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49
result(s) for
"Hatipoglu, Emine"
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Selection of metastasis competent subclones in the tumour interior
2021
The genetic evolutionary features of solid tumour growth are becoming increasingly well described, but the spatial and physical nature of subclonal growth remains unclear. Here, we utilize 102 macroscopic whole-tumour images from clear cell renal cell carcinoma patients, with matched genetic and phenotypic data from 756 biopsies. Utilizing a digital image processing pipeline, a renal pathologist marked the boundaries between tumour and normal tissue and extracted positions of boundary line and biopsy regions to
X
and
Y
coordinates. We then integrated coordinates with genomic data to map exact spatial subclone locations, revealing how genetically distinct subclones grow and evolve spatially. We observed a phenotype of advanced and more aggressive subclonal growth in the tumour centre, characterized by an elevated burden of somatic copy number alterations and higher necrosis, proliferation rate and Fuhrman grade. Moreover, we found that metastasizing subclones preferentially originate from the tumour centre. Collectively, these observations suggest a model of accelerated evolution in the tumour interior, with harsh hypoxic environmental conditions leading to a greater opportunity for driver somatic copy number alterations to arise and expand due to selective advantage. Tumour subclone growth is predominantly spatially contiguous in nature. We found only two cases of subclone dispersal, one of which was associated with metastasis. The largest subclones spatially were dominated by driver somatic copy number alterations, suggesting that a large selective advantage can be conferred to subclones upon acquisition of these alterations. In conclusion, spatial dynamics is strongly associated with genomic alterations and plays an important role in tumour evolution.
The spatial and physical nature of tumour growth remains unclear. Combining whole-tumour images from clear cell renal cell carcinoma with genomic data, the authors show more aggressive subclonal growth and metastasizing subclones in the tumour centre.
Journal Article
Spatial patterns of tumour growth impact clonal diversification in a computational model and the TRACERx Renal study
2022
Genetic intra-tumour heterogeneity fuels clonal evolution, but our understanding of clinically relevant clonal dynamics remain limited. We investigated spatial and temporal features of clonal diversification in clear cell renal cell carcinoma through a combination of modelling and real tumour analysis. We observe that the mode of tumour growth, surface or volume, impacts the extent of subclonal diversification, enabling interpretation of clonal diversity in patient tumours. Specific patterns of proliferation and necrosis explain clonal expansion and emergence of parallel evolution and microdiversity in tumours. In silico time-course studies reveal the appearance of budding structures before detectable subclonal diversification. Intriguingly, we observe radiological evidence of budding structures in early-stage clear cell renal cell carcinoma, indicating that future clonal evolution may be predictable from imaging. Our findings offer a window into the temporal and spatial features of clinically relevant clonal evolution.
A combined modelling and tumour analysis approach is used to study the temporal and spatial patterns of subclone evolution in the TRACERx renal study. Studying the tumour shape and spatial features of clonal diversity in early-stage tumours may allow the prediction of tumour progression and patterns of subclone diversification over time.
Journal Article
Geospatial immune variability illuminates differential evolution of lung adenocarcinoma
by
Zapata, Luis
,
McGranahan, Nicholas
,
Marafioti, Teresa
in
631/250/2161
,
631/67/2329
,
631/67/580
2020
Remarkable progress in molecular analyses has improved our understanding of the evolution of cancer cells toward immune escape
1
–
5
. However, the spatial configurations of immune and stromal cells, which may shed light on the evolution of immune escape across tumor geographical locations, remain unaddressed. We integrated multiregion exome and RNA-sequencing (RNA-seq) data with spatial histology mapped by deep learning in 100 patients with non-small cell lung cancer from the TRACERx cohort
6
. Cancer subclones derived from immune cold regions were more closely related in mutation space, diversifying more recently than subclones from immune hot regions. In TRACERx and in an independent multisample cohort of 970 patients with lung adenocarcinoma, tumors with more than one immune cold region had a higher risk of relapse, independently of tumor size, stage and number of samples per patient. In lung adenocarcinoma, but not lung squamous cell carcinoma, geometrical irregularity and complexity of the cancer–stromal cell interface significantly increased in tumor regions without disruption of antigen presentation. Decreased lymphocyte accumulation in adjacent stroma was observed in tumors with low clonal neoantigen burden. Collectively, immune geospatial variability elucidates tumor ecological constraints that may shape the emergence of immune-evading subclones and aggressive clinical phenotypes.
Multiregion spatial histology, exome and transcriptome data from patients with non-small cell lung cancer suggest that cancer subclones from immune cold regions diversify later than subclones from immune hot regions
Journal Article
Interplay between whole-genome doubling and the accumulation of deleterious alterations in cancer evolution
by
Dewhurst, Sally M.
,
McGranahan, Nicholas
,
Birkbak, Nicolai J.
in
38/23
,
631/114/2785
,
631/208/212
2020
Whole-genome doubling (WGD) is a prevalent event in cancer, involving a doubling of the entire chromosome complement. However, despite its prevalence and prognostic relevance, the evolutionary selection pressures for WGD in cancer have not been investigated. Here, we combine evolutionary simulations with an analysis of cancer sequencing data to explore WGD during cancer evolution. Simulations suggest that WGD can be selected to mitigate the irreversible, ratchet-like, accumulation of deleterious somatic alterations, provided that they occur at a sufficiently high rate. Consistent with this, we observe an enrichment for WGD in tumor types with extensive loss of heterozygosity, including lung squamous cell carcinoma and triple-negative breast cancers, and we find evidence for negative selection against homozygous loss of essential genes before, but not after, WGD. Finally, we demonstrate that loss of heterozygosity and temporal dissection of mutations can be exploited to identify novel tumor suppressor genes and to obtain a deeper characterization of known cancer genes.
