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Coordinated activation of candidate proto-oncogenes and cancer testes antigens via promoter demethylation in head and neck cancer and lung cancer.

Smith IM, Glazer CA, Mithani SK, Ochs MF, Sun W, Bhan S, Vostrov A, Abdullaev Z, Lobanenkov V, Gray A, Liu C, Chang SS, Ostrow KL, Westra WH, Begum S, Dhara M, Califano J - PLoS ONE (2009)

Bottom Line: Epigenetic alterations have been implicated in the pathogenesis of solid tumors, however, proto-oncogenes activated by promoter demethylation have been sporadically reported.We noted coordinated promoter demethylation and simultaneous transcriptional upregulation of proto-oncogene candidates with promoter homology, and phylogenetic footprinting of these promoters demonstrated potential recognition sites for the transcription factor BORIS.Coordinated, epigenetic unmasking of multiple genes with growth promoting activity occurs in aerodigestive cancers, and BORIS is implicated in the coordinated promoter demethylation and reactivation of epigenetically silenced genes in human cancers.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.

ABSTRACT

Background: Epigenetic alterations have been implicated in the pathogenesis of solid tumors, however, proto-oncogenes activated by promoter demethylation have been sporadically reported. We used an integrative method to analyze expression in primary head and neck squamous cell carcinoma (HNSCC) and pharmacologically demethylated cell lines to identify aberrantly demethylated and expressed candidate proto-oncogenes and cancer testes antigens in HNSCC.

Methodology/principal findings: We noted coordinated promoter demethylation and simultaneous transcriptional upregulation of proto-oncogene candidates with promoter homology, and phylogenetic footprinting of these promoters demonstrated potential recognition sites for the transcription factor BORIS. Aberrant BORIS expression correlated with upregulation of candidate proto-oncogenes in multiple human malignancies including primary non-small cell lung cancers and HNSCC, induced coordinated proto-oncogene specific promoter demethylation and expression in non-tumorigenic cells, and transformed NIH3T3 cells.

Conclusions/significance: Coordinated, epigenetic unmasking of multiple genes with growth promoting activity occurs in aerodigestive cancers, and BORIS is implicated in the coordinated promoter demethylation and reactivation of epigenetically silenced genes in human cancers.

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Related in: MedlinePlus

TKTL1 transient transfection and transcriptional repression with shRNA.(a) TKTL1 forced overexpression via transient transfection in background low expressing JHU-011 cells induces increased anchorage dependent colony formation and (b) TKTL1 shRNA in high-expressing FaDu cell line induces growth inhibition. (c) Anchorage independent growth of UM-22B cells is significantly inhibited by TKTL1 shRNA (d), with decrease in colony size. (* = p<0.01, ** = p<0.001, chi square).
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pone-0004961-g004: TKTL1 transient transfection and transcriptional repression with shRNA.(a) TKTL1 forced overexpression via transient transfection in background low expressing JHU-011 cells induces increased anchorage dependent colony formation and (b) TKTL1 shRNA in high-expressing FaDu cell line induces growth inhibition. (c) Anchorage independent growth of UM-22B cells is significantly inhibited by TKTL1 shRNA (d), with decrease in colony size. (* = p<0.01, ** = p<0.001, chi square).

Mentions: In Figure 3C, TKTL1 induced a 50.1% (±38%) increase in growth at day four. Enhanced expression of TKTL1 has recently been implicated in the conversion of cells to aerobic, glycolytic metabolism as well as increased proliferation in colon cancer cells [20]–[25]. TKTL1 is independently associated with poor survival in laryngeal carcinoma, colon and urothelial cancers, as well as distant metastasis in ovarian carcinoma [22], [23], [26] To further confirm TKTL1 as a candidate proto-oncogene in HNSCC, we performed adherent colony focus assays in TKTL1 low- expressing HNSCC cell lines JHU-011 and JHU-028, and found significant growth increase in both cell lines (Figure 4 A,B). We then employed shRNA constructs in a TKTL1 high-expressing cell line UM-22B in anchorage independent growth assays, and noted a dramatic decrease in size and number of colonies (Figure 4 C,D) compared to mock transfected cells.


