Salt-inducible kinase 3 protects tumor cells from cytotoxic T-cell attack by promoting TNF-induced NF-κB activation

Abstract

BackgroundCancer immunotherapeutic strategies showed unprecedented results in the clinic. However, many patients do not respond to immuno-oncological treatments due to the occurrence of a plethora of immunological obstacles, including tumor intrinsic mechanisms of resistance to cytotoxic T-cell (TC) attack. Thus, a deeper understanding of these mechanisms is needed to develop successful immunotherapies.MethodsTo identify novel genes that protect tumor cells from effective TC-mediated cytotoxicity, we performed a genetic screening in pancreatic cancer cells challenged with tumor-infiltrating lymphocytes and antigen-specific TCs.ResultsThe screening revealed 108 potential genes that protected tumor cells from TC attack. Among them, salt-inducible kinase 3 (SIK3) was one of the strongest hits identified in the screening. Both genetic and pharmacological inhibitions of SIK3 in tumor cells dramatically increased TC-mediated cytotoxicity in several in vitro coculture models, using different sources of tumor and TCs. Consistently, adoptive TC transfer of TILs led to tumor growth inhibition of SIK3-depleted cancer cells in vivo. Mechanistic analysis revealed that SIK3 rendered tumor cells susceptible to tumor necrosis factor (TNF) secreted by tumor-activated TCs. SIK3 promoted nuclear factor kappa B (NF-κB) nuclear translocation and inhibited caspase-8 and caspase-9 after TNF stimulation. Chromatin accessibility and transcriptome analyses showed that SIK3 knockdown profoundly impaired the expression of prosurvival genes under the TNF–NF-κB axis. TNF stimulation led to SIK3-dependent phosphorylation of the NF-κB upstream regulators inhibitory-κB kinase and NF-kappa-B inhibitor alpha on the one side, and to inhibition of histone deacetylase 4 on the other side, thus sustaining NF-κB activation and nuclear stabilization. A SIK3-dependent gene signature of TNF-mediated NF-κB activation was found in a majority of pancreatic cancers where it correlated with increased cytotoxic TC activity and poor prognosis.ConclusionOur data reveal an abundant molecular mechanism that protects tumor cells from cytotoxic TC attack and demonstrate that pharmacological inhibition of this pathway is feasible.

Identifying the prognosis implication, immunotherapy response prediction value, and potential targeted compound inhibitors of integrin subunit α3 (ITGA3) in human cancers

“…Sun et al found that LRRK2 acted as an immunosuppressive gene and was upregulated by CD8 + T cells via IFN-γ to affect cancer immunotherapy efficacy [ 43 ]. Sorrentino et al reported that SIK3 regulates tumor resistance to cytotoxic T-cell attacks by activating pro-survival and anti-apoptotic genes through the NF-κB pathway, protecting against TNF-induced cytotoxicity [ 44 ]. The result of GSEA suggests that ITGA3 may interact with related cytokines in the ECM during these immune response pathways to participate in cancer progression and immunotherapy response.…”

TSPO acts as an immune resistance gene involved in the T cell mediated immune control of glioblastoma

“…Flow cytometry was used for the detection of proteins expressed on the plasma membrane of tumor and T cells as published [ 83 ]. Tumor cells were detached from plates using PBS-EDTA, centrifuged at 500 × g for 5 min and resuspended in FACS buffer (2 × 10 5 cells/tube).…”

“…Also an up-regulation of co-inhibitory immune checkpoint molecules such as Programmed Cell Death 1 ligand 1 (PD-L1) may contribute to immune suppression in some cases, although different studies on PD-L1 expression and its` relevance in GBM immune surveillance revealed inconsistent results [ 6 , 7 , 21 , 31 ]. Therapeutic blockade of a single immune checkpoint target may lead to usage of alternative immune checkpoints and genes that confer increased resistance against the cytotoxic attack by immune cells [ 16 , 45 , 83 , 94 ]. So far, neoadjuvant anti-PD-1 therapy could not improve clinical outcomes in GB, even though it can elevate Interferon gamma (IFNγ)-related T cell responses.…”

The multiple roles of salt-inducible kinases in regulating physiology

“…However, the high occurrence of resistance to CIT greatly interferes with therapeutic efficacy. Sorrentino et al ( 186 ) discovered that SIK3, overexpressed in tumor tissues, counteracts TC cytotoxicity by upregulating TNF-induced nuclear factor-κB (NF-κB). This suggests that SIK3 is a possible endogenous mediator of resistance against TC-regulated cytotoxic molecules.…”

“…This suggests that SIK3 is a possible endogenous mediator of resistance against TC-regulated cytotoxic molecules. Therefore, inhibition of SIK3 can potentially reduce tumor growth and invasiveness ( 186 ). In light of these findings, it is suggested that combinations of biomarkers with SIK3 would aid prognosis and that SIK3 could also provide the substrate for new therapeutic applications in ovarian cancer.…”