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Asymmetric dimethylarginine attenuates serum starvation-induced apoptosis via suppression of the Fas (APO-1/CD95)/JNK (SAPK) pathway.

Li H, Zhou Y, Zhao A, Qiu Y, Xie G, Jiang Q, Zheng X, Zhong W, Sun X, Zhou Z, Jia W - Cell Death Dis (2013)

Bottom Line: ADMA treatment of LoVo cells, a human colon adenocarcinoma cell line, attenuated serum starvation-induced apoptosis and suppressed the activation of the Fas (APO-1/CD95)/JNK (SAPK) (c-Jun N terminal protein kinase/stress-activated protein kinase)pathway.ADMA also suppressed the activation of JNK triggered by death receptor ligand anti-Fas mAb and exogenous C2-ceramide.Moreover, we demonstrated that ADMA pretreatment protected LoVo cells from doxorubicin hydrochloride-induced cell death and activation of the Fas/JNK pathway.

View Article: PubMed Central - PubMed

Affiliation: 1] Center for Translational Medicine, Shanghai Jiao Tong University, Affiliated Sixth People's Hospital, Shanghai 200233, China [2] Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC 28081, USA.

ABSTRACT
Asymmetric dimethylarginine (ADMA) is synthesized by protein arginine methyltransferases during methylation of protein arginine residues and released into blood upon proteolysis. Higher concentrations of ADMA in blood have been observed in patients with metabolic diseases and certain cancers. However, the role of ADMA in colon cancer has not been well investigated. ADMA serum levels in human patients diagnosed with colon cancer were found to be higher than those present in healthy subjects. ADMA treatment of LoVo cells, a human colon adenocarcinoma cell line, attenuated serum starvation-induced apoptosis and suppressed the activation of the Fas (APO-1/CD95)/JNK (SAPK) (c-Jun N terminal protein kinase/stress-activated protein kinase)pathway. ADMA also suppressed the activation of JNK triggered by death receptor ligand anti-Fas mAb and exogenous C2-ceramide. Moreover, we demonstrated that ADMA pretreatment protected LoVo cells from doxorubicin hydrochloride-induced cell death and activation of the Fas/JNK pathway. In summary, our results suggest that the elevated ADMA in colon cancer patients may contribute to the blocking of apoptosis of cancer cells in response to stress and chemotherapy.

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Impact of ADMA on proliferation of colon cancer cells and normal fibroblasts. LoVo cells were treated with ADMA at a series of concentrations in control (a) or serum-free media (b) for 96 h or 7 days (c). CRL-1459 normal fibroblasts were cultured in serum-free media for 96 h in the presence or absence of ADMA (d). Cell viability was measured with the CCK8 kit after specific treatments. Data are presented as mean±S.E., which are representative of at least three independent experiments. The statistical significance was calculated with student t-test. C: control media (10% FBS DMEM); SS: serum starvation
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fig2: Impact of ADMA on proliferation of colon cancer cells and normal fibroblasts. LoVo cells were treated with ADMA at a series of concentrations in control (a) or serum-free media (b) for 96 h or 7 days (c). CRL-1459 normal fibroblasts were cultured in serum-free media for 96 h in the presence or absence of ADMA (d). Cell viability was measured with the CCK8 kit after specific treatments. Data are presented as mean±S.E., which are representative of at least three independent experiments. The statistical significance was calculated with student t-test. C: control media (10% FBS DMEM); SS: serum starvation

Mentions: To determine the potential role of ADMA in colon cancer development, we first investigated the impact of ADMA on the proliferation of the LoVo colon cancer cell line. We found that ADMA treatment did not impact the proliferation rate of LoVo cells in 10% FBS Dulbecco's modified Eagle's medium (DMEM) within 96 h (Figure 2a). Since tumor cells usually experience nutrient deprivation, we examined whether ADMA could enhance the endurance of tumor cells to SS. We next cultured cells in serum-free DMEM in the presence or absence of ADMA for 96 h, and found that the cells showed higher viability in the presence of ADMA at concentrations ranging from 2.5 to 100 μM (P<0.01, Figure 2b).To further determine the impact of ADMA on cell viability under SS conditions, we extended the SS conditions to 7 days and observed a significant reduction in cell viability compared to normal culture media (P<0.01). The addition of 5 or 10 μM ADMA to the serum-starved cultures significantly attenuated the SS-mediated decrease of cell viability (Figure 2c). Since tumor cells are more sensitive to nutrient deprivation, we therefore tested whether ADMA could impact the viability of normal cells. We compared the viability of normal CRL-1459 fibroblast cells treated with or without ADMA for 96 h. No significant difference was observed between the two groups (Figure 2d). Interestingly, the protective effect against SS-induced viability reduction was not observed in another two colon cancer cell lines, Caco-2 and SW480, but was observed in human liver carcinoma cell line HepG2 cells (Supplementary Figure 1). Taken together, our current results indicate that ADMA can only protect some cancer cells against SS-induced cell death, but not in normal fibroblasts and some other colon cancer cells.


