AT-9283

Metabolic reprogramming is a common feature of glioblastoma (GBM) progression and metastasis. Altered lipid metabolism is one of the most prominent metabolic alterations in cancer. Understanding the links between phospholipid remodeling and GBM tumorigenesis may help develop new anticancer strategies and improve treatments to overcome drug resistance. We used metabolomic and transcriptomic analyses to systematically investigate metabolic and molecular changes in low-grade glioma (LGG) and GBM. We then re-established the reprogrammed metabolic flux and membrane lipid composition in GBM based on metabolomic and transcriptomic analyses. By inhibiting Aurora A kinase via RNA interference (RNAi) and inhibitor treatment, we investigated the effect of Aurora A kinase on phospholipid reprogramming LPCAT1 enzyme expression and GBM cell proliferation in vitro and in vivo. We found that GBM displayed aberrant glycerophospholipid and glycerolipid metabolism compared with LGG. Metabolic profiling indicated that fatty acid synthesis and uptake for phospholipid synthesis were significantly increased in GBM compared to LGG. The unsaturated phosphatidylcholine (PC) and phosphatidylethanolamine (PE) levels were significantly decreased in GBM compared to LGG. The expression level of LPCAT1, which is required for the synthesis of saturated PC and PE, was upregulated in GBM, and the expression of LPCAT4, which is required for the synthesis of unsaturated PC and PE, was downregulated in GBM. Notably, the inhibition of Aurora A kinase by shRNA knockdown and treatment with Aurora A kinase inhibitors such as Alisertib, AMG900, or AT9283 upregulated LPCAT1 mRNA and protein expression in vitro. In vivo, the inhibition of Aurora A kinase with Alisertib increased LPCAT1 protein expression. Phospholipid remodeling and a reduction in unsaturated membrane lipid components were found in GBM. Aurora A kinase inhibition increased LPCAT1 expression and suppressed GBM cell proliferation. The combination of Aurora kinase inhibition with LPCAT1 inhibition may exert promising synergistic effects on GBM.

Introduction: Pigs are suitable donor species for xenotransplantation and biological materials from these animals are used for this purpose for many years. A major risk of xenotransplantation is a zoonosis by transspecies transmission of animal viruses. In this regard, porcine endogenous retroviruses (PERVs) are of paramount importance because some of them are able to infect human cells and could induce innate immune responses. Methods: Using a replication-competent polytropic PERV-A/C strain, we have analysed the induction of innate immune responses by this virus in human monocytes, monocyte-derived macrophages, and monocyte-derived dendritic cells. Results: PERV-A/C elevates the expression of the C-X-C motif chemokine 10 (CXCL10) up to 1,000-fold in human monocytes and monocyte-derived primary cells. In comparison to CXCL10, the levels of interferon-β (IFN-β) and interferon-stimulated gene 54 (ISG54) were almost unchanged. Heat-inactivated virus did not induce CXCL10 expression. Neither treatment with the reverse transcriptase inhibitors azidothymidine (AZT) and stavudine (d4T) nor treatment with the integrase inhibitor raltegravir (RAL) reduced the activation levels. Furthermore, depletion of SAM domain and HD domain-containing protein 1 (SAMHD1), a restriction factor that blocks PERV-A/C infection at the level of reverse transcription in these myeloid cells, had no significant effect on the CXCL10 induction level. These results imply that innate immune sensing leading to the strong CXCL10 response occurs at an early step of the replication process and does not require products of reverse transcription. Inhibition of Janus kinases (JAKs) by AT9283 prevented the observed CXCL10 induction by the virus, providing evidence that the JAK-STAT signalling pathway is involved in the CXCL10 response in theses myeloid cells. Conclusion: Our findings highlight PERVs as inducers of the pro-inflammatory chemokine CXCL10 and other innate immune responses in human monocytes and derived cells with potential implications in the context of xenotransplantation.