Abstract
Bruton’s tyrosine kinase (BTK) and phosphoinositide 3-kinase (PI3K) in the B-cell receptor (BCR) signaling pathway are considered potential therapeutic targets for the treatment of B-cell lymphomas, among which, diffuse large B-cell lymphoma (DLBCL) is the most common type. Herein, we comparatively evaluated the single and combined application of the BTK inhibitor ibrutinib and the selective PI3Kγ inhibitor AS-605240 in the canine DLBCL cell line CLBL-1. For further comparison, key findings were additionally analyzed in canine B-cell leukemia GL-1 and human DLBCL cell line SU-DHL-4. While ibrutinib alone induced significant anti-proliferative effects on all cell lines in a dose-dependent manner, AS-605240 only induced anti-proliferative effects at high concentrations. Interestingly, ibrutinib and AS-605240 acted synergistically, reducing cell proliferation and increasing apoptosis/necrosis in all cell lines and inducing morphological changes in CLBL-1. Moreover, the combined application of ibrutinib and AS-605240 reduced relative phosphorylation and, in some instances, the levels of the BTK, AKT, GSK3β, and ERK proteins. Comparative variant analysis of RNA-seq data among canine B- and T-lymphoid cell lines and primary B-cell lymphoma samples revealed potentially high-impact somatic variants in the genes that encode PI3K, which may explain why AS-605240 does not singly inhibit the proliferation of cell lines. The combination of ibrutinib and AS-605240 represents a promising approach that warrants further in vivo evaluation in dogs, potentially bearing significant value for the treatment of human DLBCL.
Highlights
The past decades have witnessed an increase in the incidence of lymphoma in humans and dogs
Compared to the DMSO control, ibrutinib showed anti-proliferative effects on CLBL-1 beginning at 1 μM at all time points, while the reference cell lines GL-1 and SU-DHL-4 showed significant (p < 0.05, two-tailed t-test) reduction at 2.5 μM at selective time points (Figure 1A, Supplementary Table S1A–C)
Exposure to 5 μM ibrutinib led to a significant (p < 0.05, two-tailed t-test) reduction in the number of vital cells in all cell lines at all time points
Summary
The past decades have witnessed an increase in the incidence of lymphoma in humans and dogs. Due to similarities in molecular biology, treatment, and outcome, canine B-cell lymphoma is considered as a spontaneously arising animal model of human non-Hodgkin lymphoma (NHL) [2,3]. Diffuse large B-cell lymphoma (DLBCL) is the most frequent B-cell lymphoma; the survival of patients in absence of treatment is limited to a few weeks or months [4]. Conventional first-line therapeutic interventions are CHOP (cyclophosphamide, hydroxydaunorubicin, vincristine, prednisolone)-based protocols similar to those used in humans. While 85–90% of canine patients respond to CHOP, most of them relapse and develop resistance to the initial therapeutic protocol within 12 months, mostly with fatal outcome [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
