Adjacent Normal Tissue Samples Research Articles

DNA methylation-based depiction of the immune microenvironment and immune-associated long non-coding RNAs in oral cavity squamous cell carcinomas

Oral cavity squamous cell carcinoma (OSCC) is a complex and dynamic disease characterized by clinicopathological and molecular heterogeneity. Spatial and temporal heterogeneity of cell subpopulations has been associated with cancer progression and implicated in the prognosis and therapy response. Emerging evidence indicates that aberrant epigenetic profiles in OSCC may foster an immunosuppressive tumor microenvironment by modulating the expression of immune-related long non-coding RNAs (lncRNAs). DNA methylation analysis was performed in 46 matched OSCC and normal adjacent tissue samples using a genome-wide platform (Infinium HumanMethylation450 BeadChip). Reference-based computational deconvolution (MethylCIBERSORT) was applied to infer the immune cell composition of the bulk samples. The expression levels of genes encoding immune markers and differentially methylated lncRNAs were investigated using The Cancer Genome Atlas dataset. OSCC specimens presented distinct immune cell composition, including the enrichment of monocyte lineage cells, natural killer cells, cytotoxic T-lymphocytes, regulatory T-lymphocytes, and neutrophils. In contrast, B-lymphocytes, effector T-lymphocytes, and fibroblasts were diminished in tumor samples. The hypomethylation of three immune-associated lncRNAs (MEG3, MIR155HG, and WFDC21P) at individual CpG sites was confirmed by bisulfite-pyrosequencing. Also, the upregulation of a set of immune markers (FOXP3, GZMB, IL10, IL2RA, TGFB, IFNG, TDO2, IDO1, and HIF1A) was detected. The immune cell composition, immune markers alteration, and dysregulation of immune-associated lncRNAs reinforce the impact of the immune microenvironment in OSCC. These concurrent factors contribute to tumor heterogeneity, suggesting that epi-immunotherapy could be an efficient alternative to treat OSCC.

Identification of autophagy and angiogenesis modulators in colorectal cancer based on bioinformatics analysis

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer-related death worldwide. The purpose of this study was to discover novel molecular pathways and potential prognosis biomarkers. To achieve this, we acquired five microarray datasets from the Gene Expression Omnibus (GEO) database. We identified differentially expressed genes between CRC and adjacent normal tissue samples and further validated them using The Cancer Genome Atlas (TCGA) database. Using various analytical approaches, including the construction of a competing endogenous RNA (ceRNA) network, Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes pathway analyses, as well as survival analysis, we identified key genes and pathways associated with the diagnosis and prognosis of CRC. We obtained a total of 185 differentially expressed genes, comprising 17 lncRNAs, 30 miRNAs, and 138 mRNAs. The ceRNA network consisted of 17 lncRNAs, 25 miRNAs, and 7 mRNAs. Among the 7 mRNAs involved in the ceRNA network, SLC7A5 and KRT80 were found to be upregulated, while ADIPOQ, CCBE1, KCNB1, CADM2, and CHRDL1 were downregulated in CRC. Further analysis revealed that ADIPOQ and SLC7A5 are involved in the AMPK and mTOR signaling pathway, respectively. In addition, survival analysis demonstrated a statistically significant relationship between ADIPOQ, SLC7A5, and overall survival rates in CRC patients. In conclusion, our findings suggest that downregulation of ADIPOQ and upregulation of SLC7A5 in tumor cells lead to increased mTORC1 activity, reduced autophagy, enhanced angiogenesis, and ultimately contribute to cancer progression and decreased survival in CRC patients.

Prognostic and clinicopathological significance of MRC2 expression in head and neck squamous cell carcinoma

