library(tidyverse)
library(readr)
rpkm_data <- read.csv("rpkm.csv", stringsAsFactors = FALSE)

Data cleaning

Remove unnecesary and non numeric columns as linear model works best with numeric dataframes only

rpkm2 <- rpkm_data[, - c(1:2)]
str(rpkm2)
## 'data.frame':    814 obs. of  23 variables:
##  $ MCF7_ER_veh              : int  3 4 13 2 1 1 5 2 6 1 ...
##  $ MCF7_ER_E2               : int  4 4 13 2 1 2 8 2 5 4 ...
##  $ MCF7_FoxA1_veh           : int  1 0 3 2 1 0 3 2 3 0 ...
##  $ MCF7_FoxA1_E2            : int  1 1 6 2 1 0 4 2 3 2 ...
##  $ MCF7_AP2g_veh            : int  0 3 4 0 0 2 2 0 2 0 ...
##  $ MCF7_AP2g_E2             : int  2 4 7 1 1 1 3 1 3 1 ...
##  $ MCF7_TEAD4_veh           : int  2 3 6 1 1 1 3 2 3 0 ...
##  $ MCF7_TCF12_veh           : int  3 3 6 2 1 1 6 2 5 0 ...
##  $ MCF7_P300_veh            : int  2 4 7 2 0 1 3 1 2 2 ...
##  $ MCF7_H3K27ac_veh         : int  1 4 8 2 1 2 6 1 3 1 ...
##  $ Ishikawa_TEAD4_veh       : int  7 4 6 2 1 3 9 5 6 5 ...
##  $ Ishikawa_TCF12_veh       : int  7 4 10 2 0 3 10 5 6 6 ...
##  $ Ishikawa_FoxM1_veh       : int  6 4 6 2 0 3 9 5 5 5 ...
##  $ Ishikawa_CEBPB_veh       : int  6 4 5 2 0 2 9 5 6 6 ...
##  $ Ishikawa_P300_veh        : int  6 4 6 2 0 3 10 4 6 6 ...
##  $ Ishikawa_H3K27ac_veh     : int  1 4 4 2 0 2 3 1 3 3 ...
##  $ ERE_motif.total.         : int  0 4 6 2 10 2 5 2 2 4 ...
##  $ Fox_motif.total.         : int  1 0 3 0 0 0 1 0 0 0 ...
##  $ AP2_motif.total.         : int  3 2 14 0 0 0 1 0 0 0 ...
##  $ TEAD_motif.total.        : int  0 0 3 0 3 0 1 1 1 1 ...
##  $ TCF_motif.total.         : int  1 1 0 0 0 0 1 0 0 2 ...
##  $ CEBP_motif.total.        : int  0 0 0 0 0 0 0 2 0 1 ...
##  $ Fold.Change.MCF7.Ishikawa: num  0.0274 0.4903 0.4094 0.1786 18.515 ...

Remove NAs from the dataset. Previously before cleaning the data there were 82 NAs. They can either be removed or rplaced with zeros unless they have significance in the dataset.

rpkm2 <- na.omit(rpkm2)

sum(is.na(rpkm2))
## [1] 0

Explore the dependent variable to be modeled, check if the data is normalized or with the standard scale. The fold change is used in this case as the depended variable and the rest of the columns used as predictos of the fold chage. First, we need to examine the dependent varibe, confirm if it as a numric vector and if not transform it. Also, we can verify whether it is normally distibuted though it is not very necessary but essential for smooth modeling with linear regression.

str(rpkm2$Fold.Change.MCF7.Ishikawa)
##  num [1:814] 0.0274 0.4903 0.4094 0.1786 18.515 ...
summary(rpkm2$Fold.Change.MCF7.Ishikawa)
##     Min.  1st Qu.   Median     Mean  3rd Qu.     Max. 
##    0.000    0.175    0.580   23.225    1.937 6659.016

Normalize the dataset

normalize <- function(x){
  return((x - min(x)) / (max(x) -min(x)))
}

Confirm whether the normalize function is effective

normalize(c(1:5))
## [1] 0.00 0.25 0.50 0.75 1.00

Normalize the dataset

lm_rpkm2_n <- as.data.frame(lapply(rpkm2, normalize))
summary(lm_rpkm2_n$Fold.Change.MCF7.Ishikawa)
##      Min.   1st Qu.    Median      Mean   3rd Qu.      Max. 
## 0.0000000 0.0000263 0.0000872 0.0034878 0.0002909 1.0000000
par(mar = c(1,1,1,1))

