Statistics Seminar: Yang -- Statistical issues in identification of miRNA regulatory modules and their targets

Jean Yee Hwa Yang
School of Mathematics and Statistics
University of Sydney

Location: Carslaw 173

Time:  2pm Friday, September 4, 2009

Title: Statistical issues in identification of miRNA regulatory modules and their targets

Abstract:
MicroRNAs (miRNAs) are short non-coding RNA molecules that act as
post-transcriptional regulators of mRNA. Since miRNAs can act as
oncogenes or tumour suppressors, an understanding of their regulatory
mechanism could provide new insights into cancer and other diseases. The
first part of the talk, I will discuss an odds-ratio (OR) statistic for
identification of regulatory miRNAs. It is based on integrative analysis
of miRNA and mRNA microarray data and is suitable for short time course
microarray data. The OR-statistic can be used for (i) identification of
miRNAs with regulatory potential, (ii) identification of miRNA-target
mRNA pairs, and (iii) identification of time lags between changes in
miRNA expression and those of its target mRNAs. We applied the
OR-statistic to a cancer data set and identified a small set of miRNAs
that were negatively correlated to mRNAs.

One major challenge in the identification of target-mRNAs is the need to
accommodate the many-to-many mapping between miRNAs and mRNAs: a miRNA
can target hundreds of mRNAs and several miRNAs target a single mRNA. In
this talk, I will discuss a statistical approach for determining the
miRNA regulatory modules and their target-mRNA modules.  A simulation
study is performed to determine whether the majority of mRNAs in a given
module are indeed targeted by a small set of miRNAs. The preliminary
results are encouraging even for low accuracy of predicted miRNA
targets.


Joint work with Vivek Jayaswal