Limits...
Alectinib (CH5424802) antagonizes ABCB1- and ABCG2-mediated multidrug resistance in vitro , in vivo and ex vivo

View Article: PubMed Central - PubMed

ABSTRACT

Alectinib, an inhibitor of anaplastic lymphoma kinase (ALK), was approved by the Food and Drug Administration (FDA) for the treatment of patients with ALK-positive non-small cell lung cancer (NSCLC). Here we investigated the reversal effect of alectinib on multidrug resistance (MDR) induced by ATP-binding cassette (ABC) transporters, which is the primary cause of chemotherapy failure. We provide the first evidence that alectinib increases the sensitivity of ABCB1- and ABCG2-overexpressing cells to chemotherapeutic agents in vitro and in vivo. Mechanistically, alectinib increased the intracellular accumulation of ABCB1/ABCG2 substrates such as doxorubicin (DOX) and Rhodamine 123 (Rho 123) by inhibiting the efflux function of the transporters in ABCB1- or ABCG2-overexpressing cells but not in their parental sensitive cells. Furthermore, alectinib stimulated ATPase activity and competed with substrates of ABCB1 or ABCG2 and competed with [125I] iodoarylazidoprazosin (IAAP) photolabeling bound to ABCB1 or ABCG2 but neither altered the expression and localization of ABCB1 or ABCG2 nor the phosphorylation levels of AKT and ERK. Alectinib also enhanced the cytotoxicity of DOX and the intracellular accumulation of Rho 123 in ABCB1-overexpressing primary leukemia cells. These findings suggest that alectinib combined with traditional chemotherapy may be beneficial to patients with ABCB1- or ABCG2-mediated MDR.

No MeSH data available.


Related in: MedlinePlus

Alectinib increased the accumulation of Rho 123 and enhanced the cytotoxicity of DOX in ABCB1-overexpressing primary leukemia blasts. Bone marrow was collected from four newly diagnosed AML/CML patients. Mononuclear cells were isolated, and their expression levels of ABCB1 were assessed by flow cytometry (a). Intracellular accumulation of Rho 123 in primary leukemia blasts with or without alectinib treatment was analyzed by flow cytometry. VRP, an ABCB1 inhibitor, was used as a positive control (b). The results were calculated by dividing the fluorescence intensity of each sample with that of mononuclear cells treated with Rho 123 alone (c). Enhancement of DOX cytotoxicity in ABCB1-overexpressing primary leukemia blasts by alectinib (d). The data represent the mean±s.d. of at least three independent experiments. Representative results are shown in a and b. *P<0.05, **P<0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5382559&req=5

fig7: Alectinib increased the accumulation of Rho 123 and enhanced the cytotoxicity of DOX in ABCB1-overexpressing primary leukemia blasts. Bone marrow was collected from four newly diagnosed AML/CML patients. Mononuclear cells were isolated, and their expression levels of ABCB1 were assessed by flow cytometry (a). Intracellular accumulation of Rho 123 in primary leukemia blasts with or without alectinib treatment was analyzed by flow cytometry. VRP, an ABCB1 inhibitor, was used as a positive control (b). The results were calculated by dividing the fluorescence intensity of each sample with that of mononuclear cells treated with Rho 123 alone (c). Enhancement of DOX cytotoxicity in ABCB1-overexpressing primary leukemia blasts by alectinib (d). The data represent the mean±s.d. of at least three independent experiments. Representative results are shown in a and b. *P<0.05, **P<0.01.

Mentions: It has been reported that ABCB1 is expressed in both AML and CML.45, 46 To investigate whether alectinib could reverse ABCB1-mediated MDR in ex vivo, bone marrow samples were collected from resistant patients with AML or CML. Four of the eleven patient samples exhibited high expression of ABCB1 (Figure 7a). We then examined the effect of alectinib on the intracellular accumulation of Rho 123 in these ABCB1-overexpressing primary leukemia blast samples using flow cytometric analysis. As shown in Figure 7b and c, alectinib significantly increased the intracellular accumulation of Rho 123. In addition, we used MTT assays to assess the sensitization effect of alectinib in these samples. The result revealed that 1.5 μM alectinib significantly increased the sensitivity of all four samples to DOX, which exhibited similar efficiency to 10 μM VRP (Figure 7d). These results suggest that alectinib is able to sensitize ABCB1-overexpressing primary leukemia cells to conventional anticancer drugs, and thus, it might be useful in combination regimens to combat ABCB1-mediated MDR in the clinic. The schematic model illustrating the reversal of MDR by alectinib was showed in Figure 8.