Explore relationship between the variables using corelation function

cor(lm_rpkm2_n[c("MCF7_ER_veh" ,"MCF7_ER_E2" , "MCF7_FoxA1_veh"  ,  "MCF7_FoxA1_E2",
              "MCF7_AP2g_veh" , "MCF7_AP2g_E2", "MCF7_TEAD4_veh", "MCF7_TCF12_veh",
              "MCF7_P300_veh", "MCF7_H3K27ac_veh","Ishikawa_TEAD4_veh","Ishikawa_TCF12_veh",
              "Ishikawa_FoxM1_veh" , "Ishikawa_CEBPB_veh" , "Ishikawa_P300_veh","Ishikawa_H3K27ac_veh", 
              "ERE_motif.total.", "Fox_motif.total." , "AP2_motif.total." , "TEAD_motif.total." ,    
              "TCF_motif.total." ,"CEBP_motif.total.",  "Fold.Change.MCF7.Ishikawa")])
##                           MCF7_ER_veh MCF7_ER_E2 MCF7_FoxA1_veh
## MCF7_ER_veh                1.00000000 0.97932075     0.86970220
## MCF7_ER_E2                 0.97932075 1.00000000     0.84589467
## MCF7_FoxA1_veh             0.86970220 0.84589467     1.00000000
## MCF7_FoxA1_E2              0.92896064 0.91825502     0.95039846
## MCF7_AP2g_veh              0.83675811 0.80346260     0.88823013
## MCF7_AP2g_E2               0.91154864 0.89243428     0.90693301
## MCF7_TEAD4_veh             0.95218988 0.93737590     0.89900390
## MCF7_TCF12_veh             0.94475119 0.92911808     0.90445835
## MCF7_P300_veh              0.93998872 0.92663191     0.83085478
## MCF7_H3K27ac_veh           0.91425766 0.91168687     0.81931297
## Ishikawa_TEAD4_veh         0.58917357 0.58190060     0.39213694
## Ishikawa_TCF12_veh         0.64281754 0.64066914     0.42573510
## Ishikawa_FoxM1_veh         0.48902265 0.47884432     0.31503373
## Ishikawa_CEBPB_veh         0.48305327 0.47412466     0.31048212
## Ishikawa_P300_veh          0.58689557 0.58308853     0.37300717
## Ishikawa_H3K27ac_veh       0.63193564 0.62478882     0.45045749
## ERE_motif.total.           0.72942212 0.76158422     0.50914615
## Fox_motif.total.           0.61731980 0.61329182     0.68547671
## AP2_motif.total.           0.71732599 0.73029739     0.46557780
## TEAD_motif.total.          0.45664430 0.45096984     0.41967373
## TCF_motif.total.           0.35936871 0.35422283     0.18494779
## CEBP_motif.total.          0.45380117 0.44975855     0.48050084
## Fold.Change.MCF7.Ishikawa  0.03840663 0.03217865     0.09166449
##                           MCF7_FoxA1_E2 MCF7_AP2g_veh MCF7_AP2g_E2
## MCF7_ER_veh                  0.92896064    0.83675811   0.91154864
## MCF7_ER_E2                   0.91825502    0.80346260   0.89243428
## MCF7_FoxA1_veh               0.95039846    0.88823013   0.90693301
## MCF7_FoxA1_E2                1.00000000    0.87383965   0.92485082
## MCF7_AP2g_veh                0.87383965    1.00000000   0.93819786
## MCF7_AP2g_E2                 0.92485082    0.93819786   1.00000000
## MCF7_TEAD4_veh               0.93565685    0.86738593   0.92678504
## MCF7_TCF12_veh               0.93676044    0.87888074   0.93226104
## MCF7_P300_veh                0.87826175    0.88194606   0.92644187
## MCF7_H3K27ac_veh             0.86384799    0.85807770   0.90568939
## Ishikawa_TEAD4_veh           0.44455461    0.45156837   0.49876960
## Ishikawa_TCF12_veh           0.48612611    0.48857998   0.54321581
## Ishikawa_FoxM1_veh           0.34681035    0.38310746   0.41539445
## Ishikawa_CEBPB_veh           0.34781076    0.38077441   0.41328814
## Ishikawa_P300_veh            0.43168290    0.44113940   0.48967645
## Ishikawa_H3K27ac_veh         0.49770212    0.52623299   0.55786781
## ERE_motif.total.             0.61781685    0.51128127   0.61547356
## Fox_motif.total.             0.67547279    0.57558845   0.61545269
## AP2_motif.total.             0.56445337    0.51296661   0.60924232
## TEAD_motif.total.            0.42222672    0.37961696   0.40603947
## TCF_motif.total.             0.23680327    0.23637306   0.27568640
## CEBP_motif.total.            0.46429440    0.40367221   0.43333146
## Fold.Change.MCF7.Ishikawa    0.06997451    0.08843374   0.07080236
##                           MCF7_TEAD4_veh MCF7_TCF12_veh MCF7_P300_veh
## MCF7_ER_veh                   0.95218988     0.94475119    0.93998872
## MCF7_ER_E2                    0.93737590     0.92911808    0.92663191
## MCF7_FoxA1_veh                0.89900390     0.90445835    0.83085478
## MCF7_FoxA1_E2                 0.93565685     0.93676044    0.87826175
## MCF7_AP2g_veh                 0.86738593     0.87888074    0.88194606
## MCF7_AP2g_E2                  0.92678504     0.93226104    0.92644187
## MCF7_TEAD4_veh                1.00000000     0.97450583    0.92982099
## MCF7_TCF12_veh                0.97450583     1.00000000    0.92397710
## MCF7_P300_veh                 0.92982099     0.92397710    1.00000000
## MCF7_H3K27ac_veh              0.90024782     0.89586237    0.93920799
## Ishikawa_TEAD4_veh            0.55373240     0.54042656    0.61917703
## Ishikawa_TCF12_veh            0.59704648     0.58274268    0.67275128
## Ishikawa_FoxM1_veh            0.46839256     0.45281278    0.52817677
## Ishikawa_CEBPB_veh            0.45976532     0.45023949    0.52248940
## Ishikawa_P300_veh             0.54363017     0.53145953    0.62227581
## Ishikawa_H3K27ac_veh          0.59526988     0.58016072    0.66429167
## ERE_motif.total.              0.65770977     0.64752562    0.69893406
## Fox_motif.total.              0.59600224     0.59221425    0.56408760
## AP2_motif.total.              0.64425403     0.62888744    0.72192430
## TEAD_motif.total.             0.45385770     0.42338192    0.42951859
## TCF_motif.total.              0.29604213     0.28336815    0.38828890
## CEBP_motif.total.             