BackgroundHead and neck squamous cell carcinoma (HNSCC) is one of the most aggressive types of cancers worldwide, with metastasis being the major cause of death. Recent research suggests that changes in the expression of MRC2 (mannose receptor, C-type 2) may play a role in the development and progression of various cancers; however, its expression pattern in HNSCC/ OSCC is unknown. This study aimed to elucidate the clinicopathological significance and prognostic role of MRC2 expression in HNSCC, including OSCC. Materials and methodsIn the present study, we assessed the potential roles of MRC2 in expression, prognostic value, immune infiltration and functional enrichment analysis in HNSCC patients by using different bioinformatics databases. We then validated MRC2 gene expression in 30 OSCC and adjacent normal tissue samples using quantitative reverse transcription PCR (RT-qPCR). ResultsMRC2 mRNA and protein expression were significantly upregulated in OSCC and HNSCC patients compared to that in adjacent normal tissues. Upregulated MRC2 expression was associated with poor overall survival. Increased MRC2 expression has also been linked to an aggressive clinicopathological features including advanced stages, grade, metastasis and HPV status. Interestingly, our in silico results strongly suggest that the MRC2 gene and protein interaction networks are associated with HNSCC development. Moreover, the tumor infiltration level was significantly correlated with HPV-negative HNSCC patients. ConclusionOur results suggest that MRC2 could be used as a novel prognostic marker and therapeutic target for HNSCC.

Survivin Expression in Luminal Breast Cancer and Adjacent Normal Tissue for Immuno-Oncology Applications.

Survivin (BIRC5) is a tumor-associated antigen (TAA) overexpressed in various tumors but present at low to undetectable levels in normal tissue. Survivin is known to have a high expression in breast cancer (e.g., Ductal Carcinoma in situ (DCIS) and triple negative breast cancer). Previous studies have not compared survivin expression levels in DCIS tumor samples to levels in adjacent, normal breast tissue from the same patient. To ensure the effective use of survivin as a target for T cell immunotherapy of breast cancer, it is essential to ascertain the varying levels of survivin expression between DCIS tumor tissue samples and the adjacent normal breast tissue taken from the same patient simultaneously. Next-generation sequencing of RNA (RNA-seq) in normal breast tissue and tumor breast tissue from five women presenting with DCIS for lumpectomy was used to identify sequence variation and expression levels of survivin. The identity of both tumor and adjacent normal tissue samples were corroborated by histopathology. Survivin was overexpressed in human breast tissue tumor samples relative to the corresponding adjacent human normal breast tissue. Wild-type survivin transcripts were the predominant species identified in all tumor tissue sequenced. This study demonstrates upregulated expression of wild type survivin in DCIS tumor tissue versus normal breast tissue taken from the same patient at the same time, and provides evidence that developing selective cytotoxic T lymphocyte (CTL) immunotherapy for DCIS targeting survivin warrants further study.

Exploring breast tissue microbial composition and the association with breast cancer risk factors

BackgroundMicrobial dysbiosis has emerged as an important element in the development and progression of various cancers, including breast cancer. However, the microbial composition of the breast from healthy individuals, even relative to risk of developing breast cancer, remains unclear. Here, we performed a comprehensive analysis of the microbiota of the normal breast tissue, which was analyzed in relation to the microbial composition of the tumor and adjacent normal tissue.MethodsThe study cohorts included 403 cancer-free women (who donated normal breast tissue cores) and 76 breast cancer patients (who donated tumor and/or adjacent normal tissue samples). Microbiome profiling was obtained by sequencing the nine hypervariable regions of the 16S rRNA gene (V1V2, V2V3, V3V4, V4V5, V5V7, and V7V9). Transcriptome analysis was also performed on 190 normal breast tissue samples. Breast cancer risk score was assessed using the Tyrer-Cuzick risk model.ResultsThe V1V2 amplicon sequencing resulted more suitable for the analysis of the normal breast microbiome and identified Lactobacillaceae (Firmicutes phylum), Acetobacterraceae, and Xanthomonadaceae (both Proteobacteria phylum) as the most abundant families in the normal breast. However, Ralstonia (Proteobacteria phylum) was more abundant in both breast tumors and histologically normal tissues adjacent to malignant tumors. We also conducted a correlation analysis between the microbiome and known breast cancer risk factors. Abundances of the bacterial taxa Acetotobacter aceti, Lactobacillus vini, Lactobacillus paracasei, and Xanthonomas sp. were associated with age (p < 0.0001), racial background (p < 0.0001), and parity (p < 0.0001). Finally, transcriptome analysis of normal breast tissues showed an enrichment in metabolism- and immune-related genes in the tissues with abundant Acetotobacter aceti, Lactobacillus vini, Lactobacillus paracasei, and Xanthonomas sp., whereas the presence of Ralstonia in the normal tissue was linked to dysregulation of genes involved in the carbohydrate metabolic pathway.ConclusionsThis study defines the microbial features of normal breast tissue, thus providing a basis to understand cancer-related dysbiosis. Moreover, the findings reveal that lifestyle factors can significantly affect the normal breast microbial composition.

