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microRNA let-7c is essential for the anisomycin-elicited apoptosis in Jurkat T cells by linking JNK1/2 to AP-1/STAT1/STAT3 signaling.

Zhou Z, Lu X, Wang J, Xiao J, Liu J, Xing F - Sci Rep (2016)

Bottom Line: The results showed that anisomycin sufficiently promoted the apoptosis in human leukemic Jurkat T cells at a quite low dose. microRNA let-7c (let-7c) contributed to the anisomycin-induced apoptosis, which could be abrogated by the inactivation of JNK signaling.The let-7c deficiency reduced the AP-1, STAT1 and Bim activities, and enhanced the STAT3 and Bcl-xL, alleviating the anisomycin-induced apoptosis.This provides a novel insight into the mechanism by which anisomycin leads to the tumor cell apoptosis, potentially laying the foundations for its development and clinical application.

View Article: PubMed Central - PubMed

Affiliation: Institute of Tissue Transplantation and Immunology, Department of Immunobiology, Jinan University, Guangzhou 510632, China.

ABSTRACT
Anisomycin, an antibiotic produced by Streptomyces griseolus, strongly induces apoptosis in various tumor cells in vitro, superior dramatically to adriamycin. The present study aims to elucidate its detailed mechanistic process. The results showed that anisomycin sufficiently promoted the apoptosis in human leukemic Jurkat T cells at a quite low dose. microRNA let-7c (let-7c) contributed to the anisomycin-induced apoptosis, which could be abrogated by the inactivation of JNK signaling. The let-7c over-expression and the addition of its mimics facilitated the activation of AP-1, STAT1 and Bim by linking JNK1/2 to AP-1/STAT1, but rather inhibited the activation of STAT3 and Bcl-xL by connecting JNK1/2 to STAT3, followed by the augmented apoptosis in the cells. The let-7c deficiency reduced the AP-1, STAT1 and Bim activities, and enhanced the STAT3 and Bcl-xL, alleviating the anisomycin-induced apoptosis. The knockdown of the bim gene repressed the anisomycin-boosted apoptosis through the attenuation of the active Bak and Bax. The findings indicate for the first time that miR let-7c is essential for the anisomycin-triggered apoptosis by linking JNK1/2 to AP-1/STAT1/STAT3/Bim/Bcl-xL/Bax/Bak signaling. This provides a novel insight into the mechanism by which anisomycin leads to the tumor cell apoptosis, potentially laying the foundations for its development and clinical application.

No MeSH data available.


Related in: MedlinePlus

Role of Bim in the anisomycin-induced apoptosis in Jurkat T cells.The Jurkat T cells were transfected with 100 nM of Bim-targeting siRNA or control siRNA for 24 h to knockdown the bim gene. Then, 40 ng/ml of anisomycin was added into the cells for 24 or 48 h. (A) The Bim mRNA expression was evaluated by the real-time qRT-PCR. (B) The level of Bim protein was determined by Western blotting. (C–E) The levels of active Bak, Bax and active Bax were also measured through Western blotting. (F) The apoptotic proportion of the treated cells was analyzed by flow cytometry. (G) In situ immunofluorescence staining was performed for the changes of the active Bak and Bax in the treated cells (×200). The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, Δp < 0.05 and ΔΔp < 0.01 vs. the anisomycin group, #p < 0.05 and ##p < 0.01 vs. the Bim siRNA group.
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f7: Role of Bim in the anisomycin-induced apoptosis in Jurkat T cells.The Jurkat T cells were transfected with 100 nM of Bim-targeting siRNA or control siRNA for 24 h to knockdown the bim gene. Then, 40 ng/ml of anisomycin was added into the cells for 24 or 48 h. (A) The Bim mRNA expression was evaluated by the real-time qRT-PCR. (B) The level of Bim protein was determined by Western blotting. (C–E) The levels of active Bak, Bax and active Bax were also measured through Western blotting. (F) The apoptotic proportion of the treated cells was analyzed by flow cytometry. (G) In situ immunofluorescence staining was performed for the changes of the active Bak and Bax in the treated cells (×200). The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, Δp < 0.05 and ΔΔp < 0.01 vs. the anisomycin group, #p < 0.05 and ##p < 0.01 vs. the Bim siRNA group.

Mentions: The anisomycin-promoted Bim mRNA expression was reversed by knocking down the bim gene in the cells (Fig. 7A). The alterations in Bim, active Bak and active Bax proteins showed the consistent tendency (Fig. 7B–E). The knockdown of the bim gene could impede anisomycin to boost the apoptosis of the cells (Fig. 7F). This could be further supported through the in situ immunofluorescence staining (Fig. 7G). These results demonstrate that Bim mediates the anisomycin-induced apoptosis by the active Bak and Bax.


microRNA let-7c is essential for the anisomycin-elicited apoptosis in Jurkat T cells by linking JNK1/2 to AP-1/STAT1/STAT3 signaling.

