GENOME AMPLIFICATION TOLERANT TO SAMPLE DEGRADATION

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DESCRIPTION (provided by applicant): Genomic, epigenetic and gene expression analysis from archived formalin-fixed paraffin embedded (FFPE) tissue samples with known clinical outcomes provides a unique opportunity for extraction of genetic information leading to improved cancer diagnosis, prognosis and therapy. However, extensive genotyping or microarray profiling on homogeneous cell populations within these samples often requires whole genome/mRNA amplification prior to screening. Major hurdles to this process are the introduction of amplification bias and the inhibitory effects of formalin fixation on DNA/RNA amplification. We have developed (RCA-RCA), a novel method based on isothermal rolling-circle amplification, that overcomes the limitations and promises to provide the needed link between obtaining a minute biopsy from partially degraded, FFPE samples and genotyping or micro-array screening. RCA-RCA enables whole genome/mRNA amplification that can be adjusted to the degree of FFPE sample degradation, as this is assessed via real time PCR. Thereby RCA-RCA enables retrieval of the maximum possible amount of information from the degraded sample. In the revised application, apart from adopting the Study Section's recommendations, a further enhancement of RCA-RCA is included, mRCA-RCA. mRCA-RCA amplifies DNA while retaining epigenetic modifications on a genome-wide basis ('whole methylome amplification'), thereby allowing highly expanded detection of methylation in fresh or FFPE samples. The R21 phase will examine the maximum capabilities of the technology and establish criteria for adjusting RCA-RCA to conform to the condition of the specific FFPE sample. The R33 phase will develop the technology for obtaining minute cancer biopsies from FFPE samples, assessing sample quality, and amplifying the whole genome/methylome (DNA) or transcriptome (RNA) without introducing amplification bias. Subsequently it will establish criteria and will validate the utility of the amplified material as input for the most frequently used molecular assays (mutation/SNP detection, microsatellite instability/LOH, array-CGH, expression profiling and methylation detection). By removing problems associated with sample degradation and biases associated with amplification this project will enable application of the newest technologies to the analysis of minute biopsies from archived tissue with known outcomes, thereby accelerating the process of candidate gene discovery.