Long non-coding RNAs CCAT1 and CCAT2 in colorectal liver metastases are tumor-suppressive via MYC interaction and might predict patient outcomes.

Liver metastases severely reduce the long term survival of colorectal cancer patients. Long non-coding RNAs (lncRNAs) CCAT1 and CCAT2 have previously been found to be associated with impaired patient outcomes in primary colorectal cancer. We aimed to elucidate the role of CCAT1 and CCAT2 in colorectal liver metastases. Total RNA was isolated from 97 human tissue samples of colorectal liver metastases and adjacent normal liver tissue. Gene expression analysis was performed by RT-qPCR and Multiplex ELISA and correlated with patient characteristics and survival. Gene expression, cancer cell migration, invasion, and proliferation were studied after siRNA-mediated knockdown of CCAT1, CCAT2, and MYC in metastatic colorectal cancer cell lines Colo205 and HROC277Met2. Elevated expression levels of lncRNAs CCAT1 and CCAT2, and their common target MYC in colorectal liver metastases were associated with prolonged progression-free survival after liver resection. High expression of CCAT1 was likewise associated with prolonged overall survival. Knockdown of CCAT1, CCAT2, and MYC resulted in increased migratory and invasive potential in metastatic colorectal cancer cell lines. Gene expression analysis revealed alterations in constituents of Wnt signaling following knockdown. Our findings demonstrate tumor-suppressive functions of lncRNAs CCAT1 and CCAT2 in colorectal liver metastases. They suppress Wnt signaling directly and indirectly through target gene MYC and might prevent further metastatic spread from colorectal liver metastases.

Abstract A017: Molecular analysis of matched PIN, invasive prostate cancer, and adjacent normal prostate tissue samples reveal distinct transcriptional signatures and clonal relationships

Abstract Background: Prostate cancer (PCa) is highly heterogeneous, and while some tumors remain indolent throughout a patient's lifetime, others are highly aggressive, leading to significant morbidity and death. The current methods for PCa diagnosis and prognosis are highly suboptimal, resulting in over-diagnosis and overtreatment of many clinically insignificant tumors. To understand the nature of PCa heterogeneity, we conducted comprehensive genomic analyses on matched samples of adjacent normal prostate tissue, prostate intraepithelial neoplasia (PIN), and invasive PCa. Methods: To investigate the changes cells undergo during PCa development and progression, we analyzed genomic and transcriptomic alterations in 92 adjacent normal, 80 PIN, and 99 PCa samples from 34 patients. For each sample type, both epithelial and stromal components were analyzed separately using laser capture microdissection of formalin fixed paraffin embedded tissue. Transcriptomic analysis was performed using smart3-SEQ and copy number analysis was performed by low-pass whole genome sequencing (WGS). The samples were analyzed as three separate data sets. Results: We studied the spectrum of molecular changes present in both epithelial and stromal samples. A negative-binomial regression model was used to identify differentially expressed genes between adjacent normal prostate tissue and invasive PCa in epithelium and stroma separately using the discovery data set. The resulting gene lists were used to perform non-negative matrix factorization clustering of all samples in the three datasets separately. This analysis identified two epithelial and two stromal clusters with distinct RNA expression profiles in all three data sets. For invasive PCa samples, all except three epithelial samples and five stromal samples clustered in the ‘invasive-like’ clusters. Similarly for adjacent normal samples, all except three of the epithelial and six of the stromal samples clustered as ‘normal-like’ across the three datasets. For PIN samples, 54% of epithelial and 62% of stromal samples classified as ‘normal-like’. We performed phylogenetic analysis of WGS data and identified PIN lesions with and without clear clonal relation to invasive PCa lesions. Recurrent copy number variations were identified in both PIN and PCa lesions. Conclusion. We identified two distinct epithelial and two distinct stromal expression clusters with ‘invasive-like’ and ‘normal-like’ signatures. WGS analysis revealed recurrent copy number alterations in PIN and PCa lesions, and evidence of clonal relationships between PIN and invasive PCa. These studies provide new insight into PIN biology and the relationship between PIN and invasive PCa. Citation Format: Siri H. Strand, Okyaz Eminaga, Sujay Vennam, Chunfang Zhu, Jason Wang, Sushama Varma, Rosalie Nolley, Christian Kunder, Jonathan Pollack, Andreas Roeder, Karina D. Sorensen, James D. Brooks, Robert B. West. Molecular analysis of matched PIN, invasive prostate cancer, and adjacent normal prostate tissue samples reveal distinct transcriptional signatures and clonal relationships [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A017.

