scholarly journals Experimental and Meta-Analytic Validation of RNA Sequencing Signatures for Predicting Status of Microsatellite Instability

2021 ◽  
Vol 8 ◽  
Author(s):  
Maksim Sorokin ◽  
Elizaveta Rabushko ◽  
Victor Efimov ◽  
Elena Poddubskaya ◽  
Marina Sekacheva ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Esophageal Cancer ◽  
Microsatellite Instability ◽  
Endometrial Carcinoma ◽  
Rna Sequencing ◽  
Wide Spectrum ◽  
The Cancer Genome Atlas ◽  
Laboratory Diagnostics ◽  
Reaction Products ◽  
Uterine Carcinosarcoma

Microsatellite instability (MSI) is an important diagnostic and prognostic cancer biomarker. In colorectal, cervical, ovarian, and gastric cancers, it can guide the prescription of chemotherapy and immunotherapy. In laboratory diagnostics of susceptible tumors, MSI is routinely detected by the size of marker polymerase chain reaction products encompassing frequent microsatellite expansion regions. Alternatively, MSI status is screened indirectly by immunohistochemical interrogation of microsatellite binding proteins. RNA sequencing (RNAseq) profiling is an emerging source of data for a wide spectrum of cancer biomarkers. Recently, three RNAseq-based gene signatures were deduced for establishing MSI status in tumor samples. They had 25, 15, and 14 gene products with only one common gene. However, they were developed and tested on the incomplete literature of The Cancer Genome Atlas (TCGA) sampling and never validated experimentally on independent RNAseq samples. In this study, we, for the first time, systematically validated these three RNAseq MSI signatures on the literature colorectal cancer (CRC) (n = 619), endometrial carcinoma (n = 533), gastric cancer (n = 380), uterine carcinosarcoma (n = 55), and esophageal cancer (n = 83) samples and on the set of experimental CRC RNAseq samples (n = 23) for tumors with known MSI status. We found that all three signatures performed well with area under the curve (AUC) ranges of 0.94–1 for the experimental CRCs and 0.94–1 for the TCGA CRC, esophageal cancer, and uterine carcinosarcoma samples. However, for the TCGA endometrial carcinoma and gastric cancer samples, only two signatures were effective with AUC 0.91–0.97, whereas the third signature showed a significantly lower AUC of 0.69–0.88. Software for calculating these MSI signatures using RNAseq data is included.

scholarly journals Characteristics of Subtypes Within Microsatellite Instability-high Gastric Cancer Based on a Gene Signature Related to Immune Microenvironment Components

2020 ◽  
Author(s):  
Xiaolong Wu ◽  
Xiangyu Gao ◽  
Xiaofang Xing ◽  
Xianzi Wen ◽  
Ziyu Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Microsatellite Instability ◽  
Cancer Patients ◽  
Immune Checkpoint ◽  
Differentially Expressed Gene ◽  
The Cancer Genome Atlas ◽  
Immune Microenvironment ◽  
Clinical Prognosis ◽  
Time Signature ◽  
Gastric Cancer Patients

Abstract Background: Gastric cancer patients with microsatellite instability-high (MSI-H) status have a better clinical prognosis and higher response rate to immune checkpoint inhibitors. However, recent studies have suggested that some molecular pathways in MSI-H tumors could affect tumor immune microenvironment (TIME) components, thereby leading to immunotherapy resistance. We aimed to establish subtypes based on the TIME components of MSI-H gastric cancer and analyze the characteristics of each subtype. Methods: Cohorts from the Cancer Genome Atlas, the Asian Cancer Research Group, and Peking University Cancer Hospital were used for this study. CIBERSORT software was used to analyze the TIME components. A set of genes based on the TIME component characteristics, which we named the MSI-TIME signature, was defined using k-means cluster and differentially expressed gene analysis. Results: By using the MSI-TIME signature in the aforementioned cohorts for cluster analysis, the TIME subtypes within MSI-H gastric cancer (MSI-S1, MSI-S2) were established; the differences between the subgroups were reflected in multiple aspects. The MSI-S1 subtype was characterized by a high density of CD8+ T cells, high expression levels of immune checkpoint molecules including PD-L1, PD-L2, CTLA-4, and a high T-cell inflammation level. Patients with the MSI-S1 subtype could also benefit from adjuvant chemotherapy. In contrast, the WNT/β-catenin pathway was enriched in the MSI-S2 subtype. Conclusion: We found that patients with MSI-H gastric cancer showed very different TIME characteristics and could be divided into two subtypes accordingly. These results might benefit MSI-H gastric cancer patients developing individualized treatment strategies in the future.

scholarly journals Characterization of the prognostic values of the NDRG family in gastric cancer