Zhou Z, Lu X, Wang J, Xiao J, Liu J, Xing F - Sci Rep (2016)

Role of Bim in the anisomycin-induced apoptosis in Jurkat T cells.The Jurkat T cells were transfected with 100 nM of Bim-targeting siRNA or control siRNA for 24 h to knockdown the bim gene. Then, 40 ng/ml of anisomycin was added into the cells for 24 or 48 h. (A) The Bim mRNA expression was evaluated by the real-time qRT-PCR. (B) The level of Bim protein was determined by Western blotting. (C–E) The levels of active Bak, Bax and active Bax were also measured through Western blotting. (F) The apoptotic proportion of the treated cells was analyzed by flow cytometry. (G) In situ immunofluorescence staining was performed for the changes of the active Bak and Bax in the treated cells (×200). The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, Δp < 0.05 and ΔΔp < 0.01 vs. the anisomycin group, #p < 0.05 and ##p < 0.01 vs. the Bim siRNA group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834478&req=5

f7: Role of Bim in the anisomycin-induced apoptosis in Jurkat T cells.The Jurkat T cells were transfected with 100 nM of Bim-targeting siRNA or control siRNA for 24 h to knockdown the bim gene. Then, 40 ng/ml of anisomycin was added into the cells for 24 or 48 h. (A) The Bim mRNA expression was evaluated by the real-time qRT-PCR. (B) The level of Bim protein was determined by Western blotting. (C–E) The levels of active Bak, Bax and active Bax were also measured through Western blotting. (F) The apoptotic proportion of the treated cells was analyzed by flow cytometry. (G) In situ immunofluorescence staining was performed for the changes of the active Bak and Bax in the treated cells (×200). The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, Δp < 0.05 and ΔΔp < 0.01 vs. the anisomycin group, #p < 0.05 and ##p < 0.01 vs. the Bim siRNA group.
Mentions: The anisomycin-promoted Bim mRNA expression was reversed by knocking down the bim gene in the cells (Fig. 7A). The alterations in Bim, active Bak and active Bax proteins showed the consistent tendency (Fig. 7B–E). The knockdown of the bim gene could impede anisomycin to boost the apoptosis of the cells (Fig. 7F). This could be further supported through the in situ immunofluorescence staining (Fig. 7G). These results demonstrate that Bim mediates the anisomycin-induced apoptosis by the active Bak and Bax.

Bottom Line: The results showed that anisomycin sufficiently promoted the apoptosis in human leukemic Jurkat T cells at a quite low dose. microRNA let-7c (let-7c) contributed to the anisomycin-induced apoptosis, which could be abrogated by the inactivation of JNK signaling.The let-7c deficiency reduced the AP-1, STAT1 and Bim activities, and enhanced the STAT3 and Bcl-xL, alleviating the anisomycin-induced apoptosis.This provides a novel insight into the mechanism by which anisomycin leads to the tumor cell apoptosis, potentially laying the foundations for its development and clinical application.

View Article: PubMed Central - PubMed

Affiliation: Institute of Tissue Transplantation and Immunology, Department of Immunobiology, Jinan University, Guangzhou 510632, China.

ABSTRACT
Anisomycin, an antibiotic produced by Streptomyces griseolus, strongly induces apoptosis in various tumor cells in vitro, superior dramatically to adriamycin. The present study aims to elucidate its detailed mechanistic process. The results showed that anisomycin sufficiently promoted the apoptosis in human leukemic Jurkat T cells at a quite low dose. microRNA let-7c (let-7c) contributed to the anisomycin-induced apoptosis, which could be abrogated by the inactivation of JNK signaling. The let-7c over-expression and the addition of its mimics facilitated the activation of AP-1, STAT1 and Bim by linking JNK1/2 to AP-1/STAT1, but rather inhibited the activation of STAT3 and Bcl-xL by connecting JNK1/2 to STAT3, followed by the augmented apoptosis in the cells. The let-7c deficiency reduced the AP-1, STAT1 and Bim activities, and enhanced the STAT3 and Bcl-xL, alleviating the anisomycin-induced apoptosis. The knockdown of the bim gene repressed the anisomycin-boosted apoptosis through the attenuation of the active Bak and Bax. The findings indicate for the first time that miR let-7c is essential for the anisomycin-triggered apoptosis by linking JNK1/2 to AP-1/STAT1/STAT3/Bim/Bcl-xL/Bax/Bak signaling. This provides a novel insight into the mechanism by which anisomycin leads to the tumor cell apoptosis, potentially laying the foundations for its development and clinical application.

No MeSH data available.


Related in: MedlinePlus