Targeting the HTLV-I-Regulated BATF3/IRF4 Transcriptional Network in Adult T Cell Leukemia/Lymphoma.

Nakagawa M, Shaffer AL 3rd, Ceribelli M, Zhang M, Wright G, Huang DW, Xiao W, Powell J, Petrus MN, Yang Y, Phelan JD, Kohlhammer H, Dubois SP, Yoo HM, Bachy E, Webster DE, Yang Y, Xu W, Yu X, Zhao H, Bryant BR, Shimono J, Ishio T, Maeda M, Green PL, Waldmann TA, Staudt LM
Cancer Cell 34 286-297.e10 08/13/2018

Abstract

Adult T cell leukemia/lymphoma (ATLL) is a frequently incurable disease associated with the human lymphotropic virus type I (HTLV-I). RNAi screening of ATLL lines revealed that their proliferation depends on BATF3 and IRF4, which cooperatively drive ATLL-specific gene expression. HBZ, the only HTLV-I encoded transcription factor that is expressed in all ATLL cases, binds to an ATLL-specific BATF3 super-enhancer and thereby regulates the expression of BATF3 and its downstream targets, including MYC. Inhibitors of bromodomain-and-extra-terminal-domain (BET) chromatin proteins collapsed the transcriptional network directed by HBZ and BATF3, and were consequently toxic for ATLL cell lines, patient samples, and xenografts. Our study demonstrates that the HTLV-I oncogenic retrovirus exploits a regulatory module that can be attacked therapeutically with BET inhibitors.

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