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MicroRNA-21 induces resistance to the anti-tumour effect of interferon-α/5-fluorouracil in hepatocellular carcinoma cells.

Tomimaru Y, Eguchi H, Nagano H, Wada H, Tomokuni A, Kobayashi S, Marubashi S, Takeda Y, Tanemura M, Umeshita K, Doki Y, Mori M - Br. J. Cancer (2010)

Bottom Line: The aim of this study was to investigate the anti-tumour effects of microRNA (miR)-21 on the sensitivity of HCC cells to IFN-α/5-FU and whether miR-21 can be used as a predictor of the response to such therapy in HCC.Annexin V assay showed that the percentage of apoptotic cells was significantly lower in cells transfected with pre-miR-21 than control cells.The miR-21 in HCC cell lines and clinical HCC samples is a significant modulator of the anti-tumour effect of IFN-α and 5-FU.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, 2-2 Yamadaoka E-2, Osaka 565-0871, Japan.

ABSTRACT

Background: We reported recently the clinical efficiency of interferon (IFN)-α/5-fluorouracil (5-FU) combination therapy in advanced hepatocellular carcinoma (HCC). However, prediction of the response to the combination therapy remains unsatisfactory. The aim of this study was to investigate the anti-tumour effects of microRNA (miR)-21 on the sensitivity of HCC cells to IFN-α/5-FU and whether miR-21 can be used as a predictor of the response to such therapy in HCC.

Methods: Changes in the sensitivity of HCC cells (PLC/PRF/5 and HepG2) to IFN-α/5-FU were examined after transfection with pre-miR-21 or anti-miR-21. The correlation between miR-21 expression level, evaluated by qRT-PCR, and response to the therapy was also investigated in clinical HCC specimens.

Results: Hepatocellular carcinoma cells transfected with pre-miR-21 were significantly resistant to IFN-α/5-FU. Annexin V assay showed that the percentage of apoptotic cells was significantly lower in cells transfected with pre-miR-21 than control cells. Transfection of anti-miR-21 rendered HCC cells sensitive to IFN-α/5-FU, and such sensitivity was weakened by transfection of siRNAs of target molecules, PETN and PDCD4. miR-21 expression in clinical HCC specimens was significantly associated with the clinical response to the IFN-α/5-FU combination therapy and survival rate.

Conclusions: The miR-21 in HCC cell lines and clinical HCC samples is a significant modulator of the anti-tumour effect of IFN-α and 5-FU. This suggests that miR-21 is a potentially suitable marker for the prediction of the clinical response to the IFN-α/5-FU combination therapy.

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Changes in anti-tumour effects of the combination of IFN-α and 5-FU after transfection of anti-miR-21 and/or siRNA against PTEN or PDCD4 in PLC/PRF/5 and HepG2. The MTT assay indicated a weaker anti-tumour effect of 10 IU per ml IFN-α and 0.5 μg per ml 5-FU following transfection of PTEN or PDCD4 siRNA, and that the enhanced growth-inhibitory effect by anti-miR-21 transfection was also weakened after the addition of PTEN or PDCD4 siRNA (*P<0.05).
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fig5: Changes in anti-tumour effects of the combination of IFN-α and 5-FU after transfection of anti-miR-21 and/or siRNA against PTEN or PDCD4 in PLC/PRF/5 and HepG2. The MTT assay indicated a weaker anti-tumour effect of 10 IU per ml IFN-α and 0.5 μg per ml 5-FU following transfection of PTEN or PDCD4 siRNA, and that the enhanced growth-inhibitory effect by anti-miR-21 transfection was also weakened after the addition of PTEN or PDCD4 siRNA (*P<0.05).

Mentions: We next sought to identify the target molecule responsible for the miR-21-induced resistance. As a potential target molecule, we focused on PTEN and PDCD4, which were confirmed as target molecules by the aforementioned results and also reported previously to be related to apoptosis and drug sensitivity (Jansen et al, 2004; Yu et al, 2008; Vaidya et al, 2009; Li et al, 2010). Downregulation of PTEN and PDCD4 expression by their respective siRNAs, PLC/PRF/5, and HepG2 cells became more resistant to the combination therapy (10 IU per ml IFN-α and 0.5 μg per ml 5-FU) (Figure 5). In addition, the enhanced growth-inhibitory effect by the aforementioned anti-miR-21 transfection was weakened after the addition of PTEN or PDCD4 siRNA (Figure 5). These findings suggest that PTEN and PDCD4 are responsible, at least in part, for the miR-21-induced resistance.


