Intra-tumor heterogeneity of cancer cells and its implications for cancer treatment.
Ontology highlight
ABSTRACT:
SUBMITTER: Sun XX
PROVIDER: S-EPMC4648179 | biostudies-other | 2015 Oct
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The evolution of pediatric solid tumors is poorly understood. There is conflicting evidence of intra-tumor genetic homogeneity vs. heterogeneity (ITGH) in a small number of studies in pediatric solid tumors. A number of copy number aberrations (CNA) are proposed as prognostic biomarkers to stratify patients, for example 1q+ in Wilms tumor (WT); current clinical trials use only one sample per tumor to profile this genetic biomarker. We multisampled 20 WT cases and assessed genome-wide allele-specific CNA and loss of heterozygosity, and inferred tumor evolution, using Illumina CytoSNP12v2.1 arrays, a custom analysis pipeline, and the MEDICC algorithm. We found remarkable diversity of ITGH and evolutionary trajectories in WT. 1q+ is heterogeneous in the majority of tumors with this change, with variable evolutionary timing. We estimate that at least three samples per tumor are needed to detect >95% of cases with 1q+. In contrast, somatic 11p15 LOH is uniformly an early event in WT development. We find evidence of two separate tumor origins in unilateral disease with divergent histology, and in bilateral WT. We also show subclonal changes related to differential response to chemotherapy. Rational trial design to include biomarkers in risk stratification requires tumor multisampling and reliable delineation of ITGH and tumor evolution.
| S-EPMC4972528 | biostudies-literature
Project description:Colorectal cancer arises in part from the cumulative effects of multiple gene lesions. Recent studies in selected cancer types have revealed significant intra-tumor genetic heterogeneity and highlighted its potential role in disease progression and resistance to therapy. We hypothesized the existence of significant intra-tumor genetic heterogeneity in rectal cancers involving variations in localized somatic mutations and copy number abnormalities. Two or three spatially disparate regions from each of six rectal tumors were dissected and subjected to the next-generation whole-exome DNA sequencing, Oncoscan SNP arrays, and targeted confirmatory sequencing and analysis. The resulting data were integrated to define subclones using SciClone. Mutant-allele tumor heterogeneity (MATH) scores, mutant allele frequency correlation, and mutation percent concordance were calculated, and copy number analysis including measurement of correlation between samples was performed. Somatic mutations profiles in individual cancers were similar to prior studies, with some variants found in previously reported significantly mutated genes and many patient-specific mutations in each tumor. Significant intra-tumor heterogeneity was identified in the spatially disparate regions of individual cancers. All tumors had some heterogeneity but the degree of heterogeneity was quite variable in the samples studied. We found that 67-97% of exonic somatic mutations were shared among all regions of an individual's tumor. The SciClone computational method identified 2-8 shared and unshared subclones in the spatially disparate areas in each tumor. MATH scores ranged from 7 to 41. Allele frequency correlation scores ranged from R(2)=0.69-0.96. Measurements of correlation between samples for copy number changes varied from R(2)=0.74-0.93. All tumors had some heterogeneity, but the degree was highly variable in the samples studied. The occurrence of significant intra-tumor heterogeneity may allow selected tumors to have a genetic reservoir to draw from in their evolutionary response to therapy and other challenges.
| S-EPMC4695247 | biostudies-literature
Project description:Intra-tumor heterogeneity (ITH) is a barrier to effective therapy. However, it is largely unknown how ITH is established at the onset of tumor progression, such as in colorectal cancer (CRC). Here, we integrate single-cell RNA-seq and functional validation to show that asymmetric division of CRC stem-like cells (CCSC) is critical for early ITH establishment. We find that CCSC-derived xenografts contain seven cell subtypes, including CCSCs, that dynamically change during CRC xenograft progression. Furthermore, three of the subtypes are generated by asymmetric division of CCSCs. They are functionally distinct, and appear at the early stage of xenografts. In particular, we identify a chemoresistant and an invasive subtype, and investigate the regulators that control their generation. Finally, we show that targeting the regulators influences cell subtype composition and CRC progression. Our findings demonstrate that asymmetric division of CCSCs contributes to the early establishment of ITH. Targeting asymmetric division may alter ITH and benefit CRC therapy.
| S-SCDT-10_15252-EMBR_202256416 | biostudies-other
Project description:Preclinical in vitro models provide an essential tool to study cancer cell biology as well as aid in translational research, including drug target identification and drug discovery efforts. For any model to be clinically relevant, it needs to recapitulate the biology and cell heterogeneity of the primary tumor. We recently developed and described a conditional reprogramming (CR) cell technology that addresses many of these needs and avoids the deficiencies of most current cancer cell lines, which are usually clonal in origin. Here, we used the CR cell method to generate a collection of patient-derived cell cultures from non-small cell lung cancers (NSCLC). Whole exome sequencing and copy number variations are used for the first time to address the capability of CR cells to keep their tumor-derived heterogeneity. Our results indicated that these primary cultures largely maintained the molecular characteristics of the original tumors. Using a mutant-allele tumor heterogeneity (MATH) score, we showed that CR cells are able to keep and maintain most of the intra-tumoral heterogeneity, suggesting oligoclonality of these cultures. CR cultures therefore represent a pre-clinical lung cancer model for future basic and translational studies.
