Limits...
Epigenetic-Mediated Downregulation of μ-Protocadherin in Colorectal Tumours.

Bujko M, Kober P, Statkiewicz M, Mikula M, Ligaj M, Zwierzchowski L, Ostrowski J, Siedlecki JA - Gastroenterol Res Pract (2015)

Bottom Line: Mucin-like protocadherin is implicated in intercellular adhesion and its expression was found decreased in colorectal cancer (CRC).This study has compared MUPCDH (CDHR5) expression in three key types of colorectal tissue samples, for normal mucosa, adenoma, and carcinoma.Epigenetic mechanisms are involved in this silencing.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 5 W.K. Roentgena, 02-781 Warsaw, Poland.

ABSTRACT
Carcinogenesis involves altered cellular interaction and tissue morphology that partly arise from aberrant expression of cadherins. Mucin-like protocadherin is implicated in intercellular adhesion and its expression was found decreased in colorectal cancer (CRC). This study has compared MUPCDH (CDHR5) expression in three key types of colorectal tissue samples, for normal mucosa, adenoma, and carcinoma. A gradual decrease of mRNA levels and protein expression was observed in progressive stages of colorectal carcinogenesis which are consistent with reports of increasing MUPCDH 5' promoter region DNA methylation. High MUPCDH methylation was also observed in HCT116 and SW480 CRC cell lines that revealed low gene expression levels compared to COLO205 and HT29 cell lines which lack DNA methylation at the MUPCDH locus. Furthermore, HCT116 and SW480 showed lower levels of RNA polymerase II and histone H3 lysine 4 trimethylation (H3K4me3) as well as higher levels of H3K27 trimethylation at the MUPCDH promoter. MUPCDH expression was however restored in HCT116 and SW480 cells in the presence of 5-Aza-2'-deoxycytidine (DNA methyltransferase inhibitor). Results indicate that μ-protocadherin downregulation occurs during early stages of tumourigenesis and progression into the adenoma-carcinoma sequence. Epigenetic mechanisms are involved in this silencing.

No MeSH data available.


Related in: MedlinePlus

Immunohistochemical staining examples of mucin-like protocadherin in tissue samples. (a–c) Three examples of adenocarcinoma (AC) and matched normal colonic mucosa (NC). Two of the samples were classified as negative for membrane expression (a, b) and one as of low expression (c); (d) two examples of adenomas with moderate mucin-like protocadherin membrane expression; magnification ×100.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4417986&req=5

fig2: Immunohistochemical staining examples of mucin-like protocadherin in tissue samples. (a–c) Three examples of adenocarcinoma (AC) and matched normal colonic mucosa (NC). Two of the samples were classified as negative for membrane expression (a, b) and one as of low expression (c); (d) two examples of adenomas with moderate mucin-like protocadherin membrane expression; magnification ×100.

Mentions: Quantitative PCR-based expression analysis demonstrated significant decreases of MUPCDH levels in AD samples compared to NC (fold change of expression (FC) = 4.46; p < 0.0001) as well as in the AC samples compared to NC (FC = −8.71; p < 0.0001). Cancer tissue sections also showed a significant decrease of gene mRNA levels compared to AD (FC = 1.95; p < 0.0001) (Figure 1). The results show a stepwise downregulation of gene expression through the subsequent progression stages of colorectal tumours. This trend could be clearly observed in the immunohistochemical staining of AC sections with matched normal samples and adenomas by using the antibody against mucin-like protocadherin and then grading the staining intensity scale. High immunoreactivity was observed primarily for NC sections in the membranes of normal colonic epithelial cells with some degree of polarity in expression. Moderate expression was observed in epithelial cells located at the site of lamina muscularis but was higher in cells located closer to the intestinal lumen. The greatest expression was observed in cells of the apical epithelium layer and those of the crypt lumen. Four AC samples revealed mucin-like protocadherin expression comparable to the matched NC, whereas the expression was clearly lower in the other 10 remaining AC samples. The membrane immunoreactivity was scored as moderate, low, and undetected in 6, 2, and 2 of these AC samples, respectively. Two of the adenoma samples were classified as being of high expression, whereas the other 8 AD samples were assigned as being of moderate expression. Examples are presented in Figure 2.


