####Run through this example and try to understand what is going on with the data
####So, lets load RMarkdown
library(rmarkdown)
knitr::opts_chunk$set(echo = TRUE, message=FALSE,warning=FALSE,collapse = TRUE)
library(reshape2)
library(ggplot2)
library(dplyr)
library(plotly)
library(viridis)
library(data.table)
library(pheatmap)
library(tidyverse)
library(ggthemes)
library(clipr)
library(tidyr)
library(Rcpp)
mycolors<-c(viridis(15))
felix_cols<-mycolors[c(5,2)]
felix_4cols<-mycolors[c(15,10,8,2)]
plain_cols1<-c("blue","gray")
plain_cols2<-c("red","gray")
pats_cols<-colorRampPalette(c("#FDE725FF", "white","#440154FF"))(21)
leos_cols<-colorRampPalette(c("white","blue"))(10)
## load the dataset
read_csv("breast_cancer_cells.csv")
## # A tibble: 5,144 × 17
## Gene_Symbol Description Peptides MCF10A_1 MCF10A_2 MCF7_1 MCF7_2 MDA231_1
## <chr> <chr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 NES Nestin OS=Homo… 7 9.54 4.58 5.07 5.42 25.4
## 2 ZC3HC1 Isoform 2 of N… 2 14 11.6 6.49 6.64 9.8
## 3 CAMSAP1L1 Isoform 2 of C… 5 10.2 8.29 11.6 10.8 12.5
## 4 COBRA1 Negative elong… 3 9 6.35 13.4 14.8 14.9
## 5 HAUS6 Isoform 3 of H… 5 8.21 4.44 12.1 9.82 16.5
## 6 CHCHD4 Isoform 2 of M… 5 12.5 15.8 8.05 8.38 6.78
## 7 DHX30 Isoform 2 of P… 17 12.6 8.18 9.51 9.76 12.7
## 8 SLC12A2 Isoform 2 of S… 15 6.33 4.21 11.3 11.5 3.03
## 9 PTPRJ Receptor-type … 5 9.7 6.2 4.58 4.94 25.7
## 10 ATP6AP2 Renin receptor… 8 9.02 5.69 14.5 15.2 7.25
## # ℹ 5,134 more rows
## # ℹ 9 more variables: MDA231_2 <dbl>, MDA468_1 <dbl>, MDA468_2 <dbl>,
## # SKBR3_1 <dbl>, SKBR3_2 <dbl>, pvalue_MCF7_vs_MCF10A <dbl>,
## # pvalue_MDA231_vs_MCF10A <dbl>, pvalue_MDA468_vs_MCF10A <dbl>,
## # pvalue_SKBR3_vs_MCF10A <dbl>
breast_cancer_data<-read_csv("breast_cancer_cells.csv")
#and then view it
view(breast_cancer_data)
## now let's visualize the dataset and look for initial trends. We can do this by making a matrix so and then a heatmap to visualize the data
BC_data<-breast_cancer_data %>%
mutate(log_MCF10A=log2((MCF10A_1)/(MCF10A_2)),
log_MCF7=log2((MCF7_1)/(MCF7_2)),
log_MDA231=log2((MDA231_1)/(MDA231_2)),
log_MDA468=log2((MDA468_1)/(MDA468_2)),
log_SKBR3=log2((SKBR3_1)/(SKBR3_2)))
view(BC_data)
#make a matrix of just raw the data
BC_data_mat1<-BC_data %>%
select(log_MCF10A:log_SKBR3) %>%
as.matrix() %>%
round(.,2)
# what does that look like?
head(BC_data_mat1)
## log_MCF10A log_MCF7 log_MDA231 log_MDA468 log_SKBR3
## [1,] 1.06 -0.10 -0.11 0.23 0.58
## [2,] 0.27 -0.03 -0.07 -0.36 -0.20
## [3,] 0.30 0.09 0.30 0.17 -0.05
## [4,] 0.50 -0.15 0.40 -0.21 0.32
## [5,] 0.89 0.30 0.42 0.86 0.74
## [6,] -0.34 -0.06 -0.32 -0.68 -0.18
## make a heatmap from the data
pheatmap(BC_data_mat1, color=pats_cols,cellwidth = 30,cellheight = .03, cluster_cols = FALSE,cluster_rows = FALSE,legend = TRUE,fontsize = 7,scale = "column")
##INTERPRETATION##
## What can you see in this figure?
#This heat map shows differences in expression levels across various breast cancer cell lines. The color gradient indicates changes, with purple representing higher values and yellow representing lower values.