2019 ◽  
Vol 12 ◽  
pp. 175628481985850 ◽  
Author(s):  
Chaoran Yu ◽  
Xiaohui Hao ◽  
Sen Zhang ◽  
Wenjun Hu ◽  
Jianwen Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
T Cells ◽  
Poor Prognosis ◽  
Wide Spectrum ◽  
Mitotic Cell ◽  
High Risk Group ◽  
The Cancer Genome Atlas ◽  
Follicular Helper ◽  
Kaplan Meier ◽  
Cancer Genome Atlas

Background: The N-myc downstream-regulated gene ( NDRG) family, NDRG1-4, has been involved in a wide spectrum of biological functions in multiple cancers. However, their prognostic values remain sparse in gastric cancer (GC). Therefore, it is crucial to systematically investigate the prognostic values of the NDRG family in GC. Methods: The prognostic values of the NDRG family were evaluated by Kaplan–Meier Plotter and SurvExpress. The mRNA of the NDRG family was investigated in The Cancer Genome Atlas (TCGA). Transcription factors (TFs) and miRNAs associated with the NDRG family were predicted by NetworkAnalysis. The prognostic values of DNA methylation levels were analyzed by MethSurv. The correlation between immune cells and the NDRG family was evaluated by the Tumor Immune Estimation Resource (TIMER) database. Results: High levels of mRNA expression of NDRG2 and NDRG3 were associated with a favorable prognosis in all GCs. In HER2− GC, NDRG1 was significantly associated with a poor prognosis of GC [hazard ratio (HR) = 1.65, 95% confidence interval (CI) = 1.16–2.33, p = 0.0046]. In HER2+ GC, NDRG4 showed a poor prognosis (HR = 1.4, 95% CI: 1.06–1.85, p = 0.017). NDRG4 was an independent prognostic factor in recurrence-free survival by TCGA cohort. The low-risk NDRG-signature group displayed a significantly favorable survival outcome than the high-risk group (HR = 1.76, 95% CI: 1.2–2.59, p = 0.00385). The phosphorylated protein NDRG1 (NDRG1_pT346) displayed a favorable overall survival and was significantly associated with HER2 and phosphorylated HER2. Epidermis development was the top biological process (BP) for coexpressed genes associated with NDRG1 and NDRG4, while mitotic nuclear division and mitotic cell processes were the top BPs for NDRG2 and NDRG3, respectively. Overall, 6 CpGs of NDRG1, 4 CpGs of NDRG2, 3 CpGs of NDRG3 and 24 CpGs of NDRG4 were associated with significant prognosis. CD4+ T-cells showed the highest correlation with NDRG4 (correlation = 0.341, p = 2.14e−11). Furthermore, BCL6 in follicular helper T-cells (Tfh) cells showed the highest association with NDRG4 (correlation = 0.438, p = 00e+00). Conclusions: This study analyzed the multilevel prognostic values and biological roles of the NDRG family in GC.

scholarly journals Methylation-Based Signatures for Gastroesophageal Tumor Classification

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1208 ◽  
Author(s):  
Nikolay Alabi ◽  
Dropen Sheka ◽  
Ashar Siddiqui ◽  
Edwin Wang
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Esophageal Cancer ◽  
Treatment Options ◽  
Gastroesophageal Junction ◽  
Gene Expression Omnibus ◽  
The Cancer Genome Atlas ◽  
Validation Dataset ◽  
Transcription Start Sites ◽  
Misclassification Rates

Contention exists within the field of oncology with regards to gastroesophageal junction (GEJ) tumors, as in the past, they have been classified as gastric cancer, esophageal cancer, or a combination of both. Misclassifications of GEJ tumors ultimately influence treatment options, which may be rendered ineffective if treating for the wrong cancer attributes. It has been suggested that misclassification rates were as high as 45%, which is greater than reported for junctional cancer occurrences. Here, we aimed to use the methylation profiles of GEJ tumors to improve classifications of GEJ tumors. Four cohorts of DNA methylation profiles, containing ~27,000 (27k) methylation sites per sample, were collected from the Gene Expression Omnibus and The Cancer Genome Atlas. Tumor samples were assigned into discovery (nEC = 185, nGC = 395; EC, esophageal cancer; GC gastric cancer) and validation (nEC = 179, nGC = 369) sets. The optimized Multi-Survival Screening (MSS) algorithm was used to identify methylation biomarkers capable of distinguishing GEJ tumors. Three methylation signatures were identified: They were associated with protein binding, gene expression, and cellular component organization cellular processes, and achieved precision and recall rates of 94.7% and 99.2%, 97.6% and 96.8%, and 96.8% and 97.6%, respectively, in the validation dataset. Interestingly, the methylation sites of the signatures were very close (i.e., 170–270 base pairs) to their downstream transcription start sites (TSSs), suggesting that the methylations near TSSs play much more important roles in tumorigenesis. Here we presented the first set of methylation signatures with a higher predictive power for characterizing gastroesophageal tumors. Thus, they could improve the diagnosis and treatment of gastroesophageal tumors.