Epigenetic-Mediated Downregulation of μ-Protocadherin in Colorectal Tumours.

Bujko M, Kober P, Statkiewicz M, Mikula M, Ligaj M, Zwierzchowski L, Ostrowski J, Siedlecki JA - Gastroenterol Res Pract (2015)

Immunohistochemical staining examples of mucin-like protocadherin in tissue samples. (a–c) Three examples of adenocarcinoma (AC) and matched normal colonic mucosa (NC). Two of the samples were classified as negative for membrane expression (a, b) and one as of low expression (c); (d) two examples of adenomas with moderate mucin-like protocadherin membrane expression; magnification ×100.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4417986&req=5

fig2: Immunohistochemical staining examples of mucin-like protocadherin in tissue samples. (a–c) Three examples of adenocarcinoma (AC) and matched normal colonic mucosa (NC). Two of the samples were classified as negative for membrane expression (a, b) and one as of low expression (c); (d) two examples of adenomas with moderate mucin-like protocadherin membrane expression; magnification ×100.
Mentions: Quantitative PCR-based expression analysis demonstrated significant decreases of MUPCDH levels in AD samples compared to NC (fold change of expression (FC) = 4.46; p < 0.0001) as well as in the AC samples compared to NC (FC = −8.71; p < 0.0001). Cancer tissue sections also showed a significant decrease of gene mRNA levels compared to AD (FC = 1.95; p < 0.0001) (Figure 1). The results show a stepwise downregulation of gene expression through the subsequent progression stages of colorectal tumours. This trend could be clearly observed in the immunohistochemical staining of AC sections with matched normal samples and adenomas by using the antibody against mucin-like protocadherin and then grading the staining intensity scale. High immunoreactivity was observed primarily for NC sections in the membranes of normal colonic epithelial cells with some degree of polarity in expression. Moderate expression was observed in epithelial cells located at the site of lamina muscularis but was higher in cells located closer to the intestinal lumen. The greatest expression was observed in cells of the apical epithelium layer and those of the crypt lumen. Four AC samples revealed mucin-like protocadherin expression comparable to the matched NC, whereas the expression was clearly lower in the other 10 remaining AC samples. The membrane immunoreactivity was scored as moderate, low, and undetected in 6, 2, and 2 of these AC samples, respectively. Two of the adenoma samples were classified as being of high expression, whereas the other 8 AD samples were assigned as being of moderate expression. Examples are presented in Figure 2.

Bottom Line: Mucin-like protocadherin is implicated in intercellular adhesion and its expression was found decreased in colorectal cancer (CRC).This study has compared MUPCDH (CDHR5) expression in three key types of colorectal tissue samples, for normal mucosa, adenoma, and carcinoma.Epigenetic mechanisms are involved in this silencing.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 5 W.K. Roentgena, 02-781 Warsaw, Poland.

ABSTRACT
Carcinogenesis involves altered cellular interaction and tissue morphology that partly arise from aberrant expression of cadherins. Mucin-like protocadherin is implicated in intercellular adhesion and its expression was found decreased in colorectal cancer (CRC). This study has compared MUPCDH (CDHR5) expression in three key types of colorectal tissue samples, for normal mucosa, adenoma, and carcinoma. A gradual decrease of mRNA levels and protein expression was observed in progressive stages of colorectal carcinogenesis which are consistent with reports of increasing MUPCDH 5' promoter region DNA methylation. High MUPCDH methylation was also observed in HCT116 and SW480 CRC cell lines that revealed low gene expression levels compared to COLO205 and HT29 cell lines which lack DNA methylation at the MUPCDH locus. Furthermore, HCT116 and SW480 showed lower levels of RNA polymerase II and histone H3 lysine 4 trimethylation (H3K4me3) as well as higher levels of H3K27 trimethylation at the MUPCDH promoter. MUPCDH expression was however restored in HCT116 and SW480 cells in the presence of 5-Aza-2'-deoxycytidine (DNA methyltransferase inhibitor). Results indicate that μ-protocadherin downregulation occurs during early stages of tumourigenesis and progression into the adenoma-carcinoma sequence. Epigenetic mechanisms are involved in this silencing.

No MeSH data available.


Related in: MedlinePlus