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Hypomethylation-associated up-regulation of TCF3 expression and recurrence in stage II and III colorectal cancer.

Li C, Cai S, Wang X, Jiang Z - PLoS ONE (2014)

Bottom Line: Higher TCF3 expression indicated poor prognostic outcomes (P<0.05, log-rank test).Moreover, it was showed that promoter hypomethylation of TCF3 is associated with its up-expression.The up-regulation of TCF3, which is mainly caused by promoter hypomethylation, is one of the molecular mechanisms involved in the development and progression of CRC.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China.

ABSTRACT

Background and objectives: Transcription factor 3 (TCF3) implicates Wnt signaling pathway and regulates E-cadherin expression, which is involved in aggressiveness of tumors. This study aims to investigate the role of TCF3 in predicting prognosis of patients with stage II and III colorectal cancer (CRC).

Methods: Real-Time quantitative PCR was performed in 64 fresh CRC tissues and 6 cell lines to examine TCF3 mRNA expression. TCF3 protein expression dynamics were detected by immunohistochemistry of 118 paraffin-embedded specimens, and the clinical significance of TCF3 was assessed by clinical correlation and Kaplan-Meier analyses. Aberrant hypomethylation of TCF3 promoter was also investigated using bisulfite sequencing and methylation specific PCR.

Results: The up-regulation of TCF3 mRNA was frequently detected both in CRC tissues with recurrence and metastasis-derived cell lines. The expression level of TCF3 protein was significantly correlated with histological type (P = 0.038) and disease-free survival time (P = 0.002). Higher TCF3 expression indicated poor prognostic outcomes (P<0.05, log-rank test). Multivariate analysis also showed strong TCF3 protein expression and perineural invasion were independent adverse prognosticators in CRC (P = 0.010, 0.000). Moreover, it was showed that promoter hypomethylation of TCF3 is associated with its up-expression.

Conclusions: This study highlighted the prognostic value of TCF3 in stage II and III CRC. The up-regulation of TCF3, which is mainly caused by promoter hypomethylation, is one of the molecular mechanisms involved in the development and progression of CRC.

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Genomic architecture of the human TCF3 gene.Location of the TCF3 gene within human chromosome 19 (ch19p13.3). (a) Exon structure of the human TCF3 gene. (b) Structure of the 5′ end of the TCF3 gene. Graph of percent guanine (G) and cytosine (C) nucleotides across this region, location of the CpG dinucleotides within this region, and boundaries of the CpG island (shaded region). (c) Representative examples of the chromatograms of CpG sites obtained from bisulphite sequencing of the TCF3 fragment in CRC without recurrence (d) and with recurrence (e, f).
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pone-0112005-g004: Genomic architecture of the human TCF3 gene.Location of the TCF3 gene within human chromosome 19 (ch19p13.3). (a) Exon structure of the human TCF3 gene. (b) Structure of the 5′ end of the TCF3 gene. Graph of percent guanine (G) and cytosine (C) nucleotides across this region, location of the CpG dinucleotides within this region, and boundaries of the CpG island (shaded region). (c) Representative examples of the chromatograms of CpG sites obtained from bisulphite sequencing of the TCF3 fragment in CRC without recurrence (d) and with recurrence (e, f).

Mentions: A CpG island encompassing about 2.3 kb was found in the human TCF3 gene promoter region (Figure 4c). To understand the mechanism of TCF3 regulation in CRC, the methylation status in the promoter region of TCF3 was tested. We amplified and sequenced the promoter region of TCF3 using sodium bisulfite-treated genomic DNA prepared from CRC tissues. More densely methylated CpG sites (90.7% vs. 44.3%) were detected in non-recurrent CRC tissues in this study (Figure 4d, 4e, and 4f). To further validate the sequencing results, the promoter region was characterised by MSP using methylation or unmethylation-specific primers in 47 CRC specimens. Methylation of TCF3 was detected in 23 of (95.8%) 24 non-recurrent CRC specimens. In contrast, the frequency of methylation was noticeably lower in recurrent CRC specimens (16/23, 69.6%; P = 0.023, Figure 5a, 5b). Furthermore, it was shown that the TCF3 expression is significantly associated with the methylation status, indicating epigenetical inactivation might play an important role in regulatory of TCF3 expression (P = 0.001, Figure 5c).


