The macro-evolutionary events in esophageal squamous cell carcinoma

Area of Science:

• Genomic instability and cancer evolution
• Molecular oncology and tumor progression

Background:

• Understanding cancer genome evolution is crucial for predicting clinical outcomes and drug resistance.
• Limited studies have focused on macro-evolutionary events and genomic signatures in esophageal squamous cell carcinoma (ESCC).

Purpose of the Study:

• To investigate the underlying evolutionary characteristics of ESCC by integrating published genomic sequencing data.
• To elucidate the roles of polyploidy, whole genome doubling, loss of heterozygosity, and telomere-bounded copy number alterations in ESCC tumorigenesis.

Main Methods:

• Integration and analysis of published genomic sequencing data from ESCC.
• Investigation of polyploidy, whole genome doubling, loss of heterozygosity, and copy number alterations.
• Confirmation of telomere-bounded amplifications in a Japanese ESCC cohort.

Main Results:

• Most ESCC genomes are polyploid with high genomic instability; whole genome doubling is often a late event.
• Loss of heterozygosity frequently occurs on chromosomes with tumor suppressor genes; 40% of neutral LOH events suggest alternative formation mechanisms.
• Telomere-bounded copy number alterations are critical for oncogene/suppressor gene amplification/deletion, notably for SOX2, PIK3CA, and TERT.

Conclusions:

• ESCC evolution is characterized by punctuated karyotype changes and macro-evolutionary events.
• Whole genome doubling, neutral loss of heterozygosity, and telomere-bounded copy number alterations play significant biological roles in ESCC development.
• These findings provide insights into ESCC tumorigenesis and potential therapeutic targets.