Evaluation of epigenetic methylation biomarkers for the detection of colorectal cancer using droplet digital PCR

Colorectal cancer (CRC) is the third most common cancer worldwide. Screening programs allow early diagnosis and have improved the clinical management of this disease. Aberrant DNA methylation is increasingly being explored as potential biomarkers for many types of cancers. In this study we investigate the methylation of ten target genes in 105 CRC and paired normal adjacent colonic tissue samples using a MethylLight droplet digital PCR (ML-ddPCR) assay. Receiver operator characteristic (ROC) curves were used to determine the diagnostic performance of all target genes individually and in combination. All 515 different combinations of genes showed significantly higher levels of methylation in CRC tissue. The combination of multiple target genes into a single test generally resulted in greater diagnostic accuracy when compared to single target genes. Our data confirms that ML-ddPCR is able to reliably detect significant differences in DNA methylation between CRC tissue and normal adjacent colonic tissue in a specific selection of target genes.

High Expression of Tumor HLA-DR Predicts Better Prognosis and Response to Anti-PD-1 Therapy in Laryngeal Squamous Cell Carcinoma

BackgroundHLA-DR is expressed in epithelial and several types of tumor cells. However, the correlation between tumor-expressed HLA-DR (teHLA-DR) and patient outcome as well as its regulation on the tumor microenvironment (TME) of laryngeal squamous cell carcinoma (LSCC) are yet to be elucidated. MethodsHematoxylin and eosin (HE) staining were performed to define the tumor nest and stroma of LSCC tissue microarrays. teHLA-DR tumor cell, CD4+ and CD8+ tumor-infiltrating T lymphocytes (TITLs) were obtained and analyzed through double-labeling immunofluorescence and immunohistochemical staining. The recurrence-free (RFS) and overall survival (OS) curves were plotted using the Kaplan-Meier method and tested by the log-rank test method. Expression of teHLA-DR+ tumor cells and infiltration of T lymphocytes and their corresponding subgroups were analyzed by flow cytometry using fresh LSCC tissue samples. ResultsOur research discovered elevated expressions of multiple MHC-II-related genes in tumor compared to the adjacent normal tissue samples of LSCC patients. We also found that patients in the teHLA-DR high-expression group (teHLA-DRhigh) tend to have less tumor recurrence and better survival outcomes compared to those in the teHLA-DRlow group. Intriguingly, teHLA-DR+ tumor cells had significantly higher PD-L1 and PD-L2 expression and their TME showed increased infiltrated T lymphocytes (TITLs). Flow cytometry analysis and IHC staining indicated that CD4+ TITLs but not CD3+ total TITLs or CD8+ TITLs were significantly enriched in teHLA-DR+ tumors. ConclusionsteHLA-DR may be a predictive marker for favorable prognosis and response to anti-PD-1/PD-L1 therapy of LSCC, possibly due to the increased CD4+ TITLs in the TME.

Expression and Prognostic Value of Lgr5 in Patients with Recurrent Nasopharyngeal Carcinoma.

As a cancer stem cells (CSCs) surface marker, Lgr5 plays an important role in the signal transduction of cancer cells and is a potential biomarker for cancer diagnosis and prognosis. However, the expression and prognostic value of Lgr5 in recurrent nasopharyngeal carcinoma (rNPC) remains ambiguous. We used RNA sequencing to screen differentially expressed mRNAs in eleven specimens of rNPC tissues and five fresh adjacent normal tissue samples and the CSC marker, Lgr5, was identified. The expression level of Lgr5 in rNPC samples was also detected by immunohistochemistry and Western blot assay. The chi-square test was used to analyze the relationship between the clinicopathological variables and the immunostaining of Lgr5. The Log-rank method was used for prognosis analysis. The Cox regression model was used for univariate and multivariate analysis. Significantly elevated expression of Lgr5 in the rNPC tissues was observed compared to the normal tissues using RNA sequencing, Western blot and immunohistochemistry. The expression of Lgr5 was significantly correlated with the T stage (P=0.014). High Lgr5 expression (P=0.007), tumor necrosis (P=0.013) and WHO type II (P=0.043) in rNPC patients exhibited worse overall survival (OS). Lgr5 expression was proved to be an independent risk factor for OS (P=0.035) in multivariate analyses, and had promising predictive value for survival and recurrence in rNPC patients (area under the ROC curve: 0.711 and 0.665, P=0.017 and 0.028, respectively). Lgr5 as a CSC marker is a promising therapeutic target and could be employed to predict the survival prognosis of rNPC patients.

