Package 'KBoost'

Title: Inference of gene regulatory networks from gene expression data
Description: Reconstructing gene regulatory networks and transcription factor activity is crucial to understand biological processes and holds potential for developing personalized treatment. Yet, it is still an open problem as state-of-art algorithm are often not able to handle large amounts of data. Furthermore, many of the present methods predict numerous false positives and are unable to integrate other sources of information such as previously known interactions. Here we introduce KBoost, an algorithm that uses kernel PCA regression, boosting and Bayesian model averaging for fast and accurate reconstruction of gene regulatory networks. KBoost can also use a prior network built on previously known transcription factor targets. We have benchmarked KBoost using three different datasets against other high performing algorithms. The results show that our method compares favourably to other methods across datasets.
Authors: Luis F. Iglesias-Martinez [aut, cre] , Barbara de Kegel [aut], Walter Kolch [aut]
Maintainer: Luis F. Iglesias-Martinez <[email protected]>
License: GPL-2 | GPL-3
Version: 1.15.0
Built: 2024-10-30 07:33:36 UTC
Source: https://github.com/bioc/KBoost

Help Index


Function to add names to network for the user.

Description

Function to add names to network for the user.

Usage

add_names(grn, gen_names)

Arguments

grn

a GRN object from KBoost.

gen_names

a vector with the gene names.

Value

grn a GRN object with elements with user-defined gene names.

Examples

data(D4_multi_1)
    Net = kboost(D4_multi_1)
    g_names = matrix("G",100,1)
    for (i in seq_along(g_names)){
        g_names[i] = paste(g_names[i],toString(i), sep = "")
    }
    Net = add_names(Net,g_names)

Function to calculate the AUROC and AUPR of a known network. This function was made to test the R implementation of the KBoost Package.

Description

Function to calculate the AUROC and AUPR of a known network. This function was made to test the R implementation of the KBoost Package.

Usage

AUPR_AUROC_matrix(Net, G_mat, auto_remove, TFs, upper_limit)

Arguments

Net

An inferred gene regulatory network

G_mat

A matrix with the gold standard network.

auto_remove

TRUE if the auto-regulation is to be discarded.

TFs

the indexes of the rows of Net that are TFs.

upper_limit

Top number of edges to use.

Value

list object with AUPR and AUROC of gold standard in matrix format.

Examples

data(D4_multi_1)
    Net = kboost(D4_multi_1)
    g_mat1 = tab_2_matrix_D4(KBoost::G_D4_multi_1,100)
    aupr_auroc = AUPR_AUROC_matrix(Net$GRN,g_mat1,auto_remove = TRUE,  seq_len(100))

Function to obtain the AUPR and AUROC in the DREAM4 Multifactorial Challenge.

Description

Function to obtain the AUPR and AUROC in the DREAM4 Multifactorial Challenge.

Usage

d4_mfac(v, g, ite, write_res)

Arguments

v

a number between 0 and 1 that is the shrinkage parameter

g

a number larger than 0, width parameter for the RBF Kernel

ite

an integer with number of iterations.

write_res

a logical to indicate if the tables should be written.

Value

list with auroc and auprs of the DREAM4 multifactorial challenge.

Examples

res = d4_mfac()

Dream 4 multifactorial pertubation challenge dataset 1

Description

Each column is a gene and each row is a simulated experiment.

Usage

D4_multi_1

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(D4_multi_1)

Dream 4 multifactorial pertubation challenge dataset 2

Description

Each column is a gene and each row is a simulated experiment.

Usage

D4_multi_2

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(D4_multi_2)

Dream 4 multifactorial pertubation challenge dataset 3

Description

Each column is a gene and each row is a simulated experiment.

Usage

D4_multi_3

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(D4_multi_3)

Dream 4 multifactorial pertubation challenge dataset 4

Description

Each column is a gene and each row is a simulated experiment.

Usage

D4_multi_4

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(D4_multi_4)

Dream 4 multifactorial pertubation challenge dataset 5

Description

Each column is a gene and each row is a simulated experiment.

Usage

D4_multi_5

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(D4_multi_5)

Gold Standard Dream 4 multifactorial pertubation challenge dataset 1

Description

Each column is a gene and each row is a simulated experiment.

