Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 18 (3), 257-263

Long Non-Coding RNA GAS5 Sensitizes Renal Cell Carcinoma to Sorafenib via miR-21/SOX5 Pathway

Affiliations

Long Non-Coding RNA GAS5 Sensitizes Renal Cell Carcinoma to Sorafenib via miR-21/SOX5 Pathway

Lei Liu et al. Cell Cycle.

Abstract

Although the use of sorafenib appears to increase the survival rate of renal cell carcinoma (RCC) patients, there is also a proportion of patients who exhibit a poor primary response to sorafenib treatment. Therefore, it is critical to elucidate the mechanisms underlying sorafenib resistance and find representative biomarkers for sorafenib treatment in RCC patients. Herein, we identified that a long noncoding RNA GAS5 was downregulated in sorafenib nonresponsive RCCs. GAS5 overexpression conferred sorafenib sensitive to nonresponsive RCC cells, whereas knockdown of GAS5 promoted responsive RCC cells resistant to sorafenib treatment in vitro and in vivo. Mechanistically, GAS5 functioned as competing endogenous RNA to repress miR-21, which controlled its down-stream target SOX5. We proposed that GAS5 was responsible for sorafenib resistance in RCC cells and GAS5 exerted its function through the miR-21/ SOX5 axis. Our findings suggested that GAS5 downregulation may be a new marker of poor response to sorafenib and GAS5 could be a potential therapeutic target for sorafenib treatment in RCC.

Keywords: GAS5; RCC; Sorafenib.

Figures

Figure 1.
Figure 1.
GAS5 is preferentially downregulated in RCCs with sorafenib resistance. (a) qRT-PCR analysis of GAS5 expression levels in RCC patients’ tumors and tumor adjacent tissues (n = 15); (b) qRT-PCR analysis of GAS5 expression levels in sorafenib-responsive group (n = 8) and non-responsive group(n = 7) in RCC patients; (c) Determination of sorafenib IC50 via MTT assay in a panel of RCC cell lines; (d) qRT–PCR analysis of GAS5 expression levels in a panel of RCC cell lines. ** P < 0.01, ***P < 0.001.
Figure 2.
Figure 2.
GAS5 expression modulates sensitivity of sorafenib in RCC cells. (a) (d) qRT-PCR analysis of GAS5 expression levels in GAS5 knockdown/overexpression cells; (b) (e) MTT analysis of the cell proliferation in GAS5 knockdown/overexpression cells under the stimulation of indicated concentration of sorafenib after 48h; (c) (f) The apoptosis of GAS5 knockdown/overexpression cells under the stimulation of 5 µM sorafenib after 48h; (g) (h) Decreased tumor weight/volume in the nude mice after overexpression of GAS5 in Caki-2 cells under the treatment of sorafenib, scale bars = 1 cm.. * P < 0.05, ** P < 0.01, ***P < 0.001.
Figure 3.
Figure 3.
MiR-21 is a target of GAS5. (a) qRT-PCR analysis of miR-21 expression levels in a panel of RCC cell lines; (b) The effects of GAS5 overexpression/knockdown on miR-21 levels was measured in RCC cells by qRT-PCR; (c) The effects of miR-21 mimics/inhibitor on GAS5 levels was measured in RCC cells by qRT-PCR; (d) Schematic representation of the predicted binding site between miR-21and GAS5 and the mutated site for the reporter assays; (e) Luciferase reporter assay was performed in human embryonic kidney (HEK) 293T cells which was co-transfected with the reporter plasmid (or the corresponding mutant reporter) and the indicated miRNAs; (f) (g) Overexpression of miR-21 abolished GAS5-overexpression induced sorafenib sensitivity. * P < 0.05, ** P < 0.01, ***P < 0.001.
Figure 4.
Figure 4.
GAS5/miR-21/SOX5 axis mediates sorafenib sensitivity in RCC cells. (a)(b) The effects of miR-21 mimics/inhibitor on SOX5 levels was measured in RCC cells by qRT-PCR and western blot; (c)(d) The effects GAS5 overexpression/knockdown on SOX5 levels was measured in RCC cells by qRT-PCR and western blot; (e) Schematic representation of the predicted binding sites between SOX5 and miR-21 and the mutagenesis design for the reporter assays; (f) Luciferase reporter assay was performed in human embryonic kidney (HEK) 293T cells which was co-transfected with the reporter plasmid (or the corresponding mutant reporter) and the indicated miRNAs; (g) qRT-PCR analysis of SOX5 expression levels in sorafenib-responsive group (n = 8) and non-responsive group(n = 7) in RCC patients; (h) qRT-PCR analysis of miR-21expression levels in sorafenib-responsive group (n = 8) and non-responsive group(n = 7) in RCC patients; (i) SOX5 expression by immunohistochemistry (IHC) in sorafenib nonresponsive group (up) and sorafenib-responsive group (down) tumors in RCC patients.

Similar articles

See all similar articles

Cited by 4 articles

MeSH terms

Feedback