##Are the repeated measures/reps similar or different?
#The repeated measures appear to show some variation, with certain areas displaying stronger signals than others. However, there is some consistency within cell lines.
##What does this say about the precision and accuracy of them?
#The variation suggests some degree of measurement variability.
##How does the control compare to the variables?
#MCF10A is likely the control because it is a non-tumorigenic breast epithelial cell line, often used as a baseline in breast cancer studies. Compared to the cancerous cell lines (MCF7, MDA-MB-231, MDA-MB-468, and SKBR3), MCF10A shows different expression levels, suggesting significant variation between normal and malignant cells.
##Is this what you might expect? Why? What would you look for in the literature to support this idea?
#Yes, because cancer cell lines typically exhibit distinct gene expression profiles compared to normal cells. To support this, I would look for studies comparing gene expression in normal vs. malignant breast cells, particularly focusing on different expressed genes and pathways involved in cancer progression.
#looks like MCF10A line is different than the other cells lines. We will take a closer look at that in the next section, once we've done some further data manipulations
## first, make new columns that combine the two reps for each variable by averaging them
BC_data<-BC_data %>%
mutate(ave_MCF10A=rowMeans(select(.,MCF10A_1, MCF10A_2)),ave_MCF7=rowMeans(select(.,MCF7_1,MCF7_2)),ave_MDA231=rowMeans(select(.,MDA231_1,MDA231_2)),ave_MDA468=rowMeans(select(.,MDA468_1,MDA468_2)),ave_SKBR3=rowMeans(select(.,SKBR3_1,SKBR3_2)))
#did it create your new columns?
#YES
## then make some new columns that store the log ratios of the variable means you just created, as compared to the control
BC_data <- BC_data %>%
mutate(log2_MCF7 = log2(ave_MCF7 / ave_MCF10A),log2_MDA231 = log2(ave_MDA231 / ave_MCF10A),log2_MDA468 = log2(ave_MDA468 / ave_MCF10A),log2_SKBR3 = log2(ave_SKBR3 / ave_MCF10A))
#did it create your new columns?
#YES
## ALTERNATIVE CHOICE: make a matrix of just log values the data and a heat map of that. How do the two heat maps compare? This is not possible if your values contain 0's
BC_data_mat2 <- BC_data %>%
select(starts_with("log2_")) %>%
as.matrix() %>%
round(., 2)
pheatmap(BC_data_mat2, color=pats_cols, cellwidth=30, cellheight=0.03,
cluster_cols=FALSE, cluster_rows=FALSE, legend=TRUE,
fontsize=7, scale="column")
##BASIC VOLCANO PLOT
## Add a column that stores the negative log of the pvalue of interest (in this case, MDA231)
BC_data <- BC_data %>%
mutate(neg_log10_pval = -log10(pvalue_MDA231_vs_MCF10A))
## Use ggplot to plot the log ratio of MDA231 against the -log p-value MDA231_vs_MCF10A
volcano_plot <- BC_data %>%
ggplot(aes(x = log2_MDA231, y = neg_log10_pval)) +
geom_point(alpha = 0.7, color = "royalblue")
#to view it, type:
volcano_plot
## BETTER VOLCANO PLOT
## Define the significant ones (by using ifelse and setting # parameters) so they can be colored
BC_data <- BC_data %>%
mutate(significance = ifelse(log2_MDA231 > 1.8 & neg_log10_pval > 3.0, "UP",
ifelse(log2_MDA231 < -2.0 & neg_log10_pval > 3.0, "DOWN", "NOT SIG")))
## Some standard colors
volcano_colors <- c("UP" = "red", "DOWN" = "blue", "NOT SIG" = "gray")
## volcano plot as before with some added things
better_volcano_plot <- BC_data %>%
ggplot(aes(x = log2_MDA231, y = neg_log10_pval, color = significance,text = Gene_Symbol)) +
geom_point(alpha = 0.7) + # Add points with transparency
scale_color_manual(values = volcano_colors) + # Apply custom colors
xlim(-6, 6) + # Set X-axis limits
theme_bw() + # Use a clean theme
theme(axis.text = element_text(colour = "black", size = 14), # Improve text visibility
text = element_text(size = 14)) +
labs(x = "Log2 Fold Change (MDA231 vs MCF10A)",
y = "-log10(p-value)",
title = "Improved Volcano Plot for Breast Cancer Data")
#to view it, type
better_volcano_plot
#check viewer and / or plots to see it
## use ggplotly to see hover over the points to see the gene names. Record these for the next step
ggplotly(better_volcano_plot)
##INTERPRETATION##
## Significant up regulated are: ACSS3, PNPLA2, and PMM1
## Significant down regulated are:ADCK3, SPNS1, and HIST1H1A
#Why? How?