What Will We Expect From Novel Therapies to Esophageal and Gastric Malignancies?

2018 ◽  
pp. 249-261 ◽  
Author(s):  
Ramon Andrade De Mello ◽  
Luis Castelo-Branco ◽  
Pedro Castelo-Branco ◽  
Daniel Humberto Pozza ◽  
Louis Vermeulen ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Microsatellite Instability ◽  
Growth Factor Receptor ◽  
The Cancer Genome Atlas ◽  
Novel Therapies ◽  
Pik3ca Mutations ◽  
Barr Virus ◽  
Epstein Barr ◽  
Near Future ◽  
Parp 1

Esophageal cancer and gastric cancer are aggressive diseases for which treatment approaches are facing a new era. Some molecular pathways, such as VEGF, EGFR, fibroblast growth factor receptor, PIK3CA, and PARP-1, have been studied, and novel targeted drugs are presumed to be developed in the near future. From The Cancer Genome Atlas report, 80% of Epstein-Barr virus tumors and 42% of tumors with microsatellite instability have PIK3CA mutations, suggesting that this pathway could be reevaluated as a possible target for new systemic treatment of gastric cancer. Notably, higher PARP-1 expression can be found in gastric cancer, which might be related to more advanced disease and worse prognosis. In addition, PD-L1 expression, high microsatellite instability, and mismatch repair deficiency can be found in gastric cancer, thus suggesting that immunotherapy may also play a role in those patients. We discuss trends related to the potential of novel therapies for patients with esophageal and gastric cancers in the near future.

scholarly journals Integrative Analysis of Transcriptome Variation in Uterine Carcinosarcoma and Comparison to Sarcoma and Endometrial Carcinoma

2014 ◽  
Author(s):  
Natalie Davidson ◽  
Kjong-Van Lehmann ◽  
André Kahles ◽  
Alexendar Perez ◽  
Gunnar Rätsch
Keyword(s):  
Endometrial Carcinoma ◽  
Cancer Genomics ◽  
Expression Patterns ◽  
The Cancer Genome Atlas ◽  
Joint Analysis ◽  
Uterine Carcinosarcoma ◽  
Multiple Tumor ◽  
Depth Analysis ◽  
Similarities And Differences ◽  
Tumor Types

Large-scale cancer genomics has made a huge impact onto cancer research. It has allowed the characterization of tumor types in an unprecedented depth. More recent studies target the joint analysis of multiple tumor types to gain insight into similarities and differences on a molecular level. Here we present an analysis of Uterine Carcinosarcoma. The histological similarities to sarcomas and carcinomas warrants an in-depth analysis to Uterine Endometrial Carcinoma as well as Sarcomas and we have used data from The Cancer Genome Atlas to understand transcriptome similarities and diffrences between these tumor types. We have performed a differential transcriptome analysis of Uterine Carinosarcoma to Uterine samples from GTEx to find genes with tumor specifc splicing or expression patterns, which may not only be of interest for a deeper mechanistic understanding of the development and progression of Uterine Carcinosarcoma, but may also be potential tumor markers. Similarities and differences to Sarcomas and Endometrial Carcinomas present new opportunities for the development of new and targeted drug therapies. Finally we have also studied genetic determinants of gene expression and splicing changes and identifed germline variants that explain expression and splicing differences between individuals. This analysis demonstrates the opportunities of integrative comparative analysis between multiple tumor types.

scholarly journals HEDGEHOG/GLI Modulates the PRR11-SKA2 Bidirectional Transcription Unit in Lung Squamous Cell Carcinomas

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Yiyun Sun ◽  
Dandan Xu ◽  
Chundong Zhang ◽  
Yitao Wang ◽  
Lian Zhang ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Squamous Cell ◽  
Gene Pair ◽  
Gene List ◽  
Ectopic Expression ◽  
Lung Squamous Cell Carcinoma ◽  
Gene Set Enrichment Analysis ◽  
The Cancer Genome Atlas ◽  
Sequencing Data ◽  
Gene Set

