LSD1 inhibition improves efficacy of adoptive T cell therapy by enhancing CD8 T cell responsiveness.

The lysine-specific histone demethylase 1 A (LSD1) is involved in antitumor immunity; however, its role in shaping CD8 + T cell (CTL) differentiation and function remains largely unexplored. Here, we show that pharmacological inhibition of LSD1 (LSD1i) in CTL in the context of adoptive T cell therapy (ACT) elicits phenotypic and functional alterations, resulting in a robust antitumor immunity in preclinical models in female mice. In addition, the combination of anti-PDL1 treatment with LSD1i-based ACT eradicates the tumor and leads to long-lasting tumor-free survival in a melanoma model, complementing the limited efficacy of the immune or epigenetic therapy alone.

A Refined Single Cell Landscape of Haematopoiesis in the Mouse Foetal Liver.

During prenatal life, the foetal liver is colonised by several waves of haematopoietic progenitors to act as the main haematopoietic organ. Single cell (sc) RNA-seq has been used to identify foetal liver cell types via their transcriptomic signature and to compare gene expression patterns as haematopoietic development proceeds. To obtain a refined single cell landscape of haematopoiesis in the foetal liver, we have generated a scRNA-seq dataset from a whole mouse E12.

CDK12 promotes tumorigenesis but induces vulnerability to therapies inhibiting folate one-carbon metabolism in breast cancer.

Cyclin-dependent kinase 12 (CDK12) overexpression is implicated in breast cancer, but whether it has a primary or only a cooperative tumorigenic role is unclear. Here, we show that transgenic CDK12 overexpression in the mouse mammary gland per se is sufficient to drive the emergence of multiple and multifocal tumors, while, in cooperation with known oncogenes, it promotes earlier tumor onset and metastasis. Integrative transcriptomic, metabolomic and functional data reveal that hyperactivation of the serine-glycine-one-carbon network is a metabolic hallmark inherent to CDK12-induced tumorigenesis.

Co-targeting leukemia-initiating cells and leukemia bulk leads to disease eradication.

According to a hierarchical model, targeting leukemia-initiating cells (LICs) was speculated to achieve complete remission (CR) or cure. Nonetheless, increasing evidence emphasized the plasticity of differentiated blasts undergoing interconversion into LICs. We exploited murine models of acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia driven by the promyelocytic leukemia/retinoic acid receptor (PML-RARα) oncofusion protein, which recruits histone deacetylase (HDAC)-containing complexes.

LSD1-directed therapy affects glioblastoma tumorigenicity by deregulating the protective ATF4-dependent integrated stress response.

Glioblastoma (GBM) is a fatal tumor whose aggressiveness, heterogeneity, poor blood-brain barrier penetration, and resistance to therapy highlight the need for new targets and clinical treatments. A step toward clinical translation includes the eradication of GBM tumor-initiating cells (TICs), responsible for GBM heterogeneity and relapse. By using patient-derived TICs and xenograft orthotopic models, we demonstrated that the selective lysine-specific histone demethylase 1 inhibitor DDP_38003 (LSD1i) is able to penetrate the brain parenchyma in vivo in preclinical models, is well tolerated, and exerts antitumor activity in molecularly different GBMs.

Pharmacological inhibition of LSD1 triggers myeloid differentiation by targeting GSE1 oncogenic functions in AML.

The histone demethylase LSD1 is over-expressed in hematological tumors and has emerged as a promising target for anticancer treatment, so that several LSD1 inhibitors are under development and testing, in preclinical and clinical settings. However, the complete understanding of their complex mechanism of action is still unreached. Here, we unraveled a novel mode of action of the LSD1 inhibitors MC2580 and DDP-38003, showing that they can induce differentiation of AML cells through the downregulation of the chromatin protein GSE1.

KIT Is Required for Fetal Liver Hematopoiesis.

In the mouse embryo, endothelial cell (EC) progenitors almost concomitantly give rise to the first blood vessels in the yolk sac and the large vessels of the embryo proper. Although the first blood cells form in the yolk sac before blood vessels have assembled, consecutive waves of hematopoietic progenitors subsequently bud from hemogenic endothelium located within the wall of yolk sac and large intraembryonic vessels in a process termed endothelial-to-hematopoietic transition (endoHT). The receptor tyrosine kinase KIT is required for late embryonic erythropoiesis, but KIT is also expressed in hematopoietic progenitors that arise via endoHT from yolk sac hemogenic endothelium to generate early, transient hematopoietic waves.

Targeting the scaffolding role of LSD1 (KDM1A) poises acute myeloid leukemia cells for retinoic acid-induced differentiation.

The histone demethylase LSD1 is deregulated in several tumors, including leukemias, providing the rationale for the clinical use of LSD1 inhibitors. In acute promyelocytic leukemia (APL), pharmacological doses of retinoic acid (RA) induce differentiation of APL cells, triggering degradation of the PML-RAR oncogene. APL cells are resistant to LSD1 inhibition or knockout, but targeting LSD1 sensitizes them to physiological doses of RA without altering of PML-RAR levels, and extends survival of leukemic mice upon RA treatment.

Tuning mTORC1 activity dictates the response of acute myeloid leukemia to LSD1 inhibition.

Lysine specific demethylase-1 (LSD1) has been shown to be critical in acute myeloid leukemia (AML) pathogenesis and this has led to the development of LSD1 inhibitors (LSD1i) which are currently tested in clinical trials. Nonetheless, preclinical studies reported that AML cells frequently exhibit intrinsic resistance to LSD1 inhibition, and the molecular basis for this phenomenon is largely unknown. We explored the potential involvement of mammalian target of rapamycin (mTOR) in mediating the resistance of leukemic cells to LSD1i.

Self-renewal of tumor cells: epigenetic determinants of the cancer stem cell phenotype.

Among the functional subpopulations that coexist within the tumor, 'cancer stem cells' are characterized by increased self-renewal and the ability to derive all of the other subpopulations of tumor cells ('bulk'). The functional heterogeneity among cancer stem cells and bulk cells must reflect distinct cellular epigenetic landscapes, but - due to the difficulty to isolate bona fide cancer stem cells with a high degree of purity - those different epigenetic landscapes, and the molecular mechanisms underlying them, remain largely unknown. Cues of intratumor phenotypic plasticity complicate the interpretation of the cancer stem cell phenotype: we contend that, however, the concept of cancer stem cell has crucial therapeutic implication, and remains a key target for the exploration of the cancer epigenome.

Inhibition of histone deacetylases in cancer therapy: lessons from leukaemia.

Histone deacetylases (HDACs) are a key component of the epigenetic machinery regulating gene expression, and behave as oncogenes in several cancer types, spurring the development of HDAC inhibitors (HDACi) as anticancer drugs. This review discusses new results regarding the role of HDACs in cancer and the effect of HDACi on tumour cells, focusing on haematological malignancies, particularly acute myeloid leukaemia. Histone deacetylases may have opposite roles at different stages of tumour progression and in different tumour cell sub-populations (cancer stem cells), highlighting the importance of investigating these aspects for further improving the clinical use of HDACi in treating cancer.