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result(s) for
"Mitra, Shamik"
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Mutational and putative neoantigen load predict clinical benefit of adoptive T cell therapy in melanoma
by
Andersen, Rikke
,
Törngren, Therese
,
Rosengren, Frida
in
631/67/1813/1634
,
631/67/580
,
Antigen presentation
2017
Adoptive T-cell therapy (ACT) is a highly intensive immunotherapy regime that has yielded remarkable response rates and many durable responses in clinical trials in melanoma; however, 50–60% of the patients have no clinical benefit. Here, we searched for predictive biomarkers to ACT in melanoma. Whole exome- and transcriptome sequencing and neoantigen prediction were applied to pre-treatment samples from 27 patients recruited to a clinical phase I/II trial of ACT in stage IV melanoma. All patients had previously progressed on other immunotherapies. We report that clinical benefit is associated with significantly higher predicted neoantigen load. High mutation and predicted neoantigen load are significantly associated with improved progression-free and overall survival. Further, clinical benefit is associated with the expression of immune activation signatures including a high MHC-I antigen processing and presentation score. These results improve our understanding of mechanisms behind clinical benefit of ACT in melanoma.
Adoptive T cell therapy (ACT) has yielded high response rates in melanoma, however 50–60% of patients experience no clinical benefit. Here, the authors identify predictive biomarkers, high non-synonymous mutation and high expressed neoantigen load, that associate with clinical benefit in ACT melanoma patients.
Journal Article
Tertiary lymphoid structures improve immunotherapy and survival in melanoma
2020
Checkpoint blockade therapies that reactivate tumour-associated T cells can induce durable tumour control and result in the long-term survival of patients with advanced cancers
1
. Current predictive biomarkers for therapy response include high levels of intratumour immunological activity, a high tumour mutational burden and specific characteristics of the gut microbiota
2
,
3
. Although the role of T cells in antitumour responses has thoroughly been studied, other immune cells remain insufficiently explored. Here we use clinical samples of metastatic melanomas to investigate the role of B cells in antitumour responses, and find that the co-occurrence of tumour-associated CD8
+
T cells and CD20
+
B cells is associated with improved survival, independently of other clinical variables. Immunofluorescence staining of CXCR5 and CXCL13 in combination with CD20 reveals the formation of tertiary lymphoid structures in these CD8
+
CD20
+
tumours. We derived a gene signature associated with tertiary lymphoid structures, which predicted clinical outcomes in cohorts of patients treated with immune checkpoint blockade. Furthermore, B-cell-rich tumours were accompanied by increased levels of TCF7
+
naive and/or memory T cells. This was corroborated by digital spatial-profiling data, in which T cells in tumours without tertiary lymphoid structures had a dysfunctional molecular phenotype. Our results indicate that tertiary lymphoid structures have a key role in the immune microenvironment in melanoma, by conferring distinct T cell phenotypes. Therapeutic strategies to induce the formation of tertiary lymphoid structures should be explored to improve responses to cancer immunotherapy.
The co-occurrence of tumour-associated CD8
+
T cells and CD20
+
B cells, and the formation of tertiary lymphoid structures, are linked with improved survival in cohorts of patients with metastatic melanoma.
Journal Article
Comprehensive molecular comparison of BRCA1 hypermethylated and BRCA1 mutated triple negative breast cancers
2020
Homologous recombination deficiency (HRD) is a defining characteristic in
BRCA
-deficient breast tumors caused by genetic or epigenetic alterations in key pathway genes. We investigated the frequency of
BRCA1
promoter hypermethylation in 237 triple-negative breast cancers (TNBCs) from a population-based study using reported whole genome and RNA sequencing data, complemented with analyses of genetic, epigenetic, transcriptomic and immune infiltration phenotypes. We demonstrate that
BRCA1
promoter hypermethylation is twice as frequent as
BRCA1
pathogenic variants in early-stage TNBC and that hypermethylated and mutated cases have similarly improved prognosis after adjuvant chemotherapy.