Usage

G_D4_multi_1

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(G_D4_multi_1)

Gold Standard Dream 4 multifactorial pertubation challenge dataset 2

Description

Each column is a gene and each row is a simulated experiment.

Usage

G_D4_multi_2

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(G_D4_multi_2)

Gold Standard Dream 4 multifactorial pertubation challenge dataset 3

Description

Each column is a gene and each row is a simulated experiment.

Usage

G_D4_multi_3

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(G_D4_multi_3)

Gold Standard Dream 4 multifactorial pertubation challenge dataset 4

Description

Each column is a gene and each row is a simulated experiment.

Usage

G_D4_multi_4

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(G_D4_multi_4)

Gold Standard Dream 4 multifactorial pertubation challenge dataset 5

Description

Each column is a gene and each row is a simulated experiment.

Usage

G_D4_multi_5

Format

matrix

Source

https://www.synapse.org/#!Synapse:syn3049712/wiki/74628

References

Marbach D, Prill RJ, Schaffter T, Mattiussi C, Floreano D, and Stolovitzky G. Revealing strengths and weaknesses of methods for gene network inference. PNAS, 107(14):6286-6291, 2010. Pubmed

Examples

data(G_D4_multi_5)

Gene Regulatory Network from human ChIP-Seq data in Encode

Description

A gene regulatory network inferred from the ChIp-Seq Encode dataset Table with two columns

The fist column is a transcription factor and the second is a gene.

Usage

Gerstein_Prior_ENET_2

Format

matrix

References

Gerstein, M.B., et al. Architecture of the human regulatory network derived from ENCODE data. Nature 2012;489(7414):91-100.

Examples

data(Gerstein_Prior_ENET_2)

Function to build a prior using a previously built Network on ChIP-Seq.

Description

Function to build a prior using a previously built Network on ChIP-Seq.

Usage

get_prior_Gerstein(gen_names, TFs, pos_weight, neg_weight)

Arguments

gen_names

the gene names in Symbol nomenclature.

TFs

the indexes of gene names which are TFs.

pos_weight

the prior weight for edges previously found in Gerstein 2011

neg_weight

the prior weight for edges not found in the Gerstein 2011/

Value

matrix with prior probabilities of the Tf target edges.

Examples

gen_names = c("TP53","MDM2","FOXM1","ESR1","CTCF","YY1")
tfs = get_tfs_human(gen_names)
prior = get_prior_Gerstein(gen_names,tfs,0.6,0.4)

Function to automatically assign Human TFs given a list of Symbols.

Description

Function to automatically assign Human TFs given a list of Symbols.

Usage

get_tfs_human(gen_names)

Arguments

gen_names

a vector or matrix with the Symbol Gene Names of the system.

Value

indexes of gen_names who are TFs.

Examples

gen_names = c("TP53","MDM2","FOXM1","ESR1","CTCF")
tfs = get_tfs_human(gen_names)

Function to perform a grid search and find the hyperparameters.

Description

Function to perform a grid search and find the hyperparameters.

Usage

grid_search_kboost(dataset, vs, gs, ite)

Arguments

dataset

1 for IRMA or 2 for DREAM4 multifactorial.

vs

The range of values of v. All values need to be between 0 and 1.

gs

The range of values of g. All values need to be larger than 0.

ite

An integer that is the number of iterations, fixed in this case.

Value

list with auprs and aurocs of different values of vs and gs and ite.

Examples

res = grid_search_kboost(1,c(0.1,0.5,1),c(1,10,60,100),3)

Index of human genes' Symbols, Entrez and Ensembl for K-Boost Pacakge that correspond to transcription factors.

Description

Table with three columns corresponding to Symbol

Usage

Human_TFs

Format

matrix

References

Lambert, S.A., et al. The Human Transcription Factors. Cell 2018;172(4):650-665.

Examples

data(Human_TFs)

Function to produce the AUPR and AUROC Results on the IRMA datasets.

Description

Function to produce the AUPR and AUROC Results on the IRMA datasets.

Usage

irma_check(v, g, ite)

Arguments

v

a number between 0 and 1 that is the shrinkage parameter

g

a number larger than 0 that is the width parameter for the RBF Kernel

ite

an integer with number of iterations.

