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Cisplatin-induced epigenetic activation of miR-34a sensitizes bladder cancer cells to chemotherapy.

Li H, Yu G, Shi R, Lang B, Chen X, Xia D, Xiao H, Guo X, Guan W, Ye Z, Xiao W, Xu H - Mol. Cancer (2014)

Bottom Line: Synthetic short single or double stranded RNA oligonucleotides and lentiviral vector were used to regulate miR-34a expression in MIBC cells to investigate its function in vitro and in vivo. miR-34a expression was frequently decreased in MIBC tissues and cell lines through promoter hypermethylation while it was epigenetically increased in MIBC cells following cisplatin treatment.Furthermore, we identified CD44 as being targeted by miR-34a in MIBC cells following cisplatin treatment, and increased CD44 expression could efficiently reverse the effect of miR-34a on MIBC cell proliferation, colongenic potential and chemosensitivity.Cisplatin-based chemotherapy induced demethylation of miR-34a promoter and increased miR-34a expression, which in turn sensitized MIBC cells to cisplatin and decreased the tumorigenicity and proliferation of cancer cells that by reducing the production of CD44.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. xiaowei0041@163.com.

ABSTRACT

Background: Accumulating evidence suggests a tumor suppressive role for miR-34a in human carcinogenesis. However, its precise biological role remains largely elusive. This study aimed to reveal the association of the miR-34a expression and its modulation of sensitivity to cisplatin in muscle-invasive bladder cancer (MIBC).

Methods: miR-34a expression in MIBC cell lines and patient tissues was investigated using qPCR. The methylation analysis of miR-34a promoter region was performed by MassARRAY. Synthetic short single or double stranded RNA oligonucleotides and lentiviral vector were used to regulate miR-34a expression in MIBC cells to investigate its function in vitro and in vivo.

Results: miR-34a expression was frequently decreased in MIBC tissues and cell lines through promoter hypermethylation while it was epigenetically increased in MIBC cells following cisplatin treatment. Increased miR-34a expression significantly sensitized MIBC cells to cisplatin and inhibited the tumorigenicity and proliferation of cancer cells in vitro and in vivo. Furthermore, we identified CD44 as being targeted by miR-34a in MIBC cells following cisplatin treatment, and increased CD44 expression could efficiently reverse the effect of miR-34a on MIBC cell proliferation, colongenic potential and chemosensitivity.

Conclusions: Cisplatin-based chemotherapy induced demethylation of miR-34a promoter and increased miR-34a expression, which in turn sensitized MIBC cells to cisplatin and decreased the tumorigenicity and proliferation of cancer cells that by reducing the production of CD44.

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Overexpression of miR-34a in MIBC cells sensitized tumor cells to cisplatin chemotherapy. A) Tumor cell viability was detected by CCK-8 assay after different treatment. Data are plotted as the mean ± SEM of 3 independent experiments relative to mock treatments; B) The IC50 values for cisplatin of MIBC cell lines after transfected with miR-34a mimics (mean + SEM; n = 3; *p < 0.05); Mean xenograft tumor volume C) and weight D) in nude mice groups after indicated treatment (mean ± SEM; n = 3;).
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Figure 3: Overexpression of miR-34a in MIBC cells sensitized tumor cells to cisplatin chemotherapy. A) Tumor cell viability was detected by CCK-8 assay after different treatment. Data are plotted as the mean ± SEM of 3 independent experiments relative to mock treatments; B) The IC50 values for cisplatin of MIBC cell lines after transfected with miR-34a mimics (mean + SEM; n = 3; *p < 0.05); Mean xenograft tumor volume C) and weight D) in nude mice groups after indicated treatment (mean ± SEM; n = 3;).

Mentions: As miR-34a expression increased dramatically following cisplatin treatment, we subsequently assessed in the association between miR-34a and chemosensitivity. Results of cell viability assay clearly showed that overexpression of miR-34a in 5637, T24 and HT1376 cells could efficiently increased their sensitivity to cisplatin as compared to NC group (Figure 3A and B, P < 0.05). This observation was further confirmed in T24 cell based xenograft model by using agomir-miRNA, a chemically modified miRNA oligonucleotide conjugated with cholesterol (Figure 3C and D). Importantly, statistical analysis demonstrated that the inhibition rate of each group satisfy the formula: (miR-34a + cisplatin) > (miR-34a alone) + (cisplatin alone), which indicated the synergistic effect of miR-34a to cisplatin chemotherapy.


