Tarun Nayar wrote:
> Hi,
>
> Are there any tools out there to combine/ compare Affy gene
expression
> and aCGH data? A collaborator has 12 aCGH expts and 12 affy
expression
> chips from the same biological samples. He's interested in seeing if
> regions of CN alteration correspond to differences in gene
expression.
> We've taken a stab at writing our own program for this, now I'm
> wondering if there are any pre-made tools to do the same.
>
I don't know of R/bioc packages for doing this directly, but some
version of correlation between CGH measurements and gene expression
measures is probably useful. You can use standard R commands to do
this. Within any region of amplification, note that there will likely
be only a portion (of unknown quantity) of gene expression that is
correlated with copy number.
Sean
Hi Tarun,
I am currently developping an R package to calculate correlations
between copy number and expression measurements. Here are its main
features:
- Data pre-processing: an unambiguous mapping between genome and
transcriptome probes according to their position on the genome.
Missing DNA copy numbers
are inferred by taking advantage of the consistency of the copy
number signal along the genome.
- Statistical data analysis: for each probe, a correlation coefficient
between DNA copy number and expression data is calculated, as well as
an associated p-value. These p-values are then adjusted for multiple
comparisons (FDR or FWER).
- Data visualisation and interpretation: correlation coefficients and
associated significances can be plotted along the genome together with
cytobands; results can be exported as csv files.
As Sean mentions, our analyses show that only a subset of genes within
a region of copy number amplification or deletion have their
expression levels correlated with
DNA copy number.
I hope to be able to submit this package to Bioconductor by the end of
the summer. If you are interested in testing the package I will be
happy to share it with you as soon as it will be stable enough to be
distributed.
In case you are attending ISMB/ECCB at the end of the month, I will be
presenting a poster about this work:
"GTCA: Genome Transcriptome Correlation Analysis within R" (poster
number: I56)
Cheers,
Pierre.
Sean Davis wrote:
> Tarun Nayar wrote:
>> Hi,
>>
>> Are there any tools out there to combine/ compare Affy gene
expression
>> and aCGH data? A collaborator has 12 aCGH expts and 12 affy
expression
>> chips from the same biological samples. He's interested in seeing
if
>> regions of CN alteration correspond to differences in gene
expression.
>> We've taken a stab at writing our own program for this, now I'm
>> wondering if there are any pre-made tools to do the same.
>>
>
> I don't know of R/bioc packages for doing this directly, but some
> version of correlation between CGH measurements and gene expression
> measures is probably useful. You can use standard R commands to do
> this. Within any region of amplification, note that there will
likely
> be only a portion (of unknown quantity) of gene expression that is
> correlated with copy number.
>
> Sean
>
> _______________________________________________
> Bioconductor mailing list
> Bioconductor at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/bioconductor
> Search the archives:
http://news.gmane.org/gmane.science.biology.informatics.conductor
>
> .
>
Hi Torun,
Like Sean I too don't know of any currently available package to do
so.
However have a look at the following papers:
1. Stranger et. al.:
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_u
ids=17
289997
2. Spielman et. al.:
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_u
ids=17
206142
3. Chin et. al:
http://linkinghub.elsevier.com/retrieve/pii/S1535610806003151
Benjamin
======================================
Benjamin Otto
University Hospital Hamburg-Eppendorf
Institute For Clinical Chemistry
Martinistr. 52
D-20246 Hamburg
Tel.: +49 40 42803 1908
Fax.: +49 40 42803 4971
======================================
-----Urspr?ngliche Nachricht-----
Von: bioconductor-bounces at stat.math.ethz.ch
[mailto:bioconductor-bounces at stat.math.ethz.ch] Im Auftrag von Sean
Davis
Gesendet: Saturday, July 07, 2007 9:25 PM
An: Tarun Nayar
Cc: bioconductor at stat.math.ethz.ch
Betreff: Re: [BioC] Tools for Combining Affy and aCGH data
Tarun Nayar wrote:
> Hi,
>
> Are there any tools out there to combine/ compare Affy gene
expression
> and aCGH data? A collaborator has 12 aCGH expts and 12 affy
expression
> chips from the same biological samples. He's interested in seeing if
> regions of CN alteration correspond to differences in gene
expression.
> We've taken a stab at writing our own program for this, now I'm
> wondering if there are any pre-made tools to do the same.
>
I don't know of R/bioc packages for doing this directly, but some
version of
correlation between CGH measurements and gene expression measures is
probably useful. You can use standard R commands to do this. Within
any
region of amplification, note that there will likely be only a portion
(of
unknown quantity) of gene expression that is correlated with copy
number.
