ISA.miRNA: Calculate (predicted) miRNA target enrichment for...
In eisa: Expression data analysis via the Iterative Signature Algorithm

Description Usage Arguments Details Value Author(s) References See Also Examples

This function performs enrichment calculations with respect to predicted miRNA targets to check whether an ISA module contains many genes that are targets of the same miRNA.

1 2	ISAmiRNA (modules, ann = annotation(modules), features = featureNames(modules), hgCutoff = 0.05, correction = TRUE, correction.method = "holm")

`modules`	An `ISAModules` object, a set of ISA modules.
`ann`	Character scalar. The annotation package to be used. By default it is taken from the `modules` argument.
`features`	Character vector. The names of the features. By default it is taken from the `modules` argument.
`hgCutoff`	Numeric scalar. The cutoff value to be used for the enrichment significance. This can be changed later, without recalculating the test.
`correction`	Logical scalar, whether to perform multiple hypothesis testing correction.
`correction.method`	Character scalar, the multiple testing correction method to use. Possible values: “holm”, “hochberg”, “hommel”, “bonferroni”, “BH”, “BY”, “fdr”, “none”. See the `p.adjust` function for details on these.

miRNAs are short RNA fragments that specifically regulate (usually inhibit) the expression of genes. Some genes have been experimentally validated as targets of a given miRNA, but we currently don't know the target genes of most miRNAs.

TargetScan is a database of predicted miRNA targets. The predictions are done based many factors, including the conservation of the target region during evolution.

The hypergeometric test, a version Fisher's exact test, takes a miRNA and a gene set (in our case coming from an ISA module) and asks whether the number of genes in the set regulated by the miRNA is significantly more (or less) than what one would expect by chance.

ISAmiRNA performs the hypergeometric test for every module, for all miRNAs in the TargetScan database.

In order to use this function, TargetScan annotation packages are needed.

A miRNAListHyperGResult object.

Gabor Csardi csardi.gabor@gmail.com

Conserved Seed Pairing, Often Flanked by Adenosines, Indicates that Thousands of Human Genes are MicroRNA Targets Benjamin P Lewis, Christopher B Burge, David P Bartel. Cell, 120:15-20 (2005).

Bergmann S, Ihmels J, Barkai N: Iterative signature algorithm for the analysis of large-scale gene expression data Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Mar;67(3 Pt 1):031902. Epub 2003 Mar 11.

ISAGO, ISAKEGG and ISACHR for other enrichment calculations.

The Category package.

data(ALLModulesSmall)

if (require(targetscan.Hs.eg.db)) {
  miRNA <- ISAmiRNA(ALLModulesSmall)
  summary(miRNA, p=0.1)[[7]]
}

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Loading required package: targetscan.Hs.eg.db
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