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High levels of SIRT1 expression enhance tumorigenesis and associate with a poor prognosis of colorectal carcinoma patients.

Chen X, Sun K, Jiao S, Cai N, Zhao X, Zou H, Xie Y, Wang Z, Zhong M, Wei L - Sci Rep (2014)

Bottom Line: We found that many CRC specimens had strong SIRT1 expression, which had an obvious correlation with poor prognosis of CRC patients.Moreover, SIRT1 deficiency decreased percentage of CD133(+) cells, attenuated the abilities of colony and sphere formation, and inhibited tumorigenicity in vivo in CRC cells.Further study demonstrated that the expressions of several stemness-associated genes, including Oct4, Nanog, Cripto, Tert and Lin28, were reduced by SIRT1 knockdown in CRC cells.

View Article: PubMed Central - PubMed

Affiliation: Central Laboratory, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.

ABSTRACT
SIRT1, a NAD(+) dependent class III deacetylase, takes part in many important biological processes. Previous studies show that SIRT1 is overexpressed in some cancers and plays an essential role in tumorigenesis. However, the association between SIRT1 and colorectal cancer (CRC) is still unclear. We found that many CRC specimens had strong SIRT1 expression, which had an obvious correlation with poor prognosis of CRC patients. Meanwhile, SIRT1 expression had a co-localization with CD133, a current universal marker to characterize colorectal cancer stem cells (CSCs). In vitro studies also revealed that SIRT1 was overexpressed in colorectal CSC-like cells. Moreover, SIRT1 deficiency decreased percentage of CD133(+) cells, attenuated the abilities of colony and sphere formation, and inhibited tumorigenicity in vivo in CRC cells. Further study demonstrated that the expressions of several stemness-associated genes, including Oct4, Nanog, Cripto, Tert and Lin28, were reduced by SIRT1 knockdown in CRC cells. Taken together, our findings suggest that SIRT1 plays a crucial role in keeping the characteristics of CSCs cells. SIRT1 is a potential independent prognostic factor of CRC patients after tumor resection with curative intent, and will contribute to providing a promising new approach to target at CSCs in CRC treatment.

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SIRT1 knockdown reduces percentage of CD133+ cells and represses colony and sphere formations in CRC cells.(A) Western blotting of SIRT1 and GAPDH in HCT116 and SW620 cells transduced with SIRT1 shRNAs (ShSIRT1-1 and ShSIRT1-2) or Scr-ShRNA. (B) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (C) The colony formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (D) The sphere formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. All data are representative of three independent experiments. Significance: **P<0.01, ***P<0.001, compared with the controls.
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f4: SIRT1 knockdown reduces percentage of CD133+ cells and represses colony and sphere formations in CRC cells.(A) Western blotting of SIRT1 and GAPDH in HCT116 and SW620 cells transduced with SIRT1 shRNAs (ShSIRT1-1 and ShSIRT1-2) or Scr-ShRNA. (B) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (C) The colony formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (D) The sphere formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. All data are representative of three independent experiments. Significance: **P<0.01, ***P<0.001, compared with the controls.

Mentions: To further confirm above findings, we used ShRNA to suppress the expression of SIRT1. HCT116 and SW620 cells were transducted with anti-SIRT1 lentivirus vectors (ShSIRT1-1, ShSIRT1-2) or scrambled shRNA (Scr-ShRNA). The shRNAs effective inhibition of SIRT1 expression was confirmed by western blotting analysis (Figure 4A). The flow cytometry results illustrated that the cells transducted with SIRT1 shRNAs remarkably decreased percentages of CD133+ cells in both HCT116 and SW620 cells (Figure 4B). The colony formation assay outcome indicated that the ability of colony formation distinctly dropped following with the down-regulation of SIRT1 (Figure 4C). Simultaneously, sphere formation ability also had a positive-correlationship with the SIRT1 expression. SIRT1 knockdown obviously reduced the sphere formation in HCT116 and SW620 cells (Figure 4D). These data illustrated that SIRT1 inhibition significantly reduced the percentage of CD133+ cells and the abilities of colony and sphere formation in CRC cells.


High levels of SIRT1 expression enhance tumorigenesis and associate with a poor prognosis of colorectal carcinoma patients.

