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Anti-Proliferative Effect of Naringenin through p38-Dependent Downregulation of Cyclin D1 in Human Colorectal Cancer Cells.

Song HM, Park GH, Eo HJ, Lee JW, Kim MK, Lee JR, Lee MH, Koo JS, Jeong JB - Biomol Ther (Seoul) (2015)

Bottom Line: Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity.However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered.From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioresource Sciences, Andong National University, Andong 760-749.

ABSTRACT
Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered. Thus, in this study, we have shown that NAR down-regulates the level of cyclin D1 in human colorectal cancer cell lines, HCT116 and SW480. NAR inhibited the cell proliferation in HCT116 and SW480 cells and decreased the level of cyclin D1 protein. Inhibition of proteasomal degradation by MG132 blocked NAR-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with NAR. In addition, NAR increased the phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine blocked cyclin D1 downregulation by NAR. p38 inactivation attenuated cyclin D1 downregulation by NAR. From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation. The current study provides new mechanistic link between NAR, cyclin D1 downregulation and cell growth in human colorectal cancer cells.

No MeSH data available.


Related in: MedlinePlus

Effect of NAR on cyclin D1 level in HCT116 and SW480 cells. (A) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (B) HCT116 and SW480 cells were plated overnight and then treated with 100 μM of NAR for the indicated times. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (C) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. For RT-PCR analysis of cyclin D1 gene expression, total RNA was prepared after NAR treatment for 24 h. Actin and GAPDH were used as internal control for Western blot analysis and RP-PCR, respectively.
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f2-bt-23-339: Effect of NAR on cyclin D1 level in HCT116 and SW480 cells. (A) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (B) HCT116 and SW480 cells were plated overnight and then treated with 100 μM of NAR for the indicated times. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (C) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. For RT-PCR analysis of cyclin D1 gene expression, total RNA was prepared after NAR treatment for 24 h. Actin and GAPDH were used as internal control for Western blot analysis and RP-PCR, respectively.

Mentions: To test whether NAR down-regulates the level of cyclin D1, HCT116 and SW480 cells were treated with 0, 50, 100 and 200 μM of NAR for 24 h and then Western blot was performed. As shown in Fig. 2A, NAR dose-dependently decreased the level of cyclin D1 in both HCT116 and SW480 cells. In time-course experiments (Fig. 2B), cyclin D1 started to decrease at 3 h after NAR treatment in HCT116 cells, while NAR decreased cyclin D1 level at 1 h after treatment in SW480 cells. To determine if downregulation of cyclin D1 by NAR is responsible for the transcriptional inhibition, we evaluated mRNA level of cyclin D1 in HCT116 and SW480 cells. As a result (Fig. 2C), 200 μM of NAR slightly attenuated the expression of cyclin D1 mRNA in HCT116 cells, which indicates that cyclin D1 downregulation by high dose (200 μM) of NAR may partially result from the transcriptional inhibition of cyclin D1. However, mRNA level of cyclin D1 was not affected by treatment of NAR in SW480 cells. From these results, NAR may decrease protein stability of cyclin D1 because downregulation of cyclin D1 protein level by NAR is more sensitive than that of mRNA level.


Anti-Proliferative Effect of Naringenin through p38-Dependent Downregulation of Cyclin D1 in Human Colorectal Cancer Cells.

Song HM, Park GH, Eo HJ, Lee JW, Kim MK, Lee JR, Lee MH, Koo JS, Jeong JB - Biomol Ther (Seoul) (2015)

Effect of NAR on cyclin D1 level in HCT116 and SW480 cells. (A) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (B) HCT116 and SW480 cells were plated overnight and then treated with 100 μM of NAR for the indicated times. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (C) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. For RT-PCR analysis of cyclin D1 gene expression, total RNA was prepared after NAR treatment for 24 h. Actin and GAPDH were used as internal control for Western blot analysis and RP-PCR, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4489828&req=5

f2-bt-23-339: Effect of NAR on cyclin D1 level in HCT116 and SW480 cells. (A) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (B) HCT116 and SW480 cells were plated overnight and then treated with 100 μM of NAR for the indicated times. Cell lysates were subjected to SDS-PAGE and Western blot was performed using antibodies against cyclin D1 and actin. (C) HCT116 and SW480 cells were plated overnight and then treated with NAR at the indicated concentrations for 24 h. For RT-PCR analysis of cyclin D1 gene expression, total RNA was prepared after NAR treatment for 24 h. Actin and GAPDH were used as internal control for Western blot analysis and RP-PCR, respectively.
Mentions: To test whether NAR down-regulates the level of cyclin D1, HCT116 and SW480 cells were treated with 0, 50, 100 and 200 μM of NAR for 24 h and then Western blot was performed. As shown in Fig. 2A, NAR dose-dependently decreased the level of cyclin D1 in both HCT116 and SW480 cells. In time-course experiments (Fig. 2B), cyclin D1 started to decrease at 3 h after NAR treatment in HCT116 cells, while NAR decreased cyclin D1 level at 1 h after treatment in SW480 cells. To determine if downregulation of cyclin D1 by NAR is responsible for the transcriptional inhibition, we evaluated mRNA level of cyclin D1 in HCT116 and SW480 cells. As a result (Fig. 2C), 200 μM of NAR slightly attenuated the expression of cyclin D1 mRNA in HCT116 cells, which indicates that cyclin D1 downregulation by high dose (200 μM) of NAR may partially result from the transcriptional inhibition of cyclin D1. However, mRNA level of cyclin D1 was not affected by treatment of NAR in SW480 cells. From these results, NAR may decrease protein stability of cyclin D1 because downregulation of cyclin D1 protein level by NAR is more sensitive than that of mRNA level.

Bottom Line: Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity.However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered.From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioresource Sciences, Andong National University, Andong 760-749.

ABSTRACT
Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered. Thus, in this study, we have shown that NAR down-regulates the level of cyclin D1 in human colorectal cancer cell lines, HCT116 and SW480. NAR inhibited the cell proliferation in HCT116 and SW480 cells and decreased the level of cyclin D1 protein. Inhibition of proteasomal degradation by MG132 blocked NAR-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with NAR. In addition, NAR increased the phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine blocked cyclin D1 downregulation by NAR. p38 inactivation attenuated cyclin D1 downregulation by NAR. From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation. The current study provides new mechanistic link between NAR, cyclin D1 downregulation and cell growth in human colorectal cancer cells.

No MeSH data available.


Related in: MedlinePlus