0.47780070     0.47905281    0.41026363
## Fold.Change.MCF7.Ishikawa     0.05372959     0.05945942    0.04585309
##                           MCF7_H3K27ac_veh Ishikawa_TEAD4_veh
## MCF7_ER_veh                     0.91425766         0.58917357
## MCF7_ER_E2                      0.91168687         0.58190060
## MCF7_FoxA1_veh                  0.81931297         0.39213694
## MCF7_FoxA1_E2                   0.86384799         0.44455461
## MCF7_AP2g_veh                   0.85807770         0.45156837
## MCF7_AP2g_E2                    0.90568939         0.49876960
## MCF7_TEAD4_veh                  0.90024782         0.55373240
## MCF7_TCF12_veh                  0.89586237         0.54042656
## MCF7_P300_veh                   0.93920799         0.61917703
## MCF7_H3K27ac_veh                1.00000000         0.61938363
## Ishikawa_TEAD4_veh              0.61938363         1.00000000
## Ishikawa_TCF12_veh              0.66645290         0.96920689
## Ishikawa_FoxM1_veh              0.53328934         0.95457756
## Ishikawa_CEBPB_veh              0.53321753         0.94515475
## Ishikawa_P300_veh               0.62181210         0.97513805
## Ishikawa_H3K27ac_veh            0.68197726         0.88458045
## ERE_motif.total.                0.67965988         0.45423220
## Fox_motif.total.                0.57472842         0.21241283
## AP2_motif.total.                0.68151280         0.55536471
## TEAD_motif.total.               0.44152828         0.54079312
## TCF_motif.total.                0.38480685         0.48779443
## CEBP_motif.total.               0.38807826         0.32638685
## Fold.Change.MCF7.Ishikawa       0.04594538        -0.08190802
##                           Ishikawa_TCF12_veh Ishikawa_FoxM1_veh
## MCF7_ER_veh                       0.64281754         0.48902265
## MCF7_ER_E2                        0.64066914         0.47884432
## MCF7_FoxA1_veh                    0.42573510         0.31503373
## MCF7_FoxA1_E2                     0.48612611         0.34681035
## MCF7_AP2g_veh                     0.48857998         0.38310746
## MCF7_AP2g_E2                      0.54321581         0.41539445
## MCF7_TEAD4_veh                    0.59704648         0.46839256
## MCF7_TCF12_veh                    0.58274268         0.45281278
## MCF7_P300_veh                     0.67275128         0.52817677
## MCF7_H3K27ac_veh                  0.66645290         0.53328934
## Ishikawa_TEAD4_veh                0.96920689         0.95457756
## Ishikawa_TCF12_veh                1.00000000         0.92829952
## Ishikawa_FoxM1_veh                0.92829952         1.00000000
## Ishikawa_CEBPB_veh                0.92493926         0.95561394
## Ishikawa_P300_veh                 0.97176311         0.94317156
## Ishikawa_H3K27ac_veh              0.89916605         0.86182682
## ERE_motif.total.                  0.51083356         0.34703814
## Fox_motif.total.                  0.24198020         0.14166582
## AP2_motif.total.                  0.60711626         0.47594055
## TEAD_motif.total.                 0.53803575         0.52727707
## TCF_motif.total.                  0.48968910         0.46612118
## CEBP_motif.total.                 0.32568462         0.29140231
## Fold.Change.MCF7.Ishikawa        -0.08202009        -0.08296293
##                           Ishikawa_CEBPB_veh Ishikawa_P300_veh
## MCF7_ER_veh                       0.48305327        0.58689557
## MCF7_ER_E2                        0.47412466        0.58308853
## MCF7_FoxA1_veh                    0.31048212        0.37300717
## MCF7_FoxA1_E2                     0.34781076        0.43168290
## MCF7_AP2g_veh                     0.38077441        0.44113940
## MCF7_AP2g_E2                      0.41328814        0.48967645
## MCF7_TEAD4_veh                    0.45976532        0.54363017
## MCF7_TCF12_veh                    0.45023949        0.53145953
## MCF7_P300_veh                     0.52248940        0.62227581
## MCF7_H3K27ac_veh                  0.53321753        0.62181210
## Ishikawa_TEAD4_veh                0.94515475        0.97513805
## Ishikawa_TCF12_veh                0.92493926        0.97176311
## Ishikawa_FoxM1_veh                0.95561394        0.94317156
## Ishikawa_CEBPB_veh                1.00000000        0.94257666
## Ishikawa_P300_veh                 0.94257666        1.00000000
## Ishikawa_H3K27ac_veh              0.85387405        0.88950428
## ERE_motif.total.                  0.34829488        0.47639890
## Fox_motif.total.                  0.14134456        0.20601074
## AP2_motif.total.                  0.45258459        0.56760255
## TEAD_motif.total.                 0.51280466        0.52674344
## TCF_motif.total.                  0.44097579        0.49038683
## CEBP_motif.total.                 0.30743884        0.30646605
## Fold.Change.MCF7.Ishikawa        -0.07892432       -0.08502347
##                           Ishikawa_H3K27ac_veh ERE_motif.total.
## MCF7_ER_veh                         0.63193564     0.7294221242
## MCF7_ER_E2                          0.62478882     0.7615842158
## MCF7_FoxA1_veh                      0.45045749     0.5091461478
## MCF7_FoxA1_E2                       0.49770212     0.6178168474
## MCF7_AP2g_veh                       0.52623299     0.5112812749
## MCF7_AP2g_E2                        0.55786781     0.6154735565
## MCF7_TEAD4_veh                      0.59526988     0.6577097702
## MCF7_TCF12_veh                      0.58016072     0.6475256153
## MCF7_P300_veh                       0.66429167     0.6989340608
## MCF7_H3K27ac_veh                    0.68197726     0.6796598830
## Ishikawa_TEAD4_veh                  0.88458045     0.4542321964
## Ishikawa_TCF12_veh                  0.89916605     0.5108335561
## Ishikawa_FoxM1_veh                  0.86182682     0.3470381383
## Ishikawa_CEBPB_veh                  0.85387405     0.3482948799
## Ishikawa_P300_veh                   0.88950428     0.4763988971
## Ishikawa_H3K27ac_veh                1.00000000     0.4770300805
## ERE_motif.total.                    