COMBINED EFFECTS OF PI3K INHIBITOR, COPANLISIB WITH ABL TYROSINE KINASE INHIBITORS IN PH-POSITIVE LEUKEMIA CELLS
(Abstract release date: 05/21/15)
EHA Library. Okabe S. 06/12/15; 102764; PB1728
Disclosure(s): TOKYO MEDICAL UNIVERSITYDepartment of Hematology
Dr. Seiichi Okabe
Contributions
Contributions
Abstract
Abstract: PB1728
Type: Publication Only
Background
ABL tyrosine kinase inhibitor (TKI), imatinib and second-generation ABL TKIs, nilotinib and dasatinib have demonstrated the potency against chronic myeloid leukemia (CML) patients. However, resistance to ABL TKI can develop in CML patients due to BCR-ABL point mutations. Moreover, ABL TKIs cannot eradicate leukemia stem cells (LSCs), thus, TKIs do not appear to lead to a cure the diseases. Therefore, new approach against BCR-ABL mutant cells and LSCs may improve the outcome of BCR-ABL-positive leukemia patients. Phosphoinositide 3-kinase (PI3K) pathway regulates cell metabolism, proliferation and survival. Furthermore, aberrant activation of PI3K signaling pathway has been shown to be important in initiation maintenance of human cancers. Copanlisib, also known as BAY80-6946 is a potent pan-class I PI3K inhibitor against PI3Kα and PI3Kδ with potential anti-neoplastic activity. Copanlisib is being investigated in a pivotal phase 2 clinical trial against hematological malignancies such as malignant lymphoma.
Aims
We hypothesized that targeting PI3K, in combination with ABL TKI, would result in enhanced therapeutic activity in Philadelphia chromosome (Ph)-positive leukemia cells including T315I mutation and ABL TKI resistant.
Methods
We investigated the combination therapy with a copanlisib and an ABL TKIs (imatinib, nilotinib and ponatinib) by using the BCR-ABL positive cell line, K562, murine Ba/F3 cell line which was transfected with T315I mutant, nilotinib resistant K562, ponatinib resistant Ba/F3 cells and primary samples.
Results
72 h treatment of copanlisib exhibits cell growth inhibition against K562 cells in a dose dependent manner. The treatment of imatinib, nilotinib and ponatinib exhibits cell growth inhibition partially against K562 cells in the presence of feeder cell line, HS-5. We found that mRNA of PI3K subunit, p110δ is significantly increased after a co-culture with HS-5 in K562 and primary CD34 positive CML samples. We examined the intracellular signaling after treatment of copanlisib. High concentration of copanlisib reduced the phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein. Activity of poly (ADP-ribose) polymerase (PARP) was increased. Phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein was reduced after imatinib and copanlisib treatment. We investigated the copanlisib activity against T315I positive cells. Copanlisib potently induced cell growth inhibition of Ba/F3 T315I cells. Combined treatment of Ba/F3 T315I cells with ponatinib and copanlisib caused significantly more cytotoxicity than each drug alone. Phosphorylation of BCR-ABL and Crk-L was reduced and cleaved PARP was increased after ponatinib and copanlisib treatment. To assess the activity of copanlisib and ponatinib, we performed to test on CML tumor formation in mice. We injected nude mice subcutaneously with Ba/F3 T315I mutant cells. A dose of 20 mg/kg/day p.o of ponatinib and 6 mg/kg/three times per week i.p of copanlisib inhibited tumor growth and reduced tumor volume compared with control mice. We examined the intracellular signaling of tumor model. Phosphorylation of Crk-L and S6 ribosomal protein was reduced and cleaved PARP was increased. Treatments were well tolerated with no animal health concerns observed. We also found that the treatment of copanlisib exhibits cell growth inhibition against Ba/F3 ponatinib resistant cells, K562 nilotinib resistant cells and primary samples.
Summary
Our preclinical results indicated that administration of the PI3K inhibitor, copanlisib may be a powerful strategy against ABL TKI resistant cells and enhance cytotoxic effects of ABL TKI against those Ph-positive leukemia cells.
Keyword(s): Chronic myeloid leukemia, Leukemic stem cell, PI3 kinase
Session topic: Publication Only
Type: Publication Only
Background
ABL tyrosine kinase inhibitor (TKI), imatinib and second-generation ABL TKIs, nilotinib and dasatinib have demonstrated the potency against chronic myeloid leukemia (CML) patients. However, resistance to ABL TKI can develop in CML patients due to BCR-ABL point mutations. Moreover, ABL TKIs cannot eradicate leukemia stem cells (LSCs), thus, TKIs do not appear to lead to a cure the diseases. Therefore, new approach against BCR-ABL mutant cells and LSCs may improve the outcome of BCR-ABL-positive leukemia patients. Phosphoinositide 3-kinase (PI3K) pathway regulates cell metabolism, proliferation and survival. Furthermore, aberrant activation of PI3K signaling pathway has been shown to be important in initiation maintenance of human cancers. Copanlisib, also known as BAY80-6946 is a potent pan-class I PI3K inhibitor against PI3Kα and PI3Kδ with potential anti-neoplastic activity. Copanlisib is being investigated in a pivotal phase 2 clinical trial against hematological malignancies such as malignant lymphoma.
