TARGETING PROTEIN KINASE CK1A IN THE BONE MARROW MICROENVIRONMENT: A NEW POSSIBLE THERAPEUTIC APPROACH FOR MULTIPLE MYELOMA THERAPY?
(Abstract release date: 05/19/16)
EHA Library. Carrino M. 06/09/16; 132785; E1236
Ms. Marilena Carrino
Contributions
Contributions
Abstract
Abstract: E1236
Type: Eposter Presentation
Background
Multiple myeloma (MM) is an incurable blood tumor arising from plasma cells.This malignancy is characterized by a multistep pathogenesis during which plasma cells progressively accumulate in the bone marrow (BM) and in the late stages of the disease spread to the peripheral blood and other tissues. Contacts between MM cells and the surrounding hematopoietic and non-hematopoietic (stromal) cells activate paracrine and autocrine intercellular loops, which support tumor cell growth and provide a protective niche against cytotoxic agents. Despite significant improvements in the overall survival over the last years, patients frequently develop resistance to many chemotherapeutic agents, therefore new curative strategies are urgently needed.Protein Kinase CK1α (CK1α) is a Ser/Thr kinase that we found overexpressed in a fraction of MM patients and cell lines. It is essential for the regulation of BM microenvironment dependent pathways (such as WNT/β-catenin and PI3K/AKT) important for plasma cell survival, suggesting a possible function of CK1α in the microenvironment dependent progression of this disease.
Aims
We aimed at evaluating whether or not CK1α inactivation in MM plasma cells could overcome the BM microenvironment protection, affecting cells growth and proliferation by impinging on survival signaling pathways associated to chemotherapeutic resistance.We also aimed to outline whether CK1α inactivation in the BM microenvironment context, could potentiate the therapeutic effect of drugs approved for the treatment of MM, such as Bortezomib.
Methods
Patient derived plasma cells and the BM microenvironment dependent MM cell lines INA-6 and SaMMi (a patient derived MM cell line, newly generated in our laboratory) were used. A model of BM microenvironment was established colturing MM cells with HS-5 stromal cells or with BM stromal cells (BMSC) from MM patients. RNA interference for CK1α was obtained through the generation of IPTG inducible MM clones. CK1 inhibition was obtained with D4476. Apoptosis was investigated with AnnexinV/PI staining and FACS analysis. CK1α downstream pathways were analyzed by WB.
Results
We found that CK1 inhibition caused apoptosis of MM cell lines and patient derived plasma cells. The presence of a defensive BM microenvironment did not protect MM cells from D4476-induced cell death. These results were confirmed also by RNA interference using siRNAs targeting the α isoform of CK1.We investigated also the effects of CK1α inactivation on the microenvironment-dependent prosurvival pathways WNT/β-catenin and PI3K/AKT and found a proteasome independent reduction of both β-catenin and AKT proteins expression. Furthermore CK1α inhibition enhanced Bortezomib induced cytotoxicity not only on plasma cells grown alone, but also on cells co-cultured with protective stromal cells.
Conclusion
Our results indicate that by impinging on critical microenvironment dependent survival pathways, CK1α inactivation leads to MM cell apoptosis and empowers Bortezomib induced cytotoxicity, overcoming stromal cell dependent protection and resistance to chemotherapeutic agents.These results might predict a possible use of CK1α inhibitors in the clinical setting as a new therapeutic approach for MM therapy.
Session topic: E-poster
Keyword(s): Kinase, Microenvironment, Multiple myeloma
Type: Eposter Presentation
Background
Multiple myeloma (MM) is an incurable blood tumor arising from plasma cells.This malignancy is characterized by a multistep pathogenesis during which plasma cells progressively accumulate in the bone marrow (BM) and in the late stages of the disease spread to the peripheral blood and other tissues. Contacts between MM cells and the surrounding hematopoietic and non-hematopoietic (stromal) cells activate paracrine and autocrine intercellular loops, which support tumor cell growth and provide a protective niche against cytotoxic agents. Despite significant improvements in the overall survival over the last years, patients frequently develop resistance to many chemotherapeutic agents, therefore new curative strategies are urgently needed.Protein Kinase CK1α (CK1α) is a Ser/Thr kinase that we found overexpressed in a fraction of MM patients and cell lines. It is essential for the regulation of BM microenvironment dependent pathways (such as WNT/β-catenin and PI3K/AKT) important for plasma cell survival, suggesting a possible function of CK1α in the microenvironment dependent progression of this disease.
