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Current anticancer therapies cannot eliminate all cancer cells, which hijack normal arginine methylation as a means to promote their maintenance via unknown mechanisms. Here we show that targeting protein arginine N-methyltransferase 9 (PRMT9), whose activities are elevated in blasts and leukemia stem cells (LSCs) from patients with acute myeloid leukemia (AML), eliminates disease via cancer-intrinsic mechanisms and cancer-extrinsic type I interferon (IFN)-associated immunity. PRMT9 ablation in AML cells decreased the arginine methylation of regulators of RNA translation and the DNA damage response, suppressing cell survival. Notably, PRMT9 inhibition promoted DNA damage and activated cyclic GMP-AMP synthase, which underlies the type I IFN response. Genetically activating cyclic GMP-AMP synthase in AML cells blocked leukemogenesis. We also report synergy of a PRMT9 inhibitor with anti-programmed cell death protein 1 in eradicating AML. Overall, we conclude that PRMT9 functions in survival and immune evasion of both LSCs and non-LSCs; targeting PRMT9 may represent a potential anticancer strategy., (© 2024. The Author(s).)

Introduction: Venetoclax is a treatment option in patients with acute myeloid leukemia (AML) in both the front-line and relapsed/refractory settings. Initiation of therapy has been previously restricted to the inpatient setting at some institutions due to a risk of tumor lysis syndrome (TLS) and limitations in medication access efficiency given the high cost of therapy., Methods: We assessed the safety of initiating venetoclax in the outpatient setting through a single-arm, retrospective study of adult AML patients between April 1, 2019 and June 30, 2020., Results: Eighty-two patients started venetoclax during this time, with 47 (57%) patients initiated in the outpatient setting. Fifty-five percent of patients received venetoclax as first-line treatment for AML (n = 45) and 45% of patients received venetoclax for relapsed/refractory AML (n = 37). Successful initiation, defined as no hospitalizations secondary to TLS within seven days of therapy initiation, occurred in 98% of patients. The rate of TLS was 2.1% (n = 1) following venetoclax initiation. TLS symptoms were managed during hospitalization, requiring only one day of missed AML therapy. Median turnaround time for medication access was three days. Hospitalizations within seven days occurred in 17% of patients (n = 8), with the majority due to febrile neutropenia., Conclusions: The results of our study provide further evidence for the safety and feasibility of initiating venetoclax in the outpatient setting with a pharmacist-led interdisciplinary protocol., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: The Pediatric Preclinical Testing Program (PPTP) is an initiative supported by the National Cancer Institute (NCI) to identify novel therapeutic agents that may have significant activity against childhood cancers. The PPTP has established panels of childhood cancer xenografts and cell lines to be used for in vivo and in vitro testing. These include panels for Wilms tumor, sarcomas (rhabdomyosarcoma, Ewing sarcoma, and osteosarcoma), neuroblastoma, brain tumors (glioblastoma, ependymoma, and medulloblastoma), rhabdoid tumors (CNS and renal), and acute lymphoblastic leukemia (ALL). Here, we describe the characteristics of the in vivo tumor panels and report results for the in vivo evaluation of two standard agents, vincristine and cyclophosphamide., Procedures: Solid tumors were grown subcutaneously in immune-deficient mice and tumor dimensions were measured weekly. ALL xenografts were inoculated intravenously and human CD45-positive cells were enumerated weekly., Results: Vincristine-induced objective responses in 6 of 24 (25%) and cyclophosphamide-induced objective responses in 18 of 28 (64%) solid tumor models. Comparable assessments of high levels of activity for these two agents were obtained using a tumor growth delay (TGD) measure. Both agents induced regressions in each of the ALL models evaluated., Conclusions: We have established 51 solid tumor and 10 ALL in vivo models. The models identify vincristine and cyclophosphamide as having broad-spectrum activity. The PPTP tumor panels appear to generally recapitulate the activity of these agents against specific childhood cancers and to have the potential for identifying novel agents having significant clinical activity., (2007 Wiley-Liss, Inc)

Myocarditis has been shown to be a common cause of cardiomyopathy; it is believed to account for 25% of all cases of heart failure in humans. Unfortunately, the disease is difficult to detect clinically before a myopathic process ensues. Treatment of myocarditis-induced heart failure includes the standard regimen of diuretics, digoxin, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and beta-adrenergic blockers. Treatment of myocarditis itself is dependent on the etiology of the illness. Additional treatments under investigation for viral and autoimmune myocarditis include immunosuppressants, nonsteroidal anti-inflammatory agents, immunoglobulins, immunomodulators, and antivirals, with no specific therapy having a real advantage over standard treatment for heart failure. Despite advances in treatment, more work needs to be done in the early detection of myocarditis. In addition, better means need to be established for distinguishing between viral and noninfectious autoimmune forms of the disease so that appropriate treatment can be instituted.

VNP40101M, or 1,2-bis(methylsulfonyl)-1-(2-choloroethyl)-2-(methylamino)carbonylhydrazine (Cloretazine), is a bifunctional prodrug that belongs to a class of DNA-modifying agents-the sulfonylhydrazines-that has been synthesized and been shown to have activity against a wide spectrum of xenografts. The current study was designed to assess the activity of VNP40101M administered at a dose of 18 mg/kg daily for five days against a panel of human adult and pediatric CNS tumors growing subcutaneously or intracranially in athymic nude mice. The results demonstrated statistically significant (p < 0.05) growth delays of 15.0, 8.3, 51.0, 60+, 60+, and 60+ days in subcutaneous xenografts derived from childhood glioblastoma multiforme (D-456 MG), childhood ependymoma (D-528 EP and D-612 EP), childhood medulloblastoma (D-425 MED), and adult malignant glioma (D-245 MG and D-54 MG), respectively, with corresponding tumor regressions in 10 of 10, 4 of 10, 8 of 10, 9 of 10, 9 of 10, and 10 of 10 treated mice, respectively. Delayed toxicity was seen more than 60 days after treatment, with 23 deaths in 100 treated animals, despite a median weight loss of only 0.06%. In mice bearing intracranial D-245 MG xenografts, treatment with VNP40101M at a dose of 18 mg/kg daily for five days produced a 50% increase in median survival compared with controls. Additional experiments conducted against subcutaneous D-245 MG xenografts by using reduced doses of 13.5 or 9.0 mg/kg daily for five days demonstrated tumor growth delays of 82.2 and 53.5 days, with corresponding tumor regressions in 8 of 9 and 9 of 10 treated mice, respectively (all values, p < 0.001), with one toxic death. These findings suggest that VNP40101M is active in the treatment of a wide range of human central nervous system tumors and warrants translation to the clinic.