Abstract LB005: Insights of renal cell carcinoma from multiomic perspective

Abstract Introduction: Clear cell renal carcinoma is the most frequent form of renal malignancy, with an increasing incidence rate worldwide. In this study we used a multi-omic approach to differentiate normal and tumor tissues in clear cell Renal Cell Carcinoma (ccRCC). Methods: Using transcriptomic data of patients with malignant and adjacent normal tissue samples from gene chip and RNA-Seq cohorts, we identified the top genes over-expressed in ccRCC. We collected surgically resected ccRCC specimens to further investigate the transcriptomic results on the proteome level. The differential protein abundance was evaluated using targeted mass spectrometry (MS). Results: We assembled a database of more than 600 renal tissue samples from NCBI GEO and TCGA and used these to uncover the top genes with higher expression in ccRCC. For protein level analysis 162 malignant and normal kidney tissue samples have been acquired. The most consistently upregulated genes were IGFBP3, PLIN2, PLOD2, PFKP, VEGFA, and CCND1 (p&amp;lt;1E-05 for each gene). Mass spectrometry further validated the differential protein abundance of these genes (IGFBP3, p = 7.53E-18; PLIN2, p = 3.9E-39; PLOD2, p = 6.51E-36; PFKP, p = 1.01E-47; VEGFA, p = 1.40E-22; CCND1, p= 1.04E-24). We also identified proteins correlating with overall survival. Conclusions: We used transcriptomic and proteomic data to identify a minimal panel of proteins highly specific for clear cell renal carcinoma tissues. The introduced gene panel could be used as a promising tool in the clinical setting. Citation Format: Aron Bartha, Zsuzsanna Darula, Gyongyi Munkacsy, Eva Klement, David Fenyo, Peter Nyirady, Balazs Gyorffy. Insights of renal cell carcinoma from multiomic perspective [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB005.

Abstract LB131: Association between epigenetic heterogeneity of esophageal adenocarcinoma and response to first-line immunochemotherapy in LUD2015-005 Trial

Abstract Immune checkpoint inhibitors (ICI) were recently approved as a first-line treatment for inoperable esophageal adenocarcinomas (EAC) in combination with chemotherapy (CTX). Unfortunately, even though EAC has one of the highest tumor mutation burdens among all cancer types, response to immunochemotherapy (ICI+CTX) is highly variable, and the underlying molecular basis is incompletely understood. While genomic features such as mutations and copy number alterations in EAC are highly variable across samples, DNA methylation array data from numerous studies suggested that EAC can be clustered into a few consistent subtypes. We thus hypothesize that epigenetic heterogeneity of EAC may contribute to or associate with patients’ heterogeneous response to ICI+CTX, possibly through modulation of key genes or neoantigens. To test this hypothesis, we took advantage of a unique ICI+CTX LUD2015-005 trial in which inoperable EAC patients received first-line ICI for four weeks (ICI-4W), followed by ICI+CTX. Instead of methylation array, we also used a new DNA methylation sequencing technology, TET-Assisted Pyridine-Borane Sequencing (TAPS), on 64 tumor and 15 adjacent normal tissue samples collected from 23 EAC patients before and throughout treatment. Unlike prior studies that used methylation arrays which only cover ~2.5% of all CpG sites in the genome, TAPS detects genome-wide, base-resolution DNA methylation information. Furthermore, many previous studies did not account for variability in tumor content between samples, which could impact downstream DNA methylation analyses. In view of this, we proposed an analytical framework that includes tumor content and local copy number as key parameters, which estimates the tumor and stromal methylation and tests for differentially methylated regions (DMR). We also performed unsupervised clustering based on large scale genome-wide methylation pattern and revealed 2 major tumor clusters. Using the whole genome data, we identified a large set of shared tumor-specific DMRs, revealing that hypomethylation across wide regions of the genome and hypermethylation of certain gene bodies are common features in EAC. We also identified a set of shared outcome-associated DMRs in pre-treatment samples, which predicts better progression-free survival at 12 months. We further performed subgroup analysis of the 2 tumor clusters. Interestingly, we found higher numbers of cluster-specific prognostic DMRs with stronger effect sizes. This suggests that tumor subtypes may respond differently to treatment, and should be considered separately in statistical analyses. Altogether, these results indicate that a detailed understanding of tumor epigenetic heterogeneity will improve patient stratification in immunochemotherapy. Citation Format: Phil F. Xie, Jaeho Chang, Paulina Siejka-Zielińska, Masato Inoue, Magdalena Drożdż, Joseph A. Chadwick, Thomas M. Carroll, Richard P. Owen, Michael J. White, Joseph Kaplinsky, Robert Amess, Mark Middleton, Skirmantas Kriaucionis, Chunxiao Song, Benjamin Schuster-Böckler, Xin Lu. Association between epigenetic heterogeneity of esophageal adenocarcinoma and response to first-line immunochemotherapy in LUD2015-005 Trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB131.

