Ingo Lange

High-risk neuroblastoma (HRNB) is an extracranial solid pediatric cancer. Despite the plethora of treatments available for HRNB, up to 65% of patients are refractory or exhibit an initial response to treatment that transitions to therapy-resistant relapse, which is invariably fatal. A key feature that promotes HRNB progression is aberrant calcium (Ca2+) signaling. Ca2+ signaling is regulated by several druggable channel proteins, offering tremendous therapeutic potential. Unfortunately, many of the Ca2+ channels in HRNB also perform fundamental functions in normal healthy cells, hence targeting them increases the potential for adverse effects. To overcome this challenge, we sought to identify novel Ca2+ signaling pathways that are observed in HRNB but not normal non-cancerous cells with the hypothesis that these novel pathways may serve as potential therapeutic targets. One Ca2+ signaling pathway that is deregulated in HRNB is store-operated Ca2+ entry (SOCE). SOCE relays the release of Ca2+ from the endoplasmic reticulum (ER) and Ca2+ influx via the plasma membrane and promotes cancer drug resistance by regulating transcriptional programming and the induction of mitochondrial Ca2+ (mtCa2+)-dependent signaling. mtCa2+ signaling is critical for cellular metabolism, reactive oxygen production, cell cycle, and proliferation and has a key role in the regulation of cell death. Therefore, a dynamic interplay between ER, SOCE, and mitochondria tightly regulates cell survival and apoptosis. From a library of synthesized novel molecules, we identified two structurally related compounds that uniquely disrupt the dynamic interplay between SOCE, ER, and mitochondrial signaling pathways and induce cell death in HRNB. Our results revealed that compounds 248 and 249 activate distinct aberrant Ca2+ signals that are unique to relapsed HRNB and could be exploited to induce mtCa+ overload, a novel calcium influx current, and subsequent cell death. These findings establish a potential new pathway of calcium-mediated cell death; targeting this pathway could be critical for the treatment of refractory and relapsed HRNB.

Methylnissolin-3-O-β-d-glucopyranoside (MNG) is a pterocarpan analog, which protects EA.hy926 cells against oxidative damage through the Nrf2/HO-1 pathway. However, the effects of MNG on obesity-induced inflammatory responses in adipocyte-macrophage co-culture remain unclear. A differentiated murine preadipocyte cell line (3T3-L1) was co-cultured with a murine macrophage cell line (RAW264.7). Intracellular lipid accumulation was determined using Oil Red O staining. Western blotting was performed to investigate the expression of adipogenesis- and inflammation-associated proteins. Cell culture supernatants were assayed using ELISA kits to measure the levels of proinflammatory cytokines such as interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1). MNG inhibited lipid accumulation and the production of IL-6 and MCP-1 in the 3T3-L1 and RAW264.7 cell co-culture. Moreover, MNG inhibited the protein expression of CCAAT/enhancer-binding protein alpha (C/EBPα), C/EBPβ, peroxisome proliferator-activated receptor γ (PPARγ), cyclooxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS) under the same co-culture conditions. MNG also inhibited IL-6 and MCP-1 production compared with the co-culture control. These findings demonstrate that MNG inhibited lipid accumulation and inflammatory response by downregulating IL-6 and MCP-1 production and protein expression of C/EBPβ, C/EBPα, PPARγ, COX-2, and iNOS in co-culture conditions with 3T3-L1 and RAW264.7 cells. These results suggest that MNG may be beneficial in preventing obesity-related inflammatory status.

FTY-720 induces apoptosis in Neuroblastoma via multiple signaling pathways FTY-720 induces apoptosis in Neuroblastoma via multiple signaling pathways