Patterns of psychotropic medication prescribing and potential drug-hormone interactions among transgender and gender-diverse adults within 2 years of hormone therapy.

BACKGROUND: Transgender and gender-diverse (TGD) people have a high prevalence of psychotropic medication use, yet knowledge about the patient-level psychotropic medication burden is limited. TGD patients may take hormone therapy to meet their gender expression goals. Potential drug-hormone interactions exist between psychotropic medications and hormone therapy, requiring increased knowledge about psychotropic medication use for TGD adults undergoing hormone therapy. OBJECTIVES: The objective of this study was to examine the extent of psychotropic medication polypharmacy in a cohort of TGD adults within 2 years of starting hormone therapy. We also characterized potential drug-hormone interactions and the association with psychotropic polypharmacy. METHODS: Retrospective cross-sectional analysis of patients with ≥1 transgender health-related visit (2007-2017) in the University of Washington Medical System (Seattle, WA). Eligible patients had ≥1 psychotropic medication including antidepressants, antipsychotics, mood stabilizers, and sedative-hypnotics ordered within 2 years of starting hormone therapy (testosterone or estradiol with or without spironolactone, progesterone, finasteride, or dutasteride). We defined psychotropic polypharmacy as ≥2 psychotropic medication orders with overlapping treatment durations for at least 90 days and characterized potential drug-hormone interactions (Lexicomp, Hudson, OH). We descriptively summarized patients with and without polypharmacy (frequencies and percentages) and compared drug-hormone interactions using chi-square or Fishers exact tests (P < 0.05 considered significant). RESULTS: A total of 184 patients had ≥1 psychotropic medication order within 2 years of hormone therapy; 68 patients (37.0%) had psychotropic polypharmacy. The most frequent type of psychotropic polypharmacy was antidepressant+sedative-hypnotic (18 of 68, 26.5%). More patients had a potential drug-hormone interaction among those with psychotropic polypharmacy (23 of 68, 33.8%) versus those without (8 of 116, 6.9%, P < 0.001). CONCLUSION: Among TGD patients on psychotropic medications within 2 years of hormone therapy, one-third had psychotropic polypharmacy. Most polypharmacy types appeared to align with mental health treatment guidelines. The number of patients with a potential drug-hormone interaction was significantly higher among those with polypharmacy. Prospective studies are needed to characterize drug-hormone interactions.

Asxl1 deletion disrupts MYC and RNA polymerase II function in granulocyte progenitors.

Mutations in the gene Additional Sex-Combs Like 1 (ASXL1) are recurrent in myeloid malignancies as well as the pre-malignant condition clonal hematopoiesis, where they are universally associated with poor prognosis. However, the role of ASXL1 in myeloid lineage maturation is incompletely described. To define the role of ASXL1 in myelopoiesis, we employed single cell RNA sequencing and a murine model of hematopoietic-specific Asxl1 deletion. In granulocyte progenitors, Asxl1 deletion leads to hyperactivation of MYC and a quantitative decrease in neutrophil production. This loss of granulocyte production was not accompanied by significant changes in the landscape of covalent histone modifications. However, Asxl1 deletion results in a decrease in RNAPII promoter-proximal pausing in granulocyte progenitors, indicative of a global increase in productive transcription. These results suggest that ASXL1 inhibits productive transcription in granulocyte progenitors, identifying a new role for this epigenetic regulator in myeloid development.

Mutated SETBP1 activates transcription of Myc programs to accelerate CSF3R-driven myeloproliferative neoplasms.

Colony stimulating factor 3 receptor (CSF3R) mutations lead to JAK pathway activation and are the molecular hallmark of chronic neutrophilic leukemia (CNL). Approximately half of patients with CNL also have mutations in SET binding protein 1 (SETBP1). In this study, we developed models of SETBP1-mutated leukemia to understand the role that SETBP1 plays in CNL. SETBP1 mutations promote self-renewal of CSF3R-mutated hematopoietic progenitors in vitro and prevent cells from undergoing terminal differentiation. In vivo, SETBP1 mutations accelerate leukemia progression, leading to the rapid development of hepatosplenomegaly and granulocytosis. Through transcriptomic and epigenomic profiling, we found that SETBP1 enhances progenitor-associated programs, most strongly upregulating Myc and Myc target genes. This upregulation of Myc can be reversed by LSD1 inhibitors. In summary, we found that SETBP1 mutations promote aggressive hematopoietic cell expansion when expressed with mutated CSF3R through the upregulation of Myc-associated gene expression programs.