The Local Tumor Microbiome Is Associated with Survival in Late-Stage Colorectal Cancer Patients.

The gut microbiome is associated with survival in colorectal cancer. Single organisms have been identified as markers of poor prognosis. However, in situ imaging of tumors demonstrate a polymicrobial tumor-associated community. To understand the role of these polymicrobial communities in survival, we conducted a nested case-control study in late-stage cancer patients undergoing resection for primary adenocarcinoma. The microbiome of paired tumor and adjacent normal tissue samples was profiled using 16S rRNA sequencing. We found a consistent difference in the microbiome between paired tumor and adjacent tissue, despite strong individual microbial identities. Furthermore, a larger difference between normal and tumor tissue was associated with prognosis: patients with shorter survival had a larger difference between normal and tumor tissue. Within the tumor tissue, we identified a 39-member community statistic associated with survival; for every log2-fold increase in this value, an individual's odds of survival increased by 20% (odds ratio survival 1.20; 95% confidence interval = 1.04 to 1.33). Our results suggest that a polymicrobial tumor-specific microbiome is associated with survival in late-stage colorectal cancer patients. IMPORTANCE Microbiome studies in colorectal cancer (CRC) have primarily focused on the role of single organisms in cancer progression. Recent work has identified specific organisms throughout the intestinal tract, which may affect survival; however, the results are inconsistent. We found differences between the tumor microbiome and the microbiome of the rest of the intestine in patients, and the magnitude of this difference was associated with survival, or, the more like a healthy gut a tumor looked, the better a patient's prognosis. Our results suggest that future microbiome-based interventions to affect survival in CRC will need to target the tumor community.

Network and functional analyses of differentially expressed genes in gastric cancer provide new biomarkers associated with disease pathogenesis

BackgroundGastric cancer is a dominant source of cancer-related death around the globe and a serious threat to human health. However, there are very few practical diagnostic approaches and biomarkers for the treatment of this complex disease.MethodsThis study aimed to evaluate the association between differentially expressed genes (DEGs), which may function as potential biomarkers, and the diagnosis and treatment of gastric cancer (GC). We constructed a protein-protein interaction network from DEGs followed by network clustering. Members of the two most extensive modules went under the enrichment analysis. We introduced a number of hub genes and gene families playing essential roles in oncogenic pathways and the pathogenesis of gastric cancer. Enriched terms for Biological Process were obtained from the “GO” repository.ResultsA total of 307 DEGs were identified between GC and their corresponding normal adjacent tissue samples in GSE63089 datasets, including 261 upregulated and 261 downregulated genes. The top five hub genes in the PPI network were CDK1, CCNB1, CCNA2, CDC20, and PBK. They are involved in focal adhesion formation, extracellular matrix remodeling, cell migration, survival signals, and cell proliferation. No significant survival result was found for these hub genes.ConclusionsUsing comprehensive analysis and bioinformatics methods, important key pathways and pivotal genes related to GC progression were identified, potentially informing further studies and new therapeutic targets for GC treatment.

