Germline Neurofibromin 1 mutation enhances the anti-tumour immune response and decreases juvenile myelomonocytic leukaemia tumourigenicity.

Juvenile myelomonocytic leukaemia (JMML) is an aggressive paediatric leukaemia characterized by mutations in five canonical RAS pathway genes, including the NF1 gene. JMML is driven by germline NF1 gene mutations, with additional somatic aberrations resulting in the NF1 biallelic inactivation, leading to disease progression. Germline mutations in the NF1 gene alone primarily cause benign neurofibromatosis type 1 (NF1) tumours rather than malignant JMML, yet the underlying mechanism remains unclear. Here, we demonstrate that with reduced NF1 gene dose, immune cells are promoted in anti-tumour immune response. Comparing the biological properties of JMML and NF1 patients, we found that not only JMML but also NF1 patients driven by NF1 mutations could increase monocytes generation. But monocytes cannot further malignant development in NF1 patients. Utilizing haematopoietic and macrophage differentiation from iPSCs, we revealed that NF1 mutations or knockout (KO) recapitulated the classical haematopoietic pathological features of JMML with reduced NF1 gene dose. NF1 mutations or KO promoted the proliferation and immune function of NK cells and iMacs derived from iPSCs. Moreover, NF1-mutated iNKs had a high capacity to kill NF1-KO iMacs. NF1-mutated or KO iNKs administration delayed leukaemia progression in a xenograft animal model. Our findings demonstrate that germline NF1 mutations alone cannot directly drive JMML development and suggest a potential cell immunotherapy for JMML patients.

Optimizing the Method for Differentiation of Macrophages from Human Induced Pluripotent Stem Cells.

Macrophage is a very promising cell type for cancer immunotherapy, yet it is difficult to obtain enough functional macrophages for clinical cell therapy. Herein, we descibe a reliable method to produce functional macrophages through the differentiation of human induced pluripotent stem cells (hiPSCs). By optimizing the size control of embryoid bodies (EBs), we accelerated the differentiation process of macrophages and increased the production of macrophages without attenuating macrophage functions. Our final yield of macrophages was close to 50-fold of starting iPSCs. The macrophages showed phagocytic capacity in vitro and a xenograft tumor model. M0 macrophages could be further polarized into M1 and M2 subtypes, and M1 cells exhibited typical proinflammatory characteristics. Moreover, we found that hematopoietic differentiation originated from the outside of EB and matured inward gradually. Taken together, our protocol provides an effective method for the generation of macrophages comparable to blood-derived macrophages, which provides potential value for cell therapy and gene editing studies.

Synthesis, biological evaluation and molecular modeling studies of psammaplin A and its analogs as potent histone deacetylases inhibitors and cytotoxic agents.

In this study, a concise synthetic method of psammaplin A was achieved from 3-bromo-4-hydroxybenzaldahyde and hydantoin through a four-step synthesis via Knoevenagel condensation, hydrolysis, oximation and amidation in 37% overall yield. A collection of novel psammaplin A analogs focused on the variations of substituents at the benzene ring and modifications at the oxime moiety were synthesized. Among all the synthesized compounds, 5d and 5e showed better HDAC inhibition than psammaplin A and comparable cytotoxicity against four cancer cell lines (PC-3, MCF-7, A549 and HL-60). Molecular docking and dynamics simulation revealed that (i) hydrogen atom of the oxime group interacts with Asp99 of HDAC1 through a water bridged hydrogen bond and (ii) a hydroxyl group is optimal attached on the para-position of benzene, interacting with Glu203 at the entrance to the active site tunnel.

[Synthesis and antitumor activity of S-hexyl(heptyl) substituted ethanethioate derivatives].

To simplify the macrocyclic fragment and to modify the zinc binding group of the natural product apicidin, two series of S-hexyl (heptyl) ethanethioate derivatives were designed and synthesized. Twenty-six compounds were synthesized and confirmed with 1H NMR, IR, MS and HR-MS spectrum, which were not reported. Take vorinostat as control, their antiporliferative activities against cancer cell lines, MCF-7 and HL-60, were tested with MTT assay or trypan blue staining method. Generally in both series it was found that, the chiral carbon atom at 7 position is not necessary, compounds II-1, II-3, II-6 and II-13 showed good activity on HL-60 cells in vitro, with the IC50 values less than 10 micromol x L(-1). II-7 and II-8 showed stronger activity against MCF-7 than Vorinostat, with the IC50 of 3.19 and 6.29 micromol x L(-1), respectively.