Phylogeny launches first in situ miRNA detection service

The functional genomics service provider aims to help researchers move beyond standard whole tissue expression profiling to a more precise method that can identify the exact cells that are modulated by various miRNA molecules.

There are around 500 human miRNAs, which are a class of small non-coding RNAs that are only 19-30 nucleotides long, and distinct miRNA expression patterns have been associated with various types of cancer.

They are believed to regulate around 30 per cent of all human genes by interacting with messenger RNA (mRNA), playing a key role in many biological processes including cellular proliferation, embryonic development, and immunity.

The 11 year old CRO (contract research organisation) is currently accepting a limited number of studies for the new service.

“We are happy to collaborate with our clients and provide them with the expertise to localize and interpret miRNA expression in specific cell populations. Such information will significantly advance the understanding of the biology of miRNAs,” ​said Dr Adel Mikhail, CEO of Phylogeny, Inc.

“Equally important is that this service allows for the detection of miRNA in formalin fixed paraffin embedded (FFPE) tissue thus opening the vast collections of archival FFPE tissue for miRNA research.”​

Detecting miRNAs in situ offers more precise characterisation of miRNA related phenomena than standard tissue-wide detection approaches using modifications of well known in situ hybridisation techniques.

For detecting primary transcript miRNA and precursor miRNA the company has developed an in situ modification of the reverse transcriptase PCR (polymerase chain reaction); while for detecting mature mirNA the company has developed an in situ LNA (locked nucleic acid) probe hybridisation approach.

The reverse transcriptase in situ PCR approach amplifies a target that can then be detected by direct labelling during the amplification step or by subsequent hybridisation to a labelled probe.

Ensuring complete removal of genomic is critical for the success of the approach as it can act as a non-specific primer for the reaction.

A negative result for a given miRNA using the reverse transcriptase PCR approach effectively rules out the presence of the precursor in a given cell.

This is in contrast to in situ hybridisation with an LNA probe, where a negative result does not rule out the presence of either a precursor or mature form of a given miRNA due to the lower sensitivity of the Northern blotting technique relative to PCR.

While a positive result form the reverse transcriptase PCR method can ascertain whether the precursor of a given miRNA is being produced in the tissue of interest it cannot determine whether it is being robustly processed to the mature form.

However, by combining the results from the two techniques it can be determined whether a precursor is being robustly processed to the mature form or if the precursor is not being actively processed.