Hypomethylation-associated up-regulation of TCF3 expression and recurrence in stage II and III colorectal cancer.

Li C, Cai S, Wang X, Jiang Z - PLoS ONE (2014)

Genomic architecture of the human TCF3 gene.Location of the TCF3 gene within human chromosome 19 (ch19p13.3). (a) Exon structure of the human TCF3 gene. (b) Structure of the 5′ end of the TCF3 gene. Graph of percent guanine (G) and cytosine (C) nucleotides across this region, location of the CpG dinucleotides within this region, and boundaries of the CpG island (shaded region). (c) Representative examples of the chromatograms of CpG sites obtained from bisulphite sequencing of the TCF3 fragment in CRC without recurrence (d) and with recurrence (e, f).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4222969&req=5

pone-0112005-g004: Genomic architecture of the human TCF3 gene.Location of the TCF3 gene within human chromosome 19 (ch19p13.3). (a) Exon structure of the human TCF3 gene. (b) Structure of the 5′ end of the TCF3 gene. Graph of percent guanine (G) and cytosine (C) nucleotides across this region, location of the CpG dinucleotides within this region, and boundaries of the CpG island (shaded region). (c) Representative examples of the chromatograms of CpG sites obtained from bisulphite sequencing of the TCF3 fragment in CRC without recurrence (d) and with recurrence (e, f).
Mentions: A CpG island encompassing about 2.3 kb was found in the human TCF3 gene promoter region (Figure 4c). To understand the mechanism of TCF3 regulation in CRC, the methylation status in the promoter region of TCF3 was tested. We amplified and sequenced the promoter region of TCF3 using sodium bisulfite-treated genomic DNA prepared from CRC tissues. More densely methylated CpG sites (90.7% vs. 44.3%) were detected in non-recurrent CRC tissues in this study (Figure 4d, 4e, and 4f). To further validate the sequencing results, the promoter region was characterised by MSP using methylation or unmethylation-specific primers in 47 CRC specimens. Methylation of TCF3 was detected in 23 of (95.8%) 24 non-recurrent CRC specimens. In contrast, the frequency of methylation was noticeably lower in recurrent CRC specimens (16/23, 69.6%; P = 0.023, Figure 5a, 5b). Furthermore, it was shown that the TCF3 expression is significantly associated with the methylation status, indicating epigenetical inactivation might play an important role in regulatory of TCF3 expression (P = 0.001, Figure 5c).

Bottom Line: Higher TCF3 expression indicated poor prognostic outcomes (P<0.05, log-rank test).Moreover, it was showed that promoter hypomethylation of TCF3 is associated with its up-expression.The up-regulation of TCF3, which is mainly caused by promoter hypomethylation, is one of the molecular mechanisms involved in the development and progression of CRC.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China.

ABSTRACT

Background and objectives: Transcription factor 3 (TCF3) implicates Wnt signaling pathway and regulates E-cadherin expression, which is involved in aggressiveness of tumors. This study aims to investigate the role of TCF3 in predicting prognosis of patients with stage II and III colorectal cancer (CRC).

Methods: Real-Time quantitative PCR was performed in 64 fresh CRC tissues and 6 cell lines to examine TCF3 mRNA expression. TCF3 protein expression dynamics were detected by immunohistochemistry of 118 paraffin-embedded specimens, and the clinical significance of TCF3 was assessed by clinical correlation and Kaplan-Meier analyses. Aberrant hypomethylation of TCF3 promoter was also investigated using bisulfite sequencing and methylation specific PCR.

Results: The up-regulation of TCF3 mRNA was frequently detected both in CRC tissues with recurrence and metastasis-derived cell lines. The expression level of TCF3 protein was significantly correlated with histological type (P = 0.038) and disease-free survival time (P = 0.002). Higher TCF3 expression indicated poor prognostic outcomes (P<0.05, log-rank test). Multivariate analysis also showed strong TCF3 protein expression and perineural invasion were independent adverse prognosticators in CRC (P = 0.010, 0.000). Moreover, it was showed that promoter hypomethylation of TCF3 is associated with its up-expression.

Conclusions: This study highlighted the prognostic value of TCF3 in stage II and III CRC. The up-regulation of TCF3, which is mainly caused by promoter hypomethylation, is one of the molecular mechanisms involved in the development and progression of CRC.

Show MeSH
Related in: MedlinePlus