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RNA G-quadruplexes cause eIF4A-dependent oncogene translation in cancer.

Wolfe AL, Singh K, Zhong Y, Drewe P, Rajasekhar VK, Sanghvi VR, Mavrakis KJ, Jiang M, Roderick JE, Van der Meulen J, Schatz JH, Rodrigo CM, Zhao C, Rondou P, de Stanchina E, Teruya-Feldstein J, Kelliher MA, Speleman F, Porco JA, Pelletier J, Rätsch G, Wendel HG - Nature (2014)

Bottom Line: Accordingly, inhibition of eIF4A with silvestrol has powerful therapeutic effects against murine and human leukaemic cells in vitro and in vivo.Notably, among the most eIF4A-dependent and silvestrol-sensitive transcripts are a number of oncogenes, superenhancer-associated transcription factors, and epigenetic regulators.Hence, the 5' UTRs of select cancer genes harbour a targetable requirement for the eIF4A RNA helicase.

View Article: PubMed Central - PubMed

Affiliation: 1] Cancer Biology and Genetics, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA [2] Weill Cornell Graduate School of Medical Sciences, New York, New York 10065, USA [3].

ABSTRACT
The translational control of oncoprotein expression is implicated in many cancers. Here we report an eIF4A RNA helicase-dependent mechanism of translational control that contributes to oncogenesis and underlies the anticancer effects of silvestrol and related compounds. For example, eIF4A promotes T-cell acute lymphoblastic leukaemia development in vivo and is required for leukaemia maintenance. Accordingly, inhibition of eIF4A with silvestrol has powerful therapeutic effects against murine and human leukaemic cells in vitro and in vivo. We use transcriptome-scale ribosome footprinting to identify the hallmarks of eIF4A-dependent transcripts. These include 5' untranslated region (UTR) sequences such as the 12-nucleotide guanine quartet (CGG)4 motif that can form RNA G-quadruplex structures. Notably, among the most eIF4A-dependent and silvestrol-sensitive transcripts are a number of oncogenes, superenhancer-associated transcription factors, and epigenetic regulators. Hence, the 5' UTRs of select cancer genes harbour a targetable requirement for the eIF4A RNA helicase.

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eIF4A promotes T-ALL development in vivoa) Diagram of the NOTCH-ICN-driven murine T-ALL model; b) Kaplan-Meier analysis showing time to leukaemia development after transplantation of HPC transduced with NOTCH1-ICN and empty vector (black, n = 14), eIF4E (green, n = 4), eIF4A1 (red, n = 5), IL7r p.L242-L243insNPC (P1) (blue, n = 4), shPten (orange, n = 10); c) Experimental design of competition experiments; d) Results as percentage of each starting GFP positive population of murine T-ALL cells partially transduced with vector/GFP, sh-eIF4A, or the constitutive inhibitory 4E-binding protein (4E-BP1 (4A)), mean and standard deviations are shown, n = 3 biological replicates.
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Figure 1: eIF4A promotes T-ALL development in vivoa) Diagram of the NOTCH-ICN-driven murine T-ALL model; b) Kaplan-Meier analysis showing time to leukaemia development after transplantation of HPC transduced with NOTCH1-ICN and empty vector (black, n = 14), eIF4E (green, n = 4), eIF4A1 (red, n = 5), IL7r p.L242-L243insNPC (P1) (blue, n = 4), shPten (orange, n = 10); c) Experimental design of competition experiments; d) Results as percentage of each starting GFP positive population of murine T-ALL cells partially transduced with vector/GFP, sh-eIF4A, or the constitutive inhibitory 4E-binding protein (4E-BP1 (4A)), mean and standard deviations are shown, n = 3 biological replicates.

Mentions: NOTCH-driven T-ALL exemplifies the activation of AKT/mTORC1 and cap-dependent translation in cancer. In 36 paediatric T-ALL samples we find PTEN mutations (14%) and deletions (11%)17, NOTCH1 mutations (56%)18, and IL7R mutation (3%)19 ( Extended Data Fig. 1a–c, Suppl. Table 1). These genetic lesions promote T-ALL development in a murine T-ALL model (Figure 1a)20. Notch causes T-ALL with a mean latency of 91.5 days (n = 14), knockdown of Pten or expression of the mutant IL7r/p.L242-L243ins accelerates disease onset (PTEN: 47.1d; n = 10, p < 0.0001; IL7R: 35.5d, n = 4, p < 0.0001). Remarkably, expression of eIF4E or eIF4A1 similarly accelerates leukaemia development (eIF4E: 30.75d; n = 4, p < 0.0001; eIF4A1: n = 5, p < 0.0001) (Figure 1b, Extended Data Fig. 1d). All T-ALLs are CD4/CD8 double positive, and increased ribosomal S6 phosphorylation indicates mTORC1 activation in PTEN-deficient and IL7R expressing T-ALLs (Extended Data Fig. 1d, f–i). EIF4E and eIF4A1 are required to maintain T-ALL and cells expressing a constitutive 4E-BP1 allele (4E-BP1(4A))21 or an eIF4A1 knockdown construct are rapidly eliminated from mixed populations (Figure 1c/d; Extended Data Fig. 1e) (pVector vs. 4E-BP1(4A) = 0.000002 and pVector vs. sh-eIF4A = 0.000008).


