scholarly journals Tumor Mutation Burden, Expressed Neoantigens and the Immune Microenvironment in Diffuse Gliomas

Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 6092
Author(s):  
Guangyang Yu ◽  
Ying Pang ◽  
Mythili Merchant ◽  
Chimene Kesserwan ◽  
Vineela Gangalapudi ◽  
...  

Background: A consistent correlation between tumor mutation burden (TMB) and tumor immune microenvironment has not been observed in gliomas as in other cancers. Methods: Driver germline and somatic mutations, TMB, neoantigen, and immune cell signatures were analyzed using whole exome sequencing (WES) and transcriptome sequencing of tumor and WES of matched germline DNA in a cohort of 66 glioma samples (44 IDH-mutant and 22 IDH-wildtype). Results: Fourteen samples revealed a hypermutator phenotype (HMP). Eight pathogenic (P) or likely pathogenic (LP) germline variants were detected in 9 (19%) patients. Six of these 8 genes were DNA damage repair genes. P/LP germline variants were found in 22% of IDH-mutant gliomas and 12.5% of IDH-wildtype gliomas (p = 0.7). TMB was correlated with expressed neoantigen but showed an inverse correlation with immune score (R = −0.46, p = 0.03) in IDH-wildtype tumors and no correlation in IDH-mutant tumors. The Antigen Processing and Presentation (APP) score correlated with immune score and was surprisingly higher in NHMP versus HMP samples in IDH-wildtype gliomas, but higher in HMP versus NHMP in IDH-mutant gliomas. Conclusion: TMB was inversely correlated with immune score in IDH-wildtype gliomas and showed no correlation in IDH-mutant tumors. APP was correlated with immune score and may be further investigated as a biomarker for response to immunotherapy in gliomas. Studies of germline variants in a larger glioma cohort are warranted.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 494-494
Author(s):  
Yuanyuan Jia ◽  
Ning He ◽  
Yadong Yang ◽  
Yuliang Huang ◽  
Xiaoyu Zhang ◽  
...  

494 Background: Tumor mutation burden (TMB) has been established as a biomarker for response to immune therapy and prognosis in various cancers. However, the correlation between TMB and immune microenvironment remains unwell studied, especially in urothelial carcinoma. This study was aimed to investigate the relationship between TMB and other immunotherapy related biomarkers, including genetic alterations, APOBEC signature, microsatellite instability (MSI), PD-L1 expression and immune cell infiltration in urothelial carcinoma. Methods: 131 patients with urothelial carcinoma admitted from October 2018 to May 2020 were included. Total DNA was isolated from FFPE or fresh tissues. Mutation profiles, APOBEC signature and MSI scores were obtained by next-generation sequencing based a 642 cancer genes panel assay. PD-L1 expression, CD8+ T-cells and tumor-infiltrating lymphocytes density were evaluated by immunohistochemistry. The correlation was analyzed by Wilcoxon signed-rank test. Results: The mutation landscape showed that TP53 mutation is the most common alterations (n = 64/131, 48.9%), followed by KMT2D alterations (n = 49/131, 37.4%), KDM6A mutations (n = 42/131, 32.1%), MUC17 mutations (n = 42/131, 32.1%). The median TMB was 5.06 Muts/Mb (0-118 Muts/Mb). 2 of 131 patients showed MSI-H, who exhibited a much higher TMB (41, 118 Muts/Mb). Further analysis showed that TMB in the patients with certain gene mutations (such as TP53, KMT2D, KDM6A and MUC17) was significantly higher than those wild type ones (p < 0.05). Meanwhile, the high APOBEC-enrichment group has a higher TMB than the low APOBEC-enrichment group (p = 0.045). Furthermore,we observed that the patients with a higher PD-L1 expression (n = 28/131, 21.4%, at a combined positive score cut-off value of 10) also showed a significantly higher TMB (p = 0.016), and TMB in the patients with higher density of CD8+ T-cells (n = 42/131, 32.1%, at a cut-off value of 5%) was also significantly higher than that of the group with lower density of CD8+ T-cells (p = 0.039). Conclusions: This study provides new insights into the correlation between the TMB and the immune microenvironment in urothelial carcinoma. The result may be a reference to immunotherapy.


2021 ◽  
Author(s):  
Zhenyu Zhao ◽  
Boxue He ◽  
Qidong Cai ◽  
Pengfei Zhang ◽  
Xiong Peng ◽  
...  

