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Wig-1 regulates cell cycle arrest and cell death through the p53 targets FAS and 14-3-3σ.

Bersani C, Xu LD, Vilborg A, Lui WO, Wiman KG - Oncogene (2014)

Bottom Line: We identified 2447 transcripts with >fourfold differential expression between Wig-1 and control small interfering (si)RNA-treated HCT116 cells.We found that Wig-1 regulates FAS and 14-3-3σ mRNA independently of p53.We show that Wig-1 binds to FAS mRNA 3'-UTR and decreases its stability through an ARE in the 3'-UTR.

View Article: PubMed Central - PubMed

Affiliation: Cancer Center Karolinska (CCK), Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden.

ABSTRACT
Wig-1, also known as ZMAT3, is a p53 target gene that encodes an RNA-binding zinc-finger protein involved in the regulation of mRNA stability through binding to AU-rich elements (AREs). We have used microarray analysis to identify novel Wig-1 target mRNAs. We identified 2447 transcripts with >fourfold differential expression between Wig-1 and control small interfering (si)RNA-treated HCT116 cells. Several p53 target genes were among the deregulated transcripts. We found that Wig-1 regulates FAS and 14-3-3σ mRNA independently of p53. We show that Wig-1 binds to FAS mRNA 3'-UTR and decreases its stability through an ARE in the 3'-UTR. Depletion of Wig-1 was associated with increased cell death and reduced cell cycle arrest upon DNA damage. Our results suggest a role of Wig-1 as a survival factor that directs the p53 stress response toward cell cycle arrest rather than apoptosis through the regulation of FAS and 14-3-3σ mRNA levels.

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Wig-1 knockdown in normal fibroblasts leads to decreased survival and decreased G1 fraction upon cellular stress. FACS analysis of cell cycle distribution in HDF (AGO1519B and AGO1523C) transfected with siC or siW1 demonstrates a decrease in G1 population after gamma radiation (6 Gy, 24 h) (a). No increase in cell death was detected (b). Decreased proliferation of AGO1523C HDFs 4 days after Wig-1 knockdown and 3 days after gamma irradiation (6 Gy) is shown by live cell number count using Trypan blue exclusion (c) and Bright-field microscopy at × 100 magnification (d). Columns and error bars represent the mean±s.d.; n=3; **P<0.01; ***P<0.01.
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fig3: Wig-1 knockdown in normal fibroblasts leads to decreased survival and decreased G1 fraction upon cellular stress. FACS analysis of cell cycle distribution in HDF (AGO1519B and AGO1523C) transfected with siC or siW1 demonstrates a decrease in G1 population after gamma radiation (6 Gy, 24 h) (a). No increase in cell death was detected (b). Decreased proliferation of AGO1523C HDFs 4 days after Wig-1 knockdown and 3 days after gamma irradiation (6 Gy) is shown by live cell number count using Trypan blue exclusion (c) and Bright-field microscopy at × 100 magnification (d). Columns and error bars represent the mean±s.d.; n=3; **P<0.01; ***P<0.01.

Mentions: Next, we assessed the effect of Wig-1 silencing in primary human dermal fibroblasts (HDFs) with or without gamma irradiation. Gamma irradiation (6 Gy) induced G1 and G2 arrest after 24 h in both AGO1519B and AGO1523C HDFs, as assessed by fluorescence-activated cell sorting (FACS) (sub-G1 fraction). Wig-1 knockdown led to a significant decrease of the G1 fraction in irradiated AGO1519B (12% P-value=0.002) and AGO1523C (7% P-value=0.002) cells as compared with the irradiated control-transfected cells (Figure 3a). No significant effect on the sub-G1 population was observed after Wig-1 knockdown (Figure 3b). We assessed the effect of Wig-1 knockdown in long-term assays, as described above for HCT116 cells. Wig-1 knockdown inhibited proliferation of gamma-irradiated normal fibroblasts, as shown by counting living cells and by light microscopy (Figures 3c and d). Taken together, our data demonstrate that Wig-1 promotes cell cycle arrest in normal fibroblasts upon gamma irradiation and promotes long-term cell survival. We did not detect significant cell death in these HDFs, which may reflect the fact that normal fibroblasts show increased resistance to apoptosis.25


Wig-1 regulates cell cycle arrest and cell death through the p53 targets FAS and 14-3-3σ.