Abstract 3345: Tissue of origin (TOO) localization using targeted methylation biomarkers discovered by whole-genome bisulfite sequencing

Abstract DNA methylation is a promising biomarker for tissue of origin (TOO) localization, which is important for classification of cancer of unknown primary site (CUP) in multiple cancer early detection. The current most of CpG sites of TOO focused on CpG islands based on The Cancer Genome Atlas (TCGA) data sets, but remains largely under-explored across the whole genome. In this study, we conducted the whole-genome bisulfite sequencing (WGBS) in 481 tumor samples and 361 matched adjacent normal tissue samples for 9 common types of cancers, including lung, breast, colon, liver, stomach, lymph, pancreas, esophageal and ovarian. After adjusted the tumor cells’ DNA methylation rates, 3,000 CpG sites, 60% of which were not on CpG islands, were selected through Random Forest classifier (multi-class) to identify cancer type. To evaluate these TOO methylation biomarkers, we used Random Forest Model to predict TOO of the methylation data sets in The Cancer Genome Atlas (TCGA), including 1,704 tumor samples. The results showed that accuracy of TOO could achieve 98.5% for these tumor samples of TCGA. Among these samples, the accuracy of TOO of breast, liver, lung, colorectal and pancreas were 99.6%, 99.9%, 97.7%, 99.2% and 99.3% respectively. Several samples from Esophagus and Stomach were classified to each other, and their accuracy of TOO was relatively low, 97.6% and 96.7%. It demonstrated that these methylation biomarkers could detect multiple cancers, and the multi-class model had good performance for TOO localization. Citation Format: Qiang Wei, Wanglong Deng, Zhihui Xu, Yihui Han, Yuan Yang, Chao Zhang, Xiaoqiang Wang, Xuan Tang, Chao Song, Qing Xu, Yong Ren. Tissue of origin (TOO) localization using targeted methylation biomarkers discovered by whole-genome bisulfite sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3345.

Abstract NG06: Investigating biological mediators of social and environmental risk factors on cancer health disparities

Abstract NG06: Investigating biological mediators of social and environmental risk factors on cancer health disparities

A novel prognostic signature for clear cell renal cell carcinoma constructed using necroptosis-related miRNAs

BackgroundThis work aims to analyze the relationship between necroptosis-related microRNAs (miRNAs) and the prognosis of clear cell renal cell carcinoma (ccRCC).MethodsThe miRNAs expression profiles of ccRCC and normal renal tissues from The Cancer Genome Atlas (TCGA) database were used to construct a matrix of the 13 necroptosis-related miRNAs. Cox regression analysis was used to construct a signature to predict the overall survival of ccRCC patients. The genes targeted by the necroptosis-related miRNAs in the prognostic signature were predicted using miRNA databases. Gene Ontology (Go) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to investigate the genes targeted by the necroptosis-related miRNAs. The expression levels of selected miRNAs in 15 paired samples (of ccRCC tissues and adjacent normal renal tissues) were investigated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR).ResultsSix necroptosis-related miRNAs were found to differentially expressed between ccRCC and normal renal tissues. A prognostic signature consisting of miR-223-3p, miR-200a-5p, and miR-500a-3p was constructed using Cox regression analysis and risk scores were calculated. Multivariate Cox regression analysis showed that the hazard ratio was 2.0315 (1.2627–3.2685, P = 0.0035), indicating that the risk score of the signature was an independent risk factor. The receiver operating characteristic (ROC) curve showed that the signature has a favorable predictive capacity and the Kaplan-Meier survival analysis indicated that ccRCC patients with higher risk scores had worse prognoses (P < 0.001). The results of the RT-qPCR verified that all three miRNAs used in the signature were differentially expressed between ccRCC and normal tissues (P < 0.05).ConclusionThe three necroptosis-related-miRNAs used in this study could be a valuable signature for the prognosis of ccRCC patients. Necroptosis-related miRNAs should be further explored as prognostic indicators for ccRCC.

RIG-I Promotes Tumorigenesis and Confers Radioresistance of Esophageal Squamous Cell Carcinoma by Regulating DUSP6.

