Breast cancer is the most diagnosed cancer type in women worldwide (with ~2.3 million cases) and the primary cause of cancer-related death (0.7 million deaths) annually. Although mammography screening have significantly reduced breast cancer mortality, it has also some limitations due to the location of the cancer or the density of the breast tissue. For example, 25% of cancer in women ages 40-49 are not detectable by a mammogram screening. Moreover, X-ray based screening techniques could cause further problems including DNA damage in the tissues. For this reason, we aimed to develop a DNA origami-based technique for the early detection of cancer biomarkers.
MicroRNAs (miRNAs) are promising biomarkers for diagnostics and prognosis of cancer. These are class of non-coding endogenous small RNAs of 21-25 nucleotides in length and responsible for the regulation of gene expression. Expression levels of miRNA is dysregulated in various cancer types where they can act as either tumor suppressors or oncogenes. In cancers, multiple miRNAs are typically up or downregulated and their combined alterations are specific to individual cancers and their stages. Therefore, specific and sensitive detection and absolute quantification of multiple miRNAs can deliver essential cues to understand disease progression and have growing relevance to early cancer detection and monitoring. However, current miRNA detection techniques such as polymerization chain reaction, next generation sequencing or DNA microarray have important practical limitations and restricted multiplexing capabilities. Moreover, their routine measurement in plasma is time-consuming, costly, and requires dedicated equipment and specialized laboratories. In this project, our objective was to develop novel miRNA detection system from breast cancer cell populations and human plasma samples using bioinspired DNA origami self-assembly tool and state-of-art super resolution imaging technique, DNA-PAINT (point accumulation for imaging in nanoscale topography).