# Log2 Fold Change (LFC) > 2.0 or < -2.0 = Strong expression changes
# -log10(p-value) > 3.0 → Statistically significant
# Make a pivot longer table of the Breast cancer data for MCF10A_1:SKBR3_2
BC_long<-pivot_longer(BC_data, cols = c(MCF10A_1:SKBR3_2), names_to = 'variable')%>% select(-c(pvalue_MCF7_vs_MCF10A:significance))
head(BC_long)
## # A tibble: 6 × 5
## Gene_Symbol Description Peptides variable value
## <chr> <chr> <dbl> <chr> <dbl>
## 1 NES Nestin OS=Homo sapiens GN=NES PE=1 SV=2 7 MCF10A_1 9.54
## 2 NES Nestin OS=Homo sapiens GN=NES PE=1 SV=2 7 MCF10A_2 4.58
## 3 NES Nestin OS=Homo sapiens GN=NES PE=1 SV=2 7 MCF7_1 5.07
## 4 NES Nestin OS=Homo sapiens GN=NES PE=1 SV=2 7 MCF7_2 5.42
## 5 NES Nestin OS=Homo sapiens GN=NES PE=1 SV=2 7 MDA231_1 25.4
## 6 NES Nestin OS=Homo sapiens GN=NES PE=1 SV=2 7 MDA231_2 27.4
## based on the gene symbols from plotly, select a few proteins from the table. Select just the data and gene symbols and pivot longer
Examples_Down<-BC_long %>% filter(Gene_Symbol=="ADCK3" | Gene_Symbol=="SPNS1" | Gene_Symbol=="HIST1H1A")
head(Examples_Down)
## # A tibble: 6 × 5
## Gene_Symbol Description Peptides variable value
## <chr> <chr> <dbl> <chr> <dbl>
## 1 SPNS1 Isoform 2 of Protein spinster homolog 1 O… 1 MCF10A_1 14.2
## 2 SPNS1 Isoform 2 of Protein spinster homolog 1 O… 1 MCF10A_2 14.0
## 3 SPNS1 Isoform 2 of Protein spinster homolog 1 O… 1 MCF7_1 10.8
## 4 SPNS1 Isoform 2 of Protein spinster homolog 1 O… 1 MCF7_2 13.6
## 5 SPNS1 Isoform 2 of Protein spinster homolog 1 O… 1 MDA231_1 3.03
## 6 SPNS1 Isoform 2 of Protein spinster homolog 1 O… 1 MDA231_2 3.13
## make barplots facetted by Gene Symbol (when working with other data sets - change x=order to x = variable)
Example_plot_down <- Examples_Down %>%
ggplot(aes(x=factor(variable, levels=c('MCF10A_1','MCF10A_2','MCF7_1','MCF7_2','MDA231_1','MDA231_2','MDA468_1','MDA468_2','SKBR3_1','SKBR3_2')),
y=value)) +
geom_bar(stat="identity", fill="red") +
facet_wrap(~Gene_Symbol) +
theme_bw() +
theme(axis.text = element_text(colour = "black", size=10)) +
theme(text = element_text(size=14)) +
theme(axis.text.x = element_text(angle=45, hjust=1)) +
labs(x="Sample", y="Relative Intensity")
#check viewer and / or plots to see it
Example_plot_down
##INTERPRETATION## ## What can you see in this figure? are the repeated measures/reps similar or different? What does this say about the precision and accuracy of them? The figure presents relative intensity values for three downregulated genes (ADCK3, HIST1H1A, and SPNS1) across different breast cancer cell lines and the control (MCF10A). The repeated measures generally appear consistent, suggesting good precision. However, slight variations exist, which may indicate minor experimental variability. ##How does the control compare to the variables? Is this what you might expect? Why? What would you look for in the literature to support this idea? The control (MCF10A) generally exhibits higher relative intensity levels than the cancer cell lines, consistent with the expectation that these genes are downregulated in breast cancer. To support this, I would look for literature discussing the role of these genes in tumor suppression or cancer progression and their expression levels in normal vs. cancerous breast tissues.
