnormal signaling and restoring normal cellular behavior.
The Process of Target Identification and Validation
Target identification is the process of discovering a molecular target involved in a disease. Scientists achieve this by comparing healthy and diseased cells or tissues to find differences at the molecular level. This involves genomics (the study of genes) and proteomics (the study of proteins) to identify genes or proteins that are expressed differently in a disease state.
Once identified, a potential target undergoes validation to confirm that modulating it will produce the intended therapeutic effect. This process proves the target is involved in the disease and accessible to a drug. Validation methods include genetic techniques, like gene knockdown, to see how silencing the target affects disease symptoms in a lab setting. Pharmacological validation uses small molecules or antibodies to modulate the target’s activity, ensuring it is a viable path for drug development.
The Role of Targets in Modern Medicine
The identification of specific targets enables the creation of targeted therapies. These treatments act on specific molecules associated with a disease, leading to more effective outcomes with fewer side effects compared to treatments like chemotherapy. This approach is the basis of personalized medicine, where treatments are tailored to the molecular characteristics of a patient’s disease.
A prominent example is in oncology, where many cancer drugs interfere with molecules that help cancer cells grow and survive. For instance, tyrosine kinase inhibitors (TKIs) are drugs that block enzymes responsible for uncontrolled cell growth in certain cancers, such as chronic myeloid leukemia and non-small cell lung cancer. This precision allows the drug to attack cancer cells while sparing healthy cells.
The concept of a biological target was also central to the response to the COVID-19 pandemic. Scientists identified the ACE2 receptor as the primary entry point for the SARS-CoV-2 virus into human cells, making it a logical target for therapies and vaccines. Strategies were developed to block the virus from binding to the ACE2 receptor or to use “decoy” receptors to trap the virus before it could infect cells.