GSE76008 Processing Pipeline

GSE code_examples 1 step

Publication

The splicing factor RBM17 drives leukemic stem cell maintenance by evading nonsense-mediated decay of pro-leukemic factors.

Nature communications (2022) — PMID 35781533

Dataset

GSE76008

A 17-Gene Stemness Score for Rapid Identification of High-Risk AML Patients [Illumina]

Warning: Pipeline descriptions and code snippets may be inferred or AI-generated. Use them only as a starting point to guide analysis, and validate before use.
  1. 1

    The data were normalized with variance stabilization and quantile normalization using the lumi (v2.16.0) package in R (v3.1.0).

    $ Bash example
    # Install R (v3.1.0) if not already installed. Specific old versions of R might require manual installation or using tools like `r-env` or `conda`.
    # For example, using conda:
    # conda create -n r3.1 r-base=3.1.0 -y
    # conda activate r3.1
    
    # Install BiocManager (if not already installed)
    # R -e 'if (!requireNamespace("BiocManager", quietly = TRUE)) install.packages("BiocManager", repos="https://cran.rstudio.com")'
    
    # Install lumi package (v2.16.0) compatible with R 3.1.0 (Bioconductor 2.14)
    # R -e 'BiocManager::install("lumi", version="2.14", ask=FALSE)'
    
    # Create an R script for normalization
    cat << 'EOF' > normalize_lumi_data.R
    # Load the lumi package
    library(lumi)
    
    # --- Input data loading ---
    # This script assumes you have a LumiBatch object named 'lumi_object'
    # available in your R environment or can load it from a file.
    # Replace 'path/to/your/input_lumi_object.RData' with the actual path
    # to your LumiBatch object saved from a previous step, or
    # load raw data using lumiR() or similar.
    
    # Example: Load a pre-saved LumiBatch object
    # load("path/to/your/input_lumi_object.RData")
    # If starting from raw data, use lumiR:
    # lumi_object <- lumiR("path/to/your/raw_data.txt")
    
    # For demonstration, creating a dummy LumiBatch object if not loaded
    if (!exists("lumi_object")) {
        message("Input 'lumi_object' not found. Creating a dummy object for demonstration.")
        # Simulate expression data (e.g., 100 probes, 5 samples)
        exprs_data <- matrix(rnorm(100 * 5, mean = 1000, sd = 200), nrow = 100, ncol = 5)
        rownames(exprs_data) <- paste0("Probe", 1:100)
        colnames(exprs_data) <- paste0("Sample", 1:5)
        # Simulate pheno data
        pheno_data <- data.frame(row.names = colnames(exprs_data),
                                 Group = c("A", "A", "B", "B", "A"))
        # Create a LumiBatch object
        lumi_object <- new("LumiBatch", exprs = exprs_data, phenoData = new("AnnotatedDataFrame", data = pheno_data))
        message("Dummy LumiBatch object created.")
    }
    
    # Perform variance stabilization transformation (VST)
    # The 'lumiT' function with method="vst" performs variance stabilization.
    message("Performing variance stabilization transformation...")
    vst_lumi_object <- lumiT(lumi_object, method = "vst")
    
    # Perform quantile normalization
    # The 'lumiN' function with method="quantile" performs quantile normalization.
    message("Performing quantile normalization...")
    normalized_lumi_object <- lumiN(vst_lumi_object, method = "quantile")
    
    # --- Output data saving ---
    # Save the normalized expression matrix to a tab-separated file
    write.table(exprs(normalized_lumi_object),
                file = "normalized_expression_data.txt",
                sep = "\t", quote = FALSE, row.names = TRUE, col.names = TRUE)
    message("Normalized expression data saved to normalized_expression_data.txt")
    
    # Optionally, save the entire normalized LumiBatch object for further R analysis
    save(normalized_lumi_object, file = "normalized_lumi_object.RData")
    message("Normalized LumiBatch object saved to normalized_lumi_object.RData")
    EOF
    
    # Execute the R script using the specified R version
    # Ensure R 3.1.0 is in your PATH or specify its full path if needed.
    Rscript normalize_lumi_data.R

Tools Used

Raw Source Text
The data were normalized with variance stabilization and quantile normalization using the lumi (v2.16.0) package in R (v3.1.0).
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