Research from Aguirre de Cubas, Ph.D., showed that a common mutation in kidney tumors may also create an exploitable weakness that could lead to new precision treatments. Published in Cancer Research, the study found that clear cell renal cell carcinoma cells lacking the tumor suppressor gene SETD2 become highly dependent on the survival protein BCL-xL. Blocking BCL-xL selectively killed SETD2-deficient cancer cells while largely sparing cells with intact SETD2, revealing a promising therapeutic target.

The researchers traced this vulnerability to mitochondrial DNA leakage, which activates the cGAS-STING inflammatory pathway and makes the cancer cells both more susceptible to cell death and more visible to the immune system. The findings also suggest that mitochondrial DNA leakage, rather than previously suspected micronuclei, is a major driver of immune activation in these tumors, helping explain why kidney cancers can respond to immunotherapy despite having relatively few mutations.

The discovery has led to a new five-year National Cancer Institute R01 grant that will investigate why SETD2-deficient tumors develop this dependence on BCL-xL and whether combining BCL-xL inhibitors with immunotherapy could improve treatment for patients with aggressive kidney cancers.