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Long non-coding RNA ROR decoys gene-specific histone methylation to promote tumorigenesis.

Fan J, Xing Y, Wen X, Jia R, Ni H, He J, Ding X, Pan H, Qian G, Ge S, Hoffman AR, Zhang H, Fan X - Genome Biol. (2015)

Bottom Line: Suppression of ROR in tumors results in silencing of TESC expression, and G9A-mediated histone H3K9 methylation in the TESC promoter is restored, which significantly reduces tumor growth and metastasis.Without ROR silencing, TESC knockdown presents consistent and significant reductions in tumor progression.Our results reveal a novel mechanism by which ROR may serve as a decoy oncoRNA that blocks binding surfaces, preventing the recruitment of histone modifying enzymes, thereby specifying a new pattern of histone modifications that promote tumorigenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, 200025, P. R. China.

ABSTRACT

Background: Long non-coding RNAs (lncRNAs) are not translated into proteins and were initially considered to be part of the 'dark matter' of the genome. Recently, it has been shown that lncRNAs play a role in the recruitment of chromatin modifying complexes and can influence gene expression. However, it is unknown if lncRNAs function in a similar way in cancer.

Results: Here, we show that the lncRNA ROR occupies and activates the TESC promoter by repelling the histone G9A methyltransferase and promoting the release of histone H3K9 methylation. Suppression of ROR in tumors results in silencing of TESC expression, and G9A-mediated histone H3K9 methylation in the TESC promoter is restored, which significantly reduces tumor growth and metastasis. Without ROR silencing, TESC knockdown presents consistent and significant reductions in tumor progression.

Conclusions: Our results reveal a novel mechanism by which ROR may serve as a decoy oncoRNA that blocks binding surfaces, preventing the recruitment of histone modifying enzymes, thereby specifying a new pattern of histone modifications that promote tumorigenesis.

No MeSH data available.


Related in: MedlinePlus

TESC is a potential novel oncogene. a, b Declining cell growth in AGS (a) and HT29 (b) cells after TESC silencing. The absorbance value of the controls at day 1 was arbitrarily set at 100 %. *P <0.05: compared with the control and NC. c Images of metastatic tumor cells in TESC-silenced cells. The migratory ability of two siTESCs-treated AGS and HT29 tumor cells were significantly decreased. The migration assay was conducted 48 h after transfection with siTESCs or control siRNA. d, e Soft agar colony assay showing the ability of tumor formation in vitro. A tiny colony observed in whole-well testing (d) and under the microscope (e). Bars: 100 μm. Arrow: tumor colony. f RT-PCR showing the high expression of TESC in a variety of tumor cells. TESC was abundant in tumor cells but not in fibroblasts. gROR and TESC expressionl evels in normal tissues, colon cancer, and melanoma tissues. Both TESC and ROR were highly expressed in colon cancer and melanoma tissues compared with that of normal tissues. The expression of TESC was increased with the level of ROR in tumors. h Immunohistochemical staining of TESC in tumor and normal tissues. TESC expression in tumor sections from five colon cancer patients and five melanoma patients was higher than normal tissues (original magnification, 200×)
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Fig4: TESC is a potential novel oncogene. a, b Declining cell growth in AGS (a) and HT29 (b) cells after TESC silencing. The absorbance value of the controls at day 1 was arbitrarily set at 100 %. *P <0.05: compared with the control and NC. c Images of metastatic tumor cells in TESC-silenced cells. The migratory ability of two siTESCs-treated AGS and HT29 tumor cells were significantly decreased. The migration assay was conducted 48 h after transfection with siTESCs or control siRNA. d, e Soft agar colony assay showing the ability of tumor formation in vitro. A tiny colony observed in whole-well testing (d) and under the microscope (e). Bars: 100 μm. Arrow: tumor colony. f RT-PCR showing the high expression of TESC in a variety of tumor cells. TESC was abundant in tumor cells but not in fibroblasts. gROR and TESC expressionl evels in normal tissues, colon cancer, and melanoma tissues. Both TESC and ROR were highly expressed in colon cancer and melanoma tissues compared with that of normal tissues. The expression of TESC was increased with the level of ROR in tumors. h Immunohistochemical staining of TESC in tumor and normal tissues. TESC expression in tumor sections from five colon cancer patients and five melanoma patients was higher than normal tissues (original magnification, 200×)

Mentions: To exclude off-target effects, we then chose two validated siRNAs (siTESC and siTESC-2) for next experiments. After TESC silencing, we also found a near two-fold decline in the growth of AGS cells (Fig. 4a). In addition, TESC silenced-HT29 cells showed similarly decreased cell proliferation (Fig. 4b). To further define the role of TESC in tumor migration and formation, we first examined the ability of cells to migrate in TESC-silenced AGS and HT29 tumor cells. Following the above protocol for the transwell assay, we observed a significantly decreased metastasis rate after 48 h (Fig. 4c, lanes 3 and 4) compared with that of the controls (Fig. 4c, lanes 1 and 2). In a classical tumor formation assay in vitro, we also noticed tiny colonies in TESC-deficient cells through whole well testing (Fig. 4d, lanes 3 and 4) or under the microscope (Fig. 4e, lanes 2 and 3). These results provide direct evidence that TESC may be a newly proposed oncogene with functions in tumor growth and metastasis.Fig. 4


Long non-coding RNA ROR decoys gene-specific histone methylation to promote tumorigenesis.

