IGH::CD274 (PD-L1) rearrangement in diffuse large B cell lymphoma and its therapeutic implication.

Diffuse large B cell lymphoma (DLBCL) expresses abundant programmed death ligand 1 (PD-L1), which shields tumor cells from immune attacks through the PD-L1/PD-1 signaling axis. The mechanism of PD-L1 overexpression includes the deletion of the 3'end of PD-L1, which increases its mRNA stability, and the gain or amplification of PD-L1. Previous studies found two cases of DLBCL carrying an IGH::PD-L1 by whole genome sequencing. We describe two more such cases by a targeted DNA next-generation sequencing (NGS) capable of detecting IGH rearrangements, leading to PD-L1 overexpression. DLBCL with PD-L1 overexpression is often resistant to R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine and prednisolone). Our patients responded to a combination of R-CHOP and a PD-1 inhibitor.

EZH2 inhibitor DZNep blocks cell proliferation of GCB-DLBCL cells by upregulating p16.

Diffuse large B-cell lymphomas (DLBCLs) are phenotypically and genetically heterogeneous. Two main subgroups of DLBCL include germinal center B-cell-like (GCB) and activated B-cell-like (ABC). Molecular profiling can further classify DLBCL into four subtypes: MCD (both CD79B and MYD88 L265P), BN2 (NOTCH2 mutation or BCL6 fusion), N1 (NOTCH1 mutation), or EZB (EZH2 mutation or BCL2 fusion). EZH2 inhibitors were recommended for patients with the EZB subtype of DLBCLs; however, little is known about the therapeutic mechanisms. Our results showed that DZNep arrested G1/S phase of GCB-DLBCL cells and inhibited the cell proliferation in vitro through upregulation of p16 by demethylating its promoter. These results suggest that DZNep may have potential as a novel therapeutic agent for DFLBL therapy. This agent may serve as a novel molecular agent to be applied to GCB DLBCL.

NIR-Light- and pH-Responsive Graphene Oxide Hybrid Cyclodextrin-Based Supramolecular Hydrogels.

Here, a novel triple-responsive graphene oxide hybrid supramolecular hydrogel based on the electrostatic self-assembly between graphene oxide and a quaternized polymer and the host-guest inclusion between α-cyclodextrins and poly(ethylene glycol) monomethyl ether (mPEG) was constructed. The quaternized polymer was synthesized by quaternization between pH-sensitive poly( N, N-dimethylaminoethyl methacrylate) and bromine end-capped poly(ethylene glycol) monomethyl ether. The supramolecular hydrogels prepared from the host-guest inclusion of poly(ethylene glycol) monomethyl ether and α-cyclodextrins would turn into a mobile sol phase when the temperature was increased above a certain temperature (Tgel-sol). Graphene oxide sheets not only acted as a core material to provide additional cross-linking but also absorbed NIR light and converted NIR light into heat to trigger the gel-sol transition. The constructed graphene oxide hybrid cyclodextrin-based supramolecular hydrogels could respond to NIR light, temperature, and pH, which could be beneficial for controlled release of cargoes and would hold great promise in the field of delivery systems.

Impact of cell fusion in myeloma marrow microenvironment on tumor progression.

BACKGROUND: Mesenchymal stem cells (MSCs) represent a subset of non-hematopoietic adult stem cells, which can also fuse with other cells spontaneously in bone marrow and capable of adopting the phenotype of other cells. The fusion of somatic cells with stem cells can reprogram somatic cells to a pluripotent state. Our research on the fusion of bone marrow mesenchymal stem cells(BM-MSCs) and MM cells demonstrate that the fused cells can exhibit stemness and cancer cell-like characteristics. RESULTS: We successfully produced a hybrid cells that acquired larger size and multinucleation, in which partial chromatin condensation, a visible nucleolus, and one or more round or oval nucleus. Experiments results showed that the stemness markers highly expressed in these fused cells and there were much more chromosomes in fused cells than those in parental cells as well as exhibited increased resistance to drug treatment. CONCLUSIONS: Our results suggest that cell fusion between BM-MSCs and MM cells could contribute it genomic heterogeneity and play a role on disease progression. METHODS: We fused human BM-MSCs with MM cells lines RPMI 8226 or XG1 in vitro by polyethylene glycol (PEG), and the hybrid cells were sorted by sedimentation assays. The growth, migration, cell cycle, chromosome and drug sensitive of hybrids were assessed by cell counting, cell colony formation, transwell assays, cytogenetic assay and flow cytometry (FCM). The proteins and genes related to stemness and cytokines were tested by western blot and/or real-time quantitative RT-PCR.

Hypoxia-induced the upregulation of stromal cell-derived factor 1 in fibroblast-like synoviocytes contributes to migration of monocytes into synovium tissue in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is an auto-immune disease characterized by chronic inflammation of multiple joints. Hypoxia is a constant feature of synovial microenvironment in RA. Fibroblast-like synoviocytes (FLSs), which are potent effector cells in RA. It has been reported that large numbers of monocytes are recruited to the synovium and play an important role in synovial inflammation and tissue destruction in RA. However, the mechanism is still unclear. The aim of this study is to explore the role of hypoxia microenvironment on the recruitment of monocytes and then promote the development of RA. METHODS: Rheumatoid arthritis model was constructed. Monocytes and FLSs were isolated from rheumatoid arthritis mice. RT-PCR, western blot and ELISA were used to detect the expression of SDF-1 in FLSs. CXCR4 expression in monocytes was examined by cell immunofluorescence and flow cytometry analysis. Transwell assay was performed to evaluate the potential of cell migration. RESULTS: We demonstrated that hypoxia microenvironment enhanced SDF-1 production of FLSs, which attracted the recruitment of CXCR4-expressing monocytes to the synovium and induced monocytes differentiation into tissue macrophages. Moreover, these macrophages secreted inflammatory factors including IL-6, TNF-α, IL-1ß and MMP-3, which contributed to the synovial inflammation and tissue destruction in RA. CONCLUSION: The results of this study suggested that hypoxia microenvironment played an important role in enhancing SDF-1 production of FLSs. SDF-1/CXCR4 axis was involved in the recruitment of monocytes in RA synovium and it might be a possible way of inhibiting inflammation and bone erosion in RA.

