Dataset Information

Feedback regulations of miR-21 and MAPKs via Pdcd4 and Spry1 are involved in arsenite-induced cell malignant transformation.

ABSTRACT:

Objective

To establish the functions of miR-21 and the roles of two feedback regulation loops, miR-21-Spry1-ERK/NF-?B and miR-21-Pdcd4-JNK/c-Jun, in arsenite-transformed human embryo lung fibroblast (HELF) cells.

Methods

For arsenite-transformed HELF cells, apoptosis, clonogenicity, and capacity for migration were determined by Hoechst staining, assessment of their capacity for anchorage-independent growth, and wound-healing, respectively, after blockage, with inhibitors or with siRNAs, of signal pathways for JNK/c-Jun or ERK/NF-?B. Decreases of miR-21 levels were determined with anti-miR-21, and the up-regulation of Pdcd4 and Spry1 was assessed in transfected cells; these cells were molecularly characterized by RT-PCR, qRT-PCR, Western blots, and immunofluorescence assays.

Results

MiR-21 was highly expressed in arsenite-transformed HELF cells and normal HELF cells acutely treated with arsenite, an effect that was concomitant with activation of JNK/c-Jun and ERK/NF-?B and down-regulation of Pdcd4 and Spry1 protein levels. However, there were no significant changes in mRNA levels for Pdcd4 and Spry1, which suggested that miR-21 regulates the expressions of Pdcd4 and Spry1 through translational repression. In arsenite-transformed HELF cells, blockages of JNK/c-Jun or ERK/NF-?B with inhibitors or with siRNAs prevented the increases of miR-21and the decreases of the protein levels but not the mRNA levels of Pdcd4 and Spry1. Down-regulation of miR-21 and up-regulations of Pdcd44 or Spry1 blocked the arsenite-induced activations of JNK/c-Jun or ERK/NF-?B, indicating that knockdown of miR-21 inhibits feedback of ERK activation and JNK activation via increases of Pdcd4 and Spry1 protein levels, respectively. Moreover, in arsenite-transformed HELF cells, inhibition of miR-21 promoted cell apoptosis, inhibited clonogenicity, and reduced migration.

Conclusion

The results indicate that miR-21 is both a target and a regulator of ERK/NF-?B and JNK/c-Jun and the feedback regulations of miR-21 and MAPKs via Pdcd4 and Spry1, respectively, are involved in arsenite-induced malignant transformation of HELF cells.

SUBMITTER: Shen L

PROVIDER: S-EPMC3585869 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Feedback regulations of miR-21 and MAPKs via Pdcd4 and Spry1 are involved in arsenite-induced cell malignant transformation.

Shen Lu L Ling Min M Li Yuan Y Xu Yuan Y Zhou Yun Y Ye Jing J Pang Ying Y Zhao Yue Y Jiang Rongrong R Zhang Jianping J Liu Qizhan Q

PloS one 20130301 3

<h4>Objective</h4>To establish the functions of miR-21 and the roles of two feedback regulation loops, miR-21-Spry1-ERK/NF-κB and miR-21-Pdcd4-JNK/c-Jun, in arsenite-transformed human embryo lung fibroblast (HELF) cells.<h4>Methods</h4>For arsenite-transformed HELF cells, apoptosis, clonogenicity, and capacity for migration were determined by Hoechst staining, assessment of their capacity for anchorage-independent growth, and wound-healing, respectively, after blockage, with inhibitors or with s ...[more]

PMID: 23469214

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Dataset Information

Feedback regulations of miR-21 and MAPKs via Pdcd4 and Spry1 are involved in arsenite-induced cell malignant transformation.

Objective

Methods

Results

Conclusion

Publications

Feedback regulations of miR-21 and MAPKs via Pdcd4 and Spry1 are involved in arsenite-induced cell malignant transformation.

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