Aims
We hypothesized that targeting PI3K, in combination with ABL TKI, would result in enhanced therapeutic activity in Philadelphia chromosome (Ph)-positive leukemia cells including T315I mutation and ABL TKI resistant.
Methods
We investigated the combination therapy with a copanlisib and an ABL TKIs (imatinib, nilotinib and ponatinib) by using the BCR-ABL positive cell line, K562, murine Ba/F3 cell line which was transfected with T315I mutant, nilotinib resistant K562, ponatinib resistant Ba/F3 cells and primary samples.
Results
72 h treatment of copanlisib exhibits cell growth inhibition against K562 cells in a dose dependent manner. The treatment of imatinib, nilotinib and ponatinib exhibits cell growth inhibition partially against K562 cells in the presence of feeder cell line, HS-5. We found that mRNA of PI3K subunit, p110δ is significantly increased after a co-culture with HS-5 in K562 and primary CD34 positive CML samples. We examined the intracellular signaling after treatment of copanlisib. High concentration of copanlisib reduced the phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein. Activity of poly (ADP-ribose) polymerase (PARP) was increased. Phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein was reduced after imatinib and copanlisib treatment. We investigated the copanlisib activity against T315I positive cells. Copanlisib potently induced cell growth inhibition of Ba/F3 T315I cells. Combined treatment of Ba/F3 T315I cells with ponatinib and copanlisib caused significantly more cytotoxicity than each drug alone. Phosphorylation of BCR-ABL and Crk-L was reduced and cleaved PARP was increased after ponatinib and copanlisib treatment. To assess the activity of copanlisib and ponatinib, we performed to test on CML tumor formation in mice. We injected nude mice subcutaneously with Ba/F3 T315I mutant cells. A dose of 20 mg/kg/day p.o of ponatinib and 6 mg/kg/three times per week i.p of copanlisib inhibited tumor growth and reduced tumor volume compared with control mice. We examined the intracellular signaling of tumor model. Phosphorylation of Crk-L and S6 ribosomal protein was reduced and cleaved PARP was increased. Treatments were well tolerated with no animal health concerns observed. We also found that the treatment of copanlisib exhibits cell growth inhibition against Ba/F3 ponatinib resistant cells, K562 nilotinib resistant cells and primary samples.
Summary
Our preclinical results indicated that administration of the PI3K inhibitor, copanlisib may be a powerful strategy against ABL TKI resistant cells and enhance cytotoxic effects of ABL TKI against those Ph-positive leukemia cells.
Keyword(s): Chronic myeloid leukemia, Leukemic stem cell, PI3 kinase
Session topic: Publication Only
Abstract: PB1728
Type: Publication Only
Background
ABL tyrosine kinase inhibitor (TKI), imatinib and second-generation ABL TKIs, nilotinib and dasatinib have demonstrated the potency against chronic myeloid leukemia (CML) patients. However, resistance to ABL TKI can develop in CML patients due to BCR-ABL point mutations. Moreover, ABL TKIs cannot eradicate leukemia stem cells (LSCs), thus, TKIs do not appear to lead to a cure the diseases. Therefore, new approach against BCR-ABL mutant cells and LSCs may improve the outcome of BCR-ABL-positive leukemia patients. Phosphoinositide 3-kinase (PI3K) pathway regulates cell metabolism, proliferation and survival. Furthermore, aberrant activation of PI3K signaling pathway has been shown to be important in initiation maintenance of human cancers. Copanlisib, also known as BAY80-6946 is a potent pan-class I PI3K inhibitor against PI3Kα and PI3Kδ with potential anti-neoplastic activity. Copanlisib is being investigated in a pivotal phase 2 clinical trial against hematological malignancies such as malignant lymphoma.
Aims
We hypothesized that targeting PI3K, in combination with ABL TKI, would result in enhanced therapeutic activity in Philadelphia chromosome (Ph)-positive leukemia cells including T315I mutation and ABL TKI resistant.
Methods
We investigated the combination therapy with a copanlisib and an ABL TKIs (imatinib, nilotinib and ponatinib) by using the BCR-ABL positive cell line, K562, murine Ba/F3 cell line which was transfected with T315I mutant, nilotinib resistant K562, ponatinib resistant Ba/F3 cells and primary samples.
