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Pivotal Role of the Chromatin Protein Nupr1 in Kras-Induced Senescence and Transformation.

Grasso D, Bintz J, Lomberk G, Molejon MI, Loncle C, Garcia MN, Lopez MB, Urrutia R, Iovanna JL - Sci Rep (2015)

Bottom Line: In the current study, we report that Nupr1 acts as a gene modifier of the effect of Kras(G12D)-induced senescence by regulating Dnmt1 expression and consequently genome-wide levels of DNA methylation.This requirement of Nupr1 expression, however, is not restricted to the pancreas since in lung of Nupr1(-/-) mice the expression of Kras(G12D) induces senescence instead of transformation.Therefore, mechanistically this data reveals that epigenetic events, at least at the level of DNA methylation, modulate the functional outcome of common genetic mutations, such as Kras(G12D), during carcinogenesis.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM U1068, CNRS UMR 7258, Aix-Marseille Université and Institut Paoli-Calmettes, Parc Scientifique et Technologique de Luminy, Marseille, France.

ABSTRACT
Nupr1 is a chromatin protein, which cooperates with Kras(G12D) to induce PanIN formation and pancreatic cancer development in mice, though the molecular mechanisms underlying this effect remain to be fully characterized. In the current study, we report that Nupr1 acts as a gene modifier of the effect of Kras(G12D)-induced senescence by regulating Dnmt1 expression and consequently genome-wide levels of DNA methylation. Congruently, 5-aza-2'-deoxycytydine, a general inhibitor of DNA methylation, reverses the Kras(G12D)-induced PanIN development by promoting senescence. This requirement of Nupr1 expression, however, is not restricted to the pancreas since in lung of Nupr1(-/-) mice the expression of Kras(G12D) induces senescence instead of transformation. Therefore, mechanistically this data reveals that epigenetic events, at least at the level of DNA methylation, modulate the functional outcome of common genetic mutations, such as Kras(G12D), during carcinogenesis. The biomedical relevance of these findings lies in that they support the rational for developing similar therapeutic interventions in human aimed at controlling either the initiation or progression of cancer.

No MeSH data available.


Related in: MedlinePlus

Expression of Nupr1 switches OIS to transformation in MEFs.(A,B) MEF from LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were obtained and transduced with an adenovirus expressing the Cre recombinase. Transformation-like images were observed in Nupr1+/+ cells whereas pictures compatible with senescence were observed in the Nupr1-deficients cells. Values correspond to the percentage of senescent cells. (A) and a strong SA-βGal staining was observed in Nupr1–/– MEFS whereas no activity was detected in the Nupr1 wild-type cells (B). Tubulin and Ki-67 staining indicates a rearrangement of the cytoskeleton compatible with a senescent phenotype combined with not proliferation in Nupr1-deficients MEFs (C).
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f2: Expression of Nupr1 switches OIS to transformation in MEFs.(A,B) MEF from LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were obtained and transduced with an adenovirus expressing the Cre recombinase. Transformation-like images were observed in Nupr1+/+ cells whereas pictures compatible with senescence were observed in the Nupr1-deficients cells. Values correspond to the percentage of senescent cells. (A) and a strong SA-βGal staining was observed in Nupr1–/– MEFS whereas no activity was detected in the Nupr1 wild-type cells (B). Tubulin and Ki-67 staining indicates a rearrangement of the cytoskeleton compatible with a senescent phenotype combined with not proliferation in Nupr1-deficients MEFs (C).

Mentions: To gain insight into the cell biological phenomenon which may results from these genomic changes, we subsequently studied the cellular effect of oncogenic Kras activation using MEFs derived from Nupr1+/+; LSL-KrasG12D and Nupr1–/–; LSL-KrasG12D mice and transduced them with Cre-expressing adenovirus to activate KrasG12D. Phenotypically, Nupr1+/+; Lox-KrasG12D MEFs adopt the morphology previously described for oncogene-transformed fibroblasts and increased growth capacity (Ki-67 positive nuclei = 9.4 ± 1.2 per field) (Fig. 2C) as previously described19. In contrast, MEFs from Nupr1–/–; Lox-KrasG12D mice displayed an elongated morphology with low Ki-67 staining (Ki-67 positive nuclei = 0.5 ± 0.4 per field), features reminiscent of senescent cells (Fig. 2A,C). Finally, senescence associated (SA)-βGAL staining was positive in Nupr1–/–; Lox-KrasG12D MEFs but not in control cells as showed in Fig. 2B. Together these data demonstrate that, at the molecular level, the inactivation of Nupr1 changes DNA methylation genome-wide, while at the cellular level, it promotes Kras-induced senescence.


