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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

Nupr1 expression is necessary for transformation induced by the oncogenic Kras in lung.(A) LSL-KrasG12D; Nupr1+/+; ΔInk4a mice were treated by intratracheal administration of the adenovirus expressing the Cre recombinase and 12 weeks later the lungs were processed for H&E analysis. All animals showed adenocarcinomas indicating the efficient recombination. (B) LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were treated with the adenovirus expressing the Cre recombinase as in A and lung processed for H&E analysis and SA-βGal staining. Mice with Nupr1+/+ background show several adenoma lesions and negative SA-βGal staining whereas on the contrary lung from mice with Nupr1–/– background present almost not adenoma with positive SA-βGal staining. (C) Quantification of adenoma grade 1 and grade 2. Means ± SD; ***p < 0.001. (D) Lox (size 325 bp) and LSL (size 287 bp) KrasG12D and Nupr1 KO (size 381 bp) or wt (size 489 bp) were amplified.
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f5: Nupr1 expression is necessary for transformation induced by the oncogenic Kras in lung.(A) LSL-KrasG12D; Nupr1+/+; ΔInk4a mice were treated by intratracheal administration of the adenovirus expressing the Cre recombinase and 12 weeks later the lungs were processed for H&E analysis. All animals showed adenocarcinomas indicating the efficient recombination. (B) LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were treated with the adenovirus expressing the Cre recombinase as in A and lung processed for H&E analysis and SA-βGal staining. Mice with Nupr1+/+ background show several adenoma lesions and negative SA-βGal staining whereas on the contrary lung from mice with Nupr1–/– background present almost not adenoma with positive SA-βGal staining. (C) Quantification of adenoma grade 1 and grade 2. Means ± SD; ***p < 0.001. (D) Lox (size 325 bp) and LSL (size 287 bp) KrasG12D and Nupr1 KO (size 381 bp) or wt (size 489 bp) were amplified.

Mentions: Deletion of the Nupr1 gene in mice prevents Kras-induced PanIN development14 and PDAC in around 50% of animals25 by blocking the oncogenic Kras-dependent RelB and IER3 intracellular pathway on one hand15 and, on other hand, by regulating the role of oncogenic KrasG12D by an unknown mechanism16. Whether or not this effect is limited to the pancreatic tissue remained still unresolved. To address this issue, we first utilized the LSL-KrasG12D; ΔInk4a mice for validating Kras activation after intra-tracheal administration of the Ad-Cre adenovirus and approach which, after 12 weeks gave rise to lung adenocarcinoma (Fig. 5A). After this validation step, we administered the same treatment to the LSL-KrasG12D mice, carrying wild-type Nupr1 alleles or knockout. In this experiments, Nupr1+/+ developed a significant number of adenomas grade 1 and 2 (29.1 ± 11.3 and 6.5 ± 2.3 per slice) while Nupr1–/– mice developed fewer lesions (1.5 ± 1.0 and 0.1 ± 0.1 lesions) (Fig. 5B,C). Most importantly, whereas a significant SA-βGal activity was found in Nupr1–/– mice staining for this enzyme was no detected in Nupr1+/+ animals (Fig. 5B). Efficient recombination after Ad-Cre was validated in both Nupr1+/+ and Nupr1–/– lungs (Fig. 5D). In conclusion, in both, pancreas and lung, expression of Nupr1 seems necessary to switch KrasG12D-induced senescence to transformation.


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)

Nupr1 expression is necessary for transformation induced by the oncogenic Kras in lung.(A) LSL-KrasG12D; Nupr1+/+; ΔInk4a mice were treated by intratracheal administration of the adenovirus expressing the Cre recombinase and 12 weeks later the lungs were processed for H&E analysis. All animals showed adenocarcinomas indicating the efficient recombination. (B) LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were treated with the adenovirus expressing the Cre recombinase as in A and lung processed for H&E analysis and SA-βGal staining. Mice with Nupr1+/+ background show several adenoma lesions and negative SA-βGal staining whereas on the contrary lung from mice with Nupr1–/– background present almost not adenoma with positive SA-βGal staining. (C) Quantification of adenoma grade 1 and grade 2. Means ± SD; ***p < 0.001. (D) Lox (size 325 bp) and LSL (size 287 bp) KrasG12D and Nupr1 KO (size 381 bp) or wt (size 489 bp) were amplified.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: Nupr1 expression is necessary for transformation induced by the oncogenic Kras in lung.(A) LSL-KrasG12D; Nupr1+/+; ΔInk4a mice were treated by intratracheal administration of the adenovirus expressing the Cre recombinase and 12 weeks later the lungs were processed for H&E analysis. All animals showed adenocarcinomas indicating the efficient recombination. (B) LSL-KrasG12D; Nupr1+/+ and LSL-KrasG12D; Nupr1–/– mice were treated with the adenovirus expressing the Cre recombinase as in A and lung processed for H&E analysis and SA-βGal staining. Mice with Nupr1+/+ background show several adenoma lesions and negative SA-βGal staining whereas on the contrary lung from mice with Nupr1–/– background present almost not adenoma with positive SA-βGal staining. (C) Quantification of adenoma grade 1 and grade 2. Means ± SD; ***p < 0.001. (D) Lox (size 325 bp) and LSL (size 287 bp) KrasG12D and Nupr1 KO (size 381 bp) or wt (size 489 bp) were amplified.
Mentions: Deletion of the Nupr1 gene in mice prevents Kras-induced PanIN development14 and PDAC in around 50% of animals25 by blocking the oncogenic Kras-dependent RelB and IER3 intracellular pathway on one hand15 and, on other hand, by regulating the role of oncogenic KrasG12D by an unknown mechanism16. Whether or not this effect is limited to the pancreatic tissue remained still unresolved. To address this issue, we first utilized the LSL-KrasG12D; ΔInk4a mice for validating Kras activation after intra-tracheal administration of the Ad-Cre adenovirus and approach which, after 12 weeks gave rise to lung adenocarcinoma (Fig. 5A). After this validation step, we administered the same treatment to the LSL-KrasG12D mice, carrying wild-type Nupr1 alleles or knockout. In this experiments, Nupr1+/+ developed a significant number of adenomas grade 1 and 2 (29.1 ± 11.3 and 6.5 ± 2.3 per slice) while Nupr1–/– mice developed fewer lesions (1.5 ± 1.0 and 0.1 ± 0.1 lesions) (Fig. 5B,C). Most importantly, whereas a significant SA-βGal activity was found in Nupr1–/– mice staining for this enzyme was no detected in Nupr1+/+ animals (Fig. 5B). Efficient recombination after Ad-Cre was validated in both Nupr1+/+ and Nupr1–/– lungs (Fig. 5D). In conclusion, in both, pancreas and lung, expression of Nupr1 seems necessary to switch KrasG12D-induced senescence to transformation.

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