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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

Early stage autophagy is related to tetrandrine-induced differentiation(A) Acridine orange staining assay analysis of autophagy. NB4 cells treated with Oxidant dimethylsulfoxide (Con), 2 μM tetrandrine (Tet), 1.5 mM 3-methyladenine (3-MA), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 1.5 mM 3-MA (Tet+ 3-MA) for 10 hours. Error bars represent the mean ±SD. **p <0.01. (B) Western blot analysis of tetrandrine (Tet) induced LC3-II protein levels in the presence or absence of 1.5 mM 3-MA pretreatment for 10 hours. (C) CD14 was detected by flow cytometry of NB4 cells pretreated with 3-MA and incubated with tetrandrine (2 μM) for 4 days. (D) Western blot analysis of LC3-II and CTSD protein levels. Cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 15 mM chloroquine (CQ), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 15 mM chloroquine (Tet+ CQ) for 24 hours. (E) CD14 was measured by flow cytometry of NB4 cells that were pretreated with 15 mM CQ and then treated with tetrandrine (2 μM) for 4 days.
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Figure 6: Early stage autophagy is related to tetrandrine-induced differentiation(A) Acridine orange staining assay analysis of autophagy. NB4 cells treated with Oxidant dimethylsulfoxide (Con), 2 μM tetrandrine (Tet), 1.5 mM 3-methyladenine (3-MA), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 1.5 mM 3-MA (Tet+ 3-MA) for 10 hours. Error bars represent the mean ±SD. **p <0.01. (B) Western blot analysis of tetrandrine (Tet) induced LC3-II protein levels in the presence or absence of 1.5 mM 3-MA pretreatment for 10 hours. (C) CD14 was detected by flow cytometry of NB4 cells pretreated with 3-MA and incubated with tetrandrine (2 μM) for 4 days. (D) Western blot analysis of LC3-II and CTSD protein levels. Cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 15 mM chloroquine (CQ), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 15 mM chloroquine (Tet+ CQ) for 24 hours. (E) CD14 was measured by flow cytometry of NB4 cells that were pretreated with 15 mM CQ and then treated with tetrandrine (2 μM) for 4 days.

Mentions: Recent reports show that autophagy is a potentially important regulator of differentiation in anti-leukemic strategies. Therefore, we next investigated whether tetrandrine-induced differentiation is related to autophagy. 3-methyladenine (3-MA), a common specific inhibitor of early stage autophagy through the blockade of autophagosome maturation, was used to block tetrandrine-induced autophagy. The results showed that 3-MA not only significantly prevented the formation of the AVO fluorescent orange puncta and the LC3-II protein level (Fig. 6A and B) but also inhibited tetrandrine-induced differentiation (Fig. 6C). To examine the relationship of late-stage autophagy and cell differentiation, we treated NB4 cells with the lysosome inhibitor chloroquine (CQ) to inhibit late autophagy/lysosomal protein degradation and break the autophagic flux. As shown as Fig. 6D and E, while CQ blocked late-stage autophagic flux, it showed a synergistic induction of differentiation in combination with tetrandrine. These findings suggest that tetrandrine-induced NB4 cell differentiation is associated with early stage but not late-stage autophagy.


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)

Early stage autophagy is related to tetrandrine-induced differentiation(A) Acridine orange staining assay analysis of autophagy. NB4 cells treated with Oxidant dimethylsulfoxide (Con), 2 μM tetrandrine (Tet), 1.5 mM 3-methyladenine (3-MA), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 1.5 mM 3-MA (Tet+ 3-MA) for 10 hours. Error bars represent the mean ±SD. **p <0.01. (B) Western blot analysis of tetrandrine (Tet) induced LC3-II protein levels in the presence or absence of 1.5 mM 3-MA pretreatment for 10 hours. (C) CD14 was detected by flow cytometry of NB4 cells pretreated with 3-MA and incubated with tetrandrine (2 μM) for 4 days. (D) Western blot analysis of LC3-II and CTSD protein levels. Cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 15 mM chloroquine (CQ), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 15 mM chloroquine (Tet+ CQ) for 24 hours. (E) CD14 was measured by flow cytometry of NB4 cells that were pretreated with 15 mM CQ and then treated with tetrandrine (2 μM) for 4 days.
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Figure 6: Early stage autophagy is related to tetrandrine-induced differentiation(A) Acridine orange staining assay analysis of autophagy. NB4 cells treated with Oxidant dimethylsulfoxide (Con), 2 μM tetrandrine (Tet), 1.5 mM 3-methyladenine (3-MA), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 1.5 mM 3-MA (Tet+ 3-MA) for 10 hours. Error bars represent the mean ±SD. **p <0.01. (B) Western blot analysis of tetrandrine (Tet) induced LC3-II protein levels in the presence or absence of 1.5 mM 3-MA pretreatment for 10 hours. (C) CD14 was detected by flow cytometry of NB4 cells pretreated with 3-MA and incubated with tetrandrine (2 μM) for 4 days. (D) Western blot analysis of LC3-II and CTSD protein levels. Cells were treated with DMSO (Con), 2 μM tetrandrine (Tet), 15 mM chloroquine (CQ), and 2 μM tetrandrine (Tet) after a 1-hour pretreatment with 15 mM chloroquine (Tet+ CQ) for 24 hours. (E) CD14 was measured by flow cytometry of NB4 cells that were pretreated with 15 mM CQ and then treated with tetrandrine (2 μM) for 4 days.
Mentions: Recent reports show that autophagy is a potentially important regulator of differentiation in anti-leukemic strategies. Therefore, we next investigated whether tetrandrine-induced differentiation is related to autophagy. 3-methyladenine (3-MA), a common specific inhibitor of early stage autophagy through the blockade of autophagosome maturation, was used to block tetrandrine-induced autophagy. The results showed that 3-MA not only significantly prevented the formation of the AVO fluorescent orange puncta and the LC3-II protein level (Fig. 6A and B) but also inhibited tetrandrine-induced differentiation (Fig. 6C). To examine the relationship of late-stage autophagy and cell differentiation, we treated NB4 cells with the lysosome inhibitor chloroquine (CQ) to inhibit late autophagy/lysosomal protein degradation and break the autophagic flux. As shown as Fig. 6D and E, while CQ blocked late-stage autophagic flux, it showed a synergistic induction of differentiation in combination with tetrandrine. These findings suggest that tetrandrine-induced NB4 cell differentiation is associated with early stage but not late-stage autophagy.

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