[BioC] significance of correlation genes/miRNAs expression

[Seb]

hope this question is in topic.

I have expression values from a miRNA microarray and a gene expression
microarray in the same cel line,  some genes show opposite expression
pattern with the miRNAs that supposedly regulate them (so that's
good)...how can i evaluate the significance of that inverse
correlation?
there is any package that i could use to "evaluates" those things?

thanks

Seb