Low-pass whole genome sequencing of circulating tumor cells to evaluate chromosomal instability in triple-negative breast cancer.

Journal: Scientific reports
PMID:

Abstract

Chromosomal Instability (CIN) is a common and evolving feature in breast cancer. Large-scale Transitions (LSTs), defined as chromosomal breakages leading to gains or losses of at least 10 Mb, have recently emerged as a metric of CIN due to their standardized definition across platforms. Herein, we report the feasibility of using low-pass Whole Genome Sequencing to assess LSTs, copy number alterations (CNAs) and their relationship in individual circulating tumor cells (CTCs) of triple-negative breast cancer (TNBC) patients. Initial assessment of LSTs in breast cancer cell lines consistently showed wide-ranging values (median 22, range 4-33, mean 21), indicating heterogeneous CIN. Subsequent analysis of CTCs revealed LST values (median 3, range 0-18, mean 5), particularly low during treatment, suggesting temporal changes in CIN levels. CNAs averaged 30 (range 5-49), with loss being predominant. As expected, CTCs with higher LSTs values exhibited increased CNAs. A CNA-based classifier of individual patient-derived CTCs, developed using machine learning, identified genes associated with both DNA proliferation and repair, such as RB1, MYC, and EXO1, as significant predictors of CIN. The model demonstrated a high predictive accuracy with an Area Under the Curve (AUC) of 0.89. Overall, these findings suggest that sequencing CTCs holds the potential to facilitate CIN evaluation and provide insights into its dynamic nature over time, with potential implications for monitoring TNBC progression through iterative assessments.

Authors

  • Serena Di Cosimo
    Department of Advanced Diagnostics, Fondazione IRCCS Istituto Nazionale Dei Tumori Di Milano, Via Venezian 1, 20100, Milan, Italy.
  • Marco Silvestri
    Department of Advanced Diagnostics, Fondazione IRCCS Istituto Nazionale Dei Tumori Di Milano, Via Venezian 1, 20100, Milan, Italy. marco.silvestri@istitutotumori.mi.it.
  • Cinzia De Marco
    Department of Advanced Diagnostics, Fondazione IRCCS Istituto Nazionale Dei Tumori Di Milano, Via Venezian 1, 20100, Milan, Italy.
  • Alessia Calzoni
    Isinnova S.R.L, Brescia, Italy.
  • Maria Carmen De Santis
    Dept of Radiation Oncology 1, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
  • Maria Grazia Carnevale
    Department of Radiation Oncology, Fondazione IRCCS Istituto Nazionale Dei Tumori Di Milano, Milan, Italy.
  • Carolina Reduzzi
    Division of Hematology-Oncology, Weill Cornell Medicine, New York, NY, USA.
  • Massimo Cristofanilli
    Division of Hematology-Oncology, Weill Cornell Medicine, New York, NY, USA.
  • Vera Cappelletti
    Department of Advanced Diagnostics, Fondazione IRCCS Istituto Nazionale Dei Tumori Di Milano, Via Venezian 1, 20100, Milan, Italy.