Resolving the Haplotype Complexity of Colorectal Cancer Genomes with Droplet Barcode Sequencing

Area of Science:

• Genomics
• Cancer Biology
• Bioinformatics

Background:

• Precision medicine tailors cancer treatment to tumor-specific genomic alterations.
• Determining if genetic alterations impact protein function requires understanding allele-specific effects (haplotypes).
• Current sequencing technologies often struggle to resolve haplotype information for complex genomic alterations.

Purpose of the Study:

• To evaluate the utility of linked-read droplet barcode sequencing (DBS) for resolving haplotype complexity in colorectal cancer genomes.
• To characterize complex genetic variations, including structural variants and copy number alterations, in a haplotype-resolved manner.
• To assess the potential of haplotype information for informing personalized cancer treatment strategies.

Main Methods:

• Application of linked-read droplet barcode sequencing (DBS) technology.
• Analysis of paired tumor and normal colorectal cancer samples.
• Identification and phasing of short somatic variants, large structural variants, and copy number alterations within specific haplotypes.

Main Results:

• DBS successfully resolved haplotype complexity in colorectal cancer genomes.
• Multiple mutations were identified in cancer-related genes on one or both haplotypes.
• Haplotype-resolved structural variants and copy number alterations were detected and phased with short somatic variants.
• Identified variants implicated multiple oncogenic pathways.

Conclusions:

• Linked-read DBS technology is effective in characterizing complex genetic variations within a haplotype context.
• Haplotype information derived from DBS can provide essential insights for personalized cancer medicine.
• This approach has the potential to improve the interpretation of genomic alterations for clinical decision-making.