We investigated the expression and biological function of retinoic acid inducible gene I (RIG-I) in esophageal squamous cell carcinoma (ESCC). Materials and methods: An immunohistochemical analysis was performed on 86 pairs of tumor tissue and adjacent normal tissue samples of patients with ESCC. We generated RIG-I-overexpressing ESCC cell lines KYSE70 and KYSE450, and RIG-I- knockdown cell lines KYSE150 and KYSE510. Cell viability, migration and invasion, radioresistance, DNA damage, and cell cycle were evaluated using CCK-8, wound-healing and transwell assay, colony formation, immunofluorescence, and flow cytometry and Western blotting, respectively. RNA sequencing was performed to determine the differential gene expression between controls and RIG-I knockdown. Tumor growth and radioresistance were assessed in nude mice using xenograft models. RIG-I expression was higher in ESCC tissues compared with that in matched non-tumor tissues. RIG-I overexpressing cells had a higher proliferation rate than RIG-I knockdown cells. Moreover, the knockdown of RIG-I slowed migration and invasion rates, whereas the overexpression of RIG-I accelerated migration and invasion rates. RIG-I overexpression induced radioresistance and G2/M phase arrest and reduced DNA damage after exposure to ionizing radiations compared with controls; however, it silenced the RIG-I enhanced radiosensitivity and DNA damage, and reduced the G2/M phase arrest. RNA sequencing revealed that the downstream genes DUSP6 and RIG-I had the same biological function; silencing DUSP6 can reduce the radioresistance caused by the overexpression of RIG-I. RIG-I knockdown depleted tumor growth in vivo, and radiation exposure effectively delayed the growth of xenograft tumors compared with the control group. RIG-I enhances the progression and radioresistance of ESCC; therefore, it may be a new potential target for ESCC-targeted therapy.

Epigenetic Activation of Tensin 4 Promotes Gastric Cancer Progression.

Gastric cancer (GC) is a complex disease influenced by multiple genetic and epigenetic factors. Chronic inflammation caused by Helicobacter pylori infection and dietary risk factors can result in the accumulation of aberrant DNA methylation in gastric mucosa, which promotes GC development. Tensin 4 (TNS4), a member of the Tensin family of proteins, is localized to focal adhesion sites, which connect the extracellular matrix and cytoskeletal network. We identified upregulation of TNS4 in GC using quantitative reverse transcription PCR with 174 paired samples of GC tumors and adjacent normal tissues. Transcriptional activation of TNS4 occurred even during the early stage of tumor development. TNS4 depletion in GC cell lines that expressed high to moderate levels of TNS4, i.e., SNU-601, KATO III, and MKN74, reduced cell proliferation and migration, whereas ectopic expression of TNS4 in those lines that expressed lower levels of TNS4, i.e., SNU-638, MKN1, and MKN45 increased colony formation and cell migration. The promoter region of TNS4 was hypomethylated in GC cell lines that showed upregulation of TNS4. We also found a significant negative correlation between TNS4 expression and CpG methylation in 250 GC tumors based on The Cancer Genome Atlas (TCGA) data. This study elucidates the epigenetic mechanism of TNS4 activation and functional roles of TNS4 in GC development and progression and suggests a possible approach for future GC treatments.

Adaptive immune receptor features related to breast cancer tissue in Kenyan patients: high immunoglobulin gene expression and high levels of gamma-delta T-cells.

Characterization of the breast cancer (BC) immune response may provide information for a point of intervention, such as application of immunotherapeutic treatments. In this study, we sought to recover and characterize the adaptive immune receptor (IR) recombination reads from genomics files representing Kenyan patients, to better understand the immune response specifically related to those patients. We used a previously applied algorithm and software to obtain productive IR recombination reads from cancer and adjacent normal tissue samples representing 22 Kenyan BC patients. From both the RNAseq and exome files, there were significantly more T-cell receptor (TCR) recombination reads recovered from tumor samples compared to marginal tissue samples. Also, the immunoglobulin (IG) genes were expressed at a much higher level than the TCR genes (p-value = 0.0183) in the tumor samples. And, the tumor IG CDR3s consistently represented more positively charged amino acid R-groups, in comparison to the marginal tissue, IG CDR3s. For Kenyan patients, a high level of IG expression, representing specific CDR3 chemistries, was associated with BC. These results lay the foundation for studies that could support specific immunotherapeutic interventions for Kenyan BC patients.