BRCA1
hypermethylation confers an HRD, immune cell type, genome-wide DNA methylation, and transcriptional phenotype similar to TNBC tumors with
BRCA1
-inactivating variants, and it can be observed in matched peripheral blood of patients with tumor hypermethylation. Hypermethylation may be an early event in tumor development that progress along a common pathway with
BRCA1
-mutated disease, representing a promising DNA-based biomarker for early-stage TNBC.
BRCA-deficient breast cancer is characterised by homologous recombination deficiency. Here, the authors show that hypermethylated BRCA1 phenotypically copies mutated BRCA1 in triple negative breast cancers.
Journal Article
Molecular analyses of triple-negative breast cancer in the young and elderly
2021
Background
Breast cancer in young adults has been implicated with a worse outcome. Analyses of genomic traits associated with age have been heterogenous, likely because of an incomplete accounting for underlying molecular subtypes. We aimed to resolve whether triple-negative breast cancer (TNBC) in younger versus older patients represent similar or different molecular diseases in the context of genetic and transcriptional subtypes and immune cell infiltration.
Patients and methods
In total, 237 patients from a reported population-based south Swedish TNBC cohort profiled by RNA sequencing and whole-genome sequencing (WGS) were included. Patients were binned in 10-year intervals. Complimentary PD-L1 and CD20 immunohistochemistry and estimation of tumor-infiltrating lymphocytes (TILs) were performed. Cases were analyzed for differences in patient outcome, genomic, transcriptional, and immune landscape features versus age at diagnosis. Additionally, 560 public WGS breast cancer profiles were used for validation.
Results
Median age at diagnosis was 62 years (range 26–91). Age was not associated with invasive disease-free survival or overall survival after adjuvant chemotherapy. Among the
BRCA1
-deficient cases (82/237), 90% were diagnosed before the age of 70 and were predominantly of the basal-like subtype. In the full TNBC cohort, reported associations of patient age with changes in Ki67 expression,
PIK3CA
mutations, and a luminal androgen receptor subtype were confirmed. Within DNA repair deficiency or gene expression defined molecular subgroups, age-related alterations in, e.g., overall gene expression, immune cell marker gene expression, genetic mutational and rearrangement signatures, amount of copy number alterations, and tumor mutational burden did, however, not appear distinct. Similar non-significant associations for genetic alterations with age were obtained for other breast cancer subgroups in public WGS data. Consistent with age-related immunosenescence, TIL counts decreased linearly with patient age across different genetic TNBC subtypes.
Conclusions
Age-related alterations in TNBC, as well as breast cancer in general, need to be viewed in the context of underlying genomic phenotypes. Based on this notion, age at diagnosis alone does not appear to provide an additional layer of biological complexity above that of proposed genetic and transcriptional phenotypes of TNBC. Consequently, treatment decisions should be less influenced by age and more driven by tumor biology.
Journal Article
The Role of PTEN Loss in Immune Escape, Melanoma Prognosis and Therapy Response
by
Cabrita, Rita
,
Lövgren, Kristina
,
Carneiro, Ana
in
Cancer and Oncology
,
Cancer och onkologi
,
Cell adhesion & migration
2020
Checkpoint blockade therapies have changed the clinical management of metastatic melanoma patients considerably, showing survival benefits. Despite the clinical success, not all patients respond to treatment or they develop resistance. Although there are several treatment predictive biomarkers, understanding therapy resistance and the mechanisms of tumor immune evasion is crucial to increase the frequency of patients benefiting from treatment. The PTEN gene is thought to promote immune evasion and is frequently mutated in cancer and melanoma. Another feature of melanoma tumors that may affect the capacity of escaping T-cell recognition is melanoma cell dedifferentiation characterized by decreased expression of the microphtalmia-associated transcription factor (MITF) gene. In this study, we have explored the role of PTEN in prognosis, therapy response, and immune escape in the context of MITF expression using immunostaining and genomic data from a large cohort of metastatic melanoma. We confirmed in our cohort that PTEN alterations promote immune evasion highlighted by decreased frequency of T-cell infiltration in such tumors, resulting in a worse patient survival. More importantly, our results suggest that dedifferentiated PTEN negative melanoma tumors have poor patient outcome, no T-cell infiltration, and transcriptional properties rendering them resistant to targeted- and immuno-therapy.
