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Camel milk modulates the expression of aryl hydrocarbon receptor-regulated genes, Cyp1a1, Nqo1, and Gsta1, in murine hepatoma Hepa 1c1c7 cells.

Korashy HM, El Gendy MA, Alhaider AA, El-Kadi AO - J. Biomed. Biotechnol. (2012)

Bottom Line: In addition, camel milk significantly decreased the xenobiotic responsive element (XRE)-dependent luciferase activity, suggesting a transcriptional mechanism is involved.Furthermore, this inhibitory effect of camel milk was associated with a proportional increase in heme oxygenase 1.In conclusion, camel milk modulates the expression of Cyp1a1, Nqo1, and Gsta1 at the transcriptional and posttranscriptional levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, 11451 Riyadh, Saudi Arabia.

ABSTRACT
There is a traditional belief in the Middle East that camel milk may aid in prevention and treatment of numerous cases of cancer yet, the exact mechanism was not investigated. Therefore, we examined the ability of camel milk to modulate the expression of a well-known cancer-activating gene, Cytochrome P450 1a1 (Cyp1a1), and cancer-protective genes, NAD(P)H:quinone oxidoreductase 1 (Nqo1) and glutathione S-transferase a1 (Gsta1), in murine hepatoma Hepa 1c1c7 cell line. Our results showed that camel milk significantly inhibited the induction of Cyp1a1 gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent Cyp1a1 inducer and known carcinogenic chemical, at mRNA, protein, and activity levels in a concentration-dependent manner. In addition, camel milk significantly decreased the xenobiotic responsive element (XRE)-dependent luciferase activity, suggesting a transcriptional mechanism is involved. Furthermore, this inhibitory effect of camel milk was associated with a proportional increase in heme oxygenase 1. On the other hand, camel milk significantly induced Nqo1 and Gsta1 mRNA expression level in a concentration-dependent fashion. The RNA synthesis inhibitor, actinomycin D, completely blocked the induction of Nqo1 mRNA by camel milk suggesting the requirement of de novo RNA synthesis through a transcriptional mechanism. In conclusion, camel milk modulates the expression of Cyp1a1, Nqo1, and Gsta1 at the transcriptional and posttranscriptional levels.

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Effect of transcription inhibitor, Act-D, on the induction of Nqo1 mRNA by camel milk. Hepa 1c1c7 cells were incubated with the transcription inhibitor, Act-D (5 μg/mL), immediately before the addition of fat-free camel milk (100 μL/mL) for 6 h. The amount of Nqo1 mRNA was quantified using real-time PCR and normalized to β-actin housekeeping gene. Duplicate reactions were performed for each experiment, and the values represent mean of fold change ± SEM. (n = 4).   +P < 0.05 compared with control (sterile water-treated cells),   *P < 0.05 compared with corresponding treatment in the absence of Act-D.
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fig8: Effect of transcription inhibitor, Act-D, on the induction of Nqo1 mRNA by camel milk. Hepa 1c1c7 cells were incubated with the transcription inhibitor, Act-D (5 μg/mL), immediately before the addition of fat-free camel milk (100 μL/mL) for 6 h. The amount of Nqo1 mRNA was quantified using real-time PCR and normalized to β-actin housekeeping gene. Duplicate reactions were performed for each experiment, and the values represent mean of fold change ± SEM. (n = 4).   +P < 0.05 compared with control (sterile water-treated cells),   *P < 0.05 compared with corresponding treatment in the absence of Act-D.

Mentions: To further investigate whether camel milk (fat-free) is able to increase the de novo Nqo1 RNA synthesis, Hepa 1c1c7 cells were treated with Act-D (5 μg/mL, RNA synthesis inhibitor) immediately before the addition of camel milk (fat-free, 100 μL/mL) for additional 6 h. Thereafter, Nqo1 mRNA was quantified by real-time PCR. If camel milk increases the amount of Nqo1 mRNA through a transcriptional mechanism, a decrease in the Nqo1 mRNA level would be expected. Figure 8 shows that Act-D slightly but significantly inhibited the constitutive expression of Nqo1 mRNA, whereas markedly blocked the camel milk-induced Nqo1 mRNA by approximately 70% (Figure 8).


