A new study has discovered that two microRNAs could be used to develop the first-ever blood test for kidney cancer as well as novel treatments for this condition. These findings were presented July 26 at the 69th AACC Annual Scientific Meeting & Clinical Lab Expo in San Diego.

As with most cancers, the later a kidney tumor is found, the more dramatically the survival rate declines. 81% of patients with stage I kidney cancer live for at least five years after diagnosis, but this number drops to 53% for stage III kidney cancer, and 8% for stage IV. Kidney cancer is usually caught because of the symptoms a patient develops, but it is also possible for kidney cancer to be asymptomatic, with tumors growing quite large before causing pain or other noticeable problems.

A team of researchers led by Chunni Zhang, PhD, of Jinling Hospital in Nanjing, China, set out to determine if microRNAs could be used to develop such a test. To start, they measured the concentrations of 754 different microRNAs in blood samples from 33 patients with the most common type of kidney cancer, renal cell carcinoma, and 33 healthy individuals.

They found that blood levels of eight microRNAs were either significantly increased or decreased in the kidney cancer patients compared with the healthy controls. Of these eight microRNAs, statistical analysis revealed that the two known as miR-651 and miR-708—which decreased in the kidney cancer patients—exhibited the largest areas under the curve (0.888 and 0.832, respectively). This means that a test for these microRNAs could diagnose renal cell carcinoma with relatively high accuracy.

The researchers also investigated the functions of miR-651 and miR-708 and found evidence suggesting they act as tumor suppressors. A therapeutic that increases levels of miR-651 and miR-708 could therefore potentially serve as a new treatment for renal cell carcinoma.

“The mechanisms involved in renal cell carcinoma development and progression are unclear, and there is no standard serological biomarker to facilitate diagnosis in patients with [this disease],” said Zhang. “miR-651 and miR-708 may potentially serve as novel biomarkers for renal cell carcinoma and may act as tumor suppressors. Our findings indicate that targeting miR-651 and miR-708 by a genetic approach may provide a novel strategy for the treatment of renal cell carcinoma.”