0.47703008     1.0000000000
## Fox_motif.total.                    0.26405968     0.4123863266
## AP2_motif.total.                    0.58142840     0.6395932708
## TEAD_motif.total.                   0.50049054     0.2998504417
## TCF_motif.total.                    0.46285836     0.3430600542
## CEBP_motif.total.                   0.31010263     0.2841958812
## Fold.Change.MCF7.Ishikawa          -0.06873507    -0.0002950973
##                           Fox_motif.total. AP2_motif.total.
## MCF7_ER_veh                     0.61731980       0.71732599
## MCF7_ER_E2                      0.61329182       0.73029739
## MCF7_FoxA1_veh                  0.68547671       0.46557780
## MCF7_FoxA1_E2                   0.67547279       0.56445337
## MCF7_AP2g_veh                   0.57558845       0.51296661
## MCF7_AP2g_E2                    0.61545269       0.60924232
## MCF7_TEAD4_veh                  0.59600224       0.64425403
## MCF7_TCF12_veh                  0.59221425       0.62888744
## MCF7_P300_veh                   0.56408760       0.72192430
## MCF7_H3K27ac_veh                0.57472842       0.68151280
## Ishikawa_TEAD4_veh              0.21241283       0.55536471
## Ishikawa_TCF12_veh              0.24198020       0.60711626
## Ishikawa_FoxM1_veh              0.14166582       0.47594055
## Ishikawa_CEBPB_veh              0.14134456       0.45258459
## Ishikawa_P300_veh               0.20601074       0.56760255
## Ishikawa_H3K27ac_veh            0.26405968       0.58142840
## ERE_motif.total.                0.41238633       0.63959327
## Fox_motif.total.                1.00000000       0.31906576
## AP2_motif.total.                0.31906576       1.00000000
## TEAD_motif.total.               0.26563031       0.28931817
## TCF_motif.total.                0.12286996       0.40521788
## CEBP_motif.total.               0.33988717       0.20438752
## Fold.Change.MCF7.Ishikawa       0.07325088      -0.01808033
##                           TEAD_motif.total. TCF_motif.total.
## MCF7_ER_veh                      0.45664430       0.35936871
## MCF7_ER_E2                       0.45096984       0.35422283
## MCF7_FoxA1_veh                   0.41967373       0.18494779
## MCF7_FoxA1_E2                    0.42222672       0.23680327
## MCF7_AP2g_veh                    0.37961696       0.23637306
## MCF7_AP2g_E2                     0.40603947       0.27568640
## MCF7_TEAD4_veh                   0.45385770       0.29604213
## MCF7_TCF12_veh                   0.42338192       0.28336815
## MCF7_P300_veh                    0.42951859       0.38828890
## MCF7_H3K27ac_veh                 0.44152828       0.38480685
## Ishikawa_TEAD4_veh               0.54079312       0.48779443
## Ishikawa_TCF12_veh               0.53803575       0.48968910
## Ishikawa_FoxM1_veh               0.52727707       0.46612118
## Ishikawa_CEBPB_veh               0.51280466       0.44097579
## Ishikawa_P300_veh                0.52674344       0.49038683
## Ishikawa_H3K27ac_veh             0.50049054       0.46285836
## ERE_motif.total.                 0.29985044       0.34306005
## Fox_motif.total.                 0.26563031       0.12286996
## AP2_motif.total.                 0.28931817       0.40521788
## TEAD_motif.total.                1.00000000       0.21084411
## TCF_motif.total.                 0.21084411       1.00000000
## CEBP_motif.total.                0.28007361       0.10305200
## Fold.Change.MCF7.Ishikawa       -0.02589946      -0.01946583
##                           CEBP_motif.total. Fold.Change.MCF7.Ishikawa
## MCF7_ER_veh                      0.45380117              0.0384066325
## MCF7_ER_E2                       0.44975855              0.0321786467
## MCF7_FoxA1_veh                   0.48050084              0.0916644912
## MCF7_FoxA1_E2                    0.46429440              0.0699745094
## MCF7_AP2g_veh                    0.40367221              0.0884337407
## MCF7_AP2g_E2                     0.43333146              0.0708023599
## MCF7_TEAD4_veh                   0.47780070              0.0537295859
## MCF7_TCF12_veh                   0.47905281              0.0594594223
## MCF7_P300_veh                    0.41026363              0.0458530871
## MCF7_H3K27ac_veh                 0.38807826              0.0459453763
## Ishikawa_TEAD4_veh               0.32638685             -0.0819080185
## Ishikawa_TCF12_veh               0.32568462             -0.0820200926
## Ishikawa_FoxM1_veh               0.29140231             -0.0829629313
## Ishikawa_CEBPB_veh               0.30743884             -0.0789243191
## Ishikawa_P300_veh                0.30646605             -0.0850234748
## Ishikawa_H3K27ac_veh             0.31010263             -0.0687350679
## ERE_motif.total.                 0.28419588             -0.0002950973
## Fox_motif.total.                 0.33988717              0.0732508751
## AP2_motif.total.                 0.20438752             -0.0180803304
## TEAD_motif.total.                0.28007361             -0.0258994587
## TCF_motif.total.                 0.10305200             -0.0194658348
## CEBP_motif.total.                1.00000000              0.0303455193
## Fold.Change.MCF7.Ishikawa        0.03034552              1.0000000000

