Epigenetic priming improves salvage chemotherapy in diffuse large B-cell lymphoma via endogenous retrovirus-induced cGAS-STING activation

• Published in: Clinical epigenetics Vol. 15; no. 1; p. 75
• Main Authors: Liu, Jun, Min, Suji, Kim, Dongchan, Park, Jihyun, Park, Eunchae, Koh, Youngil, Shin, Dong-Yeop, Kim, Tae Kon, Byun, Ja Min, Yoon, Sung-Soo, Hong, Junshik
• Format: Journal Article
• Language: English
• Published: Germany BioMed Central Ltd 03.05.2023; BioMed Central; BMC
• Subjects: 5-Azacytidine; Antigens; Antineoplastic Combined Chemotherapy Protocols - pharmacology; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Ascorbic acid; Azacitidine - pharmacology; Azacitidine - therapeutic use; Azacytidine; B-cell lymphoma; Bendamustine; Cancer; Cancer therapies; Chemotherapy; Cisplatin; Clustering; Cytotoxicity; DLBCL; DNA damage; DNA Methylation; Drug dosages; Endogenous Retroviruses - genetics; Epigenesis, Genetic; Epigenetic inheritance; Epigenetics; ERVs; Gene expression; Humans; Intolerance; Lymphocytes B; Lymphoma; Lymphoma, Large B-Cell, Diffuse - drug therapy; Lymphoma, Large B-Cell, Diffuse - genetics; Lymphoma, Large B-Cell, Diffuse - pathology; Mimicry; Neoplasm Recurrence, Local - diagnosis; Non-Hodgkin's lymphomas; Platinum; Remission; Rituximab; Rituximab - therapeutic use; STING; Transplants & implants; Tumor cell lines; Vincristine; STING; DLBCL; ERVs; Cisplatin; 5-Azacytidine
• ISSN: 1868-7083; 1868-7075; 1868-7083; 1868-7075
• DOI: 10.1186/s13148-023-01493-x

Although most patients with diffuse large B-cell lymphoma (DLBCL) achieve complete remission after first-line rituximab-containing immunochemotherapy, up to 40% of patients relapse and require salvage therapy. Among those patients, a substantial proportion remain refractory to salvage therapy due to insufficient efficacy or intolerance of toxicities. A hypomethylating agent, 5-azacytidine, showed a chemosensitizing effect when primed before chemotherapy in lymphoma cell lines and newly diagnosed DLBCL patients. However, its potential to improve outcomes of salvage chemotherapy in DLBCL has not been investigated. In this study, we demonstrated the mechanism of 5-azacytidine priming as a chemosensitizer in a platinum-based salvage regimen. This chemosensitizing effect was associated with endogenous retrovirus (ERV)-induced viral mimicry responses via the cGAS-STING axis. We found deficiency of cGAS impaired the chemosensitizing effect of 5-azacytidine. Furthermore, combining vitamin C and 5-azacytidine to synergistically activate STING could be a potential remedy for insufficient priming induced by 5-azacytidine alone. Taken together, the chemosensitizing effect of 5-azacytidine could be exploited to overcome the limitations of the current platinum-containing salvage chemotherapy in DLBCL and the status of cGAS-STING has the potential to predict the efficacy of 5-azacytidine priming.