Navigating Drug Discovery with High-Throughput Screening

Author: Saba Hosseinzadeh

 

Learning Objectives

  1. Differentiate between high-throughput screening and high-throughput discovery
  2. Identify the differences between traditional screening and high-throughput screening
  3. Explain the importance of high-throughput drug discovery
  4. List and describe the steps of high-throughput screening

 

Graphical Abstract

Legend. High-throughput discovery for drugs has revolutionized the pharmaceutical industry and the field of science. It has a higher quality and time efficiency compared to traditional techniques. The importance of high-throughput discovery is especially seen in the pharmaceutical industry; typically, the drug discovery and preclinical process takes around six to seven years. With high-throughput drug discovery, it has been made possible to examine up to 100,000 compounds a day.

 

Introduction

In the past two decades, high-throughput screening (HTS) has revolutionized the biological and chemical field. However, in the first decade, it was claimed that HTS contributed to the declining productivity, as well as creativity and innovation, in drug discovery. In recent years, HTS has actually revolutionized the pharmaceutical industry through the use of automated robotics, microfluidics, and sensitive detectors, thus allowing researchers to carry out millions of assays. This has allowed researchers and scientists to file through large libraries of ~100,000 compounds to determine their drug-like properties (1).
HTS is just a small glacier compared to high-throughput discovery, which spans all of Antarctica. High-throughput discovery spans from high-throughput screening in drug discovery to high-throughput discovery of novel developmental phenotypes. HTS is under the umbrella of high-throughput discovery. There are two main goals in high-throughput discovery: to enrich the field of science and medicine, and improve the quality of life. The importance of high-throughput discovery is fairly simple: it has made it possible to examine 100,000 compounds per day, and the implementation of an automation technique has made high-throughput discovery in the science and pharmaceutical world efficient (2).

 

Traditional Screening vs. High-Throughput

Traditional methods before high-throughput discovery were superfluous and time-consuming. The table below demonstrates the differences between traditional methods and high-throughput methods. As shown in Table 1, which is based on the 96-well format, the screening ability of high-throughput compared to traditional screening increased 50 times on the low end, and 200 times on the high end (2). High-throughput discovery has led to an increase of efficacy and accuracy. The use of high-throughput discovery allows for testing to be completed using minimal amounts of test compounds.

Adaptation of High-Throughput Screening in Drug Discovery

The importance of high-throughput drug discovery is highlighted in the pharmaceutical industry. As mentioned before, high-throughput discovery has revolutionized the methodology of drug discovery. High-throughput discovery for drugs is well known for its simplicity, rapidness, low cost, and high efficiency, compared to traditional methods, as seen in Table 1.3
To further put the importance of high-throughput drug discovery in perspective, the discovery of a new drug to the development of its finished product originally took up to 12-15 years, and cost more than ~$1 billion (3). High-throughput discovery methods reduce the drug discovery and development process timeline by screening large compound libraries at a rate greater than a few thousand compounds per day (6). These screening methods characterize the toxicological, pharmacokinetic, and metabolic data of new drugs. HTS consists of a few steps, including target identification, preparation of samples, the management of compounds, development of assay, and high-throughput library screening, which will be described in detail later on.

It is clear how important high-throughput drug discovery is for the assessment of a compound’s toxicity. High-throughput systems were used to present the effects of human liver metabolism, and to evaluate the cytotoxicity of the small molecules (6). This system can be used to screen small molecules in mammalian cells.
Drug discovery is a multidisciplinary and time-consuming field, and first begins with the identification of ideal drug targets. Target validation, which determines whether the target is related, proceeds next. Modulators, such as agonists or antagonists of receptors, etc., are then identified. HTS accelerates the process by exposing the target to a large number of compounds, known as “lead” compounds (6). “Lead” compounds are chosen based on their selectivity of the target, and high-throughput discovery accelerates the drug discovery process by screening large libraries. These libraries usually consist of hundreds of thousands of drug candidates (5). Without high-throughput discovery, it would take close to 12-15 years for the drug discovery and development process.

 

Basic Steps of High-Throughput Screening

Preparation of Samples and Compound Libraries
Depending on the assay, samples are usually cellular or biochemical. High-throughput illustrates the importance of the samples to be prepared in an arrayed format (4). Although 96-well plates was described in Table 1, typical formats use 384-, 1536-, or 3456-well plates. The microplate format and color is chosen based on the nature of the sample (cellular or biochemical) and the detection assay.

Establishment of a Method Suitable for Lab Automation
High-Throughput Discovery emphasizes the importance of automation in high-throughput screening. HTS assays are typically formed in a single well, along with low amount of reagents, known as miniaturization.4 As the distinction between the positive and negative controls become more apparent, the data quality increases. This distinction allows for a lower amount of false positives.

Configuration of a Robotic Workstation
The idea of high-throughput screening utilizes a robotic platform that is able to handle multiple plates simultaneously. Thus, resulting in an accelerated data acquisition. The robotic system usually manages the microplates from station to station, with the support of one or more mechanical arms. These steps can include reagent addition, mixing, incubation, and more (4).

Acquisition and Handling of Data
Usually, high-throughput screenings acquire data by optical measurements. This determines the amount of “light” produced by the sample. However, there are varying sorts of readouts, such as fluorescent detection, light scatter, and more. Some detection modes include NanoBRET, FRET, and others depending on the sample (4).

 

Audio Recording

 

References

1. Navigating Drug Discovery with High-Throughput Screening. (n.d.). Retrieved from https://www.technologynetworks.com/drug-discovery/articles/navigating-drug-discovery-with-high-throughput-screening-297350
2. Dickinson, M. E., Flenniken, A. M., Ji, X., Teboul, L., Wong, M. D., White, J. K., Meehan, T. F., Weninger, W. J., Westerberg, H., Adissu, H., Baker, C. N., Bower, L., Brown, J. M., Caddle, L. B., Chiani, F., Clary, D., Cleak, J., Daly, M. J., Denegre, J. M., Doe, B., … Murray, S. A. (2016). High-throughput discovery of novel developmental phenotypes. Nature, 537(7621), 508–514. https://doi.org/10.1038/nature19356
3. Hajare, Ashok & Salunkhe, Sachin & Mali, Sachin & Gorde, Sonali & Nadaf, Sameer & Pishawikar, Sachin. (2013). Review on: High-throughput screening is an approach to drug discovery. American Journal of PharmTech Research. 4. 112-129.
4. High-Throughput Screening. (n.d.). Retrieved from https://pharma.bayer.com/high-throughput-screening
5. High-throughput screening (HTS). (n.d.). Retrieved from https://www.bmglabtech.com/high-throughput-screening/
6. Szymański, P., Markowicz, M., & Mikiciuk-Olasik, E. (2012). Adaptation of high-throughput screening in drug discovery-toxicological screening tests. International journal of molecular sciences, 13(1), 427–452. https://doi.org/10.3390/ijms13010427

 

Questions

  1. What is the difference between high-throughput discovery and high-throughput screening? High-throughput screening falls under the umbrella of high-throughput discovery. High-throughput discovery encompasses all the high-throughput capabilities, while high-throughput screening is a method of utilizing drug targets and compounds.
  2. Because of high-throughput discovery, up to how many compounds can be assessed a day? ~100,000 compounds
  3. What are some key differences between traditional screening methods and high-throughput screening methods? Refer to Table 1: higher screening ability with high-throughput, smaller amounts of compounds used, etc.
  4. Before high-throughput discovery, what was the average time of drug development and discovery? 12-15 years, and with high-throughput discovery, drug discovery has been accelerated.