Nanotech Sensors Devised for RNA Cancer Detection

Triangular gold nanoparticles in microRNA sensor (Indiana University-Purdue University Indianapolis)

17 November 2015. Biochemical and medical researchers developed a technique for sensitive detection of RNA in humans that in lab tests can distinguish between benign conditions and cancer. The team from the lab of chemistry professor Rajesh Sardar at Indiana University-Purdue University Indianapolis published its findings in this month’s issue of the journal ACS Nano.

Sardar’s team, with colleagues from Indiana University’s medical school, were seeking a low-cost, reusable technology to detect pancreatic cancer with microRNAs in blood. MicroRNAs are small non-coding molecules of ribonucleic acid, or RNA, that regulate gene expression by larger RNA molecules. MicroRNAs may directly influence as many as 30 percent of genes in the entire human genome, and play a role in cancer, diabetes, and cardiovascular diseases.

Pancreatic cancer is often difficult to diagnose in its early stages, because of few unique symptoms associated with the disease, and because the pancreas is hidden among other organs in the body. As a result, it is often diagnosed in later, more advanced stages of the disease, with generally a poor prognosis for survival. American Cancer Society estimates nearly 49,000 people in the U.S. will be diagnosed with pancreatic cancer this year, leading to more than 40,000 deaths.

The IUPUI team designed its sensor as a glass chip with gold triangle-shaped nanoparticles having surface plasmon resonance properties that use optical  factors to measure the holding of biomaterials on the gold surface. Those properties make it possible to identify different patterns or signatures of microRNAs in blood and other fluids.

In lab tests, the researchers dipped their sensor chip in exosomes — tiny lipid-membrane containers in cells that gather up and secrete cytoplasm, the gel-like material outside the cell nucleus — derived from blood plasma looking for a microRNA signature identifying pancreatic cancer known as microRNA-10b. The team performed these tests with plasma from people with pancreatic cancer, healthy individuals, and people with pancreatitis, a non-cancerous inflammation of the pancreas. The results showed the sensor found reliably higher numbers of microRNA-10b in the samples from cancer patients, than the other two groups.

Testing for microRNAs today requires polymerase chain reaction technology that detects DNA fingerprints in samples. Sardar says the gold nanoparticle approach is simpler and less expensive, even when using gold. He notes in a university statement that “$250 worth of gold makes 4,000 sensors. Four thousand sensors allow you to do at least 4,000 tests. The low cost makes this technique ideal for use anywhere, including in low-resource environments in this country and around the world.”

The university says a patent has been filed for the technology.

Read more:

• Penn, Epic Sciences Partner on Liquid Biopsies
• Faster Process Devised for Skin-Patch Sensors
• Study Shows Blood Test Finds Early Pancreatic Cancer
• Partnership to Study Biomarkers in Liquid Biopsies
• Nanotech Cancer Center Gains $10.1M Funding

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