Oxidized mC modulates synthetic lethality to PARP inhibitors for the treatment of leukemia

TET2 haploinsufficiency is a driving event in myeloid cancers and is associated with a worse prognosis in patients with acute myeloid leukemia (AML). Enhancing residual TET2 activity using vitamin C increases oxidized 5-methylcytosine (mC) formation and promotes active DNA demethylation via base excision repair (BER), which slows leukemia progression. We utilize genetic and compound library screening approaches to identify rational combination treatment strategies to improve use of vitamin C as an adjuvant therapy for AML. In addition to increasing the efficacy of several US Food and Drug Administration (FDA)-approved drugs, vitamin C treatment with poly-ADP-ribosyl polymerase inhibitors (PARPis) elicits a strong synergistic effect to block AML self-renewal in murine and human AML models. Vitamin-C-mediated TET activation combined with PARPis causes enrichment of chromatin-bound PARP1 at oxidized mCs and γH2AX accumulation during mid-S phase, leading to cell cycle stalling and differentiation. Given that most AML subtypes maintain residual TET2 expression, vitamin C could elicit broad efficacy as a PARPi therapeutic adjuvant.

Towards a continent-wide ecological site condition database using calibrated expert evaluations

A cost-effective way of undertaking comprehensive, continental-scale, assessments of ecological condition is needed to support large-scale conservation planning, monitoring, reporting, and decision-making. Currently, cross-jurisdictional inconsistency in assessment methods limits the capacity to scale-up monitoring. Here we present a novel way to build a coherent continent-wide site-level ecological condition dataset, using cross-calibration methods to integrate assessments from many observers. We focus on the use of condition assessments from individual expert observers, a currently untapped resource. Our approach has two components: (1) a simple online tool that captures expert assessments at specific locations; (2) a process of calibrating and rescaling disparate expert evaluations that can be applied to the data to provide a consistent dataset for use in conservation assessments. We describe a pilot study, involving 28 experts, who contributed 314 individual site condition assessments across a wide range of ecosystems and regions throughout continental Australia. A correction factor for each expert was used to rescale the contributed site condition assessment scores, based on a set of 77 photographic images, each scored for their condition by multiple experts, using a linear mixed model. Our approach shows strong promise for delivering the volumes of data required to develop continental-scale reference libraries of site condition assessments. Although developed from expert elicitation, the approach could also be used to harmonize the collation of existing condition datasets. The process we demonstrate can also facilitate online citizen scientists to make site condition assessments that can be cross-calibrated using contributed images.

B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease

Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.

Daughters of Bilitis and the Ladder that Teetered

ABSTRACT This article traces the economic history of the Daughters of Bilitis, the first national Lesbian organization, and its periodical The Ladder. Besides membership, subscriptions and fundraisers were monetary donations and in-kind "gifts" from businesses. Staff labor was volunteer. Compensation for authors was DOB's guarantee of full rights to their own work. Funding was precarious until an anonymous donor came to the rescue. Funds were funneled through a member/friend who singularly decided what project to back. Officers of the organization were not privy to an overall plan, nor any accounting of how the funds were spent. In the end, secrecy was the undoing of DOB as a national organization and the demise of The Ladder as well.