Aims
We aimed at evaluating whether or not CK1α inactivation in MM plasma cells could overcome the BM microenvironment protection, affecting cells growth and proliferation by impinging on survival signaling pathways associated to chemotherapeutic resistance.We also aimed to outline whether CK1α inactivation in the BM microenvironment context, could potentiate the therapeutic effect of drugs approved for the treatment of MM, such as Bortezomib.
Methods
Patient derived plasma cells and the BM microenvironment dependent MM cell lines INA-6 and SaMMi (a patient derived MM cell line, newly generated in our laboratory) were used. A model of BM microenvironment was established colturing MM cells with HS-5 stromal cells or with BM stromal cells (BMSC) from MM patients. RNA interference for CK1α was obtained through the generation of IPTG inducible MM clones. CK1 inhibition was obtained with D4476. Apoptosis was investigated with AnnexinV/PI staining and FACS analysis. CK1α downstream pathways were analyzed by WB.
Results
We found that CK1 inhibition caused apoptosis of MM cell lines and patient derived plasma cells. The presence of a defensive BM microenvironment did not protect MM cells from D4476-induced cell death. These results were confirmed also by RNA interference using siRNAs targeting the α isoform of CK1.We investigated also the effects of CK1α inactivation on the microenvironment-dependent prosurvival pathways WNT/β-catenin and PI3K/AKT and found a proteasome independent reduction of both β-catenin and AKT proteins expression. Furthermore CK1α inhibition enhanced Bortezomib induced cytotoxicity not only on plasma cells grown alone, but also on cells co-cultured with protective stromal cells.
Conclusion
Our results indicate that by impinging on critical microenvironment dependent survival pathways, CK1α inactivation leads to MM cell apoptosis and empowers Bortezomib induced cytotoxicity, overcoming stromal cell dependent protection and resistance to chemotherapeutic agents.These results might predict a possible use of CK1α inhibitors in the clinical setting as a new therapeutic approach for MM therapy.
Session topic: E-poster
Keyword(s): Kinase, Microenvironment, Multiple myeloma
Abstract: E1236
Type: Eposter Presentation
Background
Multiple myeloma (MM) is an incurable blood tumor arising from plasma cells.This malignancy is characterized by a multistep pathogenesis during which plasma cells progressively accumulate in the bone marrow (BM) and in the late stages of the disease spread to the peripheral blood and other tissues. Contacts between MM cells and the surrounding hematopoietic and non-hematopoietic (stromal) cells activate paracrine and autocrine intercellular loops, which support tumor cell growth and provide a protective niche against cytotoxic agents. Despite significant improvements in the overall survival over the last years, patients frequently develop resistance to many chemotherapeutic agents, therefore new curative strategies are urgently needed.Protein Kinase CK1α (CK1α) is a Ser/Thr kinase that we found overexpressed in a fraction of MM patients and cell lines. It is essential for the regulation of BM microenvironment dependent pathways (such as WNT/β-catenin and PI3K/AKT) important for plasma cell survival, suggesting a possible function of CK1α in the microenvironment dependent progression of this disease.
Aims
We aimed at evaluating whether or not CK1α inactivation in MM plasma cells could overcome the BM microenvironment protection, affecting cells growth and proliferation by impinging on survival signaling pathways associated to chemotherapeutic resistance.We also aimed to outline whether CK1α inactivation in the BM microenvironment context, could potentiate the therapeutic effect of drugs approved for the treatment of MM, such as Bortezomib.
Methods
Patient derived plasma cells and the BM microenvironment dependent MM cell lines INA-6 and SaMMi (a patient derived MM cell line, newly generated in our laboratory) were used. A model of BM microenvironment was established colturing MM cells with HS-5 stromal cells or with BM stromal cells (BMSC) from MM patients. RNA interference for CK1α was obtained through the generation of IPTG inducible MM clones. CK1 inhibition was obtained with D4476. Apoptosis was investigated with AnnexinV/PI staining and FACS analysis. CK1α downstream pathways were analyzed by WB.