Abstract Background: Lung adenocarcinoma (LUAD) accounts for a majority of cancer-related deaths worldwide annually. A recent study shows that immunotherapy is an effective method of LUAD treatment, and tumor mutation burden (TMB) was associated with the immune microenvironment and affected the immunotherapy. Exploration of the gene signature associated with tumor mutation burden and immune infiltrates in predicting prognosis in lung adenocarcinoma in this study, we explored the correlation of TMB with immune infiltration and prognosis in LUAD.Materials and Methods: In this study, we firstly got mutation data and LUAD RNA-Seq data of the LUAD from The Cancer Genome Atlas (TCGA), and according to the TMB we divided the patients into high/low-TMB levels groups. The gene ontology (GO) pathway enrichment analysis and KOBAS-Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis were utilized to explore the molecular function of the differentially expressed genes (DEGs) between the two groups. The function enrichment analyses of DEGs were related to the immune pathways. Then, the ESTIMATE algorithm, CIBERSORT, and ssGSEA analysis were utilized to identify the relationship between TMB subgroups and immune infiltration. According to the results, Venn analysis was utilized to select the immune-related genes in DEGs. Univariate and Lasso Cox proportional hazards regression analyses were performed to construct the signature which positively associated with the immune infiltration and affected the survival. Finally, we verified the correlation between the signature and immune infiltration. Result: The exploration of the immune infiltration suggested that high-TMB subgroups positively associated with the high level of immune infiltration in LUAD patients. According to the TMB-related immune signature, the patients were divided into High/Low-risk groups, and the high-risk group was positively associated with poor prognostic. The results of the PCA analysis confirmed the validity of the signature. We also verified the effectiveness of the signature in GSE30219 and GSE72094 datasets. The ROC curves and C-index suggested the good clinical application of the TMB-related immune signature in LUAD prognosis. Another result suggested that the patients of the high-risk group were positively associated with higher TMB levels, PD-L1expression, and immune infiltration levels.Conclusion: In conclusion, our signature provides potential biomarkers for studying aspects of the TMB in LUAD such as TMB affected immune microenvironment and prognosis. This signature may provide some biomarkers which could improve the biomarkers of PD-L1 immunotherapy response and were inverted for the clinical application of the TMB in LUAD. LUAD male patients with higher TMB-levels and risk scores may benefit from immunotherapy. The high-risk patients along with higher PD-L1 expression of the signature may suitable for immunotherapy and improve their survival by detecting the TMB of LUAD.


2021 ◽  
Author(s):  
Di Cao ◽  
Jun Wang ◽  
Yan Lin ◽  
Guangwei Li

Abstract Background: The therapeutic efficacy of immune checkpoint inhibitor therapy is highly influenced by tumor mutation burden (TMB). The relationship between TMB and prognosis in lower-grade glioma is still unclear. We aimed to explore the relationships and mechanisms between them in lower-grade glioma.Methods: We leveraged somatic mutation data from The Cancer Genome Atlas (TCGA). Clinical cases were divided into high- and low-TMB groups based on the median of TMB. Infiltrating immune cells were analyzed using CIBERSORT and differential expression analysis between the prognostic groups performed. The key genes were identified as intersecting between immune-related genes. Cox regression and survival analysis were performed on the intersecting genes. A total of 7 hub genes were identified. The effect of somatic copy number alterations (SCNA) of the hub genes on immune cell infiltration was analyzed using TIMER, which was used to determine the risk factors and immune infiltration status in LGG. Subsequently, based on hub genes, a TMB Prognosis Index (TMBPI) model was constructed to predict the risk in LGG patients. Besides, this model was validated using data from TCGA and Chinese Glioma Genome Atlas (CGGA).Results: High-TMB favored worse prognosis (P<0.001) and macrophage infiltration was an independent risk factor (P<0.001). In the high-TMB group (P=0.033, P=0.009), the proportion of macrophages M0 and M2 increased and monocytes decreased (P=0.006). Besides, the SCNA of the hub genes affected the level of immune cell infiltration by varying degrees among which IGF2BP3, NPNT, and PLA2G2A had a significant impact. The AUC of the ROC curve at 1-, 3- and 5-years were all above 0.74.Conclusions: This study implies that high-TMB correlated with unfavorable prognosis in lower-grade glioma. And high-TMB may have an impact on prognosis by changing tumor microenvironment, caused by the SCNAs of genes. The TMBPI model accurately predicted prognosis in LGG patients.


2022 ◽  
Vol 6 (1) ◽  
Author(s):  
Shuhang Wang ◽  
Pei Yuan ◽  
Beibei Mao ◽  
Ning Li ◽  
Jianming Ying ◽  
...  

