Cancer miRNA Profiling Plate Assay I

miRNAs have been implicated in regulating various biological processes such as cell death and cell proliferation. They can act as oncogenes and tumor suppressor genes, playing a crucial role in tumorogenesis. The change in the expression level of miRNAs is associated with dysfunction of their corresponding protein-coding gene targets, many of which are involved in initiation and progression of cancer. For example, BCL2 oncogene is targeted by miR-15a and miR-16 target, PTEN tumor suppressor by miR-21, HOXD10 by miR-10b, Pak by miR-7, MYOD1 and ER by miR-206, and Her2 by miR-125a. Signosis developed cancer miRNA plate assay kit I for quantitatively profiling the expression of seven well-known cancer related miRNAs, miRNA-15a, miR-16, miR-21, miR10b, miR-7, miR-125a and miR206. RNU48 is included for normalization.

A. Benefits:

Signosis' miRNA plate arrays offer following benefits:

• Simple - Do miRNA detection as doing ELISA. It does not need enzymatic conversion from miRNA into cDNA. The entire assay procedure is “incubation and wash”.

• Higher sensitivity and better discrimination power - The detection is approximately 100 times more sensitive than miRNA Northern blot. In addition, it has higher discrimination power than miRNA Northern blot in differetiating miRNA isoforms.

• Quantitative comparison – The difference of two or more samples in the expression of the miRNA cluster can be quantitatively analyzed.

B. Principle of the technology

In the proprietary miRNA plate assay, one miRNA molecule is flanked by a capture oligo and a biotinated detection oligo through two bridge oligos. One of the bridge oligos is partially hybridized with the miRNA molecule and the capture oligo and another one with the miRNA and the detection oligo. The hybrid is captured onto plate through hybridization with an immobilized oligo and detected by a streptavidin-HRP conjugate and chemiluminecscent substrate. This hybrid structure is sensitive to the sequence of the miRNA molecule. One nucleotide difference can prevent the formation of the hybrid and therefore miRNA isoform can be differentiated, which normally is hard to do with Northern blot. In addition, the sensitivity of the assay is higher than miRNA Northern blot assay.