We previously demonstrated that proline-rich protein 11 (PRR11) and spindle and kinetochore associated 2 (SKA2) constituted a head-to-head gene pair driven by a prototypical bidirectional promoter. This gene pair synergistically promoted the development of non-small cell lung cancer. However, the signaling pathways leading to the ectopic expression of this gene pair remains obscure. In the present study, we first analyzed the lung squamous cell carcinoma (LSCC) relevant RNA sequencing data from The Cancer Genome Atlas (TCGA) database using the correlation analysis of gene expression and gene set enrichment analysis (GSEA), which revealed that the PRR11-SKA2 correlated gene list highly resembled the Hedgehog (Hh) pathway activation-related gene set. Subsequently, GLI1/2 inhibitor GANT-61 or GLI1/2-siRNA inhibited the Hh pathway of LSCC cells, concomitantly decreasing the expression levels of PRR11 and SKA2. Furthermore, the mRNA expression profile of LSCC cells treated with GANT-61 was detected using RNA sequencing, displaying 397 differentially expressed genes (203 upregulated genes and 194 downregulated genes). Out of them, one gene set, including BIRC5, NCAPG, CCNB2, and BUB1, was involved in cell division and interacted with both PRR11 and SKA2. These genes were verified as the downregulated genes via RT-PCR and their high expression significantly correlated with the shorter overall survival of LSCC patients. Taken together, our results indicate that GLI1/2 mediates the expression of the PRR11-SKA2-centric gene set that serves as an unfavorable prognostic indicator for LSCC patients, potentializing new combinatorial diagnostic and therapeutic strategies in LSCC.

scholarly journals A Sparse and Low-Rank Regression Model for Identifying the Relationships Between DNA Methylation and Gene Expression Levels in Gastric Cancer and the Prediction of Prognosis

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 854
Author(s):  
Yishu Wang ◽  
Lingyun Xu ◽  
Dongmei Ai
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Dna Methylation ◽  
Regression Model ◽  
The Cancer Genome Atlas ◽  
Low Rank ◽  
Expression Levels ◽  
Rank Regression ◽  
Prediction Of Prognosis ◽  
Gene Expression Levels

DNA methylation is an important regulator of gene expression that can influence tumor heterogeneity and shows weak and varying expression levels among different genes. Gastric cancer (GC) is a highly heterogeneous cancer of the digestive system with a high mortality rate worldwide. The heterogeneous subtypes of GC lead to different prognoses. In this study, we explored the relationships between DNA methylation and gene expression levels by introducing a sparse low-rank regression model based on a GC dataset with 375 tumor samples and 32 normal samples from The Cancer Genome Atlas database. Differences in the DNA methylation levels and sites were found to be associated with differences in the expressed genes related to GC development. Overall, 29 methylation-driven genes were found to be related to the GC subtypes, and in the prognostic model, we explored five prognoses related to the methylation sites. Finally, based on a low-rank matrix, seven subgroups were identified with different methylation statuses. These specific classifications based on DNA methylation levels may help to account for heterogeneity and aid in personalized treatments.

scholarly journals ADAMTS12 acts as a tumor microenvironment related cancer promoter in gastric cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yangming Hou ◽  
Yingjuan Xu ◽  
Dequan Wu
Keyword(s):  
Gastric Cancer ◽  
Tumor Microenvironment ◽  
Immune Cell ◽  
Enrichment Analysis ◽  
Gene Set Enrichment Analysis ◽  
The Cancer Genome Atlas ◽  
Tumor Promoter ◽  
Protein Protein Interaction ◽  
Oxidative Phosphorylation Pathway ◽  
Cox Proportional Hazard Regression

AbstractThe infiltration degree of immune and stromal cells has been shown clinically significant in tumor microenvironment (TME). However, the utility of stromal and immune components in Gastric cancer (GC) has not been investigated in detail. In the present study, ESTIMATE and CIBERSORT algorithms were applied to calculate the immune/stromal scores and the proportion of tumor-infiltrating immune cell (TIC) in GC cohort, including 415 cases from The Cancer Genome Atlas (TCGA) database. The differentially expressed genes (DEGs) were screened by Cox proportional hazard regression analysis and protein–protein interaction (PPI) network construction. Then ADAMTS12 was regarded as one of the most predictive factors. Further analysis showed that ADAMTS12 expression was significantly higher in tumor samples and correlated with poor prognosis. Gene Set Enrichment Analysis (GSEA) indicated that in high ADAMTS12 expression group gene sets were mainly enriched in cancer and immune-related activities. In the low ADAMTS12 expression group, the genes were enriched in the oxidative phosphorylation pathway. CIBERSORT analysis for the proportion of TICs revealed that ADAMTS12 expression was positively correlated with Macrophages M0/M1/M2 and negatively correlated with T cells follicular helper. Therefore, ADAMTS12 might be a tumor promoter and responsible for TME status and tumor energy metabolic conversion.

scholarly journals Microsatellite instability in Gastric Cancer: Between lights and shadows

2021 ◽  
Vol 95 ◽  
pp. 102175
Author(s):  
Elisabetta Puliga ◽  
Simona Corso ◽  
Filippo Pietrantonio ◽  
Silvia Giordano
Keyword(s):  
Gastric Cancer ◽  
Microsatellite Instability
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