Circular RNAs (circRNAs) have recently gained substantial attention in the cancer research field where most, including the putative oncogene ciRS-7 (CDR1as), have been proposed to function as competitive endogenous RNAs (ceRNAs) by “sponging” specific microRNAs.
In this webinar, Lasse Sommer Kristensen of Aarhus University will describe his team’s work in studying the role of circRNAs in cancer. His team recently reported the first spatially resolved cellular expression patterns of ciRS-7 in colon cancer. Surprisingly, they found that ciRS-7 is completely absent in the cancer cells, but highly expressed in stromal cells within the tumor microenvironment.
In addition, they proposed a model to explain correlations between circRNA and mRNA expression, which are commonly interpreted as evidence of a ceRNA function, based on different cancer-to-stromal cell ratios among the studied tumor specimens.
Together, these results have wide implications for future circRNA studies and highlight the importance of spatially resolving expression patterns of circRNAs proposed to function as ceRNAs.
- The circular RNA named ciRS-7 is overexpressed in human cancers; however, in many types of cancer it is not expressed in the cancer cells, but abundant in stromal cells within the tumors.
- Cancer-to-stromal cell ratios contribute to correlations between circRNAs and microRNA target genes.
- Analyses of spatial expression patterns are key to understanding molecular mechanisms of circRNAs in cancer.