Journal Article
Analysis of DNA methylation patterns in the tumor immune microenvironment of metastatic melanoma
by
Carneiro, Ana
,
Brown, Kevin M.
,
Nielsen, Kari
in
B-Lymphocytes - cytology
,
B-Lymphocytes - metabolism
,
Cancer
2020
The presence of immune cells in the tumor microenvironment has been associated with response to immunotherapies across several cancer types, including melanoma. Despite its therapeutic relevance, characterization of the melanoma immune microenvironments remains insufficiently explored. To distinguish the immune microenvironment in a cohort of 180 metastatic melanoma clinical specimens, we developed a method using promoter CpG methylation of immune cell type‐specific genes extracted from genome‐wide methylation arrays. Unsupervised clustering identified three immune methylation clusters with varying levels of immune CpG methylation that are related to patient survival. Matching protein and gene expression data further corroborated the identified epigenetic characterization. Exploration of the possible immune exclusion mechanisms at play revealed likely dependency on MITF protein level and PTEN loss‐of‐function events for melanomas unresponsive to immunotherapies (immune‐low). To understand whether melanoma tumors resemble other solid tumors in terms of immune methylation characteristics, we explored 15 different solid tumor cohorts from TCGA. Low‐dimensional projection based on immune cell type‐specific methylation revealed grouping of the solid tumors in line with melanoma immune methylation clusters rather than tumor types. Association of survival outcome with immune cell type‐specific methylation differed across tumor and cell types. However, in melanomas immune cell type‐specific methylation was associated with inferior patient survival. Exploration of the immune methylation patterns in a pan‐cancer context suggested that specific immune microenvironments might occur across the cancer spectrum. Together, our findings underscore the existence of diverse immune microenvironments, which may be informative for future immunotherapeutic applications. The importance of the tumor immune microenvironment has been highlighted in multiple cancers, but information regarding the contribution of individual immune cell types is lacking for melanoma. In this study, we have sought to fill the gap by identifying distinct DNA methylation patterns for specifc immune cells. These were corroborated by other molecular correlates and found to be shared across other types of solid tomors.
Journal Article
Author Correction: Mutational and putative neoantigen load predict clinical benefit of adoptive T cell therapy in melanoma
2020
An amendment to this paper has been published and can be accessed via a link at the top of the paper.An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Journal Article
Improved survival prognostication of node-positive malignant melanoma patients utilizing shotgun proteomics guided by histopathological characterization and genomic data
by
Roger Appelqvist
,
Henrik Ekedahl
,
Maria Yakovleva
in
14/63
,
631/337/475
,
692/4028/67/1813/1634
2019
Metastatic melanoma is one of the most common deadly cancers, and robust biomarkers are still needed, e.g. to predict survival and treatment efficiency. Here, protein expression analysis of one hundred eleven melanoma lymph node metastases using high resolution mass spectrometry is coupled with in-depth histopathology analysis, clinical data and genomics profiles. This broad view of protein expression allowed to identify novel candidate protein markers that improved prediction of survival in melanoma patients. Some of the prognostic proteins have not been reported in the context of melanoma before, and few of them exhibit unexpected relationship to survival, which likely reflects the limitations of current knowledge on melanoma and shows the potential of proteomics in clinical cancer research.
Journal Article
Correction to: Molecular analyses of triple-negative breast cancer in the young and elderly
by
Boyaci, Ceren
,
Nimeus, Emma
,
Staaf, Johan
in
Analysis
,
Biomedical and Life Sciences
,
Biomedicine
2021
An amendment to this paper has been published and can be accessed via the original article.
Journal Article
Author Correction: Tertiary lymphoid structures improve immunotherapy and survival in melanoma
2020
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
Journal Article