MicroRNA-21 induces resistance to the anti-tumour effect of interferon-α/5-fluorouracil in hepatocellular carcinoma cells.

Tomimaru Y, Eguchi H, Nagano H, Wada H, Tomokuni A, Kobayashi S, Marubashi S, Takeda Y, Tanemura M, Umeshita K, Doki Y, Mori M - Br. J. Cancer (2010)

Changes in anti-tumour effects of the combination of IFN-α and 5-FU after transfection of anti-miR-21 and/or siRNA against PTEN or PDCD4 in PLC/PRF/5 and HepG2. The MTT assay indicated a weaker anti-tumour effect of 10 IU per ml IFN-α and 0.5 μg per ml 5-FU following transfection of PTEN or PDCD4 siRNA, and that the enhanced growth-inhibitory effect by anti-miR-21 transfection was also weakened after the addition of PTEN or PDCD4 siRNA (*P<0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2990590&req=5

fig5: Changes in anti-tumour effects of the combination of IFN-α and 5-FU after transfection of anti-miR-21 and/or siRNA against PTEN or PDCD4 in PLC/PRF/5 and HepG2. The MTT assay indicated a weaker anti-tumour effect of 10 IU per ml IFN-α and 0.5 μg per ml 5-FU following transfection of PTEN or PDCD4 siRNA, and that the enhanced growth-inhibitory effect by anti-miR-21 transfection was also weakened after the addition of PTEN or PDCD4 siRNA (*P<0.05).
Mentions: We next sought to identify the target molecule responsible for the miR-21-induced resistance. As a potential target molecule, we focused on PTEN and PDCD4, which were confirmed as target molecules by the aforementioned results and also reported previously to be related to apoptosis and drug sensitivity (Jansen et al, 2004; Yu et al, 2008; Vaidya et al, 2009; Li et al, 2010). Downregulation of PTEN and PDCD4 expression by their respective siRNAs, PLC/PRF/5, and HepG2 cells became more resistant to the combination therapy (10 IU per ml IFN-α and 0.5 μg per ml 5-FU) (Figure 5). In addition, the enhanced growth-inhibitory effect by the aforementioned anti-miR-21 transfection was weakened after the addition of PTEN or PDCD4 siRNA (Figure 5). These findings suggest that PTEN and PDCD4 are responsible, at least in part, for the miR-21-induced resistance.

Bottom Line: The aim of this study was to investigate the anti-tumour effects of microRNA (miR)-21 on the sensitivity of HCC cells to IFN-α/5-FU and whether miR-21 can be used as a predictor of the response to such therapy in HCC.Annexin V assay showed that the percentage of apoptotic cells was significantly lower in cells transfected with pre-miR-21 than control cells.The miR-21 in HCC cell lines and clinical HCC samples is a significant modulator of the anti-tumour effect of IFN-α and 5-FU.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Graduate School of Medicine, Osaka University, Suita, 2-2 Yamadaoka E-2, Osaka 565-0871, Japan.

ABSTRACT

Background: We reported recently the clinical efficiency of interferon (IFN)-α/5-fluorouracil (5-FU) combination therapy in advanced hepatocellular carcinoma (HCC). However, prediction of the response to the combination therapy remains unsatisfactory. The aim of this study was to investigate the anti-tumour effects of microRNA (miR)-21 on the sensitivity of HCC cells to IFN-α/5-FU and whether miR-21 can be used as a predictor of the response to such therapy in HCC.

Methods: Changes in the sensitivity of HCC cells (PLC/PRF/5 and HepG2) to IFN-α/5-FU were examined after transfection with pre-miR-21 or anti-miR-21. The correlation between miR-21 expression level, evaluated by qRT-PCR, and response to the therapy was also investigated in clinical HCC specimens.

Results: Hepatocellular carcinoma cells transfected with pre-miR-21 were significantly resistant to IFN-α/5-FU. Annexin V assay showed that the percentage of apoptotic cells was significantly lower in cells transfected with pre-miR-21 than control cells. Transfection of anti-miR-21 rendered HCC cells sensitive to IFN-α/5-FU, and such sensitivity was weakened by transfection of siRNAs of target molecules, PETN and PDCD4. miR-21 expression in clinical HCC specimens was significantly associated with the clinical response to the IFN-α/5-FU combination therapy and survival rate.

Conclusions: The miR-21 in HCC cell lines and clinical HCC samples is a significant modulator of the anti-tumour effect of IFN-α and 5-FU. This suggests that miR-21 is a potentially suitable marker for the prediction of the clinical response to the IFN-α/5-FU combination therapy.

Show MeSH
Related in: MedlinePlus