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A dual yet opposite growth-regulating function of miR-204 and its target XRN1 in prostate adenocarcinoma cells and neuroendocrine-like prostate cancer cells.

Ding M, Lin B, Li T, Liu Y, Li Y, Zhou X, Miao M, Gu J, Pan H, Yang F, Li T, Liu XY, Li R - Oncotarget (2015)

Bottom Line: Androgen-responsive genes involved in PCa progression including NED remain largely unknown.Importantly, overexpression of miR-204 and knockdown of XRN1 inhibited AR expression in PCa cells.Repression of miR-34a, a known AR-targeting miRNA, contributes AR expression by XRN1.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.

ABSTRACT
Androgen deprivation therapy in prostate cancer (PCa) causes neuroendocrine differentiation (NED) of prostatic adenocarcinomas (PAC) cells, leading to recurrence of PCa. Androgen-responsive genes involved in PCa progression including NED remain largely unknown. Here we demonstrated the importance of androgen receptor (AR)-microRNA-204 (miR-204)-XRN1 axis in PCa cell lines and the rat ventral prostate. Androgens downregulate miR-204, resulting in induction of XRN1 (5'-3' exoribonuclease 1), which we identified as a miR-204 target. miR-204 acts as a tumor suppressor in two PAC cell lines (LNCaP and 22Rv1) and as an oncomiR in two neuroendocrine-like prostate cancer (NEPC) cell lines (PC-3 and CL1). Importantly, overexpression of miR-204 and knockdown of XRN1 inhibited AR expression in PCa cells. Repression of miR-34a, a known AR-targeting miRNA, contributes AR expression by XRN1. Thus we revealed the AR-miR-204-XRN1-miR-34a positive feedback loop and a dual function of miR-204/XRN1 axis in prostate cancer.

No MeSH data available.


Related in: MedlinePlus

miR-204 and XRN1 regulate AR expression, and miR-34a is a XRN1 target that down-regulates AR(A-B) Western blot analyses of PCa cells infected with miR-204-expressing virus or transfected with XRN1-siRNA. (C and E) RT-PCR assays of CD44 and miR-34a in different PCa cells as indicated. (D) RT-qPCR assays of four AR-targeting miRNAs in LNCaP (top) and CL-1 (bottom) cells with XRN1 knockdown. Shown are mean values ± SEM. *P < 0.05; **P < 0.01. n=3. (F) Western blot analysis of the effect of miR-34a inhibitor on XRN1-siRNA-induced down-regulation of AR in LNCaP cells. (G) Schematic representation of the proposed AR/miR-204/XRN1/miR-34a feedback loop. The activation of the loop by androgen induces an up-regulation of AR signaling. The modulation is advantageous for development of aggressive phenotype of PAC.
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Figure 5: miR-204 and XRN1 regulate AR expression, and miR-34a is a XRN1 target that down-regulates AR(A-B) Western blot analyses of PCa cells infected with miR-204-expressing virus or transfected with XRN1-siRNA. (C and E) RT-PCR assays of CD44 and miR-34a in different PCa cells as indicated. (D) RT-qPCR assays of four AR-targeting miRNAs in LNCaP (top) and CL-1 (bottom) cells with XRN1 knockdown. Shown are mean values ± SEM. *P < 0.05; **P < 0.01. n=3. (F) Western blot analysis of the effect of miR-34a inhibitor on XRN1-siRNA-induced down-regulation of AR in LNCaP cells. (G) Schematic representation of the proposed AR/miR-204/XRN1/miR-34a feedback loop. The activation of the loop by androgen induces an up-regulation of AR signaling. The modulation is advantageous for development of aggressive phenotype of PAC.

Mentions: Western blotting analysis showed that miR-204 and XRN-siRNA inhibited AR expression in the two PAC cell lines (Fig. 5A and B). Androgen was reported to inhibit the transcription of p21WAF1, an inhibitor of cell cycle progression in LNCaP cells [35]. Consistent with this, miR-204 and XRN-siRNA also increased levels of p21WAF1 in two PAC cell lines (Fig. 5A and B). These results strongly suggested that down-regulation of AR by miR-204 or XRN-siRNA generates profound downstream signaling changes. In contrast to the response of p21WAF1 to miR-204 and XRN-siRNA, Cyclin D1 and Akt phosphorylation (both at T308 and S473) showed a significant up-regulation in the NEPC cell lines, but a down-regulation in the PAC cell lines overexpressing miR-204 (Fig. 5A and B). These results revealed that the dual function of miR-204/XRN1 axis is closely associated with its dual modulation of expression of these key regulators of cell cycle progression. Finally, we studied effect of XRN1 knockdown on expression of CD44, the feature of NEPC cells [8-10]. Our results showed that XRN1-siRNA increased CD44 expression in both CL1 and PC-3 cells (Fig. 5C), suggesting that by down-regulating CD44 expression XRN1 could be a potential suppressor of NE phenotype of PCa.


