Despite most acute myeloid leukemia (AML) patients achieving complete remission after induction chemotherapy, two-thirds relapse within 5 years. AML follows a cellular hierarchy sustained by leukemia stem cells (LSCs), which drive tumor progression and relapse. Little is known about the genetic determinants driving LSCs stemness properties. By identifying chromatin variants from accessibility measurements across LSCs, hematopoietic stem cells and downstream progeny, we identified transposable elements (TEs) as genetic determinants of primitive versus mature populations. Accessibility at 121 TE subfamilies distinguished LSCs from mature leukemic cells and stratified AML patients by stemness and survival. Functional assays revealed that these TE subfamilies serve as docking sites for genome topology regulators or lineage-specific transcription factors, including LYL1 in LSCs. Chromatin editing established the necessity of accessibility at LTR12C elements to maintain LSC stemness. Thus, TEs regulate primitive versus mature cell states, with distinct subfamilies underlying stemness in normal versus leukemic stem cells.

Since its discovery as a causative gene of the Immunodeficiency with Centromeric instability and Facial anomalies syndrome, ZBTB24 has emerged as a key player in DNA methylation, immunity and development. By extensively analyzing ZBTB24 genomic functions in ICF-relevant mouse and human cellular models, we document here its multiple facets as a transcription factor, with key roles in immune response-related genes expression and also in early embryonic development. Using a constitutive Zbtb24 ICF-like mutant and an auxin-inducible degron system in mouse embryonic stem cells, we showed that ZBTB24 is recruited to centromeric satellite DNA where it is required to establish and maintain the correct DNA methylation patterns through the recruitment of DNMT3B. The ability of ZBTB24 to occupy centromeric satellite DNA is conserved in human cells. Together, our results unveiled an essential and underappreciated role for ZBTB24 at mouse and human centromeric satellite repeat arrays by controlling their DNA methylation and transcription status.

Identifying drivers of cancer progression to guide treatment selection is hindered by our limited understanding of tumor heterogeneity and its impact on tumor evolution. Here, we delineate the phenotypic variability across ~300,000 cells collected from multiple tumor loci in primary prostate and matched locoregional metastases using single-cell chromatin accessibility and gene expression sequencing. We find inter-patient heterogeneity to be confined to malignant populations. Within individual tumor loci, we see phenotypic heterogeneity among malignant cell populations despite a shared clonal genotypic architecture. We also observe that malignant cell populations disseminating to locoregional lymph nodes mirror the clonal architecture and phenotypic heterogeneity across primary tumor loci, while shifting from canonical prostate-cancer states to non-canonical inflammatory-like states. Our findings suggest a bottleneck imposed during the dissemination process, funneling prostate cancer cells toward an inflammatory-like cell state. These insights into the interplay between phenotypic identity and clonal architecture refine our understanding of prostate cancer progression and suggest that convergence of cancer cells towards an inflammatory-like state underlies dissemination to lymph nodes, offering a critical framework for future studies into prostate cancer metastatic potential. Understanding tumor heterogeneity and its impact on prostate cancer progression remains elusive. Here, single nucleus snATAC and snRNA sequencing of a multi-loci sampled cohort of advanced prostate cancer patients identifies an inflammatory-like state underlying metastatic dissemination to the lymph nodes.

Extrachromosomal DNAs (ecDNAs), which replicate and segregate in a non-Mendelian manner, serve as vectors for accelerated tumor evolution. By integrating chromatin accessibility, whole-genome sequencing, and Hi-C-based genome topology data from a cohort of metastatic Castration-Resistant Prostate Cancer (mCRPC) cases, we show that epigenetically activated repeat DNA, amplified in ecDNAs, drive oncogene overexpression. Specifically, we identify a subgroup of mCRPCs (20%) characterized by clusters of accessible LINE1 repeat DNA elements flanking the androgen receptor (AR) gene. These LINE1 elements are co-amplified with AR and provide binding sites for prostate-lineage transcription factors, including AR, FOXA1 and HOXB13. Accessible LINE1 elements establish novel 3D chromatin interactions with the AR gene, forging a new regulatory plexus driving AR overexpression and confers resistance to androgen signaling inhibitors. Our findings indicate how tumor evolution is driven by the convergence of genetic and epigenetic alterations on repeat DNA, activating and amplifying them to allow oncogene overexpression.

This figure showcases the entire molecular and clinical characterization of CPC-GENE and Porto patients' groups identified using transposable element families differentially enriched between pluripotent stem cells and benign prostate tissue states

List of gRNA sequences used in this article

Individual TAD calls in all 12 tumour and 5 benign samples.

Clinical information Porto patients

This figure showcases dCas9-KRAB and H3K27ac profiling in CRISPRi 22Rv1 clones #1 and #3 nucleofected with control or Tigger3a gRNA combos (clone #2 is showcased in Figure 5)

Relationship between inter-chromosomal rearrangements and differential gene expression.

SV breakpoints detected by Hi-C in each tumour sample.

Pathwyas significantly different in all three CRISPRi 22Rv1 clones (Tigger3a vs Control)

Onco-exaptated transposable elements in reprogrammed and constant PCa patients

Top 5% transcription factor cistromes enriched at reprogrammed transposable element families (CPC-GENE reprogrammed patients)

Top 5% transcription factor cistromes enriched at reprogrammed transposable element families (Porto reprogrammed patients)

This figure complements Figure 4, showcasing the enrichment of Porto AR cistromes and AR motif over reprogrammed transposable element families (with the exception of Tigger3a and L1MB4 that are showcased in Figure 4)

Structural variant detection from Hi-C data.

Simple and complex SVs reconstructed from SV breakpoints.

Supplementary methods and supplementary figure legends

Top 5% transcription factor cistromes enriched at reprogrammed transposable element families (Porto constant patients)