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STAT3 is required for the gp130-mediated full activation of the c-myc gene.

Kiuchi N, Nakajima K, Ichiba M, Fukada T, Narimatsu M, Mizuno K, Hibi M, Hirano T - J. Exp. Med. (1999)

Bottom Line: STAT3 does so most likely by binding to cis-regulatory region(s) of the c-myc gene.We show that STAT3 binds to a region overlapping with the E2F site in the c-myc promoter and this site is critical for the c-myc gene promoter- driven transcriptional activation by IL-6 or gp130 signals.This is the first identification of the linkage between a member of the STAT family and the c-myc gene activation, and also explains how the IL-6 family of cytokines is capable of inducing the expression of the c-myc gene.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Oncology, Biomedical Research Center, Osaka University Medical School, Suita, Osaka 565-0871, Japan.

ABSTRACT
The signal transducers and activators of transcription (STAT) family members have been implicated in regulating the growth, differentiation, and death of normal and transformed cells in response to either extracellular stimuli, including cytokines and growth factors, or intracellular tyrosine kinases. c-myc expression is coordinately regulated by multiple signals in these diverse cellular responses. We show that STAT3 mostly mediates the rapid activation of the c-myc gene upon stimulation of the interleukin (IL)-6 receptor or gp130, a signal transducing subunit of the receptor complexes for the IL-6 cytokine family. STAT3 does so most likely by binding to cis-regulatory region(s) of the c-myc gene. We show that STAT3 binds to a region overlapping with the E2F site in the c-myc promoter and this site is critical for the c-myc gene promoter- driven transcriptional activation by IL-6 or gp130 signals. This is the first identification of the linkage between a member of the STAT family and the c-myc gene activation, and also explains how the IL-6 family of cytokines is capable of inducing the expression of the c-myc gene.

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Binding of STAT3  but not STAT5 to the c-myc E2F  site in IL-2–stimulated KT-3 nuclear extracts. Nuclear extracts  from IL-6–deprived KT-3 cells  either untreated (lanes 1 and 6)  or treated with IL-2 at 10 ng/ml  for 15 min (lanes 2–5 and 7–10)  were preincubated without (lanes  1, 2, 6, and 7) or with an anti-STAT1 mAb (lanes 3 and 8),  anti-Stat3 antibody (lanes 4 and  9), or anti-Stat5 antibody (lanes  5 and 10) for 30 min on ice before the addition of 32P-labeled  oligonucleotide containing the  c-myc promoter E2F site (lanes 1–5) or 32P-labeled oligonucleotide containing a Stat5 binding site (lanes 6–10), and were then subjected to electrophoresis and autoradiography. The positions of the complexes containing STAT3 or STAT5 are indicated.
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Figure 8: Binding of STAT3 but not STAT5 to the c-myc E2F site in IL-2–stimulated KT-3 nuclear extracts. Nuclear extracts from IL-6–deprived KT-3 cells either untreated (lanes 1 and 6) or treated with IL-2 at 10 ng/ml for 15 min (lanes 2–5 and 7–10) were preincubated without (lanes 1, 2, 6, and 7) or with an anti-STAT1 mAb (lanes 3 and 8), anti-Stat3 antibody (lanes 4 and 9), or anti-Stat5 antibody (lanes 5 and 10) for 30 min on ice before the addition of 32P-labeled oligonucleotide containing the c-myc promoter E2F site (lanes 1–5) or 32P-labeled oligonucleotide containing a Stat5 binding site (lanes 6–10), and were then subjected to electrophoresis and autoradiography. The positions of the complexes containing STAT3 or STAT5 are indicated.

Mentions: Next we tested the binding specificity of other STAT proteins for the c-myc E2F site. For this experiment, we first tested the nuclear extracts from IL-2–stimulated KT-3 cells (79) for STAT5 activity using EMSA with an oligonucleotide containing the STAT5 binding site (71) and a specific antibody to STAT5 that recognizes both STAT5a and 5b. As shown in Fig. 8, IL-2–stimulated KT-3 nuclear extracts showed abundant STAT5 complexes on the STAT5 probe recognizable by anti-STAT5 antibody (lane 10) and a small amount of STAT3-containing complex, which was recognized by an anti-STAT3 antibody (lane 9). The same extracts showed inducible binding activity to the c-myc E2F site (Fig. 8, lane 2). Interestingly, the anti-STAT5 antibody did not cause any shift of the complexes (Fig. 8, lane 5), whereas most of the complexes were shifted by the anti-STAT3 antibody (Fig. 8, lane 4). These results indicated that the c-myc E2F site binds preferentially to STAT3 and STAT1, but not to STAT5, and that the nuclear extracts from IL-2–stimulated KT-3 cells had STAT3 bound to the c-myc E2F binding site. Although we do not know the role of STAT3 in the IL-2 signaling pathway, this binding specificity is at least consistent with the lack of a role for STAT5 in the IL-2–induced activation of the c-myc gene.


STAT3 is required for the gp130-mediated full activation of the c-myc gene.

