International Research Journal of Biochemistry and Bioinformatics

Abstract

The body or the cancer itself produces substances known as tumor markers, typically proteins, in response to cancer growth. Tumor markers can be found in tissue, blood, or urine, and their discovery and detection may lead to an earlier diagnosis of cancer and improved therapeutic intervention. Due to their simplicity and high efficiency, colorimetric immunoassays for the detection of tumor markers have received a lot of attention. Enzyme-linked immunosorbent assays are the foundation of the colorimetric immunoassays that have been used to detect tumor markers for a long time. The remarkable achievements of nanotechnology have further provided opportunities for the creation of immunoassays of this kind. This paper will sum up late advances in the field of colorimetric immunoassays for recognizing growth markers, which is planned to give an outline in this field, as well as trial direction for the student.

Keywords

THP-1, acid conjugated to linoleic, Alpha-linolenic acid, Eicosapentaenoic corrosive, The liver's X receptor The A1 ATP-binding cassette

INTRODUCTION

Malignant growth is a main source of death around the world, causing around 13% of all human passings in 2007 (7.6 million), and passings from disease are projected to ascend, with an expected 12 million passings anticipated for 2030. More than 30% of cancer deaths could be avoided with early detection and treatment, according to the World Health Organization. Therefore, an accurate diagnosis in the early stages of cancer is one crucial factor in treatment success.

Endoscopy, cytology specimen tests, and imaging/radiology tests like X-ray, positron emission computed tomographycomputer tomography (PET-CT), and magnetic resonance imagings (MRI) are all traditional methods for diagnosing cancer. Sadly, these diagnostic techniques are expensive and time-consuming, and they are not particularly effective for early cancer diagnosis; therefore unavailable to a large number of individuals. As a result, it is of the utmost importance to develop straightforward, speedy, specific, and dependable methods for early cancer diagnosis (Sattarahmady et al., 2015).

The two antibodies "sandwich" ELISA, which measures the amount of antigen between two layers of antibodies, is the ELISA method that is utilized in colorimetric immunoassays the most frequently for the purpose of detecting tumor markers. A capture antibody is first immobilized onto a solid support in this assay. During incubation, the tumor marker that is found in a biological sample or standard mixture is bound and concentrated on the support surface. The solid support is then incubated with the solution containing the detection antibody, which binds to the tumor marker as well. The color shift brought on by the enzyme-catalytic reaction can be used to determine the quantity of the target tumor marker because the detection antibody is also tagged with particular enzymes. The experimental details are described below, primarily using a slightly altered Abcam procedure (Gupta et al., 2008).

DISCUSSION

Cancer cells and other related non-tumor cells have long been known to respond to tumor growth by releasing specific tumor markers—typically proteins—into the circulatory system. These tumor markers can be found in tissue, blood, or urine, and their concentration is correlated with the stage of cancer. Numerous protein tumor markers for a variety of cancers have been identified in conjunction with the development of proteomic technologies. Tumor marker detection has received increasing attention in recent years due to its potential application in cancer early detection. Although some novel immunoassays have been created, numerous methods have been used to create these assays. Some examples of immunoassays that have been developed for the analysis of tumor markers (Barroso et al., 2016). The colorimetric method, in which the event is revealed by a visual color change in the reaction medium, has proven to be the most convenient of the various detection methods. As a result, colorimetric sensing systems for the detection of tumor markers have evolved significantly over time. Based on enzyme-linked immunosorbent assay (ELISA), numerous colorimetric assays for detecting tumor markers have been proposed. However, low concentrations of tumor markers cannot be detected in the early stages of cancer using conventional colorimetric immunoassays that are based on ELISA. As a result, colorimetric immunoassay signal amplification methods have been the primary focus of research efforts. For instance, Lee et al. were able to do so by incorporating an enzyme-cascading step into the ELISA system. Have published a brand-new cascading ELISA with detection limits of between 100 fM and 10 pM for Alpha-fetoprotein (AFP) and prostate specific antigen (PSA) in human serum. Nanotechnology, on the other hand, is opening up new possibilities for the highly sensitive detection of tumor markers. Numerous kinds of nanomaterials have been used in colorimetric assays to detect tumor markers due to their excellent properties (Campanella et al., 2004).

Due to their distinctive optical properties, Au-NPs are the most frequently used nanomaterials for colorimetric detection of tumor markers. Their optical properties are strongly influenced not only by the size of the particles but also by their aggregation state. As a result, smaller individual nanoparticles appear wine red, whereas larger particles or aggregates of smaller particles range from deep blue to purple. Au-NPs can also be made with a wide range of biomacromolecules, like nuclear acids and enzyme-linked antibodies, thanks to their excellent biocompatibility, which greatly expands their use in the colorimetric detection of tumor markers. Accordingly, enormous quantities of Au-NPs based colorimetric immunoassays have been created for the identification of growth markers, oncogenes and even cancer cells (Sacchi et al., 1998).

Magnetic particles (MPs), like Au-NPs, can be easily separated from a matrix with the help of a magnetic field, making them a promising alternative to Au-NPs. Exploiting their novel attractive trademark as well as fantastic biocompatibility, MPs have been broadly used as a widespread partition device in the creation of colorimetric detecting frameworks for the location of cancer markers

CONCLUSION

Briefly, biotin-anti-CEA conjugated MPs are first added to the CEA, AFP, and a few nonspecific proteins-rich test solutions. After attractive detachment, CEA antigen which is caught by biotin-hostile to CEA, immobilized on the outer layer of MPs, is accordingly gathered. Therefore, HRP-anti- CEA loaded on the surface of Au-NPs may capture the CEA antigen conjugated on the surface of MPs if they are added to the collected CEA antigen solution. As a result, the test solution takes on a blue hue when TMB and H2O2 are added. On the other hand, the discovery of AFP antigen in the test arrangement can be done by rehashing the above methodology, utilizing biotin-against AFP formed MPs and Au-NPs stacked with HRP-hostile to AFP.Colorimetric measure is exceptionally straightforward and effortlessly worked, without requiring the costly instruments required in the optical immunoassay frameworks, for example, chargecoupled gadget (CCD) camera and multi-station infusion valves fixed to iridescence analyzers. In point of fact, some electrochemical approaches have also been proposed for the detection of cancer due to their simplicity and low cost. However, the experimental procedure is complicated because the current electrochemical signal amplification strategy frequently involves multiple deposition and stripping steps; whereas colorimetric methods do not necessitate complicated experimental steps and the outcomes are visible to the naked eye. As a result, there has been a growing interest in colorimetric immunoassays for the purpose of identifying tumor markers. In the meantime, the advancement of colorimetric immunoassays has been greatly aided by nanotechnology. First, MPs may be able to quickly and safely separate the target from the other species, preventing non-specific proteins from interfering with immunoassays. Second, the Au-NPs' distinctive optical properties can be used to convert the presence of target tumor markers into easily detectable signals, making the designed detection system simpler.