An experimental drug designed to block an overactive protein in kidney cancer may provide a more targeted approach to treating the common cancer and could eventually be used as a therapy for other types of the disease.
When examining human samples of kidney cancer, researchers at Mayo Clinic's Florida campus discovered that one protein--produced by the stearoyl CoA desaturase 1 (SCD1) gene--was overly active in every sample. The findings are published online in Clinical Cancer Research.
After doing a genome analysis of tissue samples from 150 patients with different stages of kidney cancer, researchers found that SCD1 was consistently overexpressed. In laboratory kidney cancer cells, scientists disabled SCD1 and observed that the tumor cells stopped growing and a large percentage died altogether. They then used an experimental drug, A939572, to inhibit the SCD1 protein in mice and found that it was effective at targeting and killing kidney cancer cells. Next, the investigators tested a combination of A939572 and the FDA-approved kidney cancer drug temsirolimus. Using both drugs together at lower doses reduced tumor growth by 60% to 70% in mice, compared to 25% percent when either agent was used alone.
"There is a clear need for new therapies for this common cancer. With very few exceptions, patients inevitably become resistant to all available treatments," said John Copland, a Mayo molecular biologist and the study's senior investigator.
The experimental drug could be a promising new therapy for clear cell renal cell carcinoma, which accounts for almost 85% of kidney cancer cases in the U.S.
In the U.S., more than 57,000 diagnoses of kidney cancer occur yearly, with 13,000 of those resulting in death. If the cancer has not yet spread, kidney cancers can typically be removed by surgery. Kidney cancers often do not respond to chemotherapy or radiotherapy, so when surgery isn't possible, freezing cancer cells through cryoablation, heating cancer cells using radiofrequency ablation, or immunotherapy might be used.
SCD1 has also been found to be overactive in other cancers, including lung, stomach, breast, prostate, ovary and colon cancers, so the scientists' findings may be relevant to the treatment of additional types of cancer.
- here's the study abstract
- read the press release