Kiuchi N, Nakajima K, Ichiba M, Fukada T, Narimatsu M, Mizuno K, Hibi M, Hirano T - J. Exp. Med. (1999)

Binding of STAT3  but not STAT5 to the c-myc E2F  site in IL-2–stimulated KT-3 nuclear extracts. Nuclear extracts  from IL-6–deprived KT-3 cells  either untreated (lanes 1 and 6)  or treated with IL-2 at 10 ng/ml  for 15 min (lanes 2–5 and 7–10)  were preincubated without (lanes  1, 2, 6, and 7) or with an anti-STAT1 mAb (lanes 3 and 8),  anti-Stat3 antibody (lanes 4 and  9), or anti-Stat5 antibody (lanes  5 and 10) for 30 min on ice before the addition of 32P-labeled  oligonucleotide containing the  c-myc promoter E2F site (lanes 1–5) or 32P-labeled oligonucleotide containing a Stat5 binding site (lanes 6–10), and were then subjected to electrophoresis and autoradiography. The positions of the complexes containing STAT3 or STAT5 are indicated.
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Related In: Results  -  Collection

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Figure 8: Binding of STAT3 but not STAT5 to the c-myc E2F site in IL-2–stimulated KT-3 nuclear extracts. Nuclear extracts from IL-6–deprived KT-3 cells either untreated (lanes 1 and 6) or treated with IL-2 at 10 ng/ml for 15 min (lanes 2–5 and 7–10) were preincubated without (lanes 1, 2, 6, and 7) or with an anti-STAT1 mAb (lanes 3 and 8), anti-Stat3 antibody (lanes 4 and 9), or anti-Stat5 antibody (lanes 5 and 10) for 30 min on ice before the addition of 32P-labeled oligonucleotide containing the c-myc promoter E2F site (lanes 1–5) or 32P-labeled oligonucleotide containing a Stat5 binding site (lanes 6–10), and were then subjected to electrophoresis and autoradiography. The positions of the complexes containing STAT3 or STAT5 are indicated.
Mentions: Next we tested the binding specificity of other STAT proteins for the c-myc E2F site. For this experiment, we first tested the nuclear extracts from IL-2–stimulated KT-3 cells (79) for STAT5 activity using EMSA with an oligonucleotide containing the STAT5 binding site (71) and a specific antibody to STAT5 that recognizes both STAT5a and 5b. As shown in Fig. 8, IL-2–stimulated KT-3 nuclear extracts showed abundant STAT5 complexes on the STAT5 probe recognizable by anti-STAT5 antibody (lane 10) and a small amount of STAT3-containing complex, which was recognized by an anti-STAT3 antibody (lane 9). The same extracts showed inducible binding activity to the c-myc E2F site (Fig. 8, lane 2). Interestingly, the anti-STAT5 antibody did not cause any shift of the complexes (Fig. 8, lane 5), whereas most of the complexes were shifted by the anti-STAT3 antibody (Fig. 8, lane 4). These results indicated that the c-myc E2F site binds preferentially to STAT3 and STAT1, but not to STAT5, and that the nuclear extracts from IL-2–stimulated KT-3 cells had STAT3 bound to the c-myc E2F binding site. Although we do not know the role of STAT3 in the IL-2 signaling pathway, this binding specificity is at least consistent with the lack of a role for STAT5 in the IL-2–induced activation of the c-myc gene.

Bottom Line: STAT3 does so most likely by binding to cis-regulatory region(s) of the c-myc gene.We show that STAT3 binds to a region overlapping with the E2F site in the c-myc promoter and this site is critical for the c-myc gene promoter- driven transcriptional activation by IL-6 or gp130 signals.This is the first identification of the linkage between a member of the STAT family and the c-myc gene activation, and also explains how the IL-6 family of cytokines is capable of inducing the expression of the c-myc gene.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Oncology, Biomedical Research Center, Osaka University Medical School, Suita, Osaka 565-0871, Japan.

ABSTRACT
The signal transducers and activators of transcription (STAT) family members have been implicated in regulating the growth, differentiation, and death of normal and transformed cells in response to either extracellular stimuli, including cytokines and growth factors, or intracellular tyrosine kinases. c-myc expression is coordinately regulated by multiple signals in these diverse cellular responses. We show that STAT3 mostly mediates the rapid activation of the c-myc gene upon stimulation of the interleukin (IL)-6 receptor or gp130, a signal transducing subunit of the receptor complexes for the IL-6 cytokine family. STAT3 does so most likely by binding to cis-regulatory region(s) of the c-myc gene. We show that STAT3 binds to a region overlapping with the E2F site in the c-myc promoter and this site is critical for the c-myc gene promoter- driven transcriptional activation by IL-6 or gp130 signals. This is the first identification of the linkage between a member of the STAT family and the c-myc gene activation, and also explains how the IL-6 family of cytokines is capable of inducing the expression of the c-myc gene.

Show MeSH
Related in: MedlinePlus