AbstractSeveral clinical trials have shown the safety and effectiveness of PD-1/PD-L1 inhibitors in neoadjuvant therapy in resectable non-small cell lung cancer (NSCLC). However, 18–83% patients can benefit from it. In this study, we aimed to assess the association of PD-L1 expression, tumor mutation burden, copy number alteration (CNA, including copy number gain and loss) burden with the pathologic response to neoadjuvant PD-1 blockade and investigate the changes in the tumor immune microenvironment (TIME) during neoadjuvant immunotherapy in NSCLC. Pre-immunotherapy treatment tumor samples from twenty-nine NSCLC patients who received neoadjuvant immunotherapy with sintilimab, an anti-PD-1 drug, were subjected to targeted DNA sequencing and PD-L1 immunochemistry staining. The pathological response was positively correlated with tumor proportion score (TPS) of PD-L1 and negatively correlated with copy number gain (CNgain) burden. Of note, the combination of CNgain burden and TPS can better stratify major pathological response (MPR) patients than did CNgain or TPS alone. Whereas, TMB showed a limited correlation with pathological regression. Additionally, PD-1 blockade led to an increase in CD8+PD-1−T cells which was clinically relevant to MPR as evaluated by multiplex immunofluorescence. A significant reduction in CD19+ cells was observed in the Non-MPR group but not in the MPR group, indicating the involvement of B cells in improving neoadjuvant immunotherapy response in NSCLC. Together, our study provides new data for the correlation of PD-L1 expression and genomic factors with drug response in neoadjuvant immunotherapy settings in NSCLC. The changes of TIME may provide novel insight into the immune responses to neoadjuvant anti-PD-1 therapy.


Author(s):  
Taisheng Liu ◽  
Liyi Guo ◽  
Guihong Liu ◽  
Xiaoshan Hu ◽  
Xiaoning Li ◽  
...  

Background: DNA methylation is an important epigenetic modification, among which 5-methylcytosine methylation (5mC) is generally associated with tumorigenesis. Nonetheless, the potential roles of 5mC regulators in the tumor microenvironment (TME) remain unclear.Methods: The 5mC modification patterns of 1,374 lung adenocarcinoma samples were analyzed systematically. The correlation between the 5mC modification and tumor microenvironment cell infiltration was further assessed. The 5mCscore was developed to evaluate tumor mutation burden, immune check-point inhibitor response, and the clinical prognosis of individual tumors.Results: Three 5mC modification patterns were established based on the clinical characteristics of 21 5mC regulators. According to the differential expression of 5mC regulators, three distinct 5mC gene cluster were also identified, which showed distinct TME immune cell infiltration patterns and clinical prognoses. The 5mCscore was constructed to evaluate the tumor mutation burden, immune check-point inhibitor response, and prognosis characteristics. We found that patients with a low 5mCscore had significant immune cell infiltration and increased clinical benefit.Conclusion: This study indicated that the 5mC modification is involved in regulating TME infiltration remodeling. Targeting 5mC modification regulators might be a novel strategy to treat lung cancer.


2021 ◽  
Author(s):  
Dade Rong ◽  
Xiaomin Chen ◽  
Daiyuan Liu ◽  
Xiangna Ni ◽  
Zhuomao Mo ◽  
...  

Abstract Background: Acute myeloid leukemia (AML) is a type of heterogeneous disease with varied prognosis, but current classification methods for AML do not play an ideal role in guiding the therapy. Emerging studies shown alteration of histone methylation is closely related to leukemogenesis. This study aimed at identifying the molecular subtypes associated with histone methylation and establishing a relevant score to predict treatment respond and prognosis in AML.Methods: Gene expression data and clinical characteristics of patients with AML were obtained from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database. Molecular subtypes were identified by consensus clustering based on the expression of 24 histone methylation modification regulators (HMMRs). The clinical and biological features of each pattern were investigated by unsupervised clustering, survival, principle component (PCA), somatic mutations, gene set variation (GSVA), tumor mutation burden (TMB) and immune cell infiltration analyses. Different expression analysis and lasso regression analysis was conducted to establish the scoring system that was explored in the role of prognosis by using receivers operating curve (ROC) analysis and univariate/multivariate Cox regression analyses. Moreover, correlation analysis was performed to investigate the value of scoring system in chemotherapeutic prediction. Finally, an independent GSE dataset was used as a reference to validate the established clustering system.Results: Two distinct histone methylation modification patterns had been identified that exhibit remarkable differences in several clinical and biological characteristics, including HMMRs’ expression, AML-M0 distribution, mutations of NPM1, survival, tumor mutation burden, somatic mutations, pathways activation and immune cell infiltration. Besides, based on the clustering, we established the scoring system, M-RiskScore. Integrated analysis demonstrated that M-RiskScore-low patients displayed a prominent survival advantage and a better respond to decitabine treatment, while the opposite site was reported to M-RiskScore-high patients but they could benefit more from IA regimen therapy.Conclusion: Our results demonstrate that detection of HMMRs’ expression is potentially useful to AML therapy decisions, and targeting histone methylation would be a more promising strategy for either AML-M0 or NPM1 mutant patients. M-RiskScore is a hopeful independent poor prognostic biomarker and be able to benefits the treatment decisions in AML.