Impact of connexin 43 coupling on survival and migration of multiple myeloma cells.

INTRODUCTION: Gap junctions (GJs) represent the best known intercellular communication (IC) system and are membrane-spanning channels that facilitate intercellular communication by allowing small signaling molecules to pass from cell to cell. In this study, we constructed an amino terminus of human Cx43 (Cx43NT-GFP), verified the overexpression of Cx43-NT in HUVEC cells and explored the impact of gap junctions (GJs) on multiple myeloma (MM). MATERIAL AND METHODS: The levels of phosphorylated Cx43(s368) and the change of MAPK pathway associated molecules (ERK1/2, JNK, p38, NFκB) were also investigated in our cell models. Cx43 mRNA and proteins were detected in both MM cell lines and mesenchymal stem cells (MSCs). Dye transfer assays demonstrated that gap junction intercellular communication (GJIC) occurring via Cx43 situated between MM and MSCs or MM and HUVECCx43NT is functional. RESULTS: Our results present evidence for a channel-dependent modulator action of connexin 43 on the migratory activity of MM cells toward MSCs or HUVECCx43-N was higher than those of spontaneous migration (p < 0.05) and protection them from apoptosis in the presence of dexamethasone via cytokines secretion. In the meantime, the migration of MM cells involves an augmented response of p38 and JNK signaling pathway of carboxyl tail of the protein. CONCLUSIONS: Our data suggest that GJIC between MM and MSCs is one of the essential factors in tumor cell proliferation and drug sensitivity, and is implicated in MM pathogenesis.

NIR Light-, Temperature-, pH-, and Redox-Responsive Polymer-Modified Reduced Graphene Oxide/Mesoporous Silica Sandwich-Like Nanocomposites for Controlled Release.

Here a novel quadruple-responsive nanocarrier based on reduced graphene oxide/mesoporous silica sandwich-like nanocomposites (rGO@MS) modified by pH- and temperature-responsive poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) with a linker of disulfide was constructed via surface-initiated atom transfer radical polymerization. The polymer chains would be used as gatekeepers to control the release of the loaded cargo molecules under pH, temperature, NIR light and redox stimuli. The cargo molecules (rhodamine B) were demonstrated to release from the polymer-modified nanocomposites triggered by the quadruple-stimuli. It is noted that the release of the loaded rhodamine B from the nanocarriers could be enhanced greatly under the synergistic effect of multiple stimuli. The prepared quadruple-responsive polymer-modified nanocomposites show a bright prospect in the field of smart nanocarriers for controlled release.

Assessment of starch-based wood adhesive quality by confocal Raman microscopic detection of reaction homogeneity.

Confocal Raman microscopy (CRM) was used to detect the reaction homogeneity of vinyl acetate grafted on starch granules and help to assess the quality of high solid content starch-based wood adhesive (HSSWA). Primarily, four experimental starch samples were investigated, and by analysis of band area ratio (carbonyl/carbohydrate) of each granule, information about reaction homogeneity was collected. The results showed that reaction extent and homogeneity were inconsistent for samples with different G values, and the distribution of ester groups on blend samples was much less uniform than grafted starch samples with the same G value, confirming that CRM was useful for determining the homogeneity of chemical modification. Afterwards, the technique was applied to research HSSWA prepared by two-stage seeded polymerization and traditional process. The distribution of ester groups was more uniform among starch granules prepared by former method, resulted in adhesive with much better performance, indicating that uniformity of polymerization was an important factor related to properties of starch-based wood adhesive.

Myeloma cells inhibit osteogenic differentiation of mesenchymal stem cells and kill osteoblasts via TRAIL-induced apoptosis.

INTRODUCTION: Myeloma bone disease (MBD) is the result of the increased activity of osteoclasts (OCs), which is not accompanied by a comparable increase of osteoblast (OB) function, thus leading to enhanced bone resorption. Osteoblasts can also regulate osteoclast activity through expression of cytokines, such as receptor activator of nuclear factor-κB ligand (RANKL), which activates osteoclast differentiation, and osteoprotegerin (OPG), which inhibits RANKL by acting as a decoy receptor. MATERIAL AND METHODS: Based on a series of 21 patients with multiple myeloma (MM) and human osteoblast cell line HFOB1.19, we provide evidence that the bone marrow-derived mesenchymal stem cells (BMMSCs) of patients with MM exhibit normal phenotype, but showed reduced efficiency to differentiate into OBs as compared with normal controls. RESULTS: In vitro assays showed that MM cells inhibited the potential of osteogenic differentiation of BMMSCs from healthy controls and rendered the OBs sensitive to TRAIL-induced apoptosis. There was no evidence of the formation of tartrate-resistant acid phosphatase positive OCs. The osteogenic differentiation of HFOB1.19 was also inhibited in the presence of RPMI 8266 or XG7 MM cells, as confirmed by von Kossa and ALP staining. Osteoblast s induced from BMMSCs supported survival and proliferation of MM cells, especially when the MM cells were cultured in medium containing rhTRAIL and dexamethasone. Multiple myeloma cells proliferated and grew well in the presence of residual OBs. CONCLUSIONS: Besides OCs, our results demonstrated that OBs and MM cells were dependent upon each other and made a microenvironment suitable for MM cells.