Newly Identified Biomarkers Could Lead to First Blood Test for RCC

Two molecules that regulate gene expression may be useful in developing the first-ever blood test for renal cell carcinoma (RCC). A study presented at the 69th AACC Annual Scientific Meeting & Clinical Lab Expo has found that two microRNAs (miR-651 and miR-708) may have the potential to serve as novel biomarkers for RCC. The two microRNAs appear to act as tumor suppressors in RCC progression by synergistically inhibiting RCC cell proliferation.

A team of researchers led by Chunni Zhang, PhD, of Jinling Hospital in Nanjing, China, measured the concentrations of 754 different microRNAs in blood samples from 33 RCC patients and 33 healthy individuals. The investigators found that blood levels of 8 microRNAs were either significantly increased or decreased in the RCC patients compared with the healthy controls.

Statistical analysis revealed that miR-651 and miR-708, which were decreased in RCC patients, exhibited the largest areas under the curve (0.888 and 0.832, respectively). The findings suggest testing for these microRNAs could diagnose RCC with relatively high accuracy.

“To our surprise, we found that these two miRNAs were also significantly downregulated in both RCC tissues specimens and human RCC cell lines. Furthermore, in vitro and in vivo experiments demonstrated that miR-651and miR-708 synergistically suppressed RCC cell proliferation and migration by targeting an oncoprotein RAP1B,” said Zhang.

She said currently the mechanisms involved in RCC development and progression remain unclear, and there is an urgent need for RCC diagnostic markers. Many patients are often diagnosed too late and have poor outcomes. Early detection could significantly lower mortality.

“Our findings provide potential novel biomarkers for RCC diagnosis and reveal possible mechanism for RCC development and progression,” Zhang told OncoTherapy Network. “Our approach may provide a novel strategy for the diagnosis and treatment of RCC.”

Christina Lockwood, MD, an associate director of the Genetics and Solid Tumor Diagnostics Laboratory at the University of Washington in Seattle, said there is a need for additional biomarkers that more readily diagnose all types of cancer at an earlier stage. She said the promise of new biomarkers is an exciting development that could easily be translated into improved clinical outcomes.

“In addition to microRNAs, new circulating tumor DNA tests, proteomics-based tests, and advanced microscopy techniques all have great potential for earlier cancer detection. In order to develop a well-validated laboratory test with established clinical utility, it will be important to independently confirm the findings in this study in additional patient cohorts across multiple institutions,” Dr. Lockwood told OncoTherapy Network.

She said this current study nicely illustrates the rapid pace of biomarker discovery that is driving precision medicine in oncology. There are already available targeted therapies that could greatly benefit RCC patients if the disease is detected at an early stage.