In new research, investigators compared iPSCs to a form of malignant cancer known as oncogenic foci that are also produced in laboratories; these cell types are used by medical researchers to create models of cancer, particularly sarcoma. Specifically, the scientists contrasted the different cells' transcriptomes, comprised of the RNA molecules or "transcripts." Unlike DNA analysis, which reflects a cell's entire genetic code whether or not the genes are active, transcriptomes reflect only the genes that are actively expressed at a given time and therefore provide a picture of actual cellular activity.
From this transcriptome analysis, the investigators found that the iPSCs and malignant sarcoma cancer cells are unexpectedly similar in several respects. Genes that were not expressed in iPSCs were also not expressed in the cancer-generating cells, including many that have properties that guide a cell to normally differentiate in certain directions. Both cell types also exhibited evidence of similar metabolic activities, another indication that they are related cell types.
"This is the first study that describes the specific molecular pathways that iPSCs and cancer cells share from a direct comparison" said Paul Knoepfler, associate professor of cell biology and human anatomy at UC Davis. "It means that much more study is required before iPSCs can be used clinically. However, our study adds to a growing knowledge base that not only will help make stem cell therapies safer, but also provide us with new understandings about the cancer-causing process and more effective ways to fight the disease."Condensed and adapted from the UC Davis announcement.