Alectinib (CH5424802) antagonizes ABCB1- and ABCG2-mediated multidrug resistance in vitro , in vivo and ex vivo
Alectinib increased the accumulation of Rho 123 and enhanced the cytotoxicity of DOX in ABCB1-overexpressing primary leukemia blasts. Bone marrow was collected from four newly diagnosed AML/CML patients. Mononuclear cells were isolated, and their expression levels of ABCB1 were assessed by flow cytometry (a). Intracellular accumulation of Rho 123 in primary leukemia blasts with or without alectinib treatment was analyzed by flow cytometry. VRP, an ABCB1 inhibitor, was used as a positive control (b). The results were calculated by dividing the fluorescence intensity of each sample with that of mononuclear cells treated with Rho 123 alone (c). Enhancement of DOX cytotoxicity in ABCB1-overexpressing primary leukemia blasts by alectinib (d). The data represent the mean±s.d. of at least three independent experiments. Representative results are shown in a and b. *P<0.05, **P<0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5382559&req=5

fig7: Alectinib increased the accumulation of Rho 123 and enhanced the cytotoxicity of DOX in ABCB1-overexpressing primary leukemia blasts. Bone marrow was collected from four newly diagnosed AML/CML patients. Mononuclear cells were isolated, and their expression levels of ABCB1 were assessed by flow cytometry (a). Intracellular accumulation of Rho 123 in primary leukemia blasts with or without alectinib treatment was analyzed by flow cytometry. VRP, an ABCB1 inhibitor, was used as a positive control (b). The results were calculated by dividing the fluorescence intensity of each sample with that of mononuclear cells treated with Rho 123 alone (c). Enhancement of DOX cytotoxicity in ABCB1-overexpressing primary leukemia blasts by alectinib (d). The data represent the mean±s.d. of at least three independent experiments. Representative results are shown in a and b. *P<0.05, **P<0.01.
Mentions: It has been reported that ABCB1 is expressed in both AML and CML.45, 46 To investigate whether alectinib could reverse ABCB1-mediated MDR in ex vivo, bone marrow samples were collected from resistant patients with AML or CML. Four of the eleven patient samples exhibited high expression of ABCB1 (Figure 7a). We then examined the effect of alectinib on the intracellular accumulation of Rho 123 in these ABCB1-overexpressing primary leukemia blast samples using flow cytometric analysis. As shown in Figure 7b and c, alectinib significantly increased the intracellular accumulation of Rho 123. In addition, we used MTT assays to assess the sensitization effect of alectinib in these samples. The result revealed that 1.5 μM alectinib significantly increased the sensitivity of all four samples to DOX, which exhibited similar efficiency to 10 μM VRP (Figure 7d). These results suggest that alectinib is able to sensitize ABCB1-overexpressing primary leukemia cells to conventional anticancer drugs, and thus, it might be useful in combination regimens to combat ABCB1-mediated MDR in the clinic. The schematic model illustrating the reversal of MDR by alectinib was showed in Figure 8.

View Article: PubMed Central - PubMed

ABSTRACT

Alectinib, an inhibitor of anaplastic lymphoma kinase (ALK), was approved by the Food and Drug Administration (FDA) for the treatment of patients with ALK-positive non-small cell lung cancer (NSCLC). Here we investigated the reversal effect of alectinib on multidrug resistance (MDR) induced by ATP-binding cassette (ABC) transporters, which is the primary cause of chemotherapy failure. We provide the first evidence that alectinib increases the sensitivity of ABCB1- and ABCG2-overexpressing cells to chemotherapeutic agents in vitro and in vivo. Mechanistically, alectinib increased the intracellular accumulation of ABCB1/ABCG2 substrates such as doxorubicin (DOX) and Rhodamine 123 (Rho 123) by inhibiting the efflux function of the transporters in ABCB1- or ABCG2-overexpressing cells but not in their parental sensitive cells. Furthermore, alectinib stimulated ATPase activity and competed with substrates of ABCB1 or ABCG2 and competed with [125I] iodoarylazidoprazosin (IAAP) photolabeling bound to ABCB1 or ABCG2 but neither altered the expression and localization of ABCB1 or ABCG2 nor the phosphorylation levels of AKT and ERK. Alectinib also enhanced the cytotoxicity of DOX and the intracellular accumulation of Rho 123 in ABCB1-overexpressing primary leukemia cells. These findings suggest that alectinib combined with traditional chemotherapy may be beneficial to patients with ABCB1- or ABCG2-mediated MDR.

No MeSH data available.


Related in: MedlinePlus