PAK4 and NAMPT as Novel Therapeutic Targets in Diffuse Large B-Cell Lymphoma, Follicular Lymphoma, and Mantle Cell Lymphoma

Abstract

Diffuse large B-cell lymphoma (DLBCL), grade 3b follicular lymphoma (FL), and mantle cell lymphoma (MCL) are aggressive non-Hodgkin’s lymphomas (NHL). Cure rates are suboptimal and novel treatment strategies are needed to improve outcomes. Here, we show that p21-activated kinase 4 (PAK4) and nicotinamide phosphoribosyl transferase (NAMPT) is critical for lymphoma subsistence. Dual targeting of PAK4-NAMPT by the Phase I small molecule KPT-9274 suppressed cell proliferation in DLBCL, FL, and MCL. Growth inhibition was concurrent with apoptosis induction alongside activation of pro-apoptotic proteins and reduced pro-survival markers. We observed NAD suppression, ATP reduction, and consequent cellular metabolic collapse in lymphoma cells due to KPT-9274 treatment. KPT-9274 in combination with standard-of-care chemotherapeutics led to superior inhibition of cell proliferation. In vivo, KPT-9274 could markedly suppress the growth of WSU-DLCL2 (DLBCL), Z-138, and JeKo-1 (MCL) sub-cutaneous xenografts, and a remarkable increase in host life span was shown, with a 50% cure of a systemic WSU-FSCCL (FL) model. Residual tumor analysis confirmed a reduction in total and phosphorylated PAK4 and activation of the pro-apoptotic cascade. This study, using various preclinical experimental models, demonstrates the therapeutic potential of targeting PAK4-NAMPT in DLBCL, FL, and MCL. The orally bioavailable, safe, and efficacious PAK4-NAMPT dual inhibitor KPT-9274 warrants further clinical investigation.

Recent advances on development of p21-activated kinase 4 inhibitors as anti-tumor agents

“…In MM1S and OPM2 murine models, exposure to KPT-9274 (100 mg/kg) significantly suppressed tumor growth ( Fulciniti et al, 2017 ). Similar tumor suppression effects were observed as well in the MV4-11 acute myeloid leukemia (AML), B-cell acute lymphoblastic leukemia (ALL) and Non-Hodgkin’s lymphomas (NHL) xenograft ( Takao et al, 2018 ; Mitchell et al, 2019 ; Khan et al, 2021 ). More appealingly, in the WSU-FSCCL xenograft model ( Khan et al, 2021 ), systemic KPT-9274 treatment remarkably prolonged the life span of mice with 50% of cure, in parallel with reduction in both total and phosphorylated PAK4 as well as increased pro-apoptotic cascade.…”

“…KPT-9274 was found to effectively suppress the cell proliferation of multiple myeloma ( Fulciniti et al, 2017 ), leukemia ( Mitchell et al, 2019 ), and lymphoma ( Khan et al, 2021 ) in a time- or dose-dependent manner with no damage on the viability of normal cells such as bone marrow stromal cells ( Fulciniti et al, 2017 ), normal hematopoietic progenitors ( Mitchell et al, 2019 ), and peripheral blood mononuclear cells ( Khan et al, 2021 ). Mechanism studies reveal that treatment with KPT-9274 induces apoptosis and cell cycle arrest, evidenced by the elevation of apoptosis-related markers cleaved caspase 3 and cleaved PARP in REH and SUP-B15 cell lines ( Takao et al, 2018 ), and reduction of cell cycle markers ( Khan et al, 2021 ) CDK2 and CDK4. Meanwhile, as a NAMPT inhibitor, KPT-9274 disrupts the binding of nicotinamide with NAMPT ( Mitchell et al, 2019 ), thus decreasing the NAD/NADH ratios and the levels of ATP in both WSU-DLCL2 and WSU-FSCCL cells ( Khan et al, 2021 ).…”

“…Mechanism studies reveal that treatment with KPT-9274 induces apoptosis and cell cycle arrest, evidenced by the elevation of apoptosis-related markers cleaved caspase 3 and cleaved PARP in REH and SUP-B15 cell lines ( Takao et al, 2018 ), and reduction of cell cycle markers ( Khan et al, 2021 ) CDK2 and CDK4. Meanwhile, as a NAMPT inhibitor, KPT-9274 disrupts the binding of nicotinamide with NAMPT ( Mitchell et al, 2019 ), thus decreasing the NAD/NADH ratios and the levels of ATP in both WSU-DLCL2 and WSU-FSCCL cells ( Khan et al, 2021 ). Furthermore, a recent report reveals that KTP-9274 disrupts lipid homeostasis and induces leukemic stem cells apoptosis by targeting NAMPT ( Subedi et al, 2021 ).…”

“…KPT-9274 was found to effectively suppress the cell proliferation of multiple myeloma (Fulciniti et al, 2017), leukemia (Mitchell et al, 2019), and lymphoma (Khan et al, 2021) in a time-or dosedependent manner with no damage on the viability of normal cells such as bone marrow stromal cells (Fulciniti et al, 2017), normal hematopoietic progenitors (Mitchell et al, 2019), and peripheral blood mononuclear cells (Khan et al, 2021). Mechanism studies reveal that treatment with KPT-9274 induces apoptosis and cell cycle arrest, evidenced by the elevation of apoptosis-related markers cleaved caspase 3 and cleaved PARP in REH and SUP-B15 cell lines (Takao et al, 2018), and reduction of cell cycle markers (Khan et al, 2021) CDK2 and CDK4. Meanwhile, as a NAMPT inhibitor, KPT-9274 disrupts the binding of nicotinamide with NAMPT (Mitchell et al, 2019), thus decreasing the NAD/NADH ratios and the levels of ATP in both WSU-DLCL2 and WSU-FSCCL cells (Khan et al, 2021).…”

NAM-NAD+-ADO metabolic reprogramming is a key factor for DNMT3A mutation to promote leukemia development through regulating cell cycle and immune microenvironment

“…In gliomas, NAMPT acts as an important dedifferentiation inducer to help glioma tumor stem-like cells (GSCs) maintain stemness and self-renewal properties [30]. High levels of NAMPT in lymphomas are associated with higher aggressiveness [31].…”