Modulation of energy metabolism to a highly glycolytic phenotype, i.e. Warburg effect, is a common phenotype of cancer and activated immune cells allowing increased biomass-production for proliferation and cell division. Endoplasmic reticulum (ER)-localized ADP-dependent glucokinase (ADPGK) has been shown to play a critical role in T cell receptor activation-induced remodeling of energy metabolism, however the underlying mechanisms remain unclear. Therefore, we established and characterized in vitro and in vivo models for ADPGK-deficiency using Jurkat T cells and zebrafish. Upon activation, ADPGK knockout Jurkat T cells displayed increased cell death and ER stress. The increase in cell death resulted from a metabolic catastrophe and knockout cells displayed severely disturbed energy metabolism hindering induction of Warburg phenotype. ADPGK knockdown in zebrafish embryos led to short, dorsalized body axis induced by elevated apoptosis. ADPGK hypomorphic zebrafish further displayed dysfunctional glucose metabolism. In both model systems loss of ADPGK function led to defective N- and O-glycosylation. Overall, our data illustrate that ADPGK is part of a glucose sensing system in the ER modulating metabolism via regulation of N- and O-glycosylation.

Warburg effect or aerobic glycolysis provides selective growth advantage to aggressive cancers. However, targeting oncogenic regulators of Warburg effect has always been challenging owing to the wide spectrum of roles of these molecules in multitude of cells. In this study, we present ADP-dependent glucokinase (ADPGK) as a novel glucose sensor and a potential onco-target in specifically high-proliferating cells in Burkitt’s lymphoma (BL). Previously, we had shownADPGKto play a major role in T-cell activation and induction of Warburg effect. We now reportADPGKknock-out Ramos BL cells display abated in vitro and in vivo tumour aggressiveness, via tumour-macrophage co-culture, migration and Zebrafish xenograft studies. We observed perturbed glycolysis and visibly reduced markers of Warburg effect inADPGKknock-out cells, finally leading to apoptosis. We found repression ofMYCproto-oncogene, and up to four-fold reduction in accumulated mutations in translocatedMYCin knock-out cells, signifying a successful targeting of the malignancy. Further, the activation induced differentiation capability of knock-out cells was impaired, owing to the inability to cope up with increased energy demands. The effects amplified greatly upon stimulation-based proliferation, thus providing a novel Burkitt’s lymphoma targeting mechanism originating from metabolic catastrophe induced in the cells by removal ofADPGK.

MYC deregulation, a cardinal event in Burkitt lymphoma (BL) pathogenesis, necessitates the elucidation of the molecular mechanisms governing MYC activation to devise innovative and effective therapeutic strategies. The t(8;14)(q24;q32) chromosomal translocation commonly observed in hematological malignancies results in MYC deregulation, endowing cancer cells with a competitive edge through heightened cell proliferation, cell cycle progression, apoptosis evasion, and metabolic reprogramming. Recent discoveries of recurrent MYC mutations in BL underscore the potential of precision medicine, employing tailored therapeutics to specifically inhibit MYC activity. However, the intricate genetic landscape of BL, featuring additional alterations, such as mutations in TP53, TCF3, and ID3, may necessitate a combinatorial approach targeting multiple oncogenic pathways for effective intervention. Despite significant strides in hematological malignancy treatment, a comprehensive understanding of the molecular mechanisms underpinning MYC’s oncogenic properties remains crucial for the potential development of highly potent and selective MYC-directed cancer therapies. This review offers an in-depth analysis of MYC translocation and its implications in Burkitt lymphoma, with a spotlight on cutting-edge advances in research and emerging therapeutic paradigms.

ID 54869 Poster Board 497 Objectives: Psoriasis is a chronic skin condition, affecting around 8 million patients in the Unites States of America. The role of T helper type 1 (Th1) and T helper type 17 (Th17) mediated cytokine pathways in psoriasis pathology has been validated clinically and antibodies targeting these cytokines are highly effective in moderate to severe psoriasis. However, these antibody therapeutics come with high costs and safety concerns. There is a huge unmet need for developing safe and effective non-steroidal therapies. Small molecule inhibitors of Th1/Th17 pathways with optimal drug like properties can effectively address patient needs; making TYK2 inhibitors (TYK2i) attractive candidates for treating psoriasis. However, given the high degree of structural similarity among JAK family, designing selective TYK2i have remained a challenge. Methods: Using an innovative structure based approach, we designed, synthesized and characterized TYK2i optimized for ideal drug like properties and JAK family selectivity using free energy perturbation (FEP) methods and medicinal chemistry based structure-activity-relationship. Compounds identified to be potent inhibitors of TYK2 along with high selectivity for TYK2 in the human kinome, were further evaluated for bioavailability in healthy mice. Selected compounds were tested for efficacy in a mouse model of human psoriasis. Female BALB/c mice were treated with imiquimod for 5 days on depilated back skin and right ear to induce psoriasis-like pathology. Animals were treated with test and reference compounds and evaluated for effects on clinical score, skin and ear thickness and skin histology (histology scoring, epidermal thickness and pSTAT3 activation). Results: Our efforts to develop selective TYK2i led to the identification of a TYK2i series with pM to low nM potencies, high selectivity for TYK2 among 468 kinases and ideal drug-like properties. These analogs dose-dependently suppressed PASI clinical scores, ear and back skin thickness and inflammation in treated mice. Additionally, back skin histology showed significant attenuation of epidermal thickening and pSTAT3 activation, comparable to known reference controls. Conclusion: We have identified selective TYK2 inhibitors that attenuate inflammation and clinical symptoms in an animal model of psoriasis. This suggests that TYK2 inhibition retains anti-inflammatory activity while eliminating potential for dose-limiting side effects observed with other systemic non-selective TYK2 or other JAK inhibitors. This research has been fully funded by Alembic Pharmaceuticals Limited.

Mammalian retina development is governed by a core set of eye-field transcription factors that orchestrate tissue lamination and neuronal connectivity through tightly regulated genetic hierarchies. The LIM homeodomain gene Lhx2 functions as a master eye-field regulator and this study identifies Dyrk1a as a previously unrecognised effector of Lhx2 -dependent programs during mouse retinal development. Conditional deletion of Dyrk1a in retinal progenitor cells led to increased apoptosis within the inner retina demonstrating a requirement for Dyrk1a in cell survival and lineage maintenance. Adult heterozygous mice exhibited dorsoventral reductions in bipolar cell number and indicated a gene-dosage-sensitive control of interneuron survival. Bipolar cell loss disrupted their mosaic organisation and resulted in diminished activity across both scotopic and photopic retinal pathways. Dyrk1a haploinsufficient mice also displayed pronounced disruption of inner plexiform layer stratification consistent with defective laminar targeting and synaptic partner integration. This study defines a gene-dosage-dependent mechanism through which transcriptional hierarchies regulate neuronal connectivity and function during mammalian retinal development.