Science News
from research organizations

Thyroid cancer biomarker assays may show inaccurate readings

Date:
November 12, 2015
Source:
Michigan Technological University
Summary:
Two thyroid cancer biomarkers go through a clumping cycle that may interfere with cancer detection tests. New research explores a driving force behind the problem: a protein with a sweet tooth.
Share:
FULL STORY

Tarun Dam and his student Ni Fan and Melanie Talaga published a news study that highlights possible inaccuracies in thyroid cancer detection tests.
Credit: Michigan Tech, Sarah Bird

Protein biomarkers are used to test for cancer before and after surgeries to remove tumors. To test thyroid malignancy, many biomarkers are tested separately to confirm cancer. However, new research from Michigan Technological University shows that the detection tests that measure two major biomarkers to diagnose thyroid cancer may be inaccurate. The study recently came out in the journal Thyroid, published by the American Thyroid Association.

One biomarker, thyroglobulin (Tg), is a glycoprotein that has sugar in its molecular structure. It's "candy-coated" says Tarun Dam, an assistant professor of chemistry at Michigan Tech who led the research. He points out that the second biomarker, galectin-3 (Gal-3) is not a glycoprotein, but "it has a sweet tooth."

And like a kindergartner on Halloween, Gal-3 can't resist Tg. The two proteins tend to clump, an interaction not accounted for in the current thyroid cancer detection assays.

The clumping cycle of Tg and Gal-3 is fairly straightforward from a biomechanics perspective. A thyroid cancer cell secretes Tg and Gal-3, and the sweet-tooth nabs the glycoprotein. As more Tg is secreted, the influx partially breaks up the larger clumps. The body can potentially remove some globs quickly, taking away some of the biomarkers before the samples are collected from the patients.

Currently, detection assays only look at Tg and Gal-3 separately. They have no way to account for the biomarkers that may be tied up or removed in clumps. Plus, there is no way to know what stage of the clumping cycle the proteins are in; they could be in a big clump, already metabolized, partially dissolved or mostly free.

Dam and his team tested the physical and biochemical properties of the biomarkers to ensure this clumping cycling was driven by the proteins' interactions.

Based on his team's findings, Dam suggests adding a step to break up the clumps before running the assay tests, which should help make the tests more accurate.


Story Source:

Materials provided by Michigan Technological University. Original written by Allison Mills. Note: Content may be edited for style and length.


Journal Reference:

  1. Ni Fan, Melanie L. Talaga, Robert K. Brown, Ashli L. Fueri, Purnima Bandyopadhyay, Tarun K. Dam. Glycan-Dependent Mutual and Reversible Sequestration of Two Thyroid Cancer Biomarkers. Thyroid, 2015; DOI: 10.1089/thy.2015.0105

Cite This Page:

Michigan Technological University. "Thyroid cancer biomarker assays may show inaccurate readings." ScienceDaily. ScienceDaily, 12 November 2015. <www.sciencedaily.com/releases/2015/11/151112155945.htm>.
Michigan Technological University. (2015, November 12). Thyroid cancer biomarker assays may show inaccurate readings. ScienceDaily. Retrieved May 28, 2017 from www.sciencedaily.com/releases/2015/11/151112155945.htm
Michigan Technological University. "Thyroid cancer biomarker assays may show inaccurate readings." ScienceDaily. www.sciencedaily.com/releases/2015/11/151112155945.htm (accessed May 28, 2017).

RELATED STORIES