Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patterns

Altered claudin expression has been described in colon, prostatic, ovarian, and breast carcinoma. However, the role of epigenetic modifications in these genes and their role in colorectal cancer is unknown. We aimed our study to investigate whether claudin protein expression and methylation of CLDN...

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Main Authors: Victoria Hahn-Strömberg, Shlear Askari, Abrar Ahmad, Rahel Befekadu, Torbjörn K Nilsson
Format: Article
Language:English
Published: SAGE Publishing 2017-04-01
Series:Tumor Biology
Online Access:https://doi.org/10.1177/1010428317697569
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author Victoria Hahn-Strömberg
Shlear Askari
Abrar Ahmad
Rahel Befekadu
Torbjörn K Nilsson
author_facet Victoria Hahn-Strömberg
Shlear Askari
Abrar Ahmad
Rahel Befekadu
Torbjörn K Nilsson
author_sort Victoria Hahn-Strömberg
collection DOAJ
description Altered claudin expression has been described in colon, prostatic, ovarian, and breast carcinoma. However, the role of epigenetic modifications in these genes and their role in colorectal cancer is unknown. We aimed our study to investigate whether claudin protein expression and methylation of CLDN can influence the tumorigenesis of colorectal cancer. A total of 31 patients diagnosed with colorectal carcinoma was used in this study. Immunohistochemical staining was used to study protein expression in both tumor and the adjacent nonneoplastic mucosa of claudin 1, 4, and 7. To detect the DNA methylation pattern of CLDN1, 4, and 7, genomic DNA was extracted from both the tumor and the adjacent nonneoplastic mucosa. Methylation analysis was carried out using bisulfite pyrosequencing. Cell membrane staining intensity of all claudins was found significantly lower in colorectal cancer tissues when compared to paired normal mucosa (p ≤ 0.001). For claudin 4, the percentage of cells staining positively was also significantly reduced (p = 0.04). In normal mucosa, cytoplasm showed no staining for claudins in any patient, whereas in paired colorectal cancer tissues, significant cytoplasmic staining appeared both for claudin 1 (p = 0.04) and claudin 4 (p = 0.01). Tumor samples were significantly hypomethylated in CLDN1 (p < 0.05). In conclusion, our results show that CLDN1 is significantly hypomethylated in tumor samples and that the membrane staining intensity for claudin 1, 4, and 7 is significantly lower in colorectal cancer tissues than in adjacent nonneoplastic tissue. Colorectal cancer cells showed dystopic cytoplasmic location of claudins.
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spelling doaj-art-a9ced0f4150a4267a61498e43ee71f482025-08-20T02:54:43ZengSAGE PublishingTumor Biology1423-03802017-04-013910.1177/1010428317697569Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patternsVictoria Hahn-Strömberg0Shlear Askari1Abrar Ahmad2Rahel Befekadu3Torbjörn K Nilsson4Department of Medical Cell Biology, Uppsala University, Uppsala, SwedenDepartment of Clinical Research, Faculty of Medicine and Health, Örebro University, Örebro, SwedenDepartment of Clinical Research, Faculty of Medicine and Health, Örebro University, Örebro, SwedenDepartment of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, SwedenDivision of Clinical Chemistry, Department of Medical Biosciences, Umeå University, Umeå, SwedenAltered claudin expression has been described in colon, prostatic, ovarian, and breast carcinoma. However, the role of epigenetic modifications in these genes and their role in colorectal cancer is unknown. We aimed our study to investigate whether claudin protein expression and methylation of CLDN can influence the tumorigenesis of colorectal cancer. A total of 31 patients diagnosed with colorectal carcinoma was used in this study. Immunohistochemical staining was used to study protein expression in both tumor and the adjacent nonneoplastic mucosa of claudin 1, 4, and 7. To detect the DNA methylation pattern of CLDN1, 4, and 7, genomic DNA was extracted from both the tumor and the adjacent nonneoplastic mucosa. Methylation analysis was carried out using bisulfite pyrosequencing. Cell membrane staining intensity of all claudins was found significantly lower in colorectal cancer tissues when compared to paired normal mucosa (p ≤ 0.001). For claudin 4, the percentage of cells staining positively was also significantly reduced (p = 0.04). In normal mucosa, cytoplasm showed no staining for claudins in any patient, whereas in paired colorectal cancer tissues, significant cytoplasmic staining appeared both for claudin 1 (p = 0.04) and claudin 4 (p = 0.01). Tumor samples were significantly hypomethylated in CLDN1 (p < 0.05). In conclusion, our results show that CLDN1 is significantly hypomethylated in tumor samples and that the membrane staining intensity for claudin 1, 4, and 7 is significantly lower in colorectal cancer tissues than in adjacent nonneoplastic tissue. Colorectal cancer cells showed dystopic cytoplasmic location of claudins.https://doi.org/10.1177/1010428317697569
spellingShingle Victoria Hahn-Strömberg
Shlear Askari
Abrar Ahmad
Rahel Befekadu
Torbjörn K Nilsson
Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patterns
Tumor Biology
title Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patterns
title_full Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patterns
title_fullStr Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patterns
title_full_unstemmed Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patterns
title_short Expression of claudin 1, claudin 4, and claudin 7 in colorectal cancer and its relation with CLDN DNA methylation patterns
title_sort expression of claudin 1 claudin 4 and claudin 7 in colorectal cancer and its relation with cldn dna methylation patterns
url https://doi.org/10.1177/1010428317697569
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