Discovery of novel small molecule inhibitors of lysine methyltransferase G9a and their mechanism in leukemia cell lines.

Lysine methyltransferase G9a regulates the transcription of multiple genes by primarily catalyzing mono- and di-methylation of histone H3 lysine 9, as well as several non-histone lysine sites. An attractive therapeutic target in treating leukemia, knockout studies of G9a in mice have found dramatically slowed proliferation and self-renewal of acute myeloid leukemia (AML) cells due to the attenuation of HoxA9-dependent transcription. In this study, a series of compounds were identified as potential inhibitors through structure-based virtual screening.

Vibsanin B preferentially targets HSP90β, inhibits interstitial leukocyte migration, and ameliorates experimental autoimmune encephalomyelitis.

Interstitial leukocyte migration plays a critical role in inflammation and offers a therapeutic target for treating inflammation-associated diseases such as multiple sclerosis. Identifying small molecules to inhibit undesired leukocyte migration provides promise for the treatment of these disorders. In this study, we identified vibsanin B, a novel macrocyclic diterpenoid isolated from Viburnum odoratissimum Ker-Gawl, that inhibited zebrafish interstitial leukocyte migration using a transgenic zebrafish line (TG:zlyz-enhanced GFP).

FTY720 induces apoptosis of M2 subtype acute myeloid leukemia cells by targeting sphingolipid metabolism and increasing endogenous ceramide levels.

The M2 subtype Acute Myeloid Leukemia (AML-M2) with t(8;21) represents an unmet challenge because of poor clinical outcomes in a sizable portion of patients. In this study,we report that FTY720 (Fingolimod), a sphingosine analogue and an FDA approved drug for treating of multiple sclerosis, shows antitumorigenic activity against the Kasumi-1 cell line, xenograft mouse models and leukemic blasts isolated from AML-M2 patients with t(8;21) translocation. Primary investigation indicated that FTY720 caused cell apoptosis through caspases and protein phosphatase 2A (PP2A) activation.

Functional and molecular features of the calmodulin-interacting protein IQCG required for haematopoiesis in zebrafish.

We previously reported a fusion protein NUP98-IQCG in an acute leukaemia, which functions as an aberrant regulator of transcriptional expression, yet the structure and function of IQCG have not been characterized. Here we use zebrafish to investigate the role of iqcg in haematopoietic development, and find that the numbers of haematopoietic stem cells and multilineage-differentiated cells are reduced in iqcg-deficient embryos. Mechanistically, IQCG binds to calmodulin (CaM) and acts as a molecule upstream of CaM-dependent kinase IV (CaMKIV).

DNA methyltransferases in hematologic malignancies.

DNA methyltransferases (DNMTs) are the key enzymes for genome methylation, which plays an important role in epigenetically regulated gene expression and repression. Mouse models with conditional knockout of the DNA methyltransferase 1 (DNMT1) and DNA methyltransferase 3A (DNMT3A) genes have revealed a role of DNA methylation in mediating the self-renewal and differentiation of normal hematopoietic stem cells (HSCs) and the leukemia stem cells (LSCs). Recently, various mutations of DNMT3A and other DNA methylation regulators have been identified in hematologic malignancies.