GSK-3β inhibitor, 9-ING-41, reduces cell viability and halts proliferation of B-cell lymphoma cell lines as a single agent and in combination with novel agents

Reem Karmali,Jeffrey A Borgia,Vineela Chukkapalli,Andrew P Mazar,Leo I Gordon,Francis J Giles,Andrey Ugolkov

doi:10.18632/oncotarget.22414

Reem Karmali, Jeffrey A Borgia + Show 5 more

Open Access

https://doi.org/10.18632/oncotarget.22414

Copy DOI

Abstract

The complexities of GSK-3β function and interactions with PI3K/AKT/mTOR signaling, cell cycling, and apoptotic pathways are poorly understood in the context of lymphomagenesis and cancer therapeutics. In this study, we explored the anti-tumor effects of the GSK-3β inhibitor, 9-ING-41, in lymphoma cell lines as a single agent and in combination with novel agents comprising BCL-2 inhibitor (Venetoclax), CDK-9 inhibitor (BAY-1143572) and p110δ-PI3K inhibitor (Idelalisib). Treatment of Daudi, SUDHL-4, Karpas 422, KPUM-UH1, and TMD8 lymphoma cell lines with 1 μM 9-ING-41 reduced cell viability by 40-70% (p<0.05) and halted proliferation. Luminex analysis of apoptotic pathways revealed a significant increase in active caspase 3 in all lymphoma cell lines (p<0.001) except TMD8 cells. Co-treating SUDHL-4 and KPUM-UH1 lymphoma cells with 0.5 μM 9-ING-41 showed 8-and 2-fold reduction in IC50 values of Venetoclax, respectively. No significant benefit for this combination was seen in other lymphoma cells tested. The combination of BAY-1143572 with 0.5 μM 9-ING-41 showed an 8-fold reduction in the IC50 value of the former in SUDHL-4 lymphoma cells alone. No significant changes in IC50 values of Idelalisib were measured across all cell lines for the combination of 9-ING-41 and Idelalisib. Further, signaling analysis via Western blot in the double-hit lymphoma cell line, KPUM-UH1, suggests that phospho-c-MYC is modified with 9-ING-41 treatment. Altogether, our data show that 9-ING-41 results in increased apoptosis and decreased proliferation in aggressive B-cell lymphoma cells and enhances the antitumor effects of BCL-2 and CDK-9 antagonists.

Highlights

The clinical course for diffuse large B-cell lymphoma (DLBCL) remains variable despite improved response and survival with the addition of the antiCD20 monoclonal antibody, rituximab, to standard chemotherapy in the late 1990’s [1, 2]
We explored the antitumor effects of the Glycogen synthase kinase (GSK)-3β inhibitor, 9-ING-41, in lymphoma cell lines as a single agent and in combination with novel agents comprising BCL-2 inhibitor (Venetoclax), cyclin-dependent kinase (CDK)-9 inhibitor (BAY-1143572) and p110δ-PI3K inhibitor (Idelalisib)
In order to better understand the signaling changes occurring in 9-ING-41-treated lymphoma cells, we focused on the double-hit lymphoma cell line (KPUM-UH1), which is typically chemo-resistant. c-MYC levels were analyzed in KPUM-UH1 cells via western blot for 9-ING-41 alone and the combination of 9-ING-41 with either Venetoclax or BAY1143572 (Supplementary Figures 3, 4). 9-ING-41 treatment alone reduced total c-MYC protein expression but showed high-molecular weight modified p-c-MYC (S62) and p-cMYC (Thr 58) (Supplementary Figures 3, 4)

Summary

INTRODUCTION

The clinical course for diffuse large B-cell lymphoma (DLBCL) remains variable despite improved response and survival with the addition of the antiCD20 monoclonal antibody, rituximab, to standard chemotherapy in the late 1990’s [1, 2]. Much focus has been placed on the role of GSK-3β in tumor progression and modulation of oncogenes (beta-catenin, cyclin D1, and c-MYC), cell cycle regulators (e.g., p27Kip1), and mediators of epithelialmesenchymal transition (e.g., snail) by GSK-3β have been described (Figure 1A) [11,12,13,14,15]. Aberrant overexpression of GSK-3β has been shown to promote tumor growth and chemotherapy resistance in various solid tumors, including pancreatic, ovarian, colon cancer, and glioblastoma [16,17,18,19,20], through differential effects on prosurvival nuclear factor (NF)-κB and c-MYC pathways as well on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and p53-mediated apoptotic mechanisms (Figure 1A) [21, 22]. We explore the effects of this inhibitor in combination with novel agents, including the BCL-2 inhibitor (Venetoclax), CDK9 inhibitor (BAY-1143572), and p110δ-PI3K inhibitor (Idelalisib), as a means of uncovering complimentary antitumor pathways that can be targeted

RESULTS

DISCUSSION

Findings

MATERIALS AND METHODS