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Purpose: BRD9 is a defining component of the noncanonical SWI/SNF complex, which regulates gene expression by controlling chromatin dynamics. Although recent studies have found an oncogenic role for BRD9 in multiple cancer types including multiple myeloma, its clinical significance and oncogenic mechanism have not yet been elucidated. Here, we sought to identify the clinical and biological impact of BRD9 in multiple myeloma, which may contribute to the development of novel therapeutic strategies. Experimental Design: We performed integrated analyses of BRD9 in vitro and in vivo using multiple myeloma cell lines and primary multiple myeloma cells in established preclinical models, which identified the molecular functions of BRD9 contributing to multiple myeloma cell survival. Results: We found that high BRD9 expression was a poor prognostic factor in multiple myeloma. Depleting BRD9 by genetic (shRNA) and pharmacologic (dBRD9-A; proteolysis-targeting chimera; BRD9 degrader) approaches downregulated ribosome biogenesis genes, decreased the expression of the master regulator MYC, and disrupted the protein-synthesis maintenance machinery, thereby inhibiting multiple myeloma cell growth in vitro and in vivo in preclinical models. Importantly, we identified that the expression of ribosome biogenesis genes was associated with the disease progression and prognosis of patients with multiple myeloma. Our results suggest that BRD9 promotes gene expression by predominantly occupying the promoter regions of ribosome biogenesis genes and cooperating with BRD4 to enhance the transcriptional function of MYC. Conclusions: Our study identifies and validates BRD9 as a novel therapeutic target in preclinical models of multiple myeloma, which provides the framework for the clinical evaluation of BRD9 degraders to improve patient