Bersani C, Xu LD, Vilborg A, Lui WO, Wiman KG - Oncogene (2014)

Wig-1 knockdown in normal fibroblasts leads to decreased survival and decreased G1 fraction upon cellular stress. FACS analysis of cell cycle distribution in HDF (AGO1519B and AGO1523C) transfected with siC or siW1 demonstrates a decrease in G1 population after gamma radiation (6 Gy, 24 h) (a). No increase in cell death was detected (b). Decreased proliferation of AGO1523C HDFs 4 days after Wig-1 knockdown and 3 days after gamma irradiation (6 Gy) is shown by live cell number count using Trypan blue exclusion (c) and Bright-field microscopy at × 100 magnification (d). Columns and error bars represent the mean±s.d.; n=3; **P<0.01; ***P<0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4150987&req=5

fig3: Wig-1 knockdown in normal fibroblasts leads to decreased survival and decreased G1 fraction upon cellular stress. FACS analysis of cell cycle distribution in HDF (AGO1519B and AGO1523C) transfected with siC or siW1 demonstrates a decrease in G1 population after gamma radiation (6 Gy, 24 h) (a). No increase in cell death was detected (b). Decreased proliferation of AGO1523C HDFs 4 days after Wig-1 knockdown and 3 days after gamma irradiation (6 Gy) is shown by live cell number count using Trypan blue exclusion (c) and Bright-field microscopy at × 100 magnification (d). Columns and error bars represent the mean±s.d.; n=3; **P<0.01; ***P<0.01.
Mentions: Next, we assessed the effect of Wig-1 silencing in primary human dermal fibroblasts (HDFs) with or without gamma irradiation. Gamma irradiation (6 Gy) induced G1 and G2 arrest after 24 h in both AGO1519B and AGO1523C HDFs, as assessed by fluorescence-activated cell sorting (FACS) (sub-G1 fraction). Wig-1 knockdown led to a significant decrease of the G1 fraction in irradiated AGO1519B (12% P-value=0.002) and AGO1523C (7% P-value=0.002) cells as compared with the irradiated control-transfected cells (Figure 3a). No significant effect on the sub-G1 population was observed after Wig-1 knockdown (Figure 3b). We assessed the effect of Wig-1 knockdown in long-term assays, as described above for HCT116 cells. Wig-1 knockdown inhibited proliferation of gamma-irradiated normal fibroblasts, as shown by counting living cells and by light microscopy (Figures 3c and d). Taken together, our data demonstrate that Wig-1 promotes cell cycle arrest in normal fibroblasts upon gamma irradiation and promotes long-term cell survival. We did not detect significant cell death in these HDFs, which may reflect the fact that normal fibroblasts show increased resistance to apoptosis.25

Bottom Line: We identified 2447 transcripts with >fourfold differential expression between Wig-1 and control small interfering (si)RNA-treated HCT116 cells.We found that Wig-1 regulates FAS and 14-3-3σ mRNA independently of p53.We show that Wig-1 binds to FAS mRNA 3'-UTR and decreases its stability through an ARE in the 3'-UTR.

View Article: PubMed Central - PubMed

Affiliation: Cancer Center Karolinska (CCK), Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden.

ABSTRACT
Wig-1, also known as ZMAT3, is a p53 target gene that encodes an RNA-binding zinc-finger protein involved in the regulation of mRNA stability through binding to AU-rich elements (AREs). We have used microarray analysis to identify novel Wig-1 target mRNAs. We identified 2447 transcripts with >fourfold differential expression between Wig-1 and control small interfering (si)RNA-treated HCT116 cells. Several p53 target genes were among the deregulated transcripts. We found that Wig-1 regulates FAS and 14-3-3σ mRNA independently of p53. We show that Wig-1 binds to FAS mRNA 3'-UTR and decreases its stability through an ARE in the 3'-UTR. Depletion of Wig-1 was associated with increased cell death and reduced cell cycle arrest upon DNA damage. Our results suggest a role of Wig-1 as a survival factor that directs the p53 stress response toward cell cycle arrest rather than apoptosis through the regulation of FAS and 14-3-3σ mRNA levels.

Show MeSH
Related in: MedlinePlus