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Tetrandrine induces autophagy and differentiation by activating ROS and Notch1 signaling in leukemia cells.

Liu T, Men Q, Wu G, Yu C, Huang Z, Liu X, Li W - Oncotarget (2015)

Bottom Line: Tetrandrine is a traditional Chinese medicinal herb extract with antitumor effects.The in vivo results indicated that low concentrations of tetrandrine inhibited leukemia cells proliferation and induced autophagy and then facilitated their differentiation, by activating ROS and Notch1 signaling.We suggest that tetrandrine is a potential agent for the treatment of APL by inducing differentiation of leukemia cells.

View Article: PubMed Central - PubMed

Affiliation: College of Life Sciences, Wuhan University, Wuhan, P. R. China.

ABSTRACT
All-trans retinoic acid (ATRA) is a differentiating agent for the treatment of acute promyelocytic leukemia (APL). However, the therapeutic efficacy of ATRA has limitations. Tetrandrine is a traditional Chinese medicinal herb extract with antitumor effects. In this study, we investigated the effects of tetrandrine on human PML-RARα-positive acute promyelocytic leukemia cells. Tetrandrine inhibited tumors in vivo. It induced autophagy and differentiation by triggering ROS generation and activating Notch1 signaling. Tetrandrine induced autophagy and differentiation in M5 type patient primary leukemia cells. The in vivo results indicated that low concentrations of tetrandrine inhibited leukemia cells proliferation and induced autophagy and then facilitated their differentiation, by activating ROS and Notch1 signaling. We suggest that tetrandrine is a potential agent for the treatment of APL by inducing differentiation of leukemia cells.

No MeSH data available.


Related in: MedlinePlus

Intracellular ROS generation is an early event of tetrandrine-induced cell autophagy and differentiation(A) Effects of tetrandrine (1, 2 μM) on intracellular ROS levels after 24 hours treatment. (B) NB4 cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 10 mM N-acetyl cysteine (NAC) or 0.2 mM Tiron, and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 10 mM NAC or 0.2 mM Tiron (Tet+ NAC or Tiron) for 24 hours. Intracellular ROS levels were measured by flow cytometry and (C) autophagy was detected with acridine orange staining assays. Error bars represent the mean ±SD. **p <0.01. (D) Western blot analysis of LC3, NICD and HES1 levels in cells after 1-hour pretreated with NAC for 24 hours. (E) Flow cytometry analysis of CD14 antigens expression on the surface of NB4 cells after 4days treatment.
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Figure 8: Intracellular ROS generation is an early event of tetrandrine-induced cell autophagy and differentiation(A) Effects of tetrandrine (1, 2 μM) on intracellular ROS levels after 24 hours treatment. (B) NB4 cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 10 mM N-acetyl cysteine (NAC) or 0.2 mM Tiron, and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 10 mM NAC or 0.2 mM Tiron (Tet+ NAC or Tiron) for 24 hours. Intracellular ROS levels were measured by flow cytometry and (C) autophagy was detected with acridine orange staining assays. Error bars represent the mean ±SD. **p <0.01. (D) Western blot analysis of LC3, NICD and HES1 levels in cells after 1-hour pretreated with NAC for 24 hours. (E) Flow cytometry analysis of CD14 antigens expression on the surface of NB4 cells after 4days treatment.

Mentions: Some chemotherapeutic agents can induce ROS generation in certain types of cancer cells, and excess ROS will trigger subsequent physiological cell signaling that regulates cell proliferation, survival and differentiation. Therefore, we next investigated whether ROS activation played an essential role in tetrandrine-induced NB4 cell autophagy and differentiation. Using H2DCFDA-based detection by flow cytometry, dose-dependent ROS accumulation was observed after tetrandrine treatment of NB4 cells (Fig. 8A). The free radical scavenger NAC and Tiron markedly abrogated tetrandrine-induced ROS generation (Fig. 8B). Importantly, pretreatment with NAC and Tiron markedly blocked tetrandrine-induced cell autophagy by decreasing AVO fluorescent orange puncta and the levels of the LC3-II protein and prevented cell differentiation by down-regulating the expression of CD14 on the surface that tetrandrine-induced NB4 cells (Fig. 8C, D and E). Moreover, Western blot results also showed that NAC notably recovered the tetrandrine-induced increase in NICD and HES1 protein levels (Fig. 8D). Taken together, these results demonstrated that activation of intracellular ROS is essential for tetrandrine-induced cell autophagy and differentiation and that ROS act upstream of Notch1 signaling.