Visualize relationships among variables in a scatter plot

pairs(lm_rpkm2_n[c("MCF7_ER_veh" ,"MCF7_ER_E2", "Ishikawa_TEAD4_veh","Ishikawa_TCF12_veh",
                "ERE_motif.total.", "Fox_motif.total.",  "Fold.Change.MCF7.Ishikawa")])

Advanced visulaization with psych package by replacing scatter plot with a corelation matrix

library(psych)
pairs.panels(lm_rpkm2_n[c("MCF7_ER_veh" ,"MCF7_ER_E2", "Ishikawa_TEAD4_veh","Ishikawa_TCF12_veh",
                         "ERE_motif.total.", "Fox_motif.total.",  "Fold.Change.MCF7.Ishikawa")])

Model 1

foldchange_model <- lm(Fold.Change.MCF7.Ishikawa ~ ., data = lm_rpkm2_n)
foldchange_model
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ ., data = lm_rpkm2_n)
## 
## Coefficients:
##          (Intercept)           MCF7_ER_veh            MCF7_ER_E2  
##            0.0070849            -0.0051824            -0.0158358  
##       MCF7_FoxA1_veh         MCF7_FoxA1_E2         MCF7_AP2g_veh  
##            0.0463409            -0.0309478             0.0358553  
##         MCF7_AP2g_E2        MCF7_TEAD4_veh        MCF7_TCF12_veh  
##           -0.0208824            -0.0077336             0.0169270  
##        MCF7_P300_veh      MCF7_H3K27ac_veh    Ishikawa_TEAD4_veh  
##            0.0286557             0.0265647            -0.0105124  
##   Ishikawa_TCF12_veh    Ishikawa_FoxM1_veh    Ishikawa_CEBPB_veh  
##           -0.0497439             0.0051204             0.0218875  
##    Ishikawa_P300_veh  Ishikawa_H3K27ac_veh      ERE_motif.total.  
##           -0.0126960            -0.0200706            -0.0003442  
##     Fox_motif.total.      AP2_motif.total.     TEAD_motif.total.  
##            0.0073116            -0.0010414            -0.0020741  
##     TCF_motif.total.     CEBP_motif.total.  
##            0.0065529             0.0049985

Evaluate model performance

summary(foldchange_model)
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ ., data = lm_rpkm2_n)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.03921 -0.00558 -0.00281  0.00048  0.98408 
## 
## Coefficients:
##                        Estimate Std. Error t value Pr(>|t|)   
## (Intercept)           0.0070849  0.0025142   2.818  0.00495 **
## MCF7_ER_veh          -0.0051824  0.0748158  -0.069  0.94479   
## MCF7_ER_E2           -0.0158358  0.0710112  -0.223  0.82359   
## MCF7_FoxA1_veh        0.0463409  0.0556191   0.833  0.40499   
## MCF7_FoxA1_E2        -0.0309478  0.0587183  -0.527  0.59830   
## MCF7_AP2g_veh         0.0358553  0.0491120   0.730  0.46556   
## MCF7_AP2g_E2         -0.0208824  0.0551927  -0.378  0.70527   
## MCF7_TEAD4_veh       -0.0077336  0.0695724  -0.111  0.91152   
## MCF7_TCF12_veh        0.0169270  0.0693525   0.244  0.80724   
## MCF7_P300_veh         0.0286557  0.0502272   0.571  0.56849   
## MCF7_H3K27ac_veh      0.0265647  0.0359297   0.739  0.45991   
## Ishikawa_TEAD4_veh   -0.0105124  0.0591543  -0.178  0.85900   
## Ishikawa_TCF12_veh   -0.0497439  0.0538556  -0.924  0.35595   
## Ishikawa_FoxM1_veh    0.0051204  0.0374910   0.137  0.89140   
## Ishikawa_CEBPB_veh    0.0218875  0.0295697   0.740  0.45940   
## Ishikawa_P300_veh    -0.0126960  0.0524470  -0.242  0.80879   
## Ishikawa_H3K27ac_veh -0.0200706  0.0222062  -0.904  0.36636   
## ERE_motif.total.     -0.0003442  0.0194229  -0.018  0.98587   
## Fox_motif.total.      0.0073116  0.0207898   0.352  0.72516   
## AP2_motif.total.     -0.0010414  0.0169557  -0.061  0.95104   
## TEAD_motif.total.    -0.0020741  0.0132117  -0.157  0.87529   
## TCF_motif.total.      0.0065529  0.0099412   0.659  0.50998   
## CEBP_motif.total.     0.0049985  0.0163569   0.306  0.76000   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.039 on 791 degrees of freedom
## Multiple R-squared:  0.03399,    Adjusted R-squared:  0.007127 
## F-statistic: 1.265 on 22 and 791 DF,  p-value: 0.1858

Outcome analysis

The summary output gives us detailed information baou the model. The residuls section provides summary statistics for the errors in our prediction. A residual equals the true value minus the predicted value.

How do we impove the model performance?

Fold change has a higher corelation with: * MCF7_FoxA1_veh 9% * MCF7_AP2g_veh 8% * MCF7_AP2g_E2 7%

  1. Add non-linear relationships to the model by: Square the independent variables having higher corelation with the dependent variable.
lm_rpkm2_n$MCF7_FoxA1_veh2 <-lm_rpkm2_n$MCF7_FoxA1_veh^2 
lm_rpkm2_n$MCF7_AP2g_veh2 <- lm_rpkm2_n$MCF7_AP2g_veh^2
lm_rpkm2_n$MCF7_AP2g_E2b <- lm_rpkm2_n$MCF7_AP2g_E2^2
  1. Add interaction effects. Some of the variables have combined effects in the fold change. These varibles include:
colnames(lm_rpkm2_n)
##  [1] "MCF7_ER_veh"               "MCF7_ER_E2"               
##  [3] "MCF7_FoxA1_veh"            "MCF7_FoxA1_E2"            
##  [5] "MCF7_AP2g_veh"             "MCF7_AP2g_E2"             
##  [7] "MCF7_TEAD4_veh"            "MCF7_TCF12_veh"           
##  [9] "MCF7_P300_veh"             "MCF7_H3K27ac_veh"         
## [11] "Ishikawa_TEAD4_veh"        "Ishikawa_TCF12_veh"       
## [13] "Ishikawa_FoxM1_veh"        "Ishikawa_CEBPB_veh"       
## [15] "Ishikawa_P300_veh"         "Ishikawa_H3K27ac_veh"     
## [17] "ERE_motif.total."          "Fox_motif.total."         
## [19] "AP2_motif.total."          "TEAD_motif.total."        
## [21] "TCF_motif.total."          "CEBP_motif.total."        
## [23] "Fold.Change.MCF7.Ishikawa" "MCF7_FoxA1_veh2"          
## [25] "MCF7_AP2g_veh2"            "MCF7_AP2g_E2b"