Pivotal Role of the Chromatin Protein Nupr1 in Kras-Induced Senescence and Transformation.

Grasso D, Bintz J, Lomberk G, Molejon MI, Loncle C, Garcia MN, Lopez MB, Urrutia R, Iovanna JL - Sci Rep (2015)

Expression of Nupr1 switches OIS to transformation in MEFs.(A,B) MEF from LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were obtained and transduced with an adenovirus expressing the Cre recombinase. Transformation-like images were observed in Nupr1+/+ cells whereas pictures compatible with senescence were observed in the Nupr1-deficients cells. Values correspond to the percentage of senescent cells. (A) and a strong SA-βGal staining was observed in Nupr1–/– MEFS whereas no activity was detected in the Nupr1 wild-type cells (B). Tubulin and Ki-67 staining indicates a rearrangement of the cytoskeleton compatible with a senescent phenotype combined with not proliferation in Nupr1-deficients MEFs (C).
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4663475&req=5

f2: Expression of Nupr1 switches OIS to transformation in MEFs.(A,B) MEF from LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were obtained and transduced with an adenovirus expressing the Cre recombinase. Transformation-like images were observed in Nupr1+/+ cells whereas pictures compatible with senescence were observed in the Nupr1-deficients cells. Values correspond to the percentage of senescent cells. (A) and a strong SA-βGal staining was observed in Nupr1–/– MEFS whereas no activity was detected in the Nupr1 wild-type cells (B). Tubulin and Ki-67 staining indicates a rearrangement of the cytoskeleton compatible with a senescent phenotype combined with not proliferation in Nupr1-deficients MEFs (C).
Mentions: To gain insight into the cell biological phenomenon which may results from these genomic changes, we subsequently studied the cellular effect of oncogenic Kras activation using MEFs derived from Nupr1+/+; LSL-KrasG12D and Nupr1–/–; LSL-KrasG12D mice and transduced them with Cre-expressing adenovirus to activate KrasG12D. Phenotypically, Nupr1+/+; Lox-KrasG12D MEFs adopt the morphology previously described for oncogene-transformed fibroblasts and increased growth capacity (Ki-67 positive nuclei = 9.4 ± 1.2 per field) (Fig. 2C) as previously described19. In contrast, MEFs from Nupr1–/–; Lox-KrasG12D mice displayed an elongated morphology with low Ki-67 staining (Ki-67 positive nuclei = 0.5 ± 0.4 per field), features reminiscent of senescent cells (Fig. 2A,C). Finally, senescence associated (SA)-βGAL staining was positive in Nupr1–/–; Lox-KrasG12D MEFs but not in control cells as showed in Fig. 2B. Together these data demonstrate that, at the molecular level, the inactivation of Nupr1 changes DNA methylation genome-wide, while at the cellular level, it promotes Kras-induced senescence.

Bottom Line: In the current study, we report that Nupr1 acts as a gene modifier of the effect of Kras(G12D)-induced senescence by regulating Dnmt1 expression and consequently genome-wide levels of DNA methylation.This requirement of Nupr1 expression, however, is not restricted to the pancreas since in lung of Nupr1(-/-) mice the expression of Kras(G12D) induces senescence instead of transformation.Therefore, mechanistically this data reveals that epigenetic events, at least at the level of DNA methylation, modulate the functional outcome of common genetic mutations, such as Kras(G12D), during carcinogenesis.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM U1068, CNRS UMR 7258, Aix-Marseille Université and Institut Paoli-Calmettes, Parc Scientifique et Technologique de Luminy, Marseille, France.

ABSTRACT
Nupr1 is a chromatin protein, which cooperates with Kras(G12D) to induce PanIN formation and pancreatic cancer development in mice, though the molecular mechanisms underlying this effect remain to be fully characterized. In the current study, we report that Nupr1 acts as a gene modifier of the effect of Kras(G12D)-induced senescence by regulating Dnmt1 expression and consequently genome-wide levels of DNA methylation. Congruently, 5-aza-2'-deoxycytydine, a general inhibitor of DNA methylation, reverses the Kras(G12D)-induced PanIN development by promoting senescence. This requirement of Nupr1 expression, however, is not restricted to the pancreas since in lung of Nupr1(-/-) mice the expression of Kras(G12D) induces senescence instead of transformation. Therefore, mechanistically this data reveals that epigenetic events, at least at the level of DNA methylation, modulate the functional outcome of common genetic mutations, such as Kras(G12D), during carcinogenesis. The biomedical relevance of these findings lies in that they support the rational for developing similar therapeutic interventions in human aimed at controlling either the initiation or progression of cancer.

No MeSH data available.


Related in: MedlinePlus