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Oncogenic Role of miR-15a-3p in 13q Amplicon-Driven Colorectal Adenoma-to-Carcinoma Progression.

de Groen FL, Timmer LM, Menezes RX, Diosdado B, Hooijberg E, Meijer GA, Steenbergen RD, Carvalho B - PLoS ONE (2015)

Bottom Line: A subset of these genes, including the mir-17~92 cluster, are functionally involved in CRC development.These results could be confirmed by qRT-PCR in a series of 100 colon adenomas and carcinomas.Functional analysis of both mature miRNAs encoded by mir-15a, i.e. miR-15a-5p and miR-15a-3p, showed that silencing of miR-15a-3p significantly inhibited viability of CRC cells.Upon silencing of miR-15a-3p, mRNA expression of both genes increased in CRC cells, supporting miR-15a-3p mediated regulation of UPC2 and COPS2 expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands.

ABSTRACT
Progression from colorectal adenoma to carcinoma is strongly associated with an accumulation of genomic alterations, including gain of chromosome 13. This gain affects the whole q arm and is present in 40%-60% of all colorectal cancers (CRCs). Several genes located at this amplicon are known to be overexpressed in carcinomas due to copy number dosage. A subset of these genes, including the mir-17~92 cluster, are functionally involved in CRC development. The present study set out to explore whether apart from mir-17~92, other miRNAs located at the 13q amplicon show a copy number dependent dosage effect that may contribute to 13q-driven colorectal adenoma-to-carcinoma progression. Integration of publically available miRNA expression, target mRNA expression and DNA copy number data from 125 CRCs yielded three miRNAs, miR-15a, -17, and -20a, of which high expression levels were significantly correlated with a 13q gain and which influenced target mRNA expression. These results could be confirmed by qRT-PCR in a series of 100 colon adenomas and carcinomas.Functional analysis of both mature miRNAs encoded by mir-15a, i.e. miR-15a-5p and miR-15a-3p, showed that silencing of miR-15a-3p significantly inhibited viability of CRC cells. Integration of miR-15a expression levels with mRNA expression data of predicted target genes identified mitochondrial uncoupling protein 2 (UCP2) and COP9 signalosome subunit 2 (COPS2) as candidates with significantly decreased expression in CRCs with 13q gain. Upon silencing of miR-15a-3p, mRNA expression of both genes increased in CRC cells, supporting miR-15a-3p mediated regulation of UPC2 and COPS2 expression. In conclusion, significant overexpression of miR-15a-3p due to gain of 13q is functionally relevant in CRC, with UCP2 and COPS2 as candidate target genes. Taken together our findings suggest that miR-15a-3p may contribute to adenoma-to-carcinoma progression.

No MeSH data available.


Related in: MedlinePlus

Analysis of mRNA expression levels of target genes in colorectal cancer cell line SW480.Relative expression of UCP2 and COPS2 in SW480 cells silenced for miR-15a-5p, -3p and miR-17 compared to a non-targeting control (* p<0.05).
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pone.0132495.g005: Analysis of mRNA expression levels of target genes in colorectal cancer cell line SW480.Relative expression of UCP2 and COPS2 in SW480 cells silenced for miR-15a-5p, -3p and miR-17 compared to a non-targeting control (* p<0.05).

Mentions: To further establish a role of miR-15a overexpression in UCP2 and COPS2 downregulation in CRC, mRNA expression levels of both genes were determined in SW480 cells, in which either miR15a-3p, miR15a-5p or control miR-17 were silenced. Compared to the non-targeting control, mRNA expression levels of UCP2 and, to a lesser extent, COPS2 were increased upon silencing of miR-15a-3p (Fig 5). Hardly any effect was seen when using antagomirs against miR-15a-5p or miR-17 (Fig 5). These results indicate that miR-15a-3p indeed targets both UCP2 and COPS2 in SW480 CRC cells.


Oncogenic Role of miR-15a-3p in 13q Amplicon-Driven Colorectal Adenoma-to-Carcinoma Progression.

de Groen FL, Timmer LM, Menezes RX, Diosdado B, Hooijberg E, Meijer GA, Steenbergen RD, Carvalho B - PLoS ONE (2015)

Analysis of mRNA expression levels of target genes in colorectal cancer cell line SW480.Relative expression of UCP2 and COPS2 in SW480 cells silenced for miR-15a-5p, -3p and miR-17 compared to a non-targeting control (* p<0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492490&req=5

pone.0132495.g005: Analysis of mRNA expression levels of target genes in colorectal cancer cell line SW480.Relative expression of UCP2 and COPS2 in SW480 cells silenced for miR-15a-5p, -3p and miR-17 compared to a non-targeting control (* p<0.05).
Mentions: To further establish a role of miR-15a overexpression in UCP2 and COPS2 downregulation in CRC, mRNA expression levels of both genes were determined in SW480 cells, in which either miR15a-3p, miR15a-5p or control miR-17 were silenced. Compared to the non-targeting control, mRNA expression levels of UCP2 and, to a lesser extent, COPS2 were increased upon silencing of miR-15a-3p (Fig 5). Hardly any effect was seen when using antagomirs against miR-15a-5p or miR-17 (Fig 5). These results indicate that miR-15a-3p indeed targets both UCP2 and COPS2 in SW480 CRC cells.

Bottom Line: A subset of these genes, including the mir-17~92 cluster, are functionally involved in CRC development.These results could be confirmed by qRT-PCR in a series of 100 colon adenomas and carcinomas.Functional analysis of both mature miRNAs encoded by mir-15a, i.e. miR-15a-5p and miR-15a-3p, showed that silencing of miR-15a-3p significantly inhibited viability of CRC cells.Upon silencing of miR-15a-3p, mRNA expression of both genes increased in CRC cells, supporting miR-15a-3p mediated regulation of UPC2 and COPS2 expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands.

ABSTRACT
Progression from colorectal adenoma to carcinoma is strongly associated with an accumulation of genomic alterations, including gain of chromosome 13. This gain affects the whole q arm and is present in 40%-60% of all colorectal cancers (CRCs). Several genes located at this amplicon are known to be overexpressed in carcinomas due to copy number dosage. A subset of these genes, including the mir-17~92 cluster, are functionally involved in CRC development. The present study set out to explore whether apart from mir-17~92, other miRNAs located at the 13q amplicon show a copy number dependent dosage effect that may contribute to 13q-driven colorectal adenoma-to-carcinoma progression. Integration of publically available miRNA expression, target mRNA expression and DNA copy number data from 125 CRCs yielded three miRNAs, miR-15a, -17, and -20a, of which high expression levels were significantly correlated with a 13q gain and which influenced target mRNA expression. These results could be confirmed by qRT-PCR in a series of 100 colon adenomas and carcinomas.Functional analysis of both mature miRNAs encoded by mir-15a, i.e. miR-15a-5p and miR-15a-3p, showed that silencing of miR-15a-3p significantly inhibited viability of CRC cells. Integration of miR-15a expression levels with mRNA expression data of predicted target genes identified mitochondrial uncoupling protein 2 (UCP2) and COP9 signalosome subunit 2 (COPS2) as candidates with significantly decreased expression in CRCs with 13q gain. Upon silencing of miR-15a-3p, mRNA expression of both genes increased in CRC cells, supporting miR-15a-3p mediated regulation of UPC2 and COPS2 expression. In conclusion, significant overexpression of miR-15a-3p due to gain of 13q is functionally relevant in CRC, with UCP2 and COPS2 as candidate target genes. Taken together our findings suggest that miR-15a-3p may contribute to adenoma-to-carcinoma progression.

No MeSH data available.


Related in: MedlinePlus