Tetrandrine induces autophagy and differentiation by activating ROS and Notch1 signaling in leukemia cells.

Liu T, Men Q, Wu G, Yu C, Huang Z, Liu X, Li W - Oncotarget (2015)

Intracellular ROS generation is an early event of tetrandrine-induced cell autophagy and differentiation(A) Effects of tetrandrine (1, 2 μM) on intracellular ROS levels after 24 hours treatment. (B) NB4 cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 10 mM N-acetyl cysteine (NAC) or 0.2 mM Tiron, and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 10 mM NAC or 0.2 mM Tiron (Tet+ NAC or Tiron) for 24 hours. Intracellular ROS levels were measured by flow cytometry and (C) autophagy was detected with acridine orange staining assays. Error bars represent the mean ±SD. **p <0.01. (D) Western blot analysis of LC3, NICD and HES1 levels in cells after 1-hour pretreated with NAC for 24 hours. (E) Flow cytometry analysis of CD14 antigens expression on the surface of NB4 cells after 4days treatment.
© Copyright Policy - open-access
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Figure 8: Intracellular ROS generation is an early event of tetrandrine-induced cell autophagy and differentiation(A) Effects of tetrandrine (1, 2 μM) on intracellular ROS levels after 24 hours treatment. (B) NB4 cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 10 mM N-acetyl cysteine (NAC) or 0.2 mM Tiron, and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 10 mM NAC or 0.2 mM Tiron (Tet+ NAC or Tiron) for 24 hours. Intracellular ROS levels were measured by flow cytometry and (C) autophagy was detected with acridine orange staining assays. Error bars represent the mean ±SD. **p <0.01. (D) Western blot analysis of LC3, NICD and HES1 levels in cells after 1-hour pretreated with NAC for 24 hours. (E) Flow cytometry analysis of CD14 antigens expression on the surface of NB4 cells after 4days treatment.
Mentions: Some chemotherapeutic agents can induce ROS generation in certain types of cancer cells, and excess ROS will trigger subsequent physiological cell signaling that regulates cell proliferation, survival and differentiation. Therefore, we next investigated whether ROS activation played an essential role in tetrandrine-induced NB4 cell autophagy and differentiation. Using H2DCFDA-based detection by flow cytometry, dose-dependent ROS accumulation was observed after tetrandrine treatment of NB4 cells (Fig. 8A). The free radical scavenger NAC and Tiron markedly abrogated tetrandrine-induced ROS generation (Fig. 8B). Importantly, pretreatment with NAC and Tiron markedly blocked tetrandrine-induced cell autophagy by decreasing AVO fluorescent orange puncta and the levels of the LC3-II protein and prevented cell differentiation by down-regulating the expression of CD14 on the surface that tetrandrine-induced NB4 cells (Fig. 8C, D and E). Moreover, Western blot results also showed that NAC notably recovered the tetrandrine-induced increase in NICD and HES1 protein levels (Fig. 8D). Taken together, these results demonstrated that activation of intracellular ROS is essential for tetrandrine-induced cell autophagy and differentiation and that ROS act upstream of Notch1 signaling.

Bottom Line: Tetrandrine is a traditional Chinese medicinal herb extract with antitumor effects.The in vivo results indicated that low concentrations of tetrandrine inhibited leukemia cells proliferation and induced autophagy and then facilitated their differentiation, by activating ROS and Notch1 signaling.We suggest that tetrandrine is a potential agent for the treatment of APL by inducing differentiation of leukemia cells.

View Article: PubMed Central - PubMed

Affiliation: College of Life Sciences, Wuhan University, Wuhan, P. R. China.

ABSTRACT
All-trans retinoic acid (ATRA) is a differentiating agent for the treatment of acute promyelocytic leukemia (APL). However, the therapeutic efficacy of ATRA has limitations. Tetrandrine is a traditional Chinese medicinal herb extract with antitumor effects. In this study, we investigated the effects of tetrandrine on human PML-RARα-positive acute promyelocytic leukemia cells. Tetrandrine inhibited tumors in vivo. It induced autophagy and differentiation by triggering ROS generation and activating Notch1 signaling. Tetrandrine induced autophagy and differentiation in M5 type patient primary leukemia cells. The in vivo results indicated that low concentrations of tetrandrine inhibited leukemia cells proliferation and induced autophagy and then facilitated their differentiation, by activating ROS and Notch1 signaling. We suggest that tetrandrine is a potential agent for the treatment of APL by inducing differentiation of leukemia cells.

No MeSH data available.


Related in: MedlinePlus