Asymmetric dimethylarginine attenuates serum starvation-induced apoptosis via suppression of the Fas (APO-1/CD95)/JNK (SAPK) pathway.

Li H, Zhou Y, Zhao A, Qiu Y, Xie G, Jiang Q, Zheng X, Zhong W, Sun X, Zhou Z, Jia W - Cell Death Dis (2013)

Impact of ADMA on proliferation of colon cancer cells and normal fibroblasts. LoVo cells were treated with ADMA at a series of concentrations in control (a) or serum-free media (b) for 96 h or 7 days (c). CRL-1459 normal fibroblasts were cultured in serum-free media for 96 h in the presence or absence of ADMA (d). Cell viability was measured with the CCK8 kit after specific treatments. Data are presented as mean±S.E., which are representative of at least three independent experiments. The statistical significance was calculated with student t-test. C: control media (10% FBS DMEM); SS: serum starvation
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824655&req=5

fig2: Impact of ADMA on proliferation of colon cancer cells and normal fibroblasts. LoVo cells were treated with ADMA at a series of concentrations in control (a) or serum-free media (b) for 96 h or 7 days (c). CRL-1459 normal fibroblasts were cultured in serum-free media for 96 h in the presence or absence of ADMA (d). Cell viability was measured with the CCK8 kit after specific treatments. Data are presented as mean±S.E., which are representative of at least three independent experiments. The statistical significance was calculated with student t-test. C: control media (10% FBS DMEM); SS: serum starvation
Mentions: To determine the potential role of ADMA in colon cancer development, we first investigated the impact of ADMA on the proliferation of the LoVo colon cancer cell line. We found that ADMA treatment did not impact the proliferation rate of LoVo cells in 10% FBS Dulbecco's modified Eagle's medium (DMEM) within 96 h (Figure 2a). Since tumor cells usually experience nutrient deprivation, we examined whether ADMA could enhance the endurance of tumor cells to SS. We next cultured cells in serum-free DMEM in the presence or absence of ADMA for 96 h, and found that the cells showed higher viability in the presence of ADMA at concentrations ranging from 2.5 to 100 μM (P<0.01, Figure 2b).To further determine the impact of ADMA on cell viability under SS conditions, we extended the SS conditions to 7 days and observed a significant reduction in cell viability compared to normal culture media (P<0.01). The addition of 5 or 10 μM ADMA to the serum-starved cultures significantly attenuated the SS-mediated decrease of cell viability (Figure 2c). Since tumor cells are more sensitive to nutrient deprivation, we therefore tested whether ADMA could impact the viability of normal cells. We compared the viability of normal CRL-1459 fibroblast cells treated with or without ADMA for 96 h. No significant difference was observed between the two groups (Figure 2d). Interestingly, the protective effect against SS-induced viability reduction was not observed in another two colon cancer cell lines, Caco-2 and SW480, but was observed in human liver carcinoma cell line HepG2 cells (Supplementary Figure 1). Taken together, our current results indicate that ADMA can only protect some cancer cells against SS-induced cell death, but not in normal fibroblasts and some other colon cancer cells.

Bottom Line: ADMA treatment of LoVo cells, a human colon adenocarcinoma cell line, attenuated serum starvation-induced apoptosis and suppressed the activation of the Fas (APO-1/CD95)/JNK (SAPK) (c-Jun N terminal protein kinase/stress-activated protein kinase)pathway.ADMA also suppressed the activation of JNK triggered by death receptor ligand anti-Fas mAb and exogenous C2-ceramide.Moreover, we demonstrated that ADMA pretreatment protected LoVo cells from doxorubicin hydrochloride-induced cell death and activation of the Fas/JNK pathway.

View Article: PubMed Central - PubMed

Affiliation: 1] Center for Translational Medicine, Shanghai Jiao Tong University, Affiliated Sixth People's Hospital, Shanghai 200233, China [2] Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC 28081, USA.

ABSTRACT
Asymmetric dimethylarginine (ADMA) is synthesized by protein arginine methyltransferases during methylation of protein arginine residues and released into blood upon proteolysis. Higher concentrations of ADMA in blood have been observed in patients with metabolic diseases and certain cancers. However, the role of ADMA in colon cancer has not been well investigated. ADMA serum levels in human patients diagnosed with colon cancer were found to be higher than those present in healthy subjects. ADMA treatment of LoVo cells, a human colon adenocarcinoma cell line, attenuated serum starvation-induced apoptosis and suppressed the activation of the Fas (APO-1/CD95)/JNK (SAPK) (c-Jun N terminal protein kinase/stress-activated protein kinase)pathway. ADMA also suppressed the activation of JNK triggered by death receptor ligand anti-Fas mAb and exogenous C2-ceramide. Moreover, we demonstrated that ADMA pretreatment protected LoVo cells from doxorubicin hydrochloride-induced cell death and activation of the Fas/JNK pathway. In summary, our results suggest that the elevated ADMA in colon cancer patients may contribute to the blocking of apoptosis of cancer cells in response to stress and chemotherapy.

Show MeSH
Related in: MedlinePlus