2020 ◽  
Author(s):  
Ting Li ◽  
Wenjia Hui ◽  
Halina Halike ◽  
Feng Gao

Abstract Background: Immunotherapy is a new strategy for Colorectal cancer (CRC) treatment. Tumor mutation burden (TMB) may act as an emerging biomarker for predicting responses to immunotherapy. Nevertheless, no studies investigate if these gene mutations correlate to TMB and tumor-infiltrating immune cells. Methods: Somatic mutation data for CRC samples were obtained from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) datasets. Then, we investigated the relationship between these mutant genes, TMB and overall survival outcomes. GSEA analysis was performed to explore the underlying mechanism of mutant gene. Finally, we further verified the connection between gene mutations and immune response.Results: We identified 17 common mutant genes shared by both two cohorts. Further analysis found that MUC4 mutation was strongly related to higher TMB and predicted a poorer prognosis. Moreover, functional enrichment analysis of samples with MUC4 mutation revealed that they were involved in regulating the natural killer cell mediated cytotoxicity signaling pathway. Significant changes in the proportion of the immune cells of CD8 T cells, activated NK cells, M1 macrophages and resting memory CD4 T cells were observed using the CIBERSORT algorithm. Conclusions: Our research revealed that MUC4 mutation significantly correlated with increased TMB, a worse prognosis and modulating the immune microenvironment, which may be considered a biomarker to predict the outcome of the immune response in colorectal cancer.


2021 ◽  
Vol 11 ◽  
Author(s):  
Hong Yuan ◽  
Jun Ji ◽  
Min Shi ◽  
Yan Shi ◽  
Jing Liu ◽  
...  

BackgroundTumor mutation burden has been proven to be a good predictor for the efficacy of immunotherapy, especially in patients with hypermutation. However, most research focused on the analysis of hypermutation in individual tumors, and there is a lack of integrated research on the hypermutation across different cancers. This study aimed to characterize hypermutated patients to distinguish between these patients and non-hypermutated patients.MethodsA total of 5,980 tumor samples involving 23 types of solid tumors from the in-house database were included in the study. Based on the cutoff value of tumor mutation burden (TMB), all samples were divided into hypermutated or non-hypermutated groups. Microsatellite instability status, PD-L1 expression and other mutation-related indicators were analyzed.ResultsAmong the 5,980 tumor samples, 1,164 were selected as samples with hypermutation. Compared with the non-hypermutated group, a significant increase in the mutation rates of DNA mismatch repair genes and polymerase genes was detected in the hypermutated group, and there was an overlap between high TMB and high microsatellite instability or high PD-L1. In addition, we found that EGFR, KRAS and PIK3CA had a high frequency of both single nucleotide variation and copy number variation mutations. These identified mutant genes were enriched in the oncogenic signaling pathway and the DNA damage repair pathway. At the same time, the somatic cell characteristics and distribution of the two groups were significantly different.ConclusionsThis study identified genetic and phenotypic characteristics of hypermutated tumors and demonstrated that DNA damage repair is critically involved in hypermutation.


2021 ◽  
Vol 22 (18) ◽  
pp. 9791
Author(s):  
João Augusto Freitas ◽  
Irene Gullo ◽  
Diogo Garcia ◽  
Sara Miranda ◽  
Louisa Spaans ◽  
...  

Background. The tumor immune microenvironment exerts a pivotal influence in tumor initiation and progression. The aim of this study was to analyze the immune context of sporadic and familial adenomatous polyposis (FAP) lesions along the colorectal adenoma–carcinoma sequence (ACS). Methods. We analyzed immune cell counts (CD3+, CD4+, CD8+, Foxp3+, and CD57+), tumor mutation burden (TMB), MHC-I expression and PD-L1 expression of 59 FAP and 74 sporadic colorectal lesions, encompassing adenomas with low-grade dysplasia (LGD) (30 FAP; 30 sporadic), adenomas with high-grade dysplasia (22 FAP; 30 sporadic), and invasive adenocarcinomas (7 FAP; 14 sporadic). Results. The sporadic colorectal ACS was characterized by (1) a stepwise decrease in immune cell counts, (2) an increase in TMB and MHC-I expression, and (3) a lower PD-L1 expression. In FAP lesions, we observed the same patterns, except for an increase in TMB along the ACS. FAP LGD lesions harbored lower Foxp3+ T cell counts than sporadic LGD lesions. A decrease in PD-L1 expression occurred earlier in FAP lesions compared to sporadic ones. Conclusions. The colorectal ACS is characterized by a progressive loss of adaptive immune infiltrate and by the establishment of a progressively immune cold microenvironment. These changes do not appear to be related with the loss of immunogenicity of tumor cells, or to the onset of an immunosuppressive tumor microenvironment.


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