Detection of differentially expressed genes in primary tumor tissues using representational differences analysis...

Area of Science:

• Molecular Biology
• Genomics
• Cancer Research

Background:

• Identifying differential gene expression is crucial in biological research.
• Comparing Ewing's sarcoma tissues with distinct clinical behaviors is important for understanding disease progression.

Purpose of the Study:

• To demonstrate the coupling of representational difference analysis (RDA) with microarray analysis for high-throughput screening.
• To identify differentially expressed genes between metastatic and localized Ewing's sarcoma tissues.

Main Methods:

• Utilized a modified representational difference analysis (RDA) protocol with reduced starting material.
• Shotgun cloned RDA output into a plasmid vector, creating a subtracted library.
• Amplified inserts and arrayed them on glass slides for microarray analysis.
• Hybridized arrays with differentially labeled amplicons and measured fluorescent signals.

Main Results:

• The fluorescent signal intensity correlated well with fragment abundance in RDA amplicons and starting mRNA.
• Analyzed 192 products, with 173 (90%) showing >2-fold differential expression.
• Identified 50 unique, differentially expressed clones.

Conclusions:

• Representational difference analysis (RDA) effectively generates an enriched library of differentially expressed genes.
• Microarray analysis enables rapid and reproducible screening of thousands of DNA molecules simultaneously.
• The combined approach yields a substantial pool of differentially expressed genes for further study.