## Same process for the upregulated ones
Examples_Up<-BC_long %>% filter(Gene_Symbol=="ACSS3" | Gene_Symbol=="PNPLA2" | Gene_Symbol=="PMM1")
head(Examples_Up)
## # A tibble: 6 × 5
## Gene_Symbol Description Peptides variable value
## <chr> <chr> <dbl> <chr> <dbl>
## 1 PMM1 Phosphomannomutase 1 OS=Homo sapiens GN=P… 1 MCF10A_1 3.34
## 2 PMM1 Phosphomannomutase 1 OS=Homo sapiens GN=P… 1 MCF10A_2 3.53
## 3 PMM1 Phosphomannomutase 1 OS=Homo sapiens GN=P… 1 MCF7_1 13.0
## 4 PMM1 Phosphomannomutase 1 OS=Homo sapiens GN=P… 1 MCF7_2 9.66
## 5 PMM1 Phosphomannomutase 1 OS=Homo sapiens GN=P… 1 MDA231_1 12.5
## 6 PMM1 Phosphomannomutase 1 OS=Homo sapiens GN=P… 1 MDA231_2 12.0
Example_plot_up<-Examples_Up %>% ggplot(aes(x=factor(variable,levels=c('MCF10A_1','MCF10A_2','MCF7_1','MCF7_2','MDA231_1','MDA231_2','MDA468_1','MDA468_2','SKBR3_1','SKBR3_2')),y=value))+
geom_bar(stat="identity",fill="royalblue")+
facet_wrap(~Gene_Symbol)+
theme_bw()+
theme(axis.text = element_text(colour = "black",size=10))+
theme(text = element_text(size=14))+
theme(axis.text.x = element_text(angle=45, hjust=1))+
labs(x="sample",y="relative intensity")
#check viewer and / or plots to see it
Example_plot_up
##INTERPRETATION## ## What can you see in this figure? are the repeated measures/reps similar or different? What does this say about the precision and accuracy of them? This figure shows relative intensity values for three upregulated genes (ACSS3, PMM1, and PNPLA2) across breast cancer cell lines and the control (MCF10A). The repeated measures appear fairly consistent, indicating good precision, though some variability is present.
##How does the control compare to the variables? Is this what you
might expect? Why? What would you look for in the literature to support
this idea?
The cancer cell lines generally show higher expression levels compared
to the control, aligning with the expectation that these genes are
upregulated in breast cancer. To support this, I would look for
literature discussing their potential roles in cancer metabolism,
proliferation, or survival advantages in breast cancer cells.
#interpretation HINT:insert a chunk and create two seprate lines of code that filter for your specific upregulated genes/proteins of interest and selects for only their gene symbols and descriptions. Do this for the downregulated as well. This will generate two list of the descriptors for each gene of interest, helping you understand your figures. Be sure to view it, not just ask for the head of the table generated.
Upregulated_Genes <- BC_data %>%
filter(Gene_Symbol %in% c("ACSS3","PMM1","PNPLA2")) %>%
select(Gene_Symbol, Description)
Downregulated_Genes <- BC_data %>%
filter(Gene_Symbol %in% c("ADCK3", "SPNS1", "HIST1H1A")) %>%
select(Gene_Symbol, Description)
##now you can knit this and publish to save and share your code. Use this to work with either the brain or breast cells and the Part_C_template to complete your lab 6 ELN. ##Annotate when you have trouble and reference which line of code you need help on ## good luck and have fun!