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18
result(s) for
"Spurr, Liam F."
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Cancer aneuploidies are shaped primarily by effects on tumour fitness
by
Ha, Gavin
,
Sarmashghi, Shahab
,
Hoyt, Stephanie H.
in
631/114/2785
,
631/181/2474
,
631/208/1405
2023
Aneuploidies—whole-chromosome or whole-arm imbalances—are the most prevalent alteration in cancer genomes
1
,
2
. However, it is still debated whether their prevalence is due to selection or ease of generation as passenger events
1
,
2
. Here we developed a method, BISCUT, that identifies loci subject to fitness advantages or disadvantages by interrogating length distributions of telomere- or centromere-bounded copy-number events. These loci were significantly enriched for known cancer driver genes, including genes not detected through analysis of focal copy-number events, and were often lineage specific. BISCUT identified the helicase-encoding gene
WRN
as a haploinsufficient tumour-suppressor gene on chromosome 8p, which is supported by several lines of evidence. We also formally quantified the role of selection and mechanical biases in driving aneuploidy, finding that rates of arm-level copy-number alterations are most highly correlated with their effects on cellular fitness
1
,
2
. These results provide insight into the driving forces behind aneuploidy and its contribution to tumorigenesis.
A study reports the development of an algorithm, BISCUT, that detects genomic loci under selective pressure by relying on the distribution of breakpoints across chromosome arms, and uses it to explore how aneuploidies affect tumorigenesis.
Journal Article
Clinical and molecular correlates of tumor aneuploidy in metastatic non-small cell lung cancer
2024
Recent studies have linked elevated tumor aneuploidy to anti-tumor immune suppression and adverse survival following immunotherapy. Herein, we provide supportive evidence for tumor aneuploidy as a biomarker of response to immunotherapy in patients with non-small cell lung cancer (NSCLC). We identify a dose–response relationship between aneuploidy score and patient outcomes. In two independent NSCLC cohorts (n = 659 patients), we demonstrate a novel association between elevated aneuploidy and non-smoking-associated oncogenic driver mutations. Lastly, we report enrichment of
TERT
amplification and immune-suppressive phenotypes of highly aneuploid NSCLC. Taken together, our findings emphasize a potentially critical role for tumor aneuploidy in guiding immunotherapy treatment strategies.
Journal Article
CDKN2A loss-of-function predicts immunotherapy resistance in non-small cell lung cancer
by
Weichselbaum, Ralph R.
,
Steinhardt, George
,
Wanjari, Pankhuri
in
631/250/251
,
631/67/1612/1350
,
631/67/69
2021
Immune checkpoint blockade (ICB) improves outcomes in non-small cell lung cancer (NSCLC) though most patients progress. There are limited data regarding molecular predictors of progression. In particular, there is controversy regarding the role of CDKN2A loss-of-function (LOF) in ICB resistance. We analyzed 139 consecutive patients with advanced NSCLC who underwent NGS prior to ICB initiation to explore the association of CDKN2A LOF with clinical outcomes. 73% were PD-L1 positive (≥ 1%). 48% exhibited high TMB (≥ 10 mutations/megabase). CDKN2A LOF was present in 26% of patients and was associated with inferior PFS (multivariate hazard ratio [MVA-HR] 1.66, 95% CI 1.02–2.63,
p
= 0.041) and OS (MVA-HR 2.08, 95% CI 1.21–3.49,
p
= 0.0087) when compared to wild-type (WT) patients. These findings held in patients with high TMB (median OS, LOF vs. WT 10.5 vs. 22.3 months;
p
= 0.069) and PD-L1 ≥ 50% (median OS, LOF vs. WT 11.1 vs. 24.2 months;
p
= 0.020), as well as in an independent dataset. CDKN2A LOF vs. WT tumors were twice as likely to experience disease progression following ICB (46% vs. 21%;
p
= 0.021). CDKN2A LOF negatively impacts clinical outcomes in advanced NSCLC treated with ICB, even in high PD-L1 and high TMB tumors. This novel finding should be prospectively validated and presents a potential therapeutic target.
Journal Article
scReQTL: an approach to correlate SNVs to gene expression from individual scRNA-seq datasets
by
Słowiński, Piotr
,
Horvath, Anelia
,
Tsaneva-Atanasova, Krasimira
in
Adipose tissue
,
Animal Genetics and Genomics
,
Biomedical and Life Sciences
2021
Background
Recently, pioneering expression quantitative trait loci (eQTL) studies on single cell RNA sequencing (scRNA-seq) data have revealed new and cell-specific regulatory single nucleotide variants (SNVs). Here, we present an alternative QTL-related approach applicable to transcribed SNV loci from scRNA-seq data: scReQTL. ScReQTL uses Variant Allele Fraction (VAF
RNA
) at expressed biallelic loci, and corelates it to gene expression from the corresponding cell.
Results
Our approach employs the advantage that, when estimated from multiple cells, VAF
RNA
can be used to assess effects of SNVs in a single sample or individual. In this setting scReQTL operates in the context of identical genotypes, where it is likely to capture RNA-mediated genetic interactions with cell-specific and transient effects. Applying scReQTL on scRNA-seq data generated on the 10 × Genomics Chromium platform using 26,640 mesenchymal cells derived from adipose tissue obtained from three healthy female donors, we identified 1272 unique scReQTLs. ScReQTLs common between individuals or cell types were consistent in terms of the directionality of the relationship and the effect size. Comparative assessment with eQTLs from bulk sequencing data showed that scReQTL analysis identifies a distinct set of SNV-gene correlations, that are substantially enriched in known gene-gene interactions and significant genome-wide association studies (GWAS) loci.
