Unlocking Biomarkers: A Secret to Personalized Medicine

Written by Ahmed Zayed | Last updated on August 4, 2023

What are biomarkers?

A biomarker (short for 'Biological Markers') is a tool used in the latest medical research to figure out and measure various processes that show the presence of a certain disease, how far it has progressed, and how it is responding to its current treatment. 

biomarker graphic

By scanning the biomarkers, researchers can find diseases at a much earlier stage which will make it easier to monitor and chart out effective treatment plans

Do you know that biomarkers are found everywhere in your body, such as your blood, tissue samples, and urine?

These are then used to diagnose and monitor a variety of diseases for example cancer, Alzheimer's disease, and cardiovascular disease. 

One of the emerging aspects of biomarker research these days is the biomarkers of aging

Potential biomarkers of aging identified so far are DNA methylation, histone modification and loss of histones are the main mechanisms. 

As a result of these biomarkers, we can identify biological aging processes, which can lead to age-related diseases, and develop treatments that might even prevent these diseases from occurring in the future. 

7 Types of Biomarkers

If you're wondering, biomarkers have nothing to do with emotions. Their sole focus is on your health.

list of biomarkers with clinical application

Thus, biomarkers come in a variety of forms, each with its own advantages and disadvantages. Find out what these amazing little things are all about.

  • Prognostic Biomarkers: When we have to predict the outcome of any condition or disease we use prognostic biomarkers as indicated by their name. In addition to determining the best course of treatment, they can also help us monitor the progression of the disease.
  • Diagnostic Biomarkers: These biomarkers are used to diagnose the presence or absence of any abnormality. Its advantage is that they confirm a diagnosis and screen for disease in high-risk category individuals.
  • Predictive Biomarkers: These biomarkers are used to guess people who are likely to respond to a particular treatment. They can help us personalize the treatment plans and avoid unnecessary hassle, hence saving the patient from a lot of pain.
  • Safety Biomarkers: These are used when we have to check the safety of a drug or treatment. They help to identify potential adverse effects and monitor their safety over a certain period.
  • Surrogate biomarkers: These biomarkers are used as a substitute for clinical endpoints in clinical trials to assess the effectiveness of a certain therapy or treatment.
  • Proximity biomarkers: To recognize the proximity of cells, biological processes, or molecules to each other.
  • Monitoring biomarkers: These biomarkers monitor the disease progression or treatment response over a while.

What are the biomarkers of aging?

Biomarkers of aging are measurable traits or molecular signs that alternate as we age and can be used to predict or examine our growth. 

These biomarkers can be used to pick out people who are growing old quicker or slower than anticipated for their chronological age and to measure the effectiveness of interventions designed for reverse aging.

10 Common Biomarkers of Aging

  1. Telomere lengthTelomeres are the defensive caps at the end of chromosomes that shorten with every cell division. Shortened telomeres have been related to age-related ailments and mortality.
  2. Epigenetic changesEpigenetic modifications, such as DNA methylation, histone modification, and miRNA expression, are adjustments to gene expression that appear without changing the DNA sequence.

    These adjustments have been proven to be related to getting older and age-related diseases.
  3. Inflammation: Chronic irritation is a hallmark of growing old and grey. It is related to many age-related diseases.

    Elevated degrees of pro-inflammatory cytokines such as IL-6 and TNF-alpha are often found in aging individuals.
  4. Oxidative stress: Reactive oxygen species (ROS) are naturally produced in cells throughout metabolism, but excess ROS can concur damage to cellular components such as DNA, proteins, and lipids.

    Increased stages of oxidative stress are related to growing older and age-related diseases.
  5. Mitochondrial dysfunction: Mitochondria are the cell's powerhouses and produce energy in the shape of ATP.

    Mitochondrial dysfunction, such as diminished  ATP production and increased production of ROS, is a classical hallmark of aging and is associated with many age-related diseases.
  6. The decline in immune function: As individuals age, their immune system becomes less effective at fighting off infections and diseases. This decline in immune function is associated with increased susceptibility to infections and age-related diseases.
  7. A decline in cognitive function: Aging is associated with a decline in cognitive function for example attention, memory, and executive function.