Chen X, Sun K, Jiao S, Cai N, Zhao X, Zou H, Xie Y, Wang Z, Zhong M, Wei L - Sci Rep (2014)

SIRT1 knockdown reduces percentage of CD133+ cells and represses colony and sphere formations in CRC cells.(A) Western blotting of SIRT1 and GAPDH in HCT116 and SW620 cells transduced with SIRT1 shRNAs (ShSIRT1-1 and ShSIRT1-2) or Scr-ShRNA. (B) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (C) The colony formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (D) The sphere formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. All data are representative of three independent experiments. Significance: **P<0.01, ***P<0.001, compared with the controls.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4265776&req=5

f4: SIRT1 knockdown reduces percentage of CD133+ cells and represses colony and sphere formations in CRC cells.(A) Western blotting of SIRT1 and GAPDH in HCT116 and SW620 cells transduced with SIRT1 shRNAs (ShSIRT1-1 and ShSIRT1-2) or Scr-ShRNA. (B) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (C) The colony formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. (D) The sphere formation analysis of control cells and cells transduced with shRNAs or Scr-ShRNA of HCT116 and SW620 cells. All data are representative of three independent experiments. Significance: **P<0.01, ***P<0.001, compared with the controls.
Mentions: To further confirm above findings, we used ShRNA to suppress the expression of SIRT1. HCT116 and SW620 cells were transducted with anti-SIRT1 lentivirus vectors (ShSIRT1-1, ShSIRT1-2) or scrambled shRNA (Scr-ShRNA). The shRNAs effective inhibition of SIRT1 expression was confirmed by western blotting analysis (Figure 4A). The flow cytometry results illustrated that the cells transducted with SIRT1 shRNAs remarkably decreased percentages of CD133+ cells in both HCT116 and SW620 cells (Figure 4B). The colony formation assay outcome indicated that the ability of colony formation distinctly dropped following with the down-regulation of SIRT1 (Figure 4C). Simultaneously, sphere formation ability also had a positive-correlationship with the SIRT1 expression. SIRT1 knockdown obviously reduced the sphere formation in HCT116 and SW620 cells (Figure 4D). These data illustrated that SIRT1 inhibition significantly reduced the percentage of CD133+ cells and the abilities of colony and sphere formation in CRC cells.

Bottom Line: We found that many CRC specimens had strong SIRT1 expression, which had an obvious correlation with poor prognosis of CRC patients.Moreover, SIRT1 deficiency decreased percentage of CD133(+) cells, attenuated the abilities of colony and sphere formation, and inhibited tumorigenicity in vivo in CRC cells.Further study demonstrated that the expressions of several stemness-associated genes, including Oct4, Nanog, Cripto, Tert and Lin28, were reduced by SIRT1 knockdown in CRC cells.

View Article: PubMed Central - PubMed

Affiliation: Central Laboratory, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.

ABSTRACT
SIRT1, a NAD(+) dependent class III deacetylase, takes part in many important biological processes. Previous studies show that SIRT1 is overexpressed in some cancers and plays an essential role in tumorigenesis. However, the association between SIRT1 and colorectal cancer (CRC) is still unclear. We found that many CRC specimens had strong SIRT1 expression, which had an obvious correlation with poor prognosis of CRC patients. Meanwhile, SIRT1 expression had a co-localization with CD133, a current universal marker to characterize colorectal cancer stem cells (CSCs). In vitro studies also revealed that SIRT1 was overexpressed in colorectal CSC-like cells. Moreover, SIRT1 deficiency decreased percentage of CD133(+) cells, attenuated the abilities of colony and sphere formation, and inhibited tumorigenicity in vivo in CRC cells. Further study demonstrated that the expressions of several stemness-associated genes, including Oct4, Nanog, Cripto, Tert and Lin28, were reduced by SIRT1 knockdown in CRC cells. Taken together, our findings suggest that SIRT1 plays a crucial role in keeping the characteristics of CSCs cells. SIRT1 is a potential independent prognostic factor of CRC patients after tumor resection with curative intent, and will contribute to providing a promising new approach to target at CSCs in CRC treatment.

Show MeSH
Related in: MedlinePlus