Researchers in The Cancer Genome Atlas (TCGA) Network have made a number of new findings about the biology and development of a rare form of kidney cancer. They found that the disease – chromophobe renal cell carcinoma (ChRCC) – stems in part from alterations in genes in the mitochondria, the cell’s energy supplier. They also discovered that the tumor is characterized by genetic rearrangements near a gene important in DNA repair and in maintaining telomerase, the enzyme which determines a cell’s lifespan. Finally, investigators also found that ChRCC is a distinct disease and shares few genomic characteristics with other kidney cancers.
In the study – the most extensive genomic view of ChRCC to date – investigators led by Chad Creighton, Ph.D., Baylor College of Medicine, Houston, and Kimryn Rathmell, M.D., Ph.D., University of North Carolina, Chapel Hill, performed a complex array of analyses, including examining the entire genomes of 50 of the 66 ChRCC tumors studied, a high number for a rare cancer. The study revealed increased numbers of mitochondria as well as mutations in mitochondrial DNA. This led researchers to discover that ChRCC tumors favor a different energy-generating process than that used by the more common clear cell kidney cancer. In addition, their findings are the first to show specific alterations affecting the TERT gene that could affect cancer development, and might help explain its increased expression – and deregulation – in cancer. Overall, the findings provide new insights into the development of more common forms of kidney cancer, and shed light on the role of mitochondria and metabolic pathways in cancer. The results also support the growing realization that both the cancer’s genomic characteristics and cell of origin matter, as many cancers consist of several individual diseases that require specific therapies. TCGA is a collaboration jointly supported and managed by the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI), both parts of the National Institutes of Health. The researchers reported their results online August 21, 2014 in Cancer Cell.