    Changes in brain structure and function, such as decreased connectivity between brain regions and decreased gray matter volume, are commonly observed in people who are growing older day by day.
  8. Hormonal changes: Changes in hormone levels which are decreased levels of testosterone in men and estrogen in women are associated with aging and age-related issues.
  9. A decline in muscle strength and mass: Aging is associated with a decline in muscle mass and strength, known as sarcopenia. This decline is associated with decreased mobility and an increased risk of falls in aging individuals.
  10. Metabolic changes: Aging is often associated with changes in metabolism, which are, lower levels of insulin sensitivity and increased insulin resistance, and vice versa. These changes are linked with an increased risk of type 2 diabetes.

Biomarkers of aging can be used to discover people who are getting older quickly or slower than predicted and to measure the effectiveness of interventions designed for gradual or reverse aging. 

How are biomarkers used as predictors of health and disease?

By presenting essential facts about an individual's current and future health status, biomarkers can be used as predictors of fitness and disease. 

Healthcare providers can monitor and measure biomarkers to identify people at risk for disease, diagnose ailments early on, and display the progression of illness and response to treatment.

detecting cancer

For example, in the case of cardiovascular disease, biomarkers such as increased blood pressure, elevated levels of low-density lipoprotein (LDL) cholesterol, and improved stages of C-reactive protein (CRP) can be used to predict an individual's risk of developing cardiovascular disease. 

Similarly, in cancer, biomarkers such as tumor size, grade, and molecular markers can be used to diagnose most cancer early and reverse their progression.

Biomarkers can additionally be used to monitor the effectiveness of treatments and interventions

For example, in the case of diabetes, biomarkers such as glycated hemoglobin (HbA1c) can be used to monitor blood sugar control and the effectiveness of diabetes management interventions such as diet and exercise. 

In cancer, biomarkers such as tumor markers can be used to monitor the effectiveness of cancer treatment and detect any recurrence of the disease.

Moreover, biomarkers can also be used as predictors of response to treatment.

For instance, in the case of depression, biomarkers such as brain-derived neurotrophic factor (BDNF) can be used to predict the response to antidepressant treatment.

Additionally, biomarkers can be used to evaluate the impact of lifestyle interventions on fitness outcomes, such as weight loss plans and exercise. 

Hence, biomarkers play an essential part in predicting health and disease, diagnosing problems early, monitoring their progression and response to various therapies, and assessing the effectiveness of their interventions. 

The use of biomarkers in healthcare is in all likelihood to proceed to grow, with new biomarkers being observed and validated for use in medical practice.

Role of biomarkers in the detection of cancer and its drug development: 

Biomarkers play a very important role in cancer detection and drug development. 

They are measurable molecular, cellular, or genetic characteristics that show the presence of cancer, guess its behavior, and assess its response to treatment.

Biomarkers can be used to diagnose cancer early on and monitor the effectiveness of ongoing therapy.

drug discovery

 Five examples of biomarkers in cancer detection and drug development:

  1. Tumor markers: Tumor markers are proteins that are produced by cancer cells or normal cells in response to cancer.

    Increased levels of tumor markers in the blood show the occurrence of cancer, and changes in tumor marker levels can be used to monitor the spread of the disease and its response to treatment.

    Examples of tumor markers include CA-125 for ovarian cancer, prostate-specific antigen (PSA) for prostate cancer, and CEA for colorectal cancer.
  1. Genetic biomarkers: Genetic biomarkers are changes in DNA that increase the risk of cancer or predict its response to a certain treatment.

    For example, mutations in the BRCA1 and BRCA2 genes increase the risk of breast and ovarian cancer and can be used to identify individuals who may benefit from prophylactic surgery or increased surveillance.

    Similarly, genetic testing can identify patients who may respond to targeted therapies, such as those with EGFR mutations in non-small cell lung cancer.
  1. Imaging biomarkers: Imaging biomarkers are changes in radiological images that indicate the location, presence, and extent of cancer spread.

