Nanopore sequencing detects structural variants in cancer

Area of Science:

• Genomics
• Cancer Research
• Bioinformatics

Background:

• Short-read sequencing limits reliable detection of structural variants (SVs) due to read length and alignment ambiguities.
• Structural variants are crucial in cancer development, affecting tumor suppressor genes like CDKN2A/p16 and SMAD4/DPC4.

Purpose of the Study:

• To evaluate the utility of third-generation nanopore sequencing for detecting structural variants (SVs) in cancer.
• To assess the sensitivity and efficiency of long-read nanopore sequencing for identifying specific cancer-associated SVs.

Main Methods:

• Utilized MinION nanopore sequencing (long reads up to 20 kb) for SV detection.
• Tested the method on well-characterized SVs, including deletions, inversions, and translocations, in pancreatic cancer cell lines.
• Employed PCR amplicon mixes to determine detection limits.

Main Results:

• Nanopore sequencing's long reads facilitate SV detection, overcoming limitations of short-read technologies.
• Successfully detected large deletions, inversions, and translocations at dilutions as low as 1:100 with minimal reads.
• Demonstrated high sensitivity for detecting cancer-associated SVs, even at low levels.

Conclusions:

• Nanopore sequencing is a viable tool for sensitive structural variant detection in cancer.
• Its speed, portability, and low cost make it suitable for molecular relapse detection, early cancer diagnosis, and therapeutic monitoring.
• Long-read sequencing significantly enhances the ability to identify complex genomic alterations in cancer.