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Cytoglobin, the newest member of the globin family, functions as a tumor suppressor gene.

ABSTRACT: Cytoglobin (CYGB) is a recently discovered vertebrate globin distantly related to myoglobin with unknown function. CYGB is assigned to chromosomal region 17q25, which is frequently lost in multiple malignancies. Previous studies failed to detect evidence for mutations in the CYGB gene. Recent studies provided preliminary evidence for increased methylation of the gene in lung cancer. Our study was aimed at investigating the role of CYGB as a tumor suppressor gene. By nested methylation-specific DNA sequencing analysis of lung and breast cancer cell lines and bronchial and mammary epithelial cell lines, we identified that methylation of a 110-bp CpG-rich segment of the CYGB promoter was correlated with gene silencing. We specifically targeted this sequence and developed a quantitative methylation-specific PCR assay, suitable for high-throughput analysis. We showed that the tumor specificity of CYGB methylation in discriminating patients with and without lung cancer, using biopsies and sputum samples. We further showed the tumor specificity of this assay with multiple other epithelial and hematologic malignancies. To show tumor suppressor activity of CYGB, we performed the following: (a) RNA interference-mediated knockdown of CYGB gene on colony formation in a CYGB expression-positive lung cancer cell line, resulting in increased colony formation; (b) enforced gene expression in CYGB expression-negative lung and breast cancer cell lines, reducing colony formation; and (c) identification of potential proximate targets down-stream of the CYGB genes. Our data constitute the first direct functional evidence for CYGB, the newest member of the globin family, as a tumor suppressor gene.

SUBMITTER: Shivapurkar N

PROVIDER: S-EPMC2849650 | biostudies-other | 2008 Sep

REPOSITORIES: biostudies-other

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Cytoglobin, the newest member of the globin family, functions as a tumor suppressor gene.

Shivapurkar Narayan N Stastny Victor V Okumura Naoki N Girard Luc L Xie Yang Y Prinsen Clemens C Thunnissen Frederik B FB Wistuba Ignacio I II Czerniak Bogdan B Frenkel Eugene E Roth Jack A JA Liloglou Triantafillos T Xinarianos George G Field John K JK Minna John D JD Gazdar Adi F AF

Cancer research 20080901 18

Cytoglobin (CYGB) is a recently discovered vertebrate globin distantly related to myoglobin with unknown function. CYGB is assigned to chromosomal region 17q25, which is frequently lost in multiple malignancies. Previous studies failed to detect evidence for mutations in the CYGB gene. Recent studies provided preliminary evidence for increased methylation of the gene in lung cancer. Our study was aimed at investigating the role of CYGB as a tumor suppressor gene. By nested methylation-specific D ...[more]

PMID: 18794132

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Dataset Information

Cytoglobin, the newest member of the globin family, functions as a tumor suppressor gene.

Publications

Cytoglobin, the newest member of the globin family, functions as a tumor suppressor gene.

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