A dual yet opposite growth-regulating function of miR-204 and its target XRN1 in prostate adenocarcinoma cells and neuroendocrine-like prostate cancer cells.

Ding M, Lin B, Li T, Liu Y, Li Y, Zhou X, Miao M, Gu J, Pan H, Yang F, Li T, Liu XY, Li R - Oncotarget (2015)

miR-204 and XRN1 regulate AR expression, and miR-34a is a XRN1 target that down-regulates AR(A-B) Western blot analyses of PCa cells infected with miR-204-expressing virus or transfected with XRN1-siRNA. (C and E) RT-PCR assays of CD44 and miR-34a in different PCa cells as indicated. (D) RT-qPCR assays of four AR-targeting miRNAs in LNCaP (top) and CL-1 (bottom) cells with XRN1 knockdown. Shown are mean values ± SEM. *P < 0.05; **P < 0.01. n=3. (F) Western blot analysis of the effect of miR-34a inhibitor on XRN1-siRNA-induced down-regulation of AR in LNCaP cells. (G) Schematic representation of the proposed AR/miR-204/XRN1/miR-34a feedback loop. The activation of the loop by androgen induces an up-regulation of AR signaling. The modulation is advantageous for development of aggressive phenotype of PAC.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4480709&req=5

Figure 5: miR-204 and XRN1 regulate AR expression, and miR-34a is a XRN1 target that down-regulates AR(A-B) Western blot analyses of PCa cells infected with miR-204-expressing virus or transfected with XRN1-siRNA. (C and E) RT-PCR assays of CD44 and miR-34a in different PCa cells as indicated. (D) RT-qPCR assays of four AR-targeting miRNAs in LNCaP (top) and CL-1 (bottom) cells with XRN1 knockdown. Shown are mean values ± SEM. *P < 0.05; **P < 0.01. n=3. (F) Western blot analysis of the effect of miR-34a inhibitor on XRN1-siRNA-induced down-regulation of AR in LNCaP cells. (G) Schematic representation of the proposed AR/miR-204/XRN1/miR-34a feedback loop. The activation of the loop by androgen induces an up-regulation of AR signaling. The modulation is advantageous for development of aggressive phenotype of PAC.
Mentions: Western blotting analysis showed that miR-204 and XRN-siRNA inhibited AR expression in the two PAC cell lines (Fig. 5A and B). Androgen was reported to inhibit the transcription of p21WAF1, an inhibitor of cell cycle progression in LNCaP cells [35]. Consistent with this, miR-204 and XRN-siRNA also increased levels of p21WAF1 in two PAC cell lines (Fig. 5A and B). These results strongly suggested that down-regulation of AR by miR-204 or XRN-siRNA generates profound downstream signaling changes. In contrast to the response of p21WAF1 to miR-204 and XRN-siRNA, Cyclin D1 and Akt phosphorylation (both at T308 and S473) showed a significant up-regulation in the NEPC cell lines, but a down-regulation in the PAC cell lines overexpressing miR-204 (Fig. 5A and B). These results revealed that the dual function of miR-204/XRN1 axis is closely associated with its dual modulation of expression of these key regulators of cell cycle progression. Finally, we studied effect of XRN1 knockdown on expression of CD44, the feature of NEPC cells [8-10]. Our results showed that XRN1-siRNA increased CD44 expression in both CL1 and PC-3 cells (Fig. 5C), suggesting that by down-regulating CD44 expression XRN1 could be a potential suppressor of NE phenotype of PCa.

Bottom Line: Androgen-responsive genes involved in PCa progression including NED remain largely unknown.Importantly, overexpression of miR-204 and knockdown of XRN1 inhibited AR expression in PCa cells.Repression of miR-34a, a known AR-targeting miRNA, contributes AR expression by XRN1.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.

ABSTRACT
Androgen deprivation therapy in prostate cancer (PCa) causes neuroendocrine differentiation (NED) of prostatic adenocarcinomas (PAC) cells, leading to recurrence of PCa. Androgen-responsive genes involved in PCa progression including NED remain largely unknown. Here we demonstrated the importance of androgen receptor (AR)-microRNA-204 (miR-204)-XRN1 axis in PCa cell lines and the rat ventral prostate. Androgens downregulate miR-204, resulting in induction of XRN1 (5'-3' exoribonuclease 1), which we identified as a miR-204 target. miR-204 acts as a tumor suppressor in two PAC cell lines (LNCaP and 22Rv1) and as an oncomiR in two neuroendocrine-like prostate cancer (NEPC) cell lines (PC-3 and CL1). Importantly, overexpression of miR-204 and knockdown of XRN1 inhibited AR expression in PCa cells. Repression of miR-34a, a known AR-targeting miRNA, contributes AR expression by XRN1. Thus we revealed the AR-miR-204-XRN1-miR-34a positive feedback loop and a dual function of miR-204/XRN1 axis in prostate cancer.

No MeSH data available.


Related in: MedlinePlus