Model 2

foldchange_model2 <- lm(Fold.Change.MCF7.Ishikawa ~ MCF7_ER_veh + MCF7_ER_E2 + MCF7_FoxA1_veh + MCF7_FoxA1_veh2 + MCF7_FoxA1_E2 + MCF7_AP2g_veh + MCF7_AP2g_veh2 + MCF7_AP2g_E2 + MCF7_AP2g_E2b + MCF7_TEAD4_veh + MCF7_TCF12_veh + MCF7_P300_veh + MCF7_H3K27ac_veh +  MCF7_ER_E2*MCF7_ER_veh + MCF7_FoxA1_E2*MCF7_ER_veh + MCF7_FoxA1_E2*MCF7_FoxA1_veh + Ishikawa_TEAD4_veh + Ishikawa_TCF12_veh +Ishikawa_P300_veh*Ishikawa_TCF12_veh + Ishikawa_FoxM1_veh + Ishikawa_CEBPB_veh + Ishikawa_P300_veh + Ishikawa_H3K27ac_veh + ERE_motif.total. + Fox_motif.total. + AP2_motif.total. + TEAD_motif.total. + TCF_motif.total. + CEBP_motif.total.,  data = lm_rpkm2_n)
foldchange_model
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ ., data = lm_rpkm2_n)
## 
## Coefficients:
##          (Intercept)           MCF7_ER_veh            MCF7_ER_E2  
##            0.0070849            -0.0051824            -0.0158358  
##       MCF7_FoxA1_veh         MCF7_FoxA1_E2         MCF7_AP2g_veh  
##            0.0463409            -0.0309478             0.0358553  
##         MCF7_AP2g_E2        MCF7_TEAD4_veh        MCF7_TCF12_veh  
##           -0.0208824            -0.0077336             0.0169270  
##        MCF7_P300_veh      MCF7_H3K27ac_veh    Ishikawa_TEAD4_veh  
##            0.0286557             0.0265647            -0.0105124  
##   Ishikawa_TCF12_veh    Ishikawa_FoxM1_veh    Ishikawa_CEBPB_veh  
##           -0.0497439             0.0051204             0.0218875  
##    Ishikawa_P300_veh  Ishikawa_H3K27ac_veh      ERE_motif.total.  
##           -0.0126960            -0.0200706            -0.0003442  
##     Fox_motif.total.      AP2_motif.total.     TEAD_motif.total.  
##            0.0073116            -0.0010414            -0.0020741  
##     TCF_motif.total.     CEBP_motif.total.  
##            0.0065529             0.0049985
summary(foldchange_model2)
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ MCF7_ER_veh + MCF7_ER_E2 + 
##     MCF7_FoxA1_veh + MCF7_FoxA1_veh2 + MCF7_FoxA1_E2 + MCF7_AP2g_veh + 
##     MCF7_AP2g_veh2 + MCF7_AP2g_E2 + MCF7_AP2g_E2b + MCF7_TEAD4_veh + 
##     MCF7_TCF12_veh + MCF7_P300_veh + MCF7_H3K27ac_veh + MCF7_ER_E2 * 
##     MCF7_ER_veh + MCF7_FoxA1_E2 * MCF7_ER_veh + MCF7_FoxA1_E2 * 
##     MCF7_FoxA1_veh + Ishikawa_TEAD4_veh + Ishikawa_TCF12_veh + 
##     Ishikawa_P300_veh * Ishikawa_TCF12_veh + Ishikawa_FoxM1_veh + 
##     Ishikawa_CEBPB_veh + Ishikawa_P300_veh + Ishikawa_H3K27ac_veh + 
##     ERE_motif.total. + Fox_motif.total. + AP2_motif.total. + 
##     TEAD_motif.total. + TCF_motif.total. + CEBP_motif.total., 
##     data = lm_rpkm2_n)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.04694 -0.00658 -0.00215  0.00187  0.97909 
## 
## Coefficients:
##                                        Estimate Std. Error t value
## (Intercept)                           0.0097124  0.0032522   2.986
## MCF7_ER_veh                           0.0142526  0.0844825   0.169
## MCF7_ER_E2                           -0.0329994  0.0875929  -0.377
## MCF7_FoxA1_veh                        0.0300464  0.0807396   0.372
## MCF7_FoxA1_veh2                       0.0597872  0.6658711   0.090
## MCF7_FoxA1_E2                        -0.0205208  0.0953446  -0.215
## MCF7_AP2g_veh                         0.0415445  0.0759843   0.547
## MCF7_AP2g_veh2                        0.0553216  0.2274725   0.243
## MCF7_AP2g_E2                          0.0197627  0.0900946   0.219
## MCF7_AP2g_E2b                        -0.1487454  0.2510729  -0.592
## MCF7_TEAD4_veh                       -0.0173425  0.0722948  -0.240
## MCF7_TCF12_veh                        0.0084150  0.0712026   0.118
## MCF7_P300_veh                         0.0324118  0.0516171   0.628
## MCF7_H3K27ac_veh                      0.0196931  0.0372757   0.528
## Ishikawa_TEAD4_veh                   -0.0139188  0.0603615  -0.231
## Ishikawa_TCF12_veh                   -0.0620911  0.0545138  -1.139
## Ishikawa_P300_veh                    -0.0468861  0.0560645  -0.836
## Ishikawa_FoxM1_veh                    0.0050049  0.0379774   0.132
## Ishikawa_CEBPB_veh                    0.0213810  0.0306297   0.698
## Ishikawa_H3K27ac_veh                 -0.0210718  0.0229861  -0.917
## ERE_motif.total.                      0.0011219  0.0198377   0.057
## Fox_motif.total.                      0.0105198  0.0209760   0.502
## AP2_motif.total.                     -0.0002350  0.0172643  -0.014
## TEAD_motif.total.                     0.0005493  0.0134460   0.041
## TCF_motif.total.                      0.0064602  0.0100552   0.642
## CEBP_motif.total.                     0.0085591  0.0167558   0.511
## MCF7_ER_veh:MCF7_ER_E2                0.0207265  0.3472578   0.060
## MCF7_ER_veh:MCF7_FoxA1_E2            -0.1034627  0.6956808  -0.149
## MCF7_FoxA1_veh:MCF7_FoxA1_E2          0.0399019  0.9490079   0.042
## Ishikawa_TCF12_veh:Ishikawa_P300_veh  0.1126627  0.0542089   2.078
##                                      Pr(>|t|)   
## (Intercept)                           0.00291 **
## MCF7_ER_veh                           0.86607   
## MCF7_ER_E2                            0.70647   
## MCF7_FoxA1_veh                        0.70989   
## MCF7_FoxA1_veh2                       0.92848   
## MCF7_FoxA1_E2                         0.82965   
## MCF7_AP2g_veh                         0.58471   
## MCF7_AP2g_veh2                        0.80791   
## MCF7_AP2g_E2                          0.82643   
## MCF7_AP2g_E2b                         0.55373   
## MCF7_TEAD4_veh                        0.81048   
## MCF7_TCF12_veh                        0.90595   
## MCF7_P300_veh                         0.53023   
## MCF7_H3K27ac_veh                      0.59743   
## Ishikawa_TEAD4_veh                    0.81769   
## Ishikawa_TCF12_veh                    0.25505   
## Ishikawa_P300_veh                     0.40325   
## Ishikawa_FoxM1_veh                    0.89519   
## Ishikawa_CEBPB_veh                    0.48536   
## Ishikawa_H3K27ac_veh                  0.35957   
## ERE_motif.total.                      0.95492   
## Fox_motif.total.                      0.61615   
## AP2_motif.total.                      0.98915   
## TEAD_motif.total.                     0.96742   
## TCF_motif.total.                      0.52075   
## CEBP_motif.total.                     0.60963   
## MCF7_ER_veh:MCF7_ER_E2                0.95242   
## MCF7_ER_veh:MCF7_FoxA1_E2             0.88181   
## MCF7_FoxA1_veh:MCF7_FoxA1_E2          0.96647   
## Ishikawa_TCF12_veh:Ishikawa_P300_veh  0.03801 * 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.03905 on 784 degrees of freedom
## Multiple R-squared:  0.04047,    Adjusted R-squared:  0.004972 
## F-statistic:  1.14 on 29 and 784 DF,  p-value: 0.2802