Value

list with aurocs and auprs for IRMA datasets

Examples

res = irma_check()

IRMA Gold Standard Network

Description

Matrix where the rows are genes and columns are transcription factor.

Usage

IRMA_Gold

Format

matrix

Source

https://www.sciencedirect.com/science/article/pii/S0092867409001561

References

Cantone, I., et al. A Yeast Synthetic Network for In Vivo Assessment of Reverse-Engineering and Modeling Approaches. Cell 2009;137(1):172-181.

Examples

data(IRMA_Gold)

IRMA Off Dataset

Description

Matrix where the rows are experiments and columns are genes for the IRMA Off dataset.

Usage

irma_off

Format

matrix

Source

https://www.sciencedirect.com/science/article/pii/S0092867409001561

References

Cantone, I., et al. A Yeast Synthetic Network for In Vivo Assessment of Reverse-Engineering and Modeling Approaches. Cell 2009;137(1):172-181.

Examples

data(irma_off)

IRMA On Dataset

Description

Matrix where the rows are experiments and columns are genes for the IRMA Off dataset.

Usage

irma_on

Format

matrix

Source

https://www.sciencedirect.com/science/article/pii/S0092867409001561

References

Cantone, I., et al. A Yeast Synthetic Network for In Vivo Assessment of Reverse-Engineering and Modeling Approaches. Cell 2009;137(1):172-181.

Examples

data(irma_on)

A function to run KBoost.

Description

A function to run KBoost.

Usage

kboost(X, TFs, g, v, prior_weights, ite)

Arguments

X

an NxG matrix with the expression values of G genes and N obvs..

TFs

a Kx1 numeric matrix with integers of columns of X that are TFs.

g

a positive no., width parameter for RBF kernel. (default g = 40)

v

a no. between 0 and 1 with the shrinkage parameter. (default v =0.1)

prior_weights

it can be a scalar or GxK. (default 0.5)

ite

an integer for the maximum number of iterations (default 3)

Value

a list with the results for kboost, with fields: GRN a matrix with the posterior edge probability after network refinement. GRN_UP a matrix with the posterior edges before refinement. model a matrix with logical values for the TFs selected for each gene. g the width parameter for the RBF kernel. v the shrinkage parameter. prior the prior of each model. TFs a matrix with integers of each gene that is a TF. prior_weights the prior_weights with which KBoost was run. run_time a sacalar with the running time.

Examples

data(D4_multi_1)
Net <- kboost(D4_multi_1)

Function for KBoost on data from a human sample annotated with Symbol names.

Description

Function for KBoost on data from a human sample annotated with Symbol names.

Usage

KBoost_human_symbol(X, gen_names, g, v, ite, pos_weight, neg_weight)

Arguments

X

an NxG matrix with the expression values of G genes and N samples.

gen_names

SYMBOL gene names corresponding to the columns of X.

g

a positive no., width parameter for the RBF kernel. (default g = 40)

v

a double between 0 and 1, the shrinkage parameter. (default v =0.1)

ite

an integer with the number of iterations (default ite = 3)

pos_weight

no. between 0 and 1. Prior that a TF regulate a gene.

neg_weight

no. between 0 and 1, for TF gene pairs not seen before.

Value

list with results of KBoost on a dataset with Symbol gene names.

Examples

X = rnorm(50,0,1)
X = matrix(X,10,5)
gen_names = c("TP53","YY1","CTCF","MDM2","ESR1")
grn = KBoost_human_symbol(X,gen_names,pos_weight = 0.6, neg_weight =0.4)

A function to perform feature normalization in kernel space.

Description

A function to perform feature normalization in kernel space.

Usage

kernel_normal(K)

Arguments

K

an NxN numeric matrix with the kernel function with N observations.

Value

feature centred kernel.

Examples

x = rnorm(100,0,1)
k = RBF_K(x,40)
k_ = kernel_normal(k)

Function to perform Kernel Principal Component Boosting

Description

Function to perform Kernel Principal Component Boosting

Usage

kernel_pc_boosting(X, Y, g, v, ite, thr)

Arguments

X

A matrix with the explanatory variables.

