Project description:Intratumor heterogeneity is a major obstacle to effective cancer treatment. Current methods to study intratumor heterogeneity using single-cell RNA sequencing (scRNAseq) lack information on the spatial organization of cells. While state-of-the art spatial transcriptomics methods capture the spatial distribution, they either lack single cell resolution or have relatively low transcript counts. Here, we introduce spatially annotated single cell sequencing, based on the previously developed functional single cell sequencing (FUNseq) technique, to spatially profile tumor cells with deep scRNA-seq and single cell resolution. Using our approach, we profiled cells located at different distances from the center of a 2D epithelial cell mass. By profiling the cell patch in concentric bands of varying width, we showed that cells at the outermost edge of the patch responded strongest to their local microenvironment, behaved most invasively, and activated the process of epithelial-to-mesenchymal transition (EMT) to migrate to lowconfluence areas. We inferred cell-cell communication networks and demonstrated that cells in the outermost ~10 cell wide band, which we termed the invasive edge, induced similar phenotypic plasticity in neighboring regions. Applying FUNseq to spatially annotate and profile tumor cells enables deep characterization of tumor subpopulations, thereby unraveling the mechanistic basis for intratumor heterogeneity.
Project description:Ependymomas exist within distinct genetic subgroups, but the molecular diversity within individual ependymomas is unknown. We performed multiplatform molecular profiling of 6 spatially-distinct samples from an ependymoma with C11orf95-RELA fusion. DNA methylation and RNA sequencing distinguished clusters of samples according to neuronal development gene expression programs that could also be delineated by differences in magnetic resonance blood perfusion. Exome sequencing and phylogenetic analysis revealed epigenomic intratumor heterogeneity, and suggested that chromosomal structural alterations may precede accumulation of single nucleotide variants during ependymoma tumorigenesis. In sum, these findings shed new light on the oncogenesis and intratumor heterogeneity of ependymoma.
Project description:Cancer is a disease of the genome. Many genomic abnormalities have been found in a variety of cancer types, which are believed to be attributable to tumorigenesis as well as resistance to treatment and recurrence. Genomic heterogeneity in the same type of cancer or within a tumor reveals the complexity of cancer biology so that intratumor heterogeneity has become an inherent feature of cancer. In this study, we use whole-exome sequencing and array comparative genomic hybridization technology to examine the mutational profiling and copy number changes from multi-region samples within an esophageal cancer in order to understand the genomic phylogeny in the evolution of intratumor heterogeneity in esophageal cancer.
Project description:Primary lymphoma of the central nervous system (PCNSL) is a diffuse large B cell lymphoma confined to the CNS. In order to elucidate its peculiar organ tropism, we generated recombinant antibodies (recAb) identical with the BCR of a series of 23 PCNSL from immunocompetent patients. While none of the recAb showed self-reactivity upon testing with common autoantigens, they recognized 1547 proteins present on a large-scale protein microarray. Interestingly, proteins recognized by the recAb are physiologically expressed by CNS neurons (GRINL1A, centaurin-α, BAIAP2). Furthermore, 87% (20/23) of the recAb including all antibodies derived from IGHV4 34 using PCNSL recognized galectin-3, which was upregulated on microglia/macrophages, astrocytes, and cerebral endothelial cells upon CNS invasion by PCNSL. Thus, PCNSL Ig may recognize CNS proteins as self-antigens. Their interaction may contribute to BCR signaling with sustained NF-κB activation and, ultimately, may foster tumor cell proliferation and survival. These data may also explain, at least in part, the affinity of the tumor cells of PCNSL to the CNS. Recombinant antibodies (recAb) identical with the BCR of a series of 23 PCNSL from immunocompetent patients.
Project description:Primary lymphoma of the central nervous system (PCNSL) is a diffuse large B cell lymphoma confined to the CNS. In order to elucidate its peculiar organ tropism, we generated recombinant antibodies (recAb) identical with the BCR of a series of 23 PCNSL from immunocompetent patients. While none of the recAb showed self-reactivity upon testing with common autoantigens, they recognized 1547 proteins present on a large-scale protein microarray. Interestingly, proteins recognized by the recAb are physiologically expressed by CNS neurons (GRINL1A, centaurin-α, BAIAP2). Furthermore, 87% (20/23) of the recAb including all antibodies derived from IGHV4 34 using PCNSL recognized galectin-3, which was upregulated on microglia/macrophages, astrocytes, and cerebral endothelial cells upon CNS invasion by PCNSL. Thus, PCNSL Ig may recognize CNS proteins as self-antigens. Their interaction may contribute to BCR signaling with sustained NF-κB activation and, ultimately, may foster tumor cell proliferation and survival. These data may also explain, at least in part, the affinity of the tumor cells of PCNSL to the CNS.
Project description:Esophageal squamous cell carcinoma (ESCC) is among the most common malignancies, but little is known about the spatial intratumor heterogeneity (ITH) and the temporal clonal evolutionary processes in this cancer. Interestingly, the epigenetic profiling also showed strong evidence of spatial ITH, and the phyloepigenetic trees were extremely similar with the phylogenetic ones, indicating the interplay and co-dependency of genetic and epigenetic alterations in ESCC. We found that several genes were both mutated and hypermethylated at their promoters, such as ASXL1 and EPHA7. Our integrated investigations of the spatial ITH and the temporal clonal evolution might provide insights into developing biomarkers for early diagnosis of ESCC, as well as personalized therapeutic targets for treating this malignancy. DNA methylation profiles of 12 tumor regions and 2 matched normal esophageal epithelial tissues from three M-WES-examined ESCC cases (ESCC01, ESCC03 and ESCC05) were performed using Illumina Infinium HumanMethylation450K platform (Illumina, San Diego, CA) at the Epigenome Center of University of Southern California.
Project description:To explore intratumor heterogeneity in gene expression profiles from patients with cervical cancer. Experimental Design: A total of 33 biopsies were obtained from 11 patients, sampling between two and five different areas for each tumor.The extracted RNA was hybridized onto the Affymetrix U133 Plus 2.0 oligonucleotide chip. The variance of expression within a patient (W), between patients (B) and the total variance (T =W + B) were calculated for each ProbeSet, and the ratio W/T was used as a measure of intratumor heterogeneity. Gene Ontology functional analysis was done to assess the function of genes that had high W/T (top 10%) and low W/T (bottom 10%) values.