Limits...
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.

Show MeSH

Related in: MedlinePlus

Pharmacological inhibition of SIRT1 reduces percentage of CD133+ cells and the colony formation in CRC cells.(A) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (B) The colony formation analysis of control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (C) The colony formation analysis of CD133+ cells and CD133- cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. (D) The sphere formation analysis of CD133+ cells and CD133− cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. All data are representative of three independent experiments. Significance: *P<0.05, **P<0.01, ***P<0.001, compared with the controls.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4265776&req=5

f3: Pharmacological inhibition of SIRT1 reduces percentage of CD133+ cells and the colony formation in CRC cells.(A) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (B) The colony formation analysis of control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (C) The colony formation analysis of CD133+ cells and CD133- cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. (D) The sphere formation analysis of CD133+ cells and CD133− cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. All data are representative of three independent experiments. Significance: *P<0.05, **P<0.01, ***P<0.001, compared with the controls.

Mentions: According to the positive-relationship between SIRT1 and CD133, we attempted to explore whether SIRT1 deficiency had an influence on the stemness of colorectal CSCs. Firstly, we used SIRT1 inhibitor nicotinamide (NAM, 20 mM) to pre-treat HCT116, SW620 and SW480 cells for 24 hours. Flow cytometry assay demonstrated that NAM significantly decreased the percentage of CD133+ cell in these three CRC cells (Figure 3A). Meanwhile, 20 mM NAM did not lead to the increase of apoptosis in these cells (figures were not shown). Then control cells and NAM pre-treated cells were seeded at 6-well plates in a density of 2000 cells/well. NAM pre-treated cells displayed lower ability of colony formation compared to the controls (Figure 3B). Then, we separated HCT116, SW620 and SW480 cells into the CD133+ cells and CD133− cells using the magnetic bead sorting. These cells were detected their abilities of colony and sphere formation in the absence or presence of 20 mM NAM. The results showed that CD133+ cells had stronger abilities of colony and sphere formation. Meanwhile, these abilities were apparently down-regulated when cells were treated by NAM. Moreover, there were no significant differences between CD133+ cells treated with NAM and CD133− cells treated with NAM in the abilities of colony and sphere formation (Figure 3C and D).


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)

Pharmacological inhibition of SIRT1 reduces percentage of CD133+ cells and the colony formation in CRC cells.(A) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (B) The colony formation analysis of control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (C) The colony formation analysis of CD133+ cells and CD133- cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. (D) The sphere formation analysis of CD133+ cells and CD133− cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. All data are representative of three independent experiments. Significance: *P<0.05, **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

f3: Pharmacological inhibition of SIRT1 reduces percentage of CD133+ cells and the colony formation in CRC cells.(A) Representative flow cytometry plots showing percentage of CD133+ cells in control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (B) The colony formation analysis of control cells and cells treated with NAM (20 mM) of HCT116, SW620 and SW480 cells. (C) The colony formation analysis of CD133+ cells and CD133- cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. (D) The sphere formation analysis of CD133+ cells and CD133− cells in the absence or presence of 20 mM NAM in HCT116, SW620 and SW480 cells. All data are representative of three independent experiments. Significance: *P<0.05, **P<0.01, ***P<0.001, compared with the controls.
Mentions: According to the positive-relationship between SIRT1 and CD133, we attempted to explore whether SIRT1 deficiency had an influence on the stemness of colorectal CSCs. Firstly, we used SIRT1 inhibitor nicotinamide (NAM, 20 mM) to pre-treat HCT116, SW620 and SW480 cells for 24 hours. Flow cytometry assay demonstrated that NAM significantly decreased the percentage of CD133+ cell in these three CRC cells (Figure 3A). Meanwhile, 20 mM NAM did not lead to the increase of apoptosis in these cells (figures were not shown). Then control cells and NAM pre-treated cells were seeded at 6-well plates in a density of 2000 cells/well. NAM pre-treated cells displayed lower ability of colony formation compared to the controls (Figure 3B). Then, we separated HCT116, SW620 and SW480 cells into the CD133+ cells and CD133− cells using the magnetic bead sorting. These cells were detected their abilities of colony and sphere formation in the absence or presence of 20 mM NAM. The results showed that CD133+ cells had stronger abilities of colony and sphere formation. Meanwhile, these abilities were apparently down-regulated when cells were treated by NAM. Moreover, there were no significant differences between CD133+ cells treated with NAM and CD133− cells treated with NAM in the abilities of colony and sphere formation (Figure 3C and D).

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