Model 3

foldchange_model3 <- lm(Fold.Change.MCF7.Ishikawa ~ MCF7_ER_veh + MCF7_ER_E2 + MCF7_FoxA1_veh + MCF7_FoxA1_veh2 + MCF7_FoxA1_E2 + MCF7_AP2g_veh + MCF7_AP2g_veh2 + MCF7_AP2g_E2 + MCF7_AP2g_E2b + MCF7_TEAD4_veh + MCF7_TCF12_veh + MCF7_P300_veh + MCF7_H3K27ac_veh +  MCF7_ER_E2*MCF7_ER_veh + MCF7_FoxA1_E2*MCF7_ER_veh + MCF7_FoxA1_E2*MCF7_FoxA1_veh + Ishikawa_TEAD4_veh + Ishikawa_TCF12_veh +Ishikawa_P300_veh*Ishikawa_TCF12_veh + Ishikawa_FoxM1_veh + Ishikawa_CEBPB_veh + Ishikawa_P300_veh + Ishikawa_H3K27ac_veh + Fox_motif.total.,  data = lm_rpkm2_n)
foldchange_model
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ ., data = lm_rpkm2_n)
## 
## Coefficients:
##          (Intercept)           MCF7_ER_veh            MCF7_ER_E2  
##            0.0070849            -0.0051824            -0.0158358  
##       MCF7_FoxA1_veh         MCF7_FoxA1_E2         MCF7_AP2g_veh  
##            0.0463409            -0.0309478             0.0358553  
##         MCF7_AP2g_E2        MCF7_TEAD4_veh        MCF7_TCF12_veh  
##           -0.0208824            -0.0077336             0.0169270  
##        MCF7_P300_veh      MCF7_H3K27ac_veh    Ishikawa_TEAD4_veh  
##            0.0286557             0.0265647            -0.0105124  
##   Ishikawa_TCF12_veh    Ishikawa_FoxM1_veh    Ishikawa_CEBPB_veh  
##           -0.0497439             0.0051204             0.0218875  
##    Ishikawa_P300_veh  Ishikawa_H3K27ac_veh      ERE_motif.total.  
##           -0.0126960            -0.0200706            -0.0003442  
##     Fox_motif.total.      AP2_motif.total.     TEAD_motif.total.  
##            0.0073116            -0.0010414            -0.0020741  
##     TCF_motif.total.     CEBP_motif.total.  
##            0.0065529             0.0049985
summary(foldchange_model3)
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ MCF7_ER_veh + MCF7_ER_E2 + 
##     MCF7_FoxA1_veh + MCF7_FoxA1_veh2 + MCF7_FoxA1_E2 + MCF7_AP2g_veh + 
##     MCF7_AP2g_veh2 + MCF7_AP2g_E2 + MCF7_AP2g_E2b + MCF7_TEAD4_veh + 
##     MCF7_TCF12_veh + MCF7_P300_veh + MCF7_H3K27ac_veh + MCF7_ER_E2 * 
##     MCF7_ER_veh + MCF7_FoxA1_E2 * MCF7_ER_veh + MCF7_FoxA1_E2 * 
##     MCF7_FoxA1_veh + Ishikawa_TEAD4_veh + Ishikawa_TCF12_veh + 
##     Ishikawa_P300_veh * Ishikawa_TCF12_veh + Ishikawa_FoxM1_veh + 
##     Ishikawa_CEBPB_veh + Ishikawa_P300_veh + Ishikawa_H3K27ac_veh + 
##     Fox_motif.total., data = lm_rpkm2_n)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.04579 -0.00652 -0.00213  0.00192  0.97865 
## 
## Coefficients:
##                                       Estimate Std. Error t value Pr(>|t|)
## (Intercept)                           0.009931   0.003218   3.086   0.0021
## MCF7_ER_veh                           0.017696   0.082925   0.213   0.8311
## MCF7_ER_E2                           -0.029268   0.085446  -0.343   0.7320
## MCF7_FoxA1_veh                        0.031818   0.079282   0.401   0.6883
## MCF7_FoxA1_veh2                       0.043253   0.662078   0.065   0.9479
## MCF7_FoxA1_E2                        -0.026021   0.094378  -0.276   0.7828
## MCF7_AP2g_veh                         0.039586   0.074670   0.530   0.5962
## MCF7_AP2g_veh2                        0.057539   0.222160   0.259   0.7957
## MCF7_AP2g_E2                          0.021213   0.088728   0.239   0.8111
## MCF7_AP2g_E2b                        -0.157928   0.246266  -0.641   0.5215
## MCF7_TEAD4_veh                       -0.018673   0.071132  -0.263   0.7930
## MCF7_TCF12_veh                        0.006860   0.070338   0.098   0.9223
## MCF7_P300_veh                         0.035225   0.049654   0.709   0.4783
## MCF7_H3K27ac_veh                      0.020129   0.036990   0.544   0.5865
## Ishikawa_TEAD4_veh                   -0.010889   0.059937  -0.182   0.8559
## Ishikawa_TCF12_veh                   -0.063861   0.054281  -1.176   0.2398
## Ishikawa_P300_veh                    -0.046562   0.055368  -0.841   0.4006
## Ishikawa_FoxM1_veh                    0.006530   0.037478   0.174   0.8617
## Ishikawa_CEBPB_veh                    0.022259   0.029835   0.746   0.4559
## Ishikawa_H3K27ac_veh                 -0.020998   0.022823  -0.920   0.3578
## Fox_motif.total.                      