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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

Blocking miRNA let-7c inhibits the anisomycin-induced apoptosis of Jurkat T cells.(A) Jurkat T cells were treated with or without 40 ng/ml of anisomycin for 24 h in the presence or absence of 10 μM SP600125. Afterwards, miR let-7c expression was measured by real-time qPCR. (B) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were exposed to or not to 40ng/ml anisomycin for 24 h. For the comparison, the untreated group and the 40 ng/ml anisomycin group were also set. Then, miR let-7c levels were measured by real-time qPCR. (C–K) The cells were treated as described above and the levels of P-c-jun, P-STAT1, P-STAT3, Bim, P-Bim, Bcl-xL and P-Bcl-xL were measured by Western blotting, and the β-actin expression was used for the normalization, in which the mRNA levels of Bim (F) and Bcl-xL (I) were simultaneously determined by RT-PCR and qPCR, respectively. (L) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were analyzed by flow cytometry for their apoptotic rate. The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, #p < 0.05 and ##p < 0.01 vs. the 40 ng/ml of anisomycin group, Δp < 0.05 and ΔΔp < 0.01 vs. the let-7c mimics group, °p < 0.05 and °°p < 0.01 vs. the let-7c inhibitor group.
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f6: Blocking miRNA let-7c inhibits the anisomycin-induced apoptosis of Jurkat T cells.(A) Jurkat T cells were treated with or without 40 ng/ml of anisomycin for 24 h in the presence or absence of 10 μM SP600125. Afterwards, miR let-7c expression was measured by real-time qPCR. (B) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were exposed to or not to 40ng/ml anisomycin for 24 h. For the comparison, the untreated group and the 40 ng/ml anisomycin group were also set. Then, miR let-7c levels were measured by real-time qPCR. (C–K) The cells were treated as described above and the levels of P-c-jun, P-STAT1, P-STAT3, Bim, P-Bim, Bcl-xL and P-Bcl-xL were measured by Western blotting, and the β-actin expression was used for the normalization, in which the mRNA levels of Bim (F) and Bcl-xL (I) were simultaneously determined by RT-PCR and qPCR, respectively. (L) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were analyzed by flow cytometry for their apoptotic rate. The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, #p < 0.05 and ##p < 0.01 vs. the 40 ng/ml of anisomycin group, Δp < 0.05 and ΔΔp < 0.01 vs. the let-7c mimics group, °p < 0.05 and °°p < 0.01 vs. the let-7c inhibitor group.

Mentions: As shown in Fig. 6, the level of miR let-7c was remarkably increased in the cells treated with 40 ng/ml anisomycin, which could be rescued using SP600125, suggesting that downstream of JNK1/2 activated by anisomycin is miR let-7c (Fig. 6A). When 50 nM of miR let-7c mimics was transfected into the cells, the level of miR let-7c was increased up to about 20-fold as compared to the control, which might be abrogated by the let-7c mimics NC (negative control) instead of miR let-7c. Furthermore, the anisomycin-induced miR let-7c enhancement could be reversed by transfecting the cells with the miR let-7c inhibitor before the anisomycin treatment, but the miR let-7c inhibitor NC had no effect on this change (Fig. 6B). These further support the foregoing findings.


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)

Blocking miRNA let-7c inhibits the anisomycin-induced apoptosis of Jurkat T cells.(A) Jurkat T cells were treated with or without 40 ng/ml of anisomycin for 24 h in the presence or absence of 10 μM SP600125. Afterwards, miR let-7c expression was measured by real-time qPCR. (B) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were exposed to or not to 40ng/ml anisomycin for 24 h. For the comparison, the untreated group and the 40 ng/ml anisomycin group were also set. Then, miR let-7c levels were measured by real-time qPCR. (C–K) The cells were treated as described above and the levels of P-c-jun, P-STAT1, P-STAT3, Bim, P-Bim, Bcl-xL and P-Bcl-xL were measured by Western blotting, and the β-actin expression was used for the normalization, in which the mRNA levels of Bim (F) and Bcl-xL (I) were simultaneously determined by RT-PCR and qPCR, respectively. (L) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were analyzed by flow cytometry for their apoptotic rate. The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, #p < 0.05 and ##p < 0.01 vs. the 40 ng/ml of anisomycin group, Δp < 0.05 and ΔΔp < 0.01 vs. the let-7c mimics group, °p < 0.05 and °°p < 0.01 vs. the let-7c inhibitor group.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: Blocking miRNA let-7c inhibits the anisomycin-induced apoptosis of Jurkat T cells.(A) Jurkat T cells were treated with or without 40 ng/ml of anisomycin for 24 h in the presence or absence of 10 μM SP600125. Afterwards, miR let-7c expression was measured by real-time qPCR. (B) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were exposed to or not to 40ng/ml anisomycin for 24 h. For the comparison, the untreated group and the 40 ng/ml anisomycin group were also set. Then, miR let-7c levels were measured by real-time qPCR. (C–K) The cells were treated as described above and the levels of P-c-jun, P-STAT1, P-STAT3, Bim, P-Bim, Bcl-xL and P-Bcl-xL were measured by Western blotting, and the β-actin expression was used for the normalization, in which the mRNA levels of Bim (F) and Bcl-xL (I) were simultaneously determined by RT-PCR and qPCR, respectively. (L) After transfected with the let-7c mimics, let-7c mimics-negative, let-7c inhibitor or let-7c inhibitor-negative, the cells were analyzed by flow cytometry for their apoptotic rate. The data are presented as the mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 vs. the untreated control, #p < 0.05 and ##p < 0.01 vs. the 40 ng/ml of anisomycin group, Δp < 0.05 and ΔΔp < 0.01 vs. the let-7c mimics group, °p < 0.05 and °°p < 0.01 vs. the let-7c inhibitor group.
Mentions: As shown in Fig. 6, the level of miR let-7c was remarkably increased in the cells treated with 40 ng/ml anisomycin, which could be rescued using SP600125, suggesting that downstream of JNK1/2 activated by anisomycin is miR let-7c (Fig. 6A). When 50 nM of miR let-7c mimics was transfected into the cells, the level of miR let-7c was increased up to about 20-fold as compared to the control, which might be abrogated by the let-7c mimics NC (negative control) instead of miR let-7c. Furthermore, the anisomycin-induced miR let-7c enhancement could be reversed by transfecting the cells with the miR let-7c inhibitor before the anisomycin treatment, but the miR let-7c inhibitor NC had no effect on this change (Fig. 6B). These further support the foregoing findings.

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