Batch-normalization of cerebellar and medulloblastoma gene expression datasets utilizing empirically defined negative control genes

Area of Science:

• Oncology
• Genomics
• Bioinformatics

Background:

• Medulloblastoma (MB) is a common pediatric brain cancer with a 70% cure rate, but survivors face significant long-term side effects.
• Molecular profiling studies in MB are often limited by small, disparate patient cohorts, hindering comprehensive analysis.
• Accurate integration of existing molecular data is crucial for improving MB treatment outcomes and minimizing adverse effects.

Purpose of the Study:

• To develop a robust methodology for integrating multiple medulloblastoma (MB) transcription datasets.
• To create a large-scale, unified dataset of MB and normal brain expression profiles.
• To enhance analytical power for future MB research, aiming to improve cure rates and reduce treatment toxicity.

Main Methods:

• Integrated 23 transcription datasets comprising 1350 MB and 291 normal brain samples.
• Employed the Removal of Unwanted Variation (RUV) method combined with a novel pipeline for empirical negative control gene identification.
• Utilized a panel of metrics to rigorously evaluate data normalization performance and batch effect removal.

Main Results:

• Successfully removed a majority of batch effects across diverse datasets.
• Generated a large-scale, integrated dataset of medulloblastoma and cerebellar expression data.
• Demonstrated a broadly applicable strategy for accurate data integration and inclusion of normal reference samples.

Conclusions:

• The developed RUV-based pipeline effectively integrates heterogeneous transcription datasets, producing a high-quality resource for medulloblastoma research.
• The integrated dataset facilitates large-scale gene expression analyses, crucial for advancing understanding and treatment of pediatric brain cancer.
• This approach offers a scalable solution for data integration in various disease research areas, paving the way for more powerful multi-cohort studies.