Mutant SETBP1 enhances NRAS-driven MAPK pathway activation to promote aggressive leukemia.

Mutations in SET-binding protein 1 (SETBP1) are associated with poor outcomes in myeloid leukemias. In the Ras-driven leukemia, juvenile myelomonocytic leukemia, SETBP1 mutations are enriched in relapsed disease. While some mechanisms for SETBP1-driven oncogenesis have been established, it remains unclear how SETBP1 specifically modulates the biology of Ras-driven leukemias. In this study, we found that when co-expressed with Ras pathway mutations, SETBP1 promoted oncogenic transformation of murine bone marrow in vitro and aggressive myeloid leukemia in vivo. We demonstrate that SETBP1 enhances the NRAS gene expression signature, driving upregulation of mitogen-activated protein kinase (MAPK) signaling and downregulation of differentiation pathways. SETBP1 also enhances NRAS-driven phosphorylation of MAPK proteins. Cells expressing NRAS and SETBP1 are sensitive to inhibitors of the MAPK pathway, and treatment with the MEK inhibitor trametinib conferred a survival benefit in a mouse model of NRAS/SETBP1-mutant disease. Our data demonstrate that despite driving enhanced MAPK signaling, SETBP1-mutant cells remain susceptible to trametinib in vitro and in vivo, providing encouraging preclinical data for the use of trametinib in SETBP1-mutant disease.

Combined inhibition of JAK/STAT pathway and lysine-specific demethylase 1 as a therapeutic strategy in CSF3R/CEBPA mutant acute myeloid leukemia.

Acute myeloid leukemia (AML) is a deadly hematologic malignancy with poor prognosis, particularly in the elderly. Even among individuals with favorable-risk disease, approximately half will relapse with conventional therapy. In this clinical circumstance, the determinants of relapse are unclear, and there are no therapeutic interventions that can prevent recurrent disease. Mutations in the transcription factor CEBPA are associated with favorable risk in AML. However, mutations in the growth factor receptor CSF3R are commonly co-occurrent in CEBPA mutant AML and are associated with an increased risk of relapse. To develop therapeutic strategies for this disease subset, we performed medium-throughput drug screening on CEBPA/CSF3R mutant leukemia cells and identified sensitivity to inhibitors of lysine-specific demethylase 1 (LSD1). Treatment of CSF3R/CEBPA mutant leukemia cells with LSD1 inhibitors reactivates differentiation-associated enhancers driving immunophenotypic and morphologic differentiation. LSD1 inhibition is ineffective as monotherapy but demonstrates synergy with inhibitors of JAK/STAT signaling, doubling median survival in vivo. These results demonstrate that combined inhibition of JAK/STAT signaling and LSD1 is a promising therapeutic strategy for CEBPA/CSF3R mutant AML.

Myeloid lineage enhancers drive oncogene synergy in CEBPA/CSF3R mutant acute myeloid leukemia.

Acute Myeloid Leukemia (AML) develops due to the acquisition of mutations from multiple functional classes. Here, we demonstrate that activating mutations in the granulocyte colony stimulating factor receptor (CSF3R), cooperate with loss of function mutations in the transcription factor CEBPA to promote acute leukemia development. The interaction between these distinct classes of mutations occurs at the level of myeloid lineage enhancers where mutant CEBPA prevents activation of a subset of differentiation associated enhancers. To confirm this enhancer-dependent mechanism, we demonstrate that CEBPA mutations must occur as the initial event in AML initiation. This improved mechanistic understanding will facilitate therapeutic development targeting the intersection of oncogene cooperativity.

Metabolic model for diversity-generating biosynthesis.

A conventional metabolic pathway leads to a specific product. In stark contrast, there are diversity-generating metabolic pathways that naturally produce different chemicals, sometimes of great diversity. We demonstrate that for one such pathway, tru, each ensuing metabolic step is slower, in parallel with the increasing potential chemical divergence generated as the pathway proceeds. Intermediates are long lived and accumulate progressively, in contrast with conventional metabolic pathways, in which the first step is rate-limiting and metabolic intermediates are short-lived. Understanding these fundamental differences enables several different practical applications, such as combinatorial biosynthesis, some of which we demonstrate here. We propose that these principles may provide a unifying framework underlying diversity-generating metabolism in many different biosynthetic pathways.