Analysis of whole-genome doubling (WGD) by using cancer sequencing data combined with simulations of tumor evolution suggests that there is negative selection against homozygous loss of essential genes before WGD but not after.
Journal Article
Spatial heterogeneity of the T cell receptor repertoire reflects the mutational landscape in lung cancer
by
Joshi, Kroopa
,
Turati, Virginia
,
Wilson, Gareth A.
in
631/67/580/1884/2323
,
Aged
,
Antigen receptors, T cell
2019
Somatic mutations together with immunoediting drive extensive heterogeneity within non-small-cell lung cancer (NSCLC). Herein we examine heterogeneity of the T cell antigen receptor (TCR) repertoire. The number of TCR sequences selectively expanded in tumors varies within and between tumors and correlates with the number of nonsynonymous mutations. Expanded TCRs can be subdivided into TCRs found in all tumor regions (ubiquitous) and those present in a subset of regions (regional). The number of ubiquitous and regional TCRs correlates with the number of ubiquitous and regional nonsynonymous mutations, respectively. Expanded TCRs form part of clusters of TCRs of similar sequence, suggestive of a spatially constrained antigen-driven process. CD8
+
tumor-infiltrating lymphocytes harboring ubiquitous TCRs display a dysfunctional tissue-resident phenotype. Ubiquitous TCRs are preferentially detected in the blood at the time of tumor resection as compared to routine follow-up. These findings highlight a noninvasive method to identify and track relevant tumor-reactive TCRs for use in adoptive T cell immunotherapy.
A survey of T cell repertoire evolution in the tumors, healthy tissue and blood of patients with early-stage untreated lung cancer offers an opportunity to monitor and identify neoantigen-specific T cells for personalized immunotherapy.
Journal Article
Deciphering the Immune Landscape in Renal Cell Carcinoma and in Anti-Pd-1 Therapy
2022
Antigen recognition and T-cell mediated cytotoxicity are major tenets of cancer immunology that are not fully understood in clear-cell renal cell carcinoma (ccRCC). We evaluated multiregional treatment naïve nephrectomy samples from 27 patients as well as bloods samples from 21 and normal kidney tissue from 11 patients from the TRACERx Renal (TRAcking Cancer Evolution through therapy [Rx]) study via high dimensional flow cytometry. Results showed that the T cells in the tumour, normal kidney and blood have different phenotypes and differentiation patterns. A predominantly exhausted CD8 cell phenotype with expression of PD-1, TIM-3, Eomes, CD38 and CD39 was seen in the tumour immune microenvironment. ADAPTeR is a phase II study evaluating nivolumab (anti-PD1 antibody) in patients with treatment-naive metastatic ccRCC. Immunophenotyping by using high dimensional flow cytometry and multiplex immunofluorescence in addition to T cell receptor (TCR) sequencing was performed on 93 pre- and post-treatment, multi-region tumour and peripheral blood samples from 15 patients. We showed that an increased Granzyme B production in the CD8 cells and higher B cell infiltration at baseline were associated with response to Nivolumab. TCR sequencing analysis showed that maintenance of expanded TCR clones during the anti-PD1 treatment which were present pre-treatment and increased clustering of TCR clonotypes are associated with response to therapy. Comparing a responder patient with a non-responder by using single cell RNA Sequencing (SC RNA Seq) showed a more dysfunctional phenotype in the responder. In addition, Nivolumab bound CD8 cells in the responder also had higher Granzyme B and TCF7 expression suggesting a more cytotoxic and progenitor-like phenotype is associated with response. This study provides important data that needs to be validated in a bigger cohort to identify biomarkers of response to anti-PD-1 therapy in ccRCC.
Dissertation
Using DNA sequencing data to quantify T cell fraction and therapy response
by
McGranahan, Nicholas
,
Litchfield, Kevin
,
Rosenthal, Rachel
in
631/114/794
,
631/250
,
631/67/580
2021
The immune microenvironment influences tumour evolution and can be both prognostic and predict response to immunotherapy
1
,
2
. However, measurements of tumour infiltrating lymphocytes (TILs) are limited by a shortage of appropriate data. Whole-exome sequencing (WES) of DNA is frequently performed to calculate tumour mutational burden and identify actionable mutations. Here we develop T cell exome TREC tool (T cell ExTRECT), a method for estimation of T cell fraction from WES samples using a signal from T cell receptor excision circle (TREC) loss during V(D)J recombination of the T cell receptor-α gene (
TCRA
(also known as
TRA
)).
TCRA
T cell fraction correlates with orthogonal TIL estimates and is agnostic to sample type. Blood
TCRA
T cell fraction is higher in females than in males and correlates with both tumour immune infiltrate and presence of bacterial sequencing reads. Tumour
TCRA
T cell fraction is prognostic in lung adenocarcinoma. Using a meta-analysis of tumours treated with immunotherapy, we show that tumour
TCRA
T cell fraction predicts immunotherapy response, providing value beyond measuring tumour mutational burden. Applying T cell ExTRECT to a multi-sample pan-cancer cohort reveals a high diversity of the degree of immune infiltration within tumours. Subclonal loss of 12q24.31–32, encompassing
SPPL3
, is associated with reduced
TCRA
T cell fraction. T cell ExTRECT provides a cost-effective technique to characterize immune infiltrate alongside somatic changes.
A robust, cost-effective technique based on whole-exome sequencing data can be used to characterize immune infiltrates, relate the extent of these infiltrates to somatic changes in tumours, and enables prediction of tumour responses to immune checkpoint inhibition therapy.
Journal Article