Noninvasive collection of cell and region specific miRNA from heterogeneous tissues.



 DESCRIPTION (provided by applicant): Micro RNAs are crucial regulators of gene expression in plants and animals. Their complex expression patterns are associated with numerous human diseases, developmental programs and often appear to be cell and tissue specific. However, our understanding of miRNA expression and function in specific cell types and tissues is limited because of difficulty in obtaining appropriate cell and region specific specimen. Current methods of cell and region specific micro RNA isolation involve two major steps: first, tissue microdissection or dissociation with a follow up cell sorting and second, isolation of micro RNA molecules from acquired cells or tissue regions. This approach is time consuming and invasive. It results in the destruction of often valuable original tissue sample and demands for the use of costly equipment (e.g. laser based microdissection or flow sorting) and prior training. Here we will develop a noninvasive method for cell- and region- specific micro RNA collection from complex heterogeneous tissues. The approach is based on the use of polysaccharide resins and their specific regional acquisition. Prior pretreatment and even coating of the tissue sections with a resin permits micro RNA absorption directly from the tissue sample. Acquisition of cell- or region specific micro RNA is performed with our recently developed KuiqpicK technology via collection of the specific resin samples from the desired tissue regions or cells using carefully controlled vacuum pulses. Resin samples containing micro RNA are collected in the barrel of the disposable capillary unit (DCU) and transferred to a test tube where the captured miRNA is eluted and may be used for a variety of downstream applications, including large scale gene expression studies. The advantage of the proposed method over current approaches is manifold, including 1) direct one step acquisition of micro RNA from the specific cells, which eliminates the need for cell and tissue collection (i.e., microdissection); 2) preservation of the original tissue integrity, which permits its use for further experimentation such as immunohistology; 3) reduction in the time and cost; 4) possibility of immediate amplification and labeling of captured micro RNA; and 5) highly specific capturing of micro RNA species.