Fan J, Xing Y, Wen X, Jia R, Ni H, He J, Ding X, Pan H, Qian G, Ge S, Hoffman AR, Zhang H, Fan X - Genome Biol. (2015)

TESC is a potential novel oncogene. a, b Declining cell growth in AGS (a) and HT29 (b) cells after TESC silencing. The absorbance value of the controls at day 1 was arbitrarily set at 100 %. *P <0.05: compared with the control and NC. c Images of metastatic tumor cells in TESC-silenced cells. The migratory ability of two siTESCs-treated AGS and HT29 tumor cells were significantly decreased. The migration assay was conducted 48 h after transfection with siTESCs or control siRNA. d, e Soft agar colony assay showing the ability of tumor formation in vitro. A tiny colony observed in whole-well testing (d) and under the microscope (e). Bars: 100 μm. Arrow: tumor colony. f RT-PCR showing the high expression of TESC in a variety of tumor cells. TESC was abundant in tumor cells but not in fibroblasts. gROR and TESC expressionl evels in normal tissues, colon cancer, and melanoma tissues. Both TESC and ROR were highly expressed in colon cancer and melanoma tissues compared with that of normal tissues. The expression of TESC was increased with the level of ROR in tumors. h Immunohistochemical staining of TESC in tumor and normal tissues. TESC expression in tumor sections from five colon cancer patients and five melanoma patients was higher than normal tissues (original magnification, 200×)
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Fig4: TESC is a potential novel oncogene. a, b Declining cell growth in AGS (a) and HT29 (b) cells after TESC silencing. The absorbance value of the controls at day 1 was arbitrarily set at 100 %. *P <0.05: compared with the control and NC. c Images of metastatic tumor cells in TESC-silenced cells. The migratory ability of two siTESCs-treated AGS and HT29 tumor cells were significantly decreased. The migration assay was conducted 48 h after transfection with siTESCs or control siRNA. d, e Soft agar colony assay showing the ability of tumor formation in vitro. A tiny colony observed in whole-well testing (d) and under the microscope (e). Bars: 100 μm. Arrow: tumor colony. f RT-PCR showing the high expression of TESC in a variety of tumor cells. TESC was abundant in tumor cells but not in fibroblasts. gROR and TESC expressionl evels in normal tissues, colon cancer, and melanoma tissues. Both TESC and ROR were highly expressed in colon cancer and melanoma tissues compared with that of normal tissues. The expression of TESC was increased with the level of ROR in tumors. h Immunohistochemical staining of TESC in tumor and normal tissues. TESC expression in tumor sections from five colon cancer patients and five melanoma patients was higher than normal tissues (original magnification, 200×)
Mentions: To exclude off-target effects, we then chose two validated siRNAs (siTESC and siTESC-2) for next experiments. After TESC silencing, we also found a near two-fold decline in the growth of AGS cells (Fig. 4a). In addition, TESC silenced-HT29 cells showed similarly decreased cell proliferation (Fig. 4b). To further define the role of TESC in tumor migration and formation, we first examined the ability of cells to migrate in TESC-silenced AGS and HT29 tumor cells. Following the above protocol for the transwell assay, we observed a significantly decreased metastasis rate after 48 h (Fig. 4c, lanes 3 and 4) compared with that of the controls (Fig. 4c, lanes 1 and 2). In a classical tumor formation assay in vitro, we also noticed tiny colonies in TESC-deficient cells through whole well testing (Fig. 4d, lanes 3 and 4) or under the microscope (Fig. 4e, lanes 2 and 3). These results provide direct evidence that TESC may be a newly proposed oncogene with functions in tumor growth and metastasis.Fig. 4

Bottom Line: Suppression of ROR in tumors results in silencing of TESC expression, and G9A-mediated histone H3K9 methylation in the TESC promoter is restored, which significantly reduces tumor growth and metastasis.Without ROR silencing, TESC knockdown presents consistent and significant reductions in tumor progression.Our results reveal a novel mechanism by which ROR may serve as a decoy oncoRNA that blocks binding surfaces, preventing the recruitment of histone modifying enzymes, thereby specifying a new pattern of histone modifications that promote tumorigenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, 200025, P. R. China.

ABSTRACT

Background: Long non-coding RNAs (lncRNAs) are not translated into proteins and were initially considered to be part of the 'dark matter' of the genome. Recently, it has been shown that lncRNAs play a role in the recruitment of chromatin modifying complexes and can influence gene expression. However, it is unknown if lncRNAs function in a similar way in cancer.

Results: Here, we show that the lncRNA ROR occupies and activates the TESC promoter by repelling the histone G9A methyltransferase and promoting the release of histone H3K9 methylation. Suppression of ROR in tumors results in silencing of TESC expression, and G9A-mediated histone H3K9 methylation in the TESC promoter is restored, which significantly reduces tumor growth and metastasis. Without ROR silencing, TESC knockdown presents consistent and significant reductions in tumor progression.

Conclusions: Our results reveal a novel mechanism by which ROR may serve as a decoy oncoRNA that blocks binding surfaces, preventing the recruitment of histone modifying enzymes, thereby specifying a new pattern of histone modifications that promote tumorigenesis.

No MeSH data available.


Related in: MedlinePlus