Results
72 h treatment of copanlisib exhibits cell growth inhibition against K562 cells in a dose dependent manner. The treatment of imatinib, nilotinib and ponatinib exhibits cell growth inhibition partially against K562 cells in the presence of feeder cell line, HS-5. We found that mRNA of PI3K subunit, p110δ is significantly increased after a co-culture with HS-5 in K562 and primary CD34 positive CML samples. We examined the intracellular signaling after treatment of copanlisib. High concentration of copanlisib reduced the phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein. Activity of poly (ADP-ribose) polymerase (PARP) was increased. Phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein was reduced after imatinib and copanlisib treatment. We investigated the copanlisib activity against T315I positive cells. Copanlisib potently induced cell growth inhibition of Ba/F3 T315I cells. Combined treatment of Ba/F3 T315I cells with ponatinib and copanlisib caused significantly more cytotoxicity than each drug alone. Phosphorylation of BCR-ABL and Crk-L was reduced and cleaved PARP was increased after ponatinib and copanlisib treatment. To assess the activity of copanlisib and ponatinib, we performed to test on CML tumor formation in mice. We injected nude mice subcutaneously with Ba/F3 T315I mutant cells. A dose of 20 mg/kg/day p.o of ponatinib and 6 mg/kg/three times per week i.p of copanlisib inhibited tumor growth and reduced tumor volume compared with control mice. We examined the intracellular signaling of tumor model. Phosphorylation of Crk-L and S6 ribosomal protein was reduced and cleaved PARP was increased. Treatments were well tolerated with no animal health concerns observed. We also found that the treatment of copanlisib exhibits cell growth inhibition against Ba/F3 ponatinib resistant cells, K562 nilotinib resistant cells and primary samples.
Summary
Our preclinical results indicated that administration of the PI3K inhibitor, copanlisib may be a powerful strategy against ABL TKI resistant cells and enhance cytotoxic effects of ABL TKI against those Ph-positive leukemia cells.
Keyword(s): Chronic myeloid leukemia, Leukemic stem cell, PI3 kinase
Session topic: Publication Only
Type: Publication Only
Background
ABL tyrosine kinase inhibitor (TKI), imatinib and second-generation ABL TKIs, nilotinib and dasatinib have demonstrated the potency against chronic myeloid leukemia (CML) patients. However, resistance to ABL TKI can develop in CML patients due to BCR-ABL point mutations. Moreover, ABL TKIs cannot eradicate leukemia stem cells (LSCs), thus, TKIs do not appear to lead to a cure the diseases. Therefore, new approach against BCR-ABL mutant cells and LSCs may improve the outcome of BCR-ABL-positive leukemia patients. Phosphoinositide 3-kinase (PI3K) pathway regulates cell metabolism, proliferation and survival. Furthermore, aberrant activation of PI3K signaling pathway has been shown to be important in initiation maintenance of human cancers. Copanlisib, also known as BAY80-6946 is a potent pan-class I PI3K inhibitor against PI3Kα and PI3Kδ with potential anti-neoplastic activity. Copanlisib is being investigated in a pivotal phase 2 clinical trial against hematological malignancies such as malignant lymphoma.
Aims
We hypothesized that targeting PI3K, in combination with ABL TKI, would result in enhanced therapeutic activity in Philadelphia chromosome (Ph)-positive leukemia cells including T315I mutation and ABL TKI resistant.
Methods
We investigated the combination therapy with a copanlisib and an ABL TKIs (imatinib, nilotinib and ponatinib) by using the BCR-ABL positive cell line, K562, murine Ba/F3 cell line which was transfected with T315I mutant, nilotinib resistant K562, ponatinib resistant Ba/F3 cells and primary samples.
Results
72 h treatment of copanlisib exhibits cell growth inhibition against K562 cells in a dose dependent manner. The treatment of imatinib, nilotinib and ponatinib exhibits cell growth inhibition partially against K562 cells in the presence of feeder cell line, HS-5. We found that mRNA of PI3K subunit, p110δ is significantly increased after a co-culture with HS-5 in K562 and primary CD34 positive CML samples. We examined the intracellular signaling after treatment of copanlisib. High concentration of copanlisib reduced the phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein. Activity of poly (ADP-ribose) polymerase (PARP) was increased. Phosphorylation of BCR-ABL, Crk-L and S6 ribosomal protein was reduced after imatinib and copanlisib treatment. We investigated the copanlisib activity against T315I positive cells. Copanlisib potently induced cell growth inhibition of Ba/F3 T315I cells. Combined treatment of Ba/F3 T315I cells with ponatinib and copanlisib caused significantly more cytotoxicity than each drug alone. Phosphorylation of BCR-ABL and Crk-L was reduced and cleaved PARP was increased after ponatinib and copanlisib treatment. To assess the activity of copanlisib and ponatinib, we performed to test on CML tumor formation in mice. We injected nude mice subcutaneously with Ba/F3 T315I mutant cells. A dose of 20 mg/kg/day p.o of ponatinib and 6 mg/kg/three times per week i.p of copanlisib inhibited tumor growth and reduced tumor volume compared with control mice. We examined the intracellular signaling of tumor model. Phosphorylation of Crk-L and S6 ribosomal protein was reduced and cleaved PARP was increased. Treatments were well tolerated with no animal health concerns observed. We also found that the treatment of copanlisib exhibits cell growth inhibition against Ba/F3 ponatinib resistant cells, K562 nilotinib resistant cells and primary samples.
Summary
Our preclinical results indicated that administration of the PI3K inhibitor, copanlisib may be a powerful strategy against ABL TKI resistant cells and enhance cytotoxic effects of ABL TKI against those Ph-positive leukemia cells.
Keyword(s): Chronic myeloid leukemia, Leukemic stem cell, PI3 kinase
Session topic: Publication Only
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