    Examples of imaging biomarkers include the degree of tumor vascularity and the size of a tumor
  2. Pharmacodynamic biomarkers: Pharmacodynamic biomarkers are molecular changes in cells and tissues that show the effectiveness of a drug on its intended target.

    For example, changes in the level of phosphorylated proteins can indicate the inhibition of specific kinase targets by small molecule inhibitors.
  1. Circulating tumor cells (CTCs): CTCs are cancer cells that have detached from the primary tumor and are circulating in the blood.

    CTCs can be isolated and analyzed to give us information about tumor biology, predict response to treatment, and monitor disease progression.

We now know that biomarkers can help healthcare providers identify patients who will benefit from a particular treatment, and they can help drug developers design and test therapies that target certain molecular pathways or genetic mutations associated with cancer.

The use of biomarkers in cancer detection and drug development is increasingly becoming an important component of customized medicine.

With advancements in medicine and the availability of more powerful tools for biomarker discovery and validation, the role of biomarkers in cancer detection and drug development is likely to continue to grow in the future.

Detection and measurement of biomarkers:

Measuring and detecting biomarkers is an important step in their clinical use for disease diagnosis, treatment, and monitoring.

The specific methods used for detecting and measuring biomarkers depend on the biological matrix and the type of biomarker in which it is present.

Here are five common methods which are used for detecting and measuring biomarkers:

  • Polymerase Chain Reaction (PCR): PCR is a molecular biology technique that is used to intensify specific DNA sequences.

    It can be used to detect and quantify genetic biomarkers such as deletions, mutations, or amplifications.

    PCR can be used in various sample types, which include tissue biopsies, blood, or other bodily fluids.
  • Enzyme-Linked Immunosorbent Assay (ELISA): ELISA is a highly sensitive and specific method for biomarker detection and is widely used in clinical and research settings.

ELISA is a commonly used method for detecting and measuring biomarkers in biological fluids. It involves using antibodies that are specific to the biomarker of interest to capture and detect it in the sample.

  • Mass Spectrometry (MS): MS can provide information on the mass and structure of the biomolecule, allowing for identification and quantification.

    MS is a powerful analytical tool used to detect and quantify biomolecules, including proteins, lipids, and small molecules. MS can be used in various sample types, including blood, urine, and tissue samples.
  • Flow Cytometry: Flow cytometry is a technique that is used to analyze cells and their properties.

    It provides information on the number, size, and complexity of cells and can be used to detect and measure biomarkers present on the surface of cells or within cells, such as intracellular cytokines,  protein expression levels and cellular DNA content .
  • Imaging techniques: Imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) can be used to detect and measure imaging biomarkers.

    These techniques provide visual and quantitative information about the location, size, and metabolic activity of tumors and other diseases.

Thus, biomarkers are important for the diagnosis, monitoring, and treatment of diseases.

The choice of the method used for detecting and measuring biomarkers depends on the biological matrix in which it is present and the type of biomarker.

Advances in technology have enabled the development of new and more sensitive methods for biomarker detection and measurement, which are likely to continue to grow in importance in the coming years.

What are some applications of biomarkers?

Biomarkers are spreading far and wide. They have a lot of applications in the field of research, medicine, environment, and drug development, let's have a look at a few of them.

To develop disease diagnosis: While diagnosing a disease most of them involve the use of biomarkers. The cornerstone of all in-vitro diagnostics is in fact biomarkers.

The initial stage of diagnostic growth is the discovery of one or more biomarkers linked to a healthy biological process, a pathogenic one, or the patient's response to a prescribed medication. 

The determination of whether a marker (or set of markers) is accurate, appropriate, and exact for assessing a planned process or a patient's reaction to therapy is made by clinical validation of biological, physiological, or morphological indicators.

To monitor various diseases: We use biomarkers to monitor the spread and treatment response to various diseases.

A perfect example could be tumor markers, as they are widely used to see the spread of cancer and its response to certain therapies.  

For the development of drugs: In medicine, biomarkers are used to identify drug targets and then see their efficacy along with the safety of that drug.