Camel milk modulates the expression of aryl hydrocarbon receptor-regulated genes, Cyp1a1, Nqo1, and Gsta1, in murine hepatoma Hepa 1c1c7 cells.

Korashy HM, El Gendy MA, Alhaider AA, El-Kadi AO - J. Biomed. Biotechnol. (2012)

Effect of transcription inhibitor, Act-D, on the induction of Nqo1 mRNA by camel milk. Hepa 1c1c7 cells were incubated with the transcription inhibitor, Act-D (5 μg/mL), immediately before the addition of fat-free camel milk (100 μL/mL) for 6 h. The amount of Nqo1 mRNA was quantified using real-time PCR and normalized to β-actin housekeeping gene. Duplicate reactions were performed for each experiment, and the values represent mean of fold change ± SEM. (n = 4).   +P < 0.05 compared with control (sterile water-treated cells),   *P < 0.05 compared with corresponding treatment in the absence of Act-D.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3345340&req=5

fig8: Effect of transcription inhibitor, Act-D, on the induction of Nqo1 mRNA by camel milk. Hepa 1c1c7 cells were incubated with the transcription inhibitor, Act-D (5 μg/mL), immediately before the addition of fat-free camel milk (100 μL/mL) for 6 h. The amount of Nqo1 mRNA was quantified using real-time PCR and normalized to β-actin housekeeping gene. Duplicate reactions were performed for each experiment, and the values represent mean of fold change ± SEM. (n = 4).   +P < 0.05 compared with control (sterile water-treated cells),   *P < 0.05 compared with corresponding treatment in the absence of Act-D.
Mentions: To further investigate whether camel milk (fat-free) is able to increase the de novo Nqo1 RNA synthesis, Hepa 1c1c7 cells were treated with Act-D (5 μg/mL, RNA synthesis inhibitor) immediately before the addition of camel milk (fat-free, 100 μL/mL) for additional 6 h. Thereafter, Nqo1 mRNA was quantified by real-time PCR. If camel milk increases the amount of Nqo1 mRNA through a transcriptional mechanism, a decrease in the Nqo1 mRNA level would be expected. Figure 8 shows that Act-D slightly but significantly inhibited the constitutive expression of Nqo1 mRNA, whereas markedly blocked the camel milk-induced Nqo1 mRNA by approximately 70% (Figure 8).

Bottom Line: In addition, camel milk significantly decreased the xenobiotic responsive element (XRE)-dependent luciferase activity, suggesting a transcriptional mechanism is involved.Furthermore, this inhibitory effect of camel milk was associated with a proportional increase in heme oxygenase 1.In conclusion, camel milk modulates the expression of Cyp1a1, Nqo1, and Gsta1 at the transcriptional and posttranscriptional levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, 11451 Riyadh, Saudi Arabia.

ABSTRACT
There is a traditional belief in the Middle East that camel milk may aid in prevention and treatment of numerous cases of cancer yet, the exact mechanism was not investigated. Therefore, we examined the ability of camel milk to modulate the expression of a well-known cancer-activating gene, Cytochrome P450 1a1 (Cyp1a1), and cancer-protective genes, NAD(P)H:quinone oxidoreductase 1 (Nqo1) and glutathione S-transferase a1 (Gsta1), in murine hepatoma Hepa 1c1c7 cell line. Our results showed that camel milk significantly inhibited the induction of Cyp1a1 gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent Cyp1a1 inducer and known carcinogenic chemical, at mRNA, protein, and activity levels in a concentration-dependent manner. In addition, camel milk significantly decreased the xenobiotic responsive element (XRE)-dependent luciferase activity, suggesting a transcriptional mechanism is involved. Furthermore, this inhibitory effect of camel milk was associated with a proportional increase in heme oxygenase 1. On the other hand, camel milk significantly induced Nqo1 and Gsta1 mRNA expression level in a concentration-dependent fashion. The RNA synthesis inhibitor, actinomycin D, completely blocked the induction of Nqo1 mRNA by camel milk suggesting the requirement of de novo RNA synthesis through a transcriptional mechanism. In conclusion, camel milk modulates the expression of Cyp1a1, Nqo1, and Gsta1 at the transcriptional and posttranscriptional levels.

Show MeSH
Related in: MedlinePlus