RNA G-quadruplexes cause eIF4A-dependent oncogene translation in cancer.

Wolfe AL, Singh K, Zhong Y, Drewe P, Rajasekhar VK, Sanghvi VR, Mavrakis KJ, Jiang M, Roderick JE, Van der Meulen J, Schatz JH, Rodrigo CM, Zhao C, Rondou P, de Stanchina E, Teruya-Feldstein J, Kelliher MA, Speleman F, Porco JA, Pelletier J, Rätsch G, Wendel HG - Nature (2014)

eIF4A promotes T-ALL development in vivoa) Diagram of the NOTCH-ICN-driven murine T-ALL model; b) Kaplan-Meier analysis showing time to leukaemia development after transplantation of HPC transduced with NOTCH1-ICN and empty vector (black, n = 14), eIF4E (green, n = 4), eIF4A1 (red, n = 5), IL7r p.L242-L243insNPC (P1) (blue, n = 4), shPten (orange, n = 10); c) Experimental design of competition experiments; d) Results as percentage of each starting GFP positive population of murine T-ALL cells partially transduced with vector/GFP, sh-eIF4A, or the constitutive inhibitory 4E-binding protein (4E-BP1 (4A)), mean and standard deviations are shown, n = 3 biological replicates.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4492470&req=5

Figure 1: eIF4A promotes T-ALL development in vivoa) Diagram of the NOTCH-ICN-driven murine T-ALL model; b) Kaplan-Meier analysis showing time to leukaemia development after transplantation of HPC transduced with NOTCH1-ICN and empty vector (black, n = 14), eIF4E (green, n = 4), eIF4A1 (red, n = 5), IL7r p.L242-L243insNPC (P1) (blue, n = 4), shPten (orange, n = 10); c) Experimental design of competition experiments; d) Results as percentage of each starting GFP positive population of murine T-ALL cells partially transduced with vector/GFP, sh-eIF4A, or the constitutive inhibitory 4E-binding protein (4E-BP1 (4A)), mean and standard deviations are shown, n = 3 biological replicates.
Mentions: NOTCH-driven T-ALL exemplifies the activation of AKT/mTORC1 and cap-dependent translation in cancer. In 36 paediatric T-ALL samples we find PTEN mutations (14%) and deletions (11%)17, NOTCH1 mutations (56%)18, and IL7R mutation (3%)19 ( Extended Data Fig. 1a–c, Suppl. Table 1). These genetic lesions promote T-ALL development in a murine T-ALL model (Figure 1a)20. Notch causes T-ALL with a mean latency of 91.5 days (n = 14), knockdown of Pten or expression of the mutant IL7r/p.L242-L243ins accelerates disease onset (PTEN: 47.1d; n = 10, p < 0.0001; IL7R: 35.5d, n = 4, p < 0.0001). Remarkably, expression of eIF4E or eIF4A1 similarly accelerates leukaemia development (eIF4E: 30.75d; n = 4, p < 0.0001; eIF4A1: n = 5, p < 0.0001) (Figure 1b, Extended Data Fig. 1d). All T-ALLs are CD4/CD8 double positive, and increased ribosomal S6 phosphorylation indicates mTORC1 activation in PTEN-deficient and IL7R expressing T-ALLs (Extended Data Fig. 1d, f–i). EIF4E and eIF4A1 are required to maintain T-ALL and cells expressing a constitutive 4E-BP1 allele (4E-BP1(4A))21 or an eIF4A1 knockdown construct are rapidly eliminated from mixed populations (Figure 1c/d; Extended Data Fig. 1e) (pVector vs. 4E-BP1(4A) = 0.000002 and pVector vs. sh-eIF4A = 0.000008).

Bottom Line: Accordingly, inhibition of eIF4A with silvestrol has powerful therapeutic effects against murine and human leukaemic cells in vitro and in vivo.Notably, among the most eIF4A-dependent and silvestrol-sensitive transcripts are a number of oncogenes, superenhancer-associated transcription factors, and epigenetic regulators.Hence, the 5' UTRs of select cancer genes harbour a targetable requirement for the eIF4A RNA helicase.

View Article: PubMed Central - PubMed

Affiliation: 1] Cancer Biology and Genetics, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA [2] Weill Cornell Graduate School of Medical Sciences, New York, New York 10065, USA [3].

ABSTRACT
The translational control of oncoprotein expression is implicated in many cancers. Here we report an eIF4A RNA helicase-dependent mechanism of translational control that contributes to oncogenesis and underlies the anticancer effects of silvestrol and related compounds. For example, eIF4A promotes T-cell acute lymphoblastic leukaemia development in vivo and is required for leukaemia maintenance. Accordingly, inhibition of eIF4A with silvestrol has powerful therapeutic effects against murine and human leukaemic cells in vitro and in vivo. We use transcriptome-scale ribosome footprinting to identify the hallmarks of eIF4A-dependent transcripts. These include 5' untranslated region (UTR) sequences such as the 12-nucleotide guanine quartet (CGG)4 motif that can form RNA G-quadruplex structures. Notably, among the most eIF4A-dependent and silvestrol-sensitive transcripts are a number of oncogenes, superenhancer-associated transcription factors, and epigenetic regulators. Hence, the 5' UTRs of select cancer genes harbour a targetable requirement for the eIF4A RNA helicase.

Show MeSH
Related in: MedlinePlus