Conclusion
ScReQTL is relevant to the rapidly growing source of scRNA-seq data and can be applied to outline SNVs potentially contributing to cell type-specific and/or dynamic genetic interactions from an individual scRNA-seq dataset.
Availability:
https://github.com/HorvathLab/NGS/tree/master/scReQTL
Journal Article
Tumor aneuploidy predicts survival following immunotherapy across multiple cancers
by
Weichselbaum, Ralph R.
,
Spurr, Liam F.
,
Pitroda, Sean P.
in
631/208/212/2166
,
631/250/251
,
631/67/1857
2022
Tumor mutational burden (TMB) has emerged as a promising biomarker of immunotherapy response across multiple cancer types; however, clinical outcomes among patients with low TMB tumors are heterogeneous. Herein, we demonstrate that tumor aneuploidy provides independent prognostic value among patients with lower TMB (<80th percentile) tumors treated with immunotherapy. A higher aneuploidy score is associated with poor prognosis following immunotherapy among tumors with low TMB, but not those with high TMB. Importantly, aneuploidy scores can be calculated from existing clinical targeted sequencing infrastructure, facilitating deployment of aneuploidy scores as a clinical biomarker.
Reanalysis of the immunotherapy-treated MSK-IMPACT cohort finds that chromosomal arm-level aneuploidy scores are an independent predictor of survival for patients with low tumor mutational burden.
Journal Article
A proliferative subtype of colorectal liver metastases exhibits hypersensitivity to cytotoxic chemotherapy
by
Weichselbaum, Ralph R.
,
Bridgewater, John A.
,
Maughan, Timothy S.
in
631/114/2163
,
631/67/1504/1885
,
631/67/69
2022
Personalized treatment approaches for patients with limited liver metastases from colorectal cancer are critically needed. By leveraging three large, independent cohorts of patients with colorectal liver metastases (
n
= 336), we found that a proliferative subtype associated with elevated CIN70 scores is linked to immune exclusion, increased metastatic proclivity, and inferior overall survival in colorectal liver metastases; however, high CIN70 scores generate a therapeutic vulnerability to DNA-damaging therapies leading to improved treatment responses. We propose CIN70 as a candidate biomarker to personalize systemic treatment options for patients with metastatic colorectal cancer. These findings are potentially broadly applicable to other human cancers.
Journal Article
PI3K Pathway Alterations in Peritoneal Metastases are Associated with Earlier Recurrence in Patients with Colorectal Cancer Undergoing Optimal Cytoreductive Surgery
by
Witmer, Hunter D. D
,
Polite, Blase
,
Turaga, Kiran K
in
1-Phosphatidylinositol 3-kinase
,
Adenomatous polyposis coli
,
Anaphase-promoting complex
2023
BackgroundColorectal cancer with peritoneal metastasis (CRC-PM) represents a biologically heterogeneous disease; yet little is known regarding the impact of tumor biology on survival outcomes following optimal cytoreductive surgery (CRS). We analyzed the frequency of alterations in cancer signaling pathways in patients with CRC-PM and their impact on recurrence-free survival (RFS) following optimal CRS.MethodsThirty-five consecutive CRC-PM patients who underwent optimal CRS/HIPEC and next generation sequencing of peritoneal metastases were included in the study. Alterations in eight cancer-related signaling pathways were analyzed: Wnt/APC, p53, RTK-RAS, PI3K, TGF-B, Notch, Myc, and cell cycle. The association of pathway alterations with RFS and OS following optimal cytoreduction was estimated using Cox proportional hazard modeling.ResultsThe most frequently altered pathways were Wnt/APC (63%), p53 (63%), RTK-RAS (60%), and PI3K (23%). Among optimally cytoreduced patients with CRC-PM, PI3K pathway alterations were an independent predictor of worse RFS (hazard ratio 3.2, 95% confidence interval CI 1.3-8.3, p = 0.01) with a clinically meaningful impact on median months to recurrence (5 vs. 13 months, p = 0.02). Alterations in p53, Wnt, and RTK-RAS pathways were not significantly associated with a difference in RFS following CRS. Alterations in the four pathways were not associated with differences in OS following CRS (median OS was 50 (interquartile range 23–80) months).ConclusionsIn patients with CRC-PM, PI3K pathway alterations are associated with earlier recurrence following optimal CRS, which may represent a distinct molecular subtype. This novel finding can tailor clinical trials by using PIK3CA-directed interventions to reduce risk of recurrence after optimal CRS.
Journal Article
ASO Visual Abstract: PI3K Pathway Alterations in Peritoneal Metastases are Associated with Earlier Recurrence for Patients with Colorectal Cancer Undergoing Optimal Cytoreductive Surgery
by
Witmer, Hunter D. D
,
Polite, Blase
,
Turaga, Kiran K
in
1-Phosphatidylinositol 3-kinase
,
Colorectal cancer
,
Colorectal carcinoma
2023
Journal Article