Cisplatin-induced epigenetic activation of miR-34a sensitizes bladder cancer cells to chemotherapy.

Li H, Yu G, Shi R, Lang B, Chen X, Xia D, Xiao H, Guo X, Guan W, Ye Z, Xiao W, Xu H - Mol. Cancer (2014)

Overexpression of miR-34a in MIBC cells sensitized tumor cells to cisplatin chemotherapy. A) Tumor cell viability was detected by CCK-8 assay after different treatment. Data are plotted as the mean ± SEM of 3 independent experiments relative to mock treatments; B) The IC50 values for cisplatin of MIBC cell lines after transfected with miR-34a mimics (mean + SEM; n = 3; *p < 0.05); Mean xenograft tumor volume C) and weight D) in nude mice groups after indicated treatment (mean ± SEM; n = 3;).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4022035&req=5

Figure 3: Overexpression of miR-34a in MIBC cells sensitized tumor cells to cisplatin chemotherapy. A) Tumor cell viability was detected by CCK-8 assay after different treatment. Data are plotted as the mean ± SEM of 3 independent experiments relative to mock treatments; B) The IC50 values for cisplatin of MIBC cell lines after transfected with miR-34a mimics (mean + SEM; n = 3; *p < 0.05); Mean xenograft tumor volume C) and weight D) in nude mice groups after indicated treatment (mean ± SEM; n = 3;).
Mentions: As miR-34a expression increased dramatically following cisplatin treatment, we subsequently assessed in the association between miR-34a and chemosensitivity. Results of cell viability assay clearly showed that overexpression of miR-34a in 5637, T24 and HT1376 cells could efficiently increased their sensitivity to cisplatin as compared to NC group (Figure 3A and B, P < 0.05). This observation was further confirmed in T24 cell based xenograft model by using agomir-miRNA, a chemically modified miRNA oligonucleotide conjugated with cholesterol (Figure 3C and D). Importantly, statistical analysis demonstrated that the inhibition rate of each group satisfy the formula: (miR-34a + cisplatin) > (miR-34a alone) + (cisplatin alone), which indicated the synergistic effect of miR-34a to cisplatin chemotherapy.

Bottom Line: Synthetic short single or double stranded RNA oligonucleotides and lentiviral vector were used to regulate miR-34a expression in MIBC cells to investigate its function in vitro and in vivo. miR-34a expression was frequently decreased in MIBC tissues and cell lines through promoter hypermethylation while it was epigenetically increased in MIBC cells following cisplatin treatment.Furthermore, we identified CD44 as being targeted by miR-34a in MIBC cells following cisplatin treatment, and increased CD44 expression could efficiently reverse the effect of miR-34a on MIBC cell proliferation, colongenic potential and chemosensitivity.Cisplatin-based chemotherapy induced demethylation of miR-34a promoter and increased miR-34a expression, which in turn sensitized MIBC cells to cisplatin and decreased the tumorigenicity and proliferation of cancer cells that by reducing the production of CD44.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. xiaowei0041@163.com.

ABSTRACT

Background: Accumulating evidence suggests a tumor suppressive role for miR-34a in human carcinogenesis. However, its precise biological role remains largely elusive. This study aimed to reveal the association of the miR-34a expression and its modulation of sensitivity to cisplatin in muscle-invasive bladder cancer (MIBC).

Methods: miR-34a expression in MIBC cell lines and patient tissues was investigated using qPCR. The methylation analysis of miR-34a promoter region was performed by MassARRAY. Synthetic short single or double stranded RNA oligonucleotides and lentiviral vector were used to regulate miR-34a expression in MIBC cells to investigate its function in vitro and in vivo.

Results: miR-34a expression was frequently decreased in MIBC tissues and cell lines through promoter hypermethylation while it was epigenetically increased in MIBC cells following cisplatin treatment. Increased miR-34a expression significantly sensitized MIBC cells to cisplatin and inhibited the tumorigenicity and proliferation of cancer cells in vitro and in vivo. Furthermore, we identified CD44 as being targeted by miR-34a in MIBC cells following cisplatin treatment, and increased CD44 expression could efficiently reverse the effect of miR-34a on MIBC cell proliferation, colongenic potential and chemosensitivity.

Conclusions: Cisplatin-based chemotherapy induced demethylation of miR-34a promoter and increased miR-34a expression, which in turn sensitized MIBC cells to cisplatin and decreased the tumorigenicity and proliferation of cancer cells that by reducing the production of CD44.

Show MeSH
Related in: MedlinePlus