| S-EPMC5840339 | biostudies-literature
Project description:Targetted confirmatory sequencing of heterogenous variants detected by exome sequencing of spatially disparate areas from six rectal tumors
2015-09-25 | PRJEB10956 | EVA
Project description:Intra-tumor heterogeneity (ITH) is a mechanism of therapeutic resistance and therefore an important clinical challenge. However, the extent, origin, and drivers of ITH across cancer types are poorly understood. To address this, we extensively characterize ITH across whole-genome sequences of 2,658 cancer samples spanning 38 cancer types. Nearly all informative samples (95.1%) contain evidence of distinct subclonal expansions with frequent branching relationships between subclones. We observe positive selection of subclonal driver mutations across most cancer types and identify cancer type-specific subclonal patterns of driver gene mutations, fusions, structural variants, and copy number alterations as well as dynamic changes in mutational processes between subclonal expansions. Our results underline the importance of ITH and its drivers in tumor evolution and provide a pan-cancer resource of comprehensively annotated subclonal events from whole-genome sequencing data.
| S-EPMC8054914 | biostudies-literature
Project description:Background: A feature of glioblastoma (GBM) is the cellular and molecular heterogeneity, both within and between tumors. This variability results in a risk for sampling bias and potential tumor escape from future targeted therapy. Heterogeneous gene expression within GBM is well documented, but little is known regarding the epigenetic heterogeneity. We therefore aimed to profile the intra-tumor DNA methylation heterogeneity in GBM. Methods: 3-4 biopsies per tumor from spatially separated regions were collected from 12 GBM patients. We performed genome-wide DNA methylation analysis (~850,000 CpG sites) and compared inter- and intra-tumor variation. Results: All samples were classified as GBM IDH wt or IDH mutated by DNA methylation profiling, but the GBM subtype differed within five tumors. Some GBM samples exhibited higher DNA methylation differences within tumors than between, and many CpG sites (mean: 17,000) had different methylation levels within the tumors. Conclusions: We demonstrated that intra-tumor DNA methylation heterogeneity is a feature of GBM. Although all biopsies were classified as GBM IDH wt/mutated by DNA methylation analysis, the assigned subtype differed in samples from the same patient. The observed DNA methylation heterogeneity within tumors is important to consider for methylation-based biomarkers and future improvements in stratification of GBM patients.
2019-02-27 | GSE116298 | GEO
Project description:IntroductionRecent studies indicated tumors may be comprised of heterogeneous molecular subtypes and incongruent molecular portraits may emerge if different areas of the tumor are sampled. This study explored the impact of intra-tumoral heterogeneity in terms of activation/phosphorylation of FDA approved drug targets and downstream kinase substrates.Material and methodsTwo independent sets of liver metastases from colorectal cancer were used to evaluate protein kinase-driven signaling networks within different areas using laser capture microdissection and reverse phase protein array.ResultsUnsupervised hierarchical clustering analysis indicated that the signaling architecture and activation of the MAPK and AKT-mTOR pathways were consistently maintained within different regions of the same biopsy. Intra-patient variability of the MAPK and AKT-mTOR pathway were <1.06 fold change, while inter-patients variability reached fold change values of 5.01.ConclusionsProtein pathway activation mapping of enriched tumor cells obtained from different regions of the same tumor indicated consistency and robustness independent of the region sampled. This suggests a dominant protein pathway network may be activated in a high percentage of the tumor cell population. Given the genomic intra-tumoral variability, our data suggest that protein/phosphoprotein signaling measurements should be integrated with genomic analysis for precision medicine based analysis.
| S-EPMC5564706 | biostudies-literature
Project description:Colorectal cancer arises in part from the cumulative effects of multiple gene lesions. Recent studies in selected cancer types have revealed significant intra-tumor genetic heterogeneity and highlighted its potential role in disease progression and resistance to therapy. We hypothesized the existence of significant intra-tumor genetic heterogeneity in rectal cancers involving variations in localized somatic mutations and copy number abnormalities. Two or three spatially disparate areas from each of six rectal tumors were dissected and subjected to next-generation whole exome DNA sequencing, Oncoscan SNP arrays, and targeted confirmatory sequencing and analysis. The resulting data were integrated to define subclones using SciClone. Mutant-allele tumor heterogeneity (MATH) scores, mutant allele frequency correlation, and mutation percent concordance were calculated, and Copy number analysis including measurement of correlation between samples was performed. Affymetrix OncoScan V3 arrays were run on all tumor samples. The OncoScan array platform consists of a set of 217k probes designed specifically for profiling tumors. The overall resolution of the assay for detecting copy number change generates data at 50-100kb resolution across a set of 891 cancer genes, and 300-400kb across the rest of the genome. Raw array florescence intensity data generated on the Affymetrix scanners in the form of CEL files were loaded into the OncoScan Console software v.1.1.0 (Affymetrix, Santa Clara, California). Quality control statistics as well as integrated OSCHP files were generated by OncoScan Console. The standard Affymetrix reference control file for OncoScan data was used for processing the arrays.
2015-09-24 | E-GEOD-73365 | biostudies-arrayexpress
Project description:Diversity within or between a tumour and metastases, known as intra-patient tumour heterogeneity develops during disease progression, and is a serious hurdle for therapy1,2,3. Metastasis is the fatal hallmark of cancer and mechanisms of colonization, the most complex step of the metastatic cascade4,5, remain ill-defined. Better understanding of cellular and molecular processes underlying intra-patient tumour heterogeneity and metastasis are pivotal for the success of personalized cancer treatment. Here, transcriptional profiling of tumours and matched metastases showed cancer site-specific phenotypes, and identified increased glucocorticoid receptor (GR) activity in the distant metastases. GR has been shown to mediate the effects of stress hormones and of their synthetic derivatives, widely used in the clinic as anti-inflammatory and immunosuppressive.
2019-03-25 | PXD009102 | Pride