For example, to target specific molecular pathways, pharmacodynamic biomarkers are used. These can be used to evaluate the effectiveness of drugs that target specific molecular pathways.

Personalized medicine: Biomarkers can be used to identify patients who are most likely to benefit from a particular treatment, leading to personalized treatment approaches.

For example, genetic biomarkers can be used to identify patients who are likely to respond to targeted therapies.

Environmental monitoring: Biomarkers can be used to monitor exposure to environmental toxins and pollutants.

For example, biomarkers of lead exposure can be measured in blood samples to monitor exposure in individuals.

Agricultural and food safety: Biomarkers can be used to monitor the safety and quality of agricultural and food products.

For example, biomarkers of pesticide exposure can be measured in food products to ensure they are safe for consumption.

Frequently Asked Questions

What is a biomarker?

A biomarker is a measurable indicator of a biological process, disease, or response to treatment.

It can be a molecule, gene, or characteristic that is found in a person's blood, urine, or tissue sample.

Biomarkers are used in medical research and clinical practice to diagnose diseases, monitor disease progression, and evaluate the effectiveness of treatments.

What are the 10 biomarkers?

The ten biomarkers are Telomere length, Epigenetic changes, Inflammation, Oxidative stress, Mitochondrial dysfunction, Decline in immune function, Decline in cognitive function, Hormonal changes, Decline in muscle mass and strength, and Metabolic changes.

What is an example of a biomarker?

One example of a biomarker is prostate-specific antigen (PSA), a protein produced by the prostate gland.

Elevated levels of PSA in the blood can be an indication of prostate cancer or other prostate-related conditions. PSA is often used as a screening tool for prostate cancer and to monitor disease progression and treatment response.

What is a biomarker in simple terms?

A biomarker is a measurable substance or characteristic that can be used to indicate the presence or progression of a disease or the effectiveness of treatment.

Biomarkers can include molecules, genes, proteins, and other measurable traits found in blood, urine, or tissue samples.

What are the most common biomarkers?

The most common biomarkers vary depending on the disease or condition being studied.

Some commonly used biomarkers include C-reactive protein, hemoglobin A1c, cholesterol, blood pressure, tumor markers, genetic markers, and inflammatory cytokines.

Other common biomarkers include various hormones, enzymes, and proteins that can be measured in blood or other bodily fluids.

Why are biomarkers used?
Biomarkers are used to provide objective, measurable evidence of the presence, progression, or treatment response to a disease or condition.

They are also used to identify individuals who are at risk for certain diseases, guide treatment decisions, and monitor the safety and efficacy of new drugs and treatments.

Conclusion:

In conclusion, biomarkers are essential tools in medical research and clinical practice.

They provide measurable evidence of the presence, progression, or treatment response of a disease or condition, help guide treatment decisions, and monitor patient outcomes.

Biomarkers can include molecules, genes, proteins, and other measurable traits found in blood, urine, or tissue samples.

They are used to identify individuals who are at risk for certain diseases, to screen for diseases, and to evaluate the safety and efficacy of new drugs and treatments.

While many biomarkers are commonly used, the choice of biomarkers depends on the specific disease or condition being studied.

Reference:

1. Strimbu, K., & Tavel, J. A. (2010). What are biomarkers? Current opinion in HIV and AIDS, 5(6), 463-466.

2. Zhang, H., Liu, Y., & Yan, J. (2018). A review of biomarkers for neurodegenerative disease: will they be clinically useful? Frontiers in aging neuroscience, 10, 349. Retrieved from https://www.frontiersin.org/articles/10.3389/fnagi.2023.1153932/full

3. Lopez-Otin, C., & Hunter, T. (2020). The regulatory crosstalk between kinases and proteases in cancer. Nature Reviews Cancer, 20(5), 303-322. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5938178/

About the author 

Dr Ahmed Zayed is a medical resident specializing in plastic surgery with years of experience in the field. He is also a writer for top-rated websites including Washington Post, Chicago Tribune, ConsumerHealthDigest, and Huffington Post


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