0.010873   0.020854   0.521   0.6022
## MCF7_ER_veh:MCF7_ER_E2                0.016146   0.343470   0.047   0.9625
## MCF7_ER_veh:MCF7_FoxA1_E2            -0.092300   0.690408  -0.134   0.8937
## MCF7_FoxA1_veh:MCF7_FoxA1_E2          0.059938   0.944407   0.063   0.9494
## Ishikawa_TCF12_veh:Ishikawa_P300_veh  0.110429   0.053449   2.066   0.0391
##                                        
## (Intercept)                          **
## MCF7_ER_veh                            
## MCF7_ER_E2                             
## MCF7_FoxA1_veh                         
## MCF7_FoxA1_veh2                        
## MCF7_FoxA1_E2                          
## MCF7_AP2g_veh                          
## MCF7_AP2g_veh2                         
## MCF7_AP2g_E2                           
## MCF7_AP2g_E2b                          
## MCF7_TEAD4_veh                         
## MCF7_TCF12_veh                         
## MCF7_P300_veh                          
## MCF7_H3K27ac_veh                       
## Ishikawa_TEAD4_veh                     
## Ishikawa_TCF12_veh                     
## Ishikawa_P300_veh                      
## Ishikawa_FoxM1_veh                     
## Ishikawa_CEBPB_veh                     
## Ishikawa_H3K27ac_veh                   
## Fox_motif.total.                       
## MCF7_ER_veh:MCF7_ER_E2                 
## MCF7_ER_veh:MCF7_FoxA1_E2              
## MCF7_FoxA1_veh:MCF7_FoxA1_E2           
## Ishikawa_TCF12_veh:Ishikawa_P300_veh * 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.03894 on 789 degrees of freedom
## Multiple R-squared:  0.03964,    Adjusted R-squared:  0.01042 
## F-statistic: 1.357 on 24 and 789 DF,  p-value: 0.1185

Model 4

foldchange_model4 <- lm(Fold.Change.MCF7.Ishikawa ~ MCF7_ER_veh + MCF7_ER_E2,  data = lm_rpkm2_n)
foldchange_model
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ ., data = lm_rpkm2_n)
## 
## Coefficients:
##          (Intercept)           MCF7_ER_veh            MCF7_ER_E2  
##            0.0070849            -0.0051824            -0.0158358  
##       MCF7_FoxA1_veh         MCF7_FoxA1_E2         MCF7_AP2g_veh  
##            0.0463409            -0.0309478             0.0358553  
##         MCF7_AP2g_E2        MCF7_TEAD4_veh        MCF7_TCF12_veh  
##           -0.0208824            -0.0077336             0.0169270  
##        MCF7_P300_veh      MCF7_H3K27ac_veh    Ishikawa_TEAD4_veh  
##            0.0286557             0.0265647            -0.0105124  
##   Ishikawa_TCF12_veh    Ishikawa_FoxM1_veh    Ishikawa_CEBPB_veh  
##           -0.0497439             0.0051204             0.0218875  
##    Ishikawa_P300_veh  Ishikawa_H3K27ac_veh      ERE_motif.total.  
##           -0.0126960            -0.0200706            -0.0003442  
##     Fox_motif.total.      AP2_motif.total.     TEAD_motif.total.  
##            0.0073116            -0.0010414            -0.0020741  
##     TCF_motif.total.     CEBP_motif.total.  
##            0.0065529             0.0049985
summary(foldchange_model4)
## 
## Call:
## lm(formula = Fold.Change.MCF7.Ishikawa ~ MCF7_ER_veh + MCF7_ER_E2, 
##     data = lm_rpkm2_n)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.01575 -0.00394 -0.00281 -0.00197  0.99623 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)
## (Intercept)  0.002296   0.001928   1.191    0.234
## MCF7_ER_veh  0.058901   0.060636   0.971    0.332
## MCF7_ER_E2  -0.045391   0.059280  -0.766    0.444
## 
## Residual standard error: 0.03915 on 811 degrees of freedom
## Multiple R-squared:  0.002196,   Adjusted R-squared:  -0.0002642 
## F-statistic: 0.8926 on 2 and 811 DF,  p-value: 0.41

Conclusion