Tetraspanin CD82 drives acute myeloid leukemia chemoresistance by modulating protein kinase C alpha and β1 integrin activation

Abstract

A principal challenge in treating acute myeloid leukemia (AML) is chemotherapy refractory disease. As such, there remains a critical need to identify key regulators of chemotherapy resistance in AML. In this study, we demonstrate that the membrane scaffold, CD82, contributes to the chemoresistant phenotype of AML. Using an RNA-seq approach, we identified the increased expression of the tetraspanin family member, CD82, in response to the chemotherapeutic, daunorubicin. Analysis of the TARGET and BEAT AML databases identifies a correlation between CD82 expression and overall survival of AML patients. Moreover, using a combination of cell lines and patient samples, we find that CD82 overexpression results in significantly reduced cell death in response to chemotherapy. Investigation of the mechanism by which CD82 promotes AML survival in response to chemotherapy identified a crucial role for enhanced protein kinase c alpha (PKCα) signaling and downstream activation of the β1 integrin. Additionally, analysis of β1 integrin clustering by super-resolution imaging demonstrates that CD82 expression promotes the formation of dense β1 integrin membrane clusters. Lastly, evaluation of survival signaling following daunorubicin treatment identified robust activation of p38 mitogen-activated protein kinase (MAPK) downstream of PKCα and β1 integrin signaling when CD82 is overexpressed. Together, these data propose a mechanism where CD82 promotes chemoresistance by increasing PKCα activation and downstream activation/clustering of β1 integrin, leading to AML cell survival via activation of p38 MAPK. These observations suggest that the CD82-PKCα signaling axis may be a potential therapeutic target for attenuating chemoresistance signaling in AML.

Literature-based translation from synthetic lethality screening into therapeutics targets: CD82 is a novel target for KRAS mutation in colon cancer

“…The RAS- mutant DLD-1 isogenic cell line was used to validate the biological relevance of CD82 in SL. CD82 , a tetraspanin family member, contributes to the chemoresistant phenotype of cancers [24] . To experimentally corroborate the CD82 dependency of KRAS -mutant cancer cells, we applied siRNA-mediated knockdown of CD82 and assessed the interaction of CD82 and KRAS based on MEK activation in CRC cell lines ( Fig.…”

Integrated N- and O-Glycomics of Acute Myeloid Leukemia (AML) Cell Lines

“…The activity of CD82 is in turn strongly modulated by its three extracellular N -glycosylation sites [ 25 ]. Interestingly, the involvement of CD82 in the chemoresistance of AML has been recently proposed [ 26 ]. In this regard, glycomics studies on adriamycin-resistant AML cell lines have also reported the involvement of α-2,6 and α-2,8 sialylation on N -glycans in chemoresistance [ 27 , 28 ].…”

Targeting integrins in drug‐resistant acute myeloid leukaemia

“…The tetraspanin superfamily is known to be associated with the activation, ligand binding, and inside-out signalling of β1 integrins and can promote cancer cell survival (Kotha et al, 2008;van Spriel et al, 2012 As a result, DNA damage repair is activated and leads to chemoresistance and AML cell survival (Floren et al, 2020). In summary, integrin β1 subunit is implicated in the chemoresistance of leukaemia by chemotherapy efflux, intracellular signalling, and apoptosis inhibition.…”