CD40 ligand induces RIP1-dependent, necroptosis-like cell death in low-grade serous but not serous borderline ovarian tumor cells

Abstract

Ovarian high-grade serous carcinomas (HGSCs) and invasive low-grade serous carcinomas (LGSCs) are considered to be distinct entities. In particular, LGSCs are thought to arise from non-invasive serous borderline ovarian tumors (SBOTs) and show poor responsiveness to conventional chemotherapy. The pro-apoptotic effects of CD40 ligand (CD40L) have been demonstrated in HGSC, though the underlying mechanisms are not fully understood. Conversely, the therapeutic potential of the CD40L-CD40 system has yet to be evaluated in LGSC. We now show that CD40 protein is focally expressed on tumor cells in two of five primary LGSCs compared with no expression in eight primary SBOTs. Treatment with CD40L or agonistic CD40 antibody decreased the viability of LGSC-derived MPSC1 and VOA1312 cells, but not SBOT3.1 cells. Small interfering RNA (siRNA) targeting CD40 was used to show that it is required for these reductions in cell viability. CD40L treatment increased cleaved caspase-3 levels in MPSC1 cells though, surprisingly, neither pan-caspase inhibitor nor caspase-3 siRNA reversed or even attenuated CD40L-induced cell death. In addition, CD40-induced cell death was not affected by knockdown of the mitochondrial proteins apoptosis-inducing factor (AIF) and endonuclease G (EndoG). Interestingly, CD40L-induced cell death was blocked by necrostatin-1, an inhibitor of receptor-interacting protein 1 (RIP1), and attenuated by inhibitors of RIP3 (GSK'872) or MLKL (mixed lineage kinase domain-like; necrosulfonamide). Our results indicate that the upregulation of CD40 may be relatively common in LGSC and that CD40 activation induces RIP1-dependent, necroptosis-like cell death in LGSC cells.

New Anti-Leukemic Effect of Carvacrol and Thymol Combination through Synergistic Induction of Different Cell Death Pathways

“…Our studies of cell death dependence on the caspase pathway and ROS generation showed that cell death induced by the potential synergistic effect of car–thy is independent of both pathways in all the cell lines treated, except for HL60, which shows a strong dependence on the caspase pathway. These results could partly explain the overexpression of Bax and CFLAR in this cell line following treatment and the inability of HL60 to express certain genes that may play a role in both apoptotic and nonapoptotic cell death pathways, such as CD40, TNF, TP53, ATF4, and ATP6V1G2 [ 32 , 33 , 34 , 35 ]. Cell death is often regulated by multiple molecular pathways and mechanisms, including apoptosis, autophagy, and necroptosis.…”

Prevention of brain damage after traumatic brain injury by pharmacological enhancement of KCNQ (Kv7, “M-type”) K+ currents in neurons

“…45,46 TNF-α is produced by microglia after a TBI 99,100 and correlates with TBI-induced hyperexcitability. 101 Additionally, upregulation of CD40L reportedly induces RIP1-dependent cell death, 102 and TNF-α blockade decreases CD40L levels 103 and CD40 activation. 104 This synergistic line of thinking is consistent with the significant linear relationship observed between RIP1, CD40L, and Iba1, and between PSVue 794 and Evans blue staining.…”

Cross‐presentation of dead‐cell‐associated antigens by DNGR‐1+ dendritic cells contributes to chronic allograft rejection in mice

“…Additionally, in allografts, expression of death receptor and necrosis related genes such as TNF, myelin-associated glycoprotein (MAG), Fas ligand (Fasl), cytochromes, and CD40 was upregulated beginning at day 1 and increasing until day 5 after transplantation (Supporting Information Fig. S1C) [38][39][40][41][42]. This was accompanied by a higher CD11c + DNGR-1 + DC infiltration of the allografts (BALB/c→C57BL/6) in comparison to syngrafts as demonstrated by double immunofluorescence staining ( Fig.…”