Coordinated activation of candidate proto-oncogenes and cancer testes antigens via promoter demethylation in head and neck cancer and lung cancer.

Smith IM, Glazer CA, Mithani SK, Ochs MF, Sun W, Bhan S, Vostrov A, Abdullaev Z, Lobanenkov V, Gray A, Liu C, Chang SS, Ostrow KL, Westra WH, Begum S, Dhara M, Califano J - PLoS ONE (2009)

TKTL1 transient transfection and transcriptional repression with shRNA.(a) TKTL1 forced overexpression via transient transfection in background low expressing JHU-011 cells induces increased anchorage dependent colony formation and (b) TKTL1 shRNA in high-expressing FaDu cell line induces growth inhibition. (c) Anchorage independent growth of UM-22B cells is significantly inhibited by TKTL1 shRNA (d), with decrease in colony size. (* = p<0.01, ** = p<0.001, chi square).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2654921&req=5

pone-0004961-g004: TKTL1 transient transfection and transcriptional repression with shRNA.(a) TKTL1 forced overexpression via transient transfection in background low expressing JHU-011 cells induces increased anchorage dependent colony formation and (b) TKTL1 shRNA in high-expressing FaDu cell line induces growth inhibition. (c) Anchorage independent growth of UM-22B cells is significantly inhibited by TKTL1 shRNA (d), with decrease in colony size. (* = p<0.01, ** = p<0.001, chi square).
Mentions: In Figure 3C, TKTL1 induced a 50.1% (±38%) increase in growth at day four. Enhanced expression of TKTL1 has recently been implicated in the conversion of cells to aerobic, glycolytic metabolism as well as increased proliferation in colon cancer cells [20]–[25]. TKTL1 is independently associated with poor survival in laryngeal carcinoma, colon and urothelial cancers, as well as distant metastasis in ovarian carcinoma [22], [23], [26] To further confirm TKTL1 as a candidate proto-oncogene in HNSCC, we performed adherent colony focus assays in TKTL1 low- expressing HNSCC cell lines JHU-011 and JHU-028, and found significant growth increase in both cell lines (Figure 4 A,B). We then employed shRNA constructs in a TKTL1 high-expressing cell line UM-22B in anchorage independent growth assays, and noted a dramatic decrease in size and number of colonies (Figure 4 C,D) compared to mock transfected cells.

Bottom Line: Epigenetic alterations have been implicated in the pathogenesis of solid tumors, however, proto-oncogenes activated by promoter demethylation have been sporadically reported.We noted coordinated promoter demethylation and simultaneous transcriptional upregulation of proto-oncogene candidates with promoter homology, and phylogenetic footprinting of these promoters demonstrated potential recognition sites for the transcription factor BORIS.Coordinated, epigenetic unmasking of multiple genes with growth promoting activity occurs in aerodigestive cancers, and BORIS is implicated in the coordinated promoter demethylation and reactivation of epigenetically silenced genes in human cancers.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.

ABSTRACT

Background: Epigenetic alterations have been implicated in the pathogenesis of solid tumors, however, proto-oncogenes activated by promoter demethylation have been sporadically reported. We used an integrative method to analyze expression in primary head and neck squamous cell carcinoma (HNSCC) and pharmacologically demethylated cell lines to identify aberrantly demethylated and expressed candidate proto-oncogenes and cancer testes antigens in HNSCC.

Methodology/principal findings: We noted coordinated promoter demethylation and simultaneous transcriptional upregulation of proto-oncogene candidates with promoter homology, and phylogenetic footprinting of these promoters demonstrated potential recognition sites for the transcription factor BORIS. Aberrant BORIS expression correlated with upregulation of candidate proto-oncogenes in multiple human malignancies including primary non-small cell lung cancers and HNSCC, induced coordinated proto-oncogene specific promoter demethylation and expression in non-tumorigenic cells, and transformed NIH3T3 cells.

Conclusions/significance: Coordinated, epigenetic unmasking of multiple genes with growth promoting activity occurs in aerodigestive cancers, and BORIS is implicated in the coordinated promoter demethylation and reactivation of epigenetically silenced genes in human cancers.

Show MeSH
Related in: MedlinePlus