Sean
_______________________________________________
Bioconductor mailing list
Bioconductor at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/bioconductor
Search the archives:
http://news.gmane.org/gmane.science.biology.informatics.conductor
--
Pflichtangaben gem?? Gesetz ?ber elektronische Handelsregister und
Genossenschaftsregister sowie das Unternehmensregister (EHUG):
Universit?tsklinikum Hamburg-Eppendorf
K?rperschaft des ?ffentlichen Rechts
Gerichtsstand: Hamburg
Vorstandsmitglieder:
Prof. Dr. J?rg F. Debatin (Vorsitzender)
Dr. Alexander Kirstein
Ricarda Klein
Prof. Dr. Dr. Uwe Koch-Gromus
I have introduced an experimental approach to the combination
of expression and CGH data in the Neve2006 package. This is
available through the Browse packages/ExperimentData path
on the portal. In the most recent devel version I introduce
a class called cghExSet that has AssayData components for
expression and logRatios, and accessors for both. a
cloneMeta slot holds an annotated data frame that names and
indexes clone locations both on chromosomes and along entire
genome.
I say it is experimental because I don't have proven workflow
examples with it. But it seems to differ from the available
CGH container designs in that it binds the sample level data
directly to the CGH assay results (and it differs
by keeping CGH and expression together).
It is unusual to push a class design in an experimental data
package but until I get comfortable with it I am keeping it
close to the data; the class definitions can be migrated to
Biobase (or some to-be-defined CGH infrastructure package)
if appropriate. In fact I am not thrilled with the current
design that I have but the interface seems ok -- that is,
the [few] methods defined seem useful, and that is what we should
focus on -- what are the methods that we want to interrogate
this combination of data most thoroughly? And then the class
definition can evolve to support those most efficiently.
Last issue: the expression data is readily annotated because
we know the platform (hgu133a) and its annotation; the clone
data is not so easy because except for a table provided with
the publication of the data to the web, i don't know the provenance
of the location assertions. If there are manufactured clone sets
used for CGH perhaps we need annotation packages for them, but
I don't know how to pursue this.
---
Vince Carey, PhD
Assoc. Prof Med (Biostatistics)
Harvard Medical School
Channing Laboratory - ph 6175252265 fa 6177311541
181 Longwood Ave Boston MA 02115 USA
stvjc at channing.harvard.edu
On Mon, 9 Jul 2007, Benjamin Otto wrote:
> Hi Torun,
Like Sean I too don't know of any currently available package to do
so.
However have a look at the following papers:
1. Stranger et. al.:
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_u
ids=17
289997
2. Spielman et. al.:
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_u
ids=17
206142
3. Chin et. al:
http://linkinghub.elsevier.com/retrieve/pii/S1535610806003151
Benjamin
======================================
Benjamin Otto
University Hospital Hamburg-Eppendorf
Institute For Clinical Chemistry
Martinistr. 52
D-20246 Hamburg
Tel.: +49 40 42803 1908
Fax.: +49 40 42803 4971
======================================
-----Urspr??ngliche Nachricht-----
Von: bioconductor-bounces at stat.math.ethz.ch
[mailto:bioconductor-bounces at stat.math.ethz.ch] Im Auftrag von Sean
Davis
Gesendet: Saturday, July 07, 2007 9:25 PM
An: Tarun Nayar
Cc: bioconductor at stat.math.ethz.ch
Betreff: Re: [BioC] Tools for Combining Affy and aCGH data
Tarun Nayar wrote:
> Hi,
>
> Are there any tools out there to combine/ compare Affy gene
expression
> and aCGH data? A collaborator has 12 aCGH expts and 12 affy
expression
> chips from the same biological samples. He's interested in seeing if
> regions of CN alteration correspond to differences in gene
expression.
> We've taken a stab at writing our own program for this, now I'm
> wondering if there are any pre-made tools to do the same.
>
I don't know of R/bioc packages for doing this directly, but some
version of
correlation between CGH measurements and gene expression measures is
probably useful. You can use standard R commands to do this. Within
any
region of amplification, note that there will likely be only a portion
(of
unknown quantity) of gene expression that is correlated with copy
number.
Sean
_______________________________________________
Bioconductor mailing list
Bioconductor at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/bioconductor
Search the archives:
http://news.gmane.org/gmane.science.biology.informatics.conductor
--
Pflichtangaben gem???? Gesetz ??ber elektronische Handelsregister und
Genossenschaftsregister sowie das Unternehmensregister (EHUG):
Universit??tsklinikum Hamburg-Eppendorf
K??rperschaft des ??ffentlichen Rechts
Gerichtsstand: Hamburg
Vorstandsmitglieder:
Prof. Dr. J??rg F. Debatin (Vorsitzender)
Dr. Alexander Kirstein
Ricarda Klein
Prof. Dr. Dr. Uwe Koch-Gromus
_______________________________________________
Bioconductor mailing list
Bioconductor at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/bioconductor
Search the archives:
http://news.gmane.org/gmane.science.biology.informatics.conductor