A Northwestern Medicine study has identified new genetic mutations in patients with Wilms tumor, the most common form of kidney tumor in children.
There are about 500 cases of Wilms tumor in the United States each year. Previously, about 15 percent of them had a known genetic cause. In the study, published in Cancer Cell, scientists reported mutations in an additional 20 percent of tumors.
“We provide evidence suggesting that these mutations result in developmental arrest and continued proliferation in stem cells during early renal development,” said study senior author Elizabeth Perlman, MD, professor in Pathology. “If this can be targeted with new therapies, future patients may experience fewer toxicities.”
With first author Amy Walz, MD, a hematology-oncology fellow in Pediatrics, Dr. Perlman and colleagues analyzed a set of 534 Wilms tumors that had been DNA sequenced. They identified new mutations in the SIX1/2, DGCR8 and DROSHA genes.
The scientists also found that a combination of mutations involved in SIX1/2 and microRNAs, RNA molecules active in gene silencing, was associated with a higher rate of death for patients with Wilms tumors.
The study’s findings point to future targets for therapies against this type of tumor and, potentially, other diseases.
“DROSHA and DGCR8 form a protein complex that is responsible for regulating expression of microRNAs, which have been shown to quite broadly regulate gene expression in development and disease,” Dr. Perlman said. “Therefore, the significance of these mutations, which have not been identified in other tumors, may extend beyond Wilms tumors.”
Dr. Perlman is a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University and the Stanley Manne Children’s Research Institute.
This work was supported National Cancer Institute (NCI) T32 CA079447; National Institutes of Health (NIH) grants U10CA42326, U10CA98543, U24 CA114766 and UO1CA88131; the American and Lebanese Syrian Associated Charities of St. Jude; and NCI grant U10 CA98543 for the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative.