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TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma.

Wang S, Xiao X, Zhou X, Huang T, Du C, Yu N, Mo Y, Lin L, Zhang J, Ma N, Murata M, Huang G, Zhang Z - BMC Cancer (2010)

Bottom Line: TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia.TFPI-2 expression could be restored in NPC cells after demethylation treatment.Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, PR China.

ABSTRACT

Background: Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, TFPI-2 was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether TFPI-2 was inactivated epigenetically in nasopharyngeal carcinoma (NPC).

Methods: Transcriptional expression levels of TFPI-2 was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of TFPI-2 as a tumor suppressor gene in NPC was addressed by re-introducing TFPI-2 expression into the NPC cell line CNE2.

Results: TFPI-2 mRNA transcription was inactivated in NPC cell lines. TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. TFPI-2 expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration.

Conclusions: Epigenetic inactivation of TFPI-2 by promoter hypermethylation is a frequent and tumor specific event in NPC. TFPI-2 might be considering as a putative tumor suppressor gene in NPC.

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Related in: MedlinePlus

Methylation-specific PCR analysis of the TFPI-2 promoter region in NPC primary tumors and normal nasopharyngeal epithelia (NNE). Four NPC primary tumors (NPC 13, 16, 24 and 34) and 4 NNE (NNE3, 7, 9 and 12) are shown as examples. U: unmethylated alleles; M: methylated alleles. The data are representative of 2 independent experiments.
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Figure 3: Methylation-specific PCR analysis of the TFPI-2 promoter region in NPC primary tumors and normal nasopharyngeal epithelia (NNE). Four NPC primary tumors (NPC 13, 16, 24 and 34) and 4 NNE (NNE3, 7, 9 and 12) are shown as examples. U: unmethylated alleles; M: methylated alleles. The data are representative of 2 independent experiments.

Mentions: The methylation status of the TFPI-2 promoter in NPC cell lines was detected by methylation-specific PCR assay. The TFPI-2 promoter was hypermethylated in 4 of 6 NPC cell lines (CNE1, CNE2, C666-1 and HONE1); only TW03 and HNE1 cells were unmethylated (Figure 2). All 12 normal nasopharyngeal epithelial tissues showed unmethylated TFPI-2 promoters. We further evaluated the methylation status of the TFPI-2 promoter in 70 NPC primary tumors. Promoter hypermethylation was detected in 88.6% (62/70) of the NPC primary tumors but in none of the 12 NNE. Representative samples are shown in Figure 3. Unmethylated amplicons were found in some but not all of the NPC biopsy samples likely because of the existence of non-malignant cells such as stromal cells in a fraction of the samples.


TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma.

Wang S, Xiao X, Zhou X, Huang T, Du C, Yu N, Mo Y, Lin L, Zhang J, Ma N, Murata M, Huang G, Zhang Z - BMC Cancer (2010)

Methylation-specific PCR analysis of the TFPI-2 promoter region in NPC primary tumors and normal nasopharyngeal epithelia (NNE). Four NPC primary tumors (NPC 13, 16, 24 and 34) and 4 NNE (NNE3, 7, 9 and 12) are shown as examples. U: unmethylated alleles; M: methylated alleles. The data are representative of 2 independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2992524&req=5

Figure 3: Methylation-specific PCR analysis of the TFPI-2 promoter region in NPC primary tumors and normal nasopharyngeal epithelia (NNE). Four NPC primary tumors (NPC 13, 16, 24 and 34) and 4 NNE (NNE3, 7, 9 and 12) are shown as examples. U: unmethylated alleles; M: methylated alleles. The data are representative of 2 independent experiments.
Mentions: The methylation status of the TFPI-2 promoter in NPC cell lines was detected by methylation-specific PCR assay. The TFPI-2 promoter was hypermethylated in 4 of 6 NPC cell lines (CNE1, CNE2, C666-1 and HONE1); only TW03 and HNE1 cells were unmethylated (Figure 2). All 12 normal nasopharyngeal epithelial tissues showed unmethylated TFPI-2 promoters. We further evaluated the methylation status of the TFPI-2 promoter in 70 NPC primary tumors. Promoter hypermethylation was detected in 88.6% (62/70) of the NPC primary tumors but in none of the 12 NNE. Representative samples are shown in Figure 3. Unmethylated amplicons were found in some but not all of the NPC biopsy samples likely because of the existence of non-malignant cells such as stromal cells in a fraction of the samples.

Bottom Line: TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia.TFPI-2 expression could be restored in NPC cells after demethylation treatment.Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, PR China.

ABSTRACT

Background: Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, TFPI-2 was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether TFPI-2 was inactivated epigenetically in nasopharyngeal carcinoma (NPC).

Methods: Transcriptional expression levels of TFPI-2 was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of TFPI-2 as a tumor suppressor gene in NPC was addressed by re-introducing TFPI-2 expression into the NPC cell line CNE2.

Results: TFPI-2 mRNA transcription was inactivated in NPC cell lines. TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. TFPI-2 expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration.

Conclusions: Epigenetic inactivation of TFPI-2 by promoter hypermethylation is a frequent and tumor specific event in NPC. TFPI-2 might be considering as a putative tumor suppressor gene in NPC.

Show MeSH
Related in: MedlinePlus