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MiR-181b regulates cisplatin chemosensitivity and metastasis by targeting TGFβR1/Smad signaling pathway in NSCLC.

Wang X, Chen X, Meng Q, Jing H, Lu H, Yang Y, Cai L, Zhao Y - Sci Rep (2015)

Bottom Line: We found that miR-181b expression levels were lower in A549/DDP cells compared with A549 cells.In addition, miR-181b could inactivate the TGFβR1/Smad signaling pathway.We also observed that decreased miR-181b expression and increased TGFβR1 expression were significantly associated with chemosensitivity to DDP and tumor metastasis in NSCLC patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medical Oncology, Harbin medical University Cancer Hospital, Harbin, Heilongjiang Province, China.

ABSTRACT
MicroRNAs (miRNAs) have been identified as important post-transcriptional regulators involved in various biological and pathological processes of cells, but their underlying mechanisms in chemosensitivity and metastasis have not been fully elucidated. The objective of this study was to identify miR-181b and its mechanism in the chemosensitivity and metastasis of NSCLC. We found that miR-181b expression levels were lower in A549/DDP cells compared with A549 cells. Functional assays showed that the overexpression of miR-181b inhibited proliferation, enhanced chemosensitivity to DDP, attenuated migration and metastatic ability in NSCLC cell lines in vitro and in vivo. TGFβR1 was subsequently identified as a novel functional target of miR-181b. TGFβR1 knockdown revealed similar effects as that of ectopic miR-181b expression, whereas overexpression of TGFβR1 rescued the function of miR-181b-mediated growth, chemosensitivity and metastasis in NSCLC cells. In addition, miR-181b could inactivate the TGFβR1/Smad signaling pathway. We also observed that decreased miR-181b expression and increased TGFβR1 expression were significantly associated with chemosensitivity to DDP and tumor metastasis in NSCLC patients. Consequently, miR-181b functions as a tumor suppressor and has an important role in proliferation, chemosensitivity to DDP and metastasis of NSCLC by targeting TGFβR1/Smad signaling pathway.

No MeSH data available.


Related in: MedlinePlus

MiR-181b regulates a Smad-dependent and a Smad-independent TGF-β signaling by suppressing TGFβR1.(a) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (b) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/ TGFβR1. (c) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (d) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/TGFβR1. GAPDH was used as an internal control.
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f6: MiR-181b regulates a Smad-dependent and a Smad-independent TGF-β signaling by suppressing TGFβR1.(a) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (b) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/ TGFβR1. (c) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (d) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/TGFβR1. GAPDH was used as an internal control.

Mentions: TGFβR1 is an important component in TGF-β signaling. Its loss or reduced expression may impair TGF-β signaling. To examine if miR-181b is involved in the abrogation of this signaling pathway, the phosphorylation of Smad3, a key protein in this pathway, was detected in A549 cells and A549/DDP cells treated with miR-181b mimics and inhibitors respectively. As shown in Fig. 6a, the introduction of miR-181b did attenuate p-Smad3 expression, whereas silencing of miR-181b increased p-Smad3 expression. Notably, the reduction of p-Smad3 expression was also observed in A549 treated with siRNA-TGFβR1, similar to the effect of miR-181b (Fig. 6b). These data indicate that miR-181b attenuates Smad-dependent TGF-β signal though suppressing TGFβR1.


MiR-181b regulates cisplatin chemosensitivity and metastasis by targeting TGFβR1/Smad signaling pathway in NSCLC.

Wang X, Chen X, Meng Q, Jing H, Lu H, Yang Y, Cai L, Zhao Y - Sci Rep (2015)

MiR-181b regulates a Smad-dependent and a Smad-independent TGF-β signaling by suppressing TGFβR1.(a) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (b) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/ TGFβR1. (c) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (d) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/TGFβR1. GAPDH was used as an internal control.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4664936&req=5

f6: MiR-181b regulates a Smad-dependent and a Smad-independent TGF-β signaling by suppressing TGFβR1.(a) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (b) Western blot detect expression of Smad3, p-Smad3, p-Akt473 and Akt in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/ TGFβR1. (c) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549, A549/miR-181b inhibitors, A549/DDP or A549/DDP/miR-181b. (d) Western blot detect expression of c-Myc, p27 and cyclin D1 in A549/miR-181b inhibitors, A549/miR-181b inhibitors/si-TGFβR1, A549/DDP/miR-181b or A549/DDP/miR-181b/TGFβR1. GAPDH was used as an internal control.
Mentions: TGFβR1 is an important component in TGF-β signaling. Its loss or reduced expression may impair TGF-β signaling. To examine if miR-181b is involved in the abrogation of this signaling pathway, the phosphorylation of Smad3, a key protein in this pathway, was detected in A549 cells and A549/DDP cells treated with miR-181b mimics and inhibitors respectively. As shown in Fig. 6a, the introduction of miR-181b did attenuate p-Smad3 expression, whereas silencing of miR-181b increased p-Smad3 expression. Notably, the reduction of p-Smad3 expression was also observed in A549 treated with siRNA-TGFβR1, similar to the effect of miR-181b (Fig. 6b). These data indicate that miR-181b attenuates Smad-dependent TGF-β signal though suppressing TGFβR1.

Bottom Line: We found that miR-181b expression levels were lower in A549/DDP cells compared with A549 cells.In addition, miR-181b could inactivate the TGFβR1/Smad signaling pathway.We also observed that decreased miR-181b expression and increased TGFβR1 expression were significantly associated with chemosensitivity to DDP and tumor metastasis in NSCLC patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medical Oncology, Harbin medical University Cancer Hospital, Harbin, Heilongjiang Province, China.

ABSTRACT
MicroRNAs (miRNAs) have been identified as important post-transcriptional regulators involved in various biological and pathological processes of cells, but their underlying mechanisms in chemosensitivity and metastasis have not been fully elucidated. The objective of this study was to identify miR-181b and its mechanism in the chemosensitivity and metastasis of NSCLC. We found that miR-181b expression levels were lower in A549/DDP cells compared with A549 cells. Functional assays showed that the overexpression of miR-181b inhibited proliferation, enhanced chemosensitivity to DDP, attenuated migration and metastatic ability in NSCLC cell lines in vitro and in vivo. TGFβR1 was subsequently identified as a novel functional target of miR-181b. TGFβR1 knockdown revealed similar effects as that of ectopic miR-181b expression, whereas overexpression of TGFβR1 rescued the function of miR-181b-mediated growth, chemosensitivity and metastasis in NSCLC cells. In addition, miR-181b could inactivate the TGFβR1/Smad signaling pathway. We also observed that decreased miR-181b expression and increased TGFβR1 expression were significantly associated with chemosensitivity to DDP and tumor metastasis in NSCLC patients. Consequently, miR-181b functions as a tumor suppressor and has an important role in proliferation, chemosensitivity to DDP and metastasis of NSCLC by targeting TGFβR1/Smad signaling pathway.

No MeSH data available.


Related in: MedlinePlus