Results
We found that CK1 inhibition caused apoptosis of MM cell lines and patient derived plasma cells. The presence of a defensive BM microenvironment did not protect MM cells from D4476-induced cell death. These results were confirmed also by RNA interference using siRNAs targeting the α isoform of CK1.We investigated also the effects of CK1α inactivation on the microenvironment-dependent prosurvival pathways WNT/β-catenin and PI3K/AKT and found a proteasome independent reduction of both β-catenin and AKT proteins expression. Furthermore CK1α inhibition enhanced Bortezomib induced cytotoxicity not only on plasma cells grown alone, but also on cells co-cultured with protective stromal cells.
Conclusion
Our results indicate that by impinging on critical microenvironment dependent survival pathways, CK1α inactivation leads to MM cell apoptosis and empowers Bortezomib induced cytotoxicity, overcoming stromal cell dependent protection and resistance to chemotherapeutic agents.These results might predict a possible use of CK1α inhibitors in the clinical setting as a new therapeutic approach for MM therapy.
Session topic: E-poster
Keyword(s): Kinase, Microenvironment, Multiple myeloma
Type: Eposter Presentation
Background
Multiple myeloma (MM) is an incurable blood tumor arising from plasma cells.This malignancy is characterized by a multistep pathogenesis during which plasma cells progressively accumulate in the bone marrow (BM) and in the late stages of the disease spread to the peripheral blood and other tissues. Contacts between MM cells and the surrounding hematopoietic and non-hematopoietic (stromal) cells activate paracrine and autocrine intercellular loops, which support tumor cell growth and provide a protective niche against cytotoxic agents. Despite significant improvements in the overall survival over the last years, patients frequently develop resistance to many chemotherapeutic agents, therefore new curative strategies are urgently needed.Protein Kinase CK1α (CK1α) is a Ser/Thr kinase that we found overexpressed in a fraction of MM patients and cell lines. It is essential for the regulation of BM microenvironment dependent pathways (such as WNT/β-catenin and PI3K/AKT) important for plasma cell survival, suggesting a possible function of CK1α in the microenvironment dependent progression of this disease.
Aims
We aimed at evaluating whether or not CK1α inactivation in MM plasma cells could overcome the BM microenvironment protection, affecting cells growth and proliferation by impinging on survival signaling pathways associated to chemotherapeutic resistance.We also aimed to outline whether CK1α inactivation in the BM microenvironment context, could potentiate the therapeutic effect of drugs approved for the treatment of MM, such as Bortezomib.
Methods
Patient derived plasma cells and the BM microenvironment dependent MM cell lines INA-6 and SaMMi (a patient derived MM cell line, newly generated in our laboratory) were used. A model of BM microenvironment was established colturing MM cells with HS-5 stromal cells or with BM stromal cells (BMSC) from MM patients. RNA interference for CK1α was obtained through the generation of IPTG inducible MM clones. CK1 inhibition was obtained with D4476. Apoptosis was investigated with AnnexinV/PI staining and FACS analysis. CK1α downstream pathways were analyzed by WB.
Results
We found that CK1 inhibition caused apoptosis of MM cell lines and patient derived plasma cells. The presence of a defensive BM microenvironment did not protect MM cells from D4476-induced cell death. These results were confirmed also by RNA interference using siRNAs targeting the α isoform of CK1.We investigated also the effects of CK1α inactivation on the microenvironment-dependent prosurvival pathways WNT/β-catenin and PI3K/AKT and found a proteasome independent reduction of both β-catenin and AKT proteins expression. Furthermore CK1α inhibition enhanced Bortezomib induced cytotoxicity not only on plasma cells grown alone, but also on cells co-cultured with protective stromal cells.
Conclusion
Our results indicate that by impinging on critical microenvironment dependent survival pathways, CK1α inactivation leads to MM cell apoptosis and empowers Bortezomib induced cytotoxicity, overcoming stromal cell dependent protection and resistance to chemotherapeutic agents.These results might predict a possible use of CK1α inhibitors in the clinical setting as a new therapeutic approach for MM therapy.
Session topic: E-poster
Keyword(s): Kinase, Microenvironment, Multiple myeloma
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