Jiang, Ming

Abstract Targeting oxidative phosphorylation (OXPHOS) represents an attractive therapeutic strategy in acute myeloid leukemia, which exhibits exceptional dependence on mitochondrial respiration compared to normal hematopoietic cells. However, clinical attempts to exploit this vulnerability have been limited by on-target toxicity to healthy tissue. Here, we comprehensively compare the cellular consequences of inhibiting distinct nodes of the electron transport chain in AML. We demonstrate that selective inhibition of the F 1 subunit of ATP synthase with EB2023 (ammocidin A) delivers an energetic stress to AML cells without the profound redox stress that characterizes complex I inhibition, preventing NAD⁺/NADH imbalance and allowing continued TCA cycling. Further, the duration of OXPHOS inhibition is transient in nature in vivo , a finding revealed through pharmacokinetic and serial pharmacodynamic monitoring of AMPK phosphorylation accompanied by OPA1-mediated mitochondrial structural remodeling that primes AML cells for BCL2 inhibitor synergy. EB2023 in combination with venetoclax demonstrates potent anti-AML activity across cell lines and patient-derived xenograft models at doses that spare normal hematopoietic progenitors and avoid the neuropathy and sustained detrimental systemic metabolic rewiring in healthy tissues associated with prior efforts to target OXPHOS. These findings establish F 1 -selective ATP synthase inhibition as a clinically actionable therapeutic strategy in AML and establish the duration of OXPHOS inhibition as a critical and previously underappreciated determinant of therapeutic index.

Abstract Background: In breast cancer, the spatial relationship between immune and tumor cells is increasingly recognized as critical in determining the efficacy of neoadjuvant therapy (NAT). This study investigated how the distribution of immune cells, particularly CD8+ T cells, relative to tumor cells affects treatment outcomes. Methods: Biopsies from 104 breast cancer patients were examined, both pre- and post-NAT, using multiplex immunohistochemistry (mIHC). This study focused on the density and distribution of CD8+ T cells, CD68+ macrophages, FoxP3+ regulatory T cells, and other immune markers. Results: The spatial proximity of CD8+ T cells within 20 µm of cancer cells (N20-CD8+T) was strongly correlated with improved clinical outcomes across diverse tumor subtypes and NAT regimens. A significant post-NAT decrease in CD4+, CD68+, and FoxP3+ cells highlights notable shifts in the tumor immune landscape. A noteworthy finding was the positive correlation between CXCL9 expression and N20-CD8+T cells, suggesting a mechanism for immune cell recruitment and interaction within the tumor microenvironment. These results highlight the complex interplay among NAT, immune cell modifications, and patient outcomes. Conclusions: This study revealed that the proximity of N20-CD8+ T cells to tumor cells is consistently associated with favorable NAT outcomes, transcending tumor subtypes, and treatment differences. This highlights the potential of immune cell dynamics, especially CD8+ T cells, as predictive biomarkers for therapeutic responses in breast cancer, underscoring their vital role in tumor immunity.

AbstractPeripheral nerve injury‐induced spinal microglial proliferation plays a pivotal role in neuropathic pain. So far, key intracellular druggable molecules involved in this process are not identified. The nuclear factor of activated T‐cells (NFAT1) is a master regulator of immune cell proliferation. Whether and how NFAT1 modulates spinal microglial proliferation during neuropathic pain remain unknown. Here it is reported that NFAT1 is persistently upregulated in microglia after spinal nerve ligation (SNL), which is regulated by TET2‐mediated DNA demethylation. Global or microglia‐specific deletion of Nfat1 attenuates SNL‐induced pain and decreases excitatory synaptic transmission of lamina II neurons. Furthermore, deletion of Nfat1 decreases microglial proliferation and the expression of multiple microglia‐related genes, such as cytokines, transmembrane signaling receptors, and transcription factors. Particularly, SNL increases the binding of NFAT1 with the promoter of Itgam, Tnf, Il‐1b, and c‐Myc in the spinal cord. Microglia‐specific overexpression of c‐MYC induces pain hypersensitivity and microglial proliferation. Finally, inhibiting NFAT1 and c‐MYC by intrathecal injection of inhibitor or siRNA alleviates SNL‐induced neuropathic pain. Collectively, NFAT1 is a hub transcription factor that regulates microglial proliferation via c‐MYC and guides the expression of the activated microglia genome. Thus, NFAT1 may be an effective target for treating neuropathic pain.