Related Experiment Video
Updated: May 6, 2026

Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
EXPANDS: expanding ploidy and allele frequency on nested subpopulations
Noemi Andor1, Julie V Harness, Sabine Müller
1Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA, Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany, Brain Tumor Research Center, University of California San Francisco, San Francisco, CA 94158, USA, Department of Neurology, University of California San Francisco, San Francisco, CA 94143, USA, Department of Pediatrics, University of California San Francisco, San Francisco, CA 94143, USA, Chair of Genome Oriented Bioinformatics, Center of Life and Food Science, Freising-Weihenstephan, Technische Universität München, 80333, Munich, Germany, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94158 and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA.
EXPANDS is a new bioinformatic tool that predicts tumor purity and subclonal composition from sequencing data. This method helps understand cancer evolution and recurrence by analyzing distinct cell subpopulations.
Area of Science:
- Bioinformatics
- Computational Biology
- Cancer Genomics
Background:
- Intra-tumoral heterogeneity arises from distinct cancer cell subpopulations.
- Clonal evolution model explains subpopulation expansion via advantageous mutations.
- Unequal therapy response of subpopulations may drive cancer recurrence.
Purpose of the Study:
- To develop a computational method for analyzing cellular subpopulation dynamics in human tumors.
- To infer tumor evolution and identify genetic drivers of cancer recurrence.
Main Methods:
- Developed EXPANDS, a bioinformatic method to estimate mutation proportions within tumor cell populations.
- Modeled cellular frequencies as probability distributions to predict mutation accumulation during clonal expansion.
- Applied EXPANDS to breast cancer whole genome data and glioblastoma multiforme samples from TCGA.
Main Results:
- EXPANDS accurately predicts tumor purity and subclonal composition from sequencing data.
- Analysis revealed significant subclonal diversity in primary glioblastoma.
- Identified subpopulation dynamics during tumor recurrence and candidate genes in adapted subpopulations.
Conclusions:
- EXPANDS provides a robust approach to dissecting tumor heterogeneity.
- Understanding subclonal architecture is crucial for predicting and overcoming cancer recurrence.
- The method aids in identifying molecular determinants of therapeutic resistance.
Related Concept Videos
Mutation, Gene Flow, and Genetic Drift
What is Population Genetics?
Hardy-Weinberg Principle
Formation of Species
Genetic Drift
Population Growth

