Methylation-Based Signatures for Gastroesophageal Tumor Classification

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 rende...

Full description

Bibliographic Details
Main Authors: Nikolay Alabi, Dropen Sheka, Ashar Siddiqui, Edwin Wang
Format: Article
Language:English
Published: MDPI AG 2020-05-01
Series:Cancers
Subjects:
Online Access:https://www.mdpi.com/2072-6694/12/5/1208
_version_ 1797568229217927168
author Nikolay Alabi
Dropen Sheka
Ashar Siddiqui
Edwin Wang
author_facet Nikolay Alabi
Dropen Sheka
Ashar Siddiqui
Edwin Wang
author_sort Nikolay Alabi
collection DOAJ
description 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 (n<sub>EC</sub> = 185, n<sub>GC</sub> = 395; EC, esophageal cancer; GC gastric cancer) and validation (n<sub>EC</sub> = 179, n<sub>GC</sub> = 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.
first_indexed 2024-03-10T19:54:26Z
format Article
id doaj.art-5756e2deb84e459886fe50a902711dde
institution Directory Open Access Journal
issn 2072-6694
language English
last_indexed 2024-03-10T19:54:26Z
publishDate 2020-05-01
publisher MDPI AG
record_format Article
series Cancers
spelling doaj.art-5756e2deb84e459886fe50a902711dde2023-11-20T00:06:04ZengMDPI AGCancers2072-66942020-05-01125120810.3390/cancers12051208Methylation-Based Signatures for Gastroesophageal Tumor ClassificationNikolay Alabi0Dropen Sheka1Ashar Siddiqui2Edwin Wang3Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 1N4, CanadaDepartment of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 1N4, CanadaCumming School of Medicine, University of Calgary, Calgary, Alberta T2N 1N4, CanadaCumming School of Medicine, University of Calgary, Calgary, Alberta T2N 1N4, CanadaContention 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 (n<sub>EC</sub> = 185, n<sub>GC</sub> = 395; EC, esophageal cancer; GC gastric cancer) and validation (n<sub>EC</sub> = 179, n<sub>GC</sub> = 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.https://www.mdpi.com/2072-6694/12/5/1208Multi-Survival Screening AlgorithmMSSmethylation array-based profilegastroesophageal junction cancerpredictorgastric cancer
spellingShingle Nikolay Alabi
Dropen Sheka
Ashar Siddiqui
Edwin Wang
Methylation-Based Signatures for Gastroesophageal Tumor Classification
Cancers
Multi-Survival Screening Algorithm
MSS
methylation array-based profile
gastroesophageal junction cancer
predictor
gastric cancer
title Methylation-Based Signatures for Gastroesophageal Tumor Classification
title_full Methylation-Based Signatures for Gastroesophageal Tumor Classification
title_fullStr Methylation-Based Signatures for Gastroesophageal Tumor Classification
title_full_unstemmed Methylation-Based Signatures for Gastroesophageal Tumor Classification
title_short Methylation-Based Signatures for Gastroesophageal Tumor Classification
title_sort methylation based signatures for gastroesophageal tumor classification
topic Multi-Survival Screening Algorithm
MSS
methylation array-based profile
gastroesophageal junction cancer
predictor
gastric cancer
url https://www.mdpi.com/2072-6694/12/5/1208
work_keys_str_mv AT nikolayalabi methylationbasedsignaturesforgastroesophagealtumorclassification
AT dropensheka methylationbasedsignaturesforgastroesophagealtumorclassification
AT asharsiddiqui methylationbasedsignaturesforgastroesophagealtumorclassification
AT edwinwang methylationbasedsignaturesforgastroesophagealtumorclassification