Y

a matrix with the variable to predict.

g

a positive number with the width parameter for the RBF Kernel.

v

a number between 0 and 1 that corresponds to the shrinkage parameter.

ite

an integer with the number of iterations.

thr

a threshold to discard Kernel principal components whose eigenvalue

Value

function an sum of squared errors.

Examples

data(D4_multi_1)
Y = scale(matrix(D4_multi_1[,91],100,1))
X = scale(D4_multi_1[,-91])
res = kernel_pc_boosting(X,Y, g= 40, v = 0.5, ite = 3, thr = 1e-10)

Function to calculate the principal components of a kernel.

Description

Function to calculate the principal components of a kernel.

Usage

KPC(K, thr)

Arguments

K

an NxN numeric matrix with the Kernel matrix.

thr

a positive scalar which is a threshold to discard eigen-vectors based on eigen-values.

Value

the kernel principal components

Examples

x = rnorm(100,0,1)
k = RBF_K(x,1)
k_ = kernel_normal(k)
kpca = KPC(k,1e-8)

Function to calculate the distance between nodes.

Description

Function to calculate the distance between nodes.

Usage

net_dist_bin(GRN, TFs, thr)

Arguments

GRN

An inferred networks with the predictive probabilities that a transcription factor regulates a gene.

TFs

A vector with indexes of the rows of GRN which correspond to TFs.

thr

A scalar between 0 and 1 that is used select the edges with large posterior probabilities.

Value

a matrix with the distances between edges.

Examples

data(D4_multi_1)
Net = kboost(D4_multi_1)
dist = net_dist_bin(Net$GRN,Net$TFs,0.1)

Function to do a heuristic post-processing that improves accuracy. Each column is multiplied by its variance.

Description

Function to do a heuristic post-processing that improves accuracy. Each column is multiplied by its variance.

Usage

net_refine(Net)

Arguments

Net

a GRN with TFs in the columns.

Value

the network with Slavek and Arodz heuristic

Examples

Net =rbeta(10000,1,2)
Net = matrix(Net,100,100)
net_ref = net_refine(Net)

Function to summarize the GRN filtered with a threshold,

Description

Function to summarize the GRN filtered with a threshold,

Usage

net_summary_bin(GRN, TFs, thr, a, b)

Arguments

GRN

An inferred network

TFs

A vector with indexes of the rows of GRN which correspond to TFs.

thr

a scalar between 0 and 1, a threshold for posterior probabilities.

a

parameter for Katz and PageRank centrality (default the inverse of the largest eigenvalue of GRN.

b

parameter for Katz and PageRank centrality (default b = 1).

Value

list with table version of the GRN, outdegree and indegree, and closeness centrality.

Examples

data(D4_multi_1)
Net = kboost(D4_multi_1)
Net_Summary = net_summary_bin(Net$GRN)

Function to calculate the RBF Kernel of a matrix X with width g.

Description

Function to calculate the RBF Kernel of a matrix X with width g.

Usage

RBF_K(x, g)

Arguments

x

an Nx1 numeric matrix with N observations.

g

a positive scalar with the width parameter.

Value

the matrix with the RBF kernel

Examples

x = rnorm(100,0,1)
k = RBF_K(x,40)

Function to produce the gold standard of the DREAM4 Multifactorial Challenge in matrix format.

Description

Function to produce the gold standard of the DREAM4 Multifactorial Challenge in matrix format.

Usage

tab_2_matrix_D4(g_table, G)

Arguments

g_table

the network in table format. The first column is the Tf, the second column the gene, and the third indicates if there is an interaction.

G

the number of genes.

Value

a network in table format transformed into a matrix.

Examples

g_table = KBoost::G_D4_multi_1
g_mat = tab_2_matrix_D4(g_table,100)

Function to write output in DREAM4 Challenge Format.

Description

Function to write output in DREAM4 Challenge Format.

Usage

write_GRN_D4(GRN, TFs, filename)

Arguments

GRN

a GxK gene regulatory network.

TFs

a K set of indixes of G that are TFs.

filename

a string with the filename.

Value

a file with the network written as a file.

Examples

data(D4_multi_1)
Net = kboost(D4_multi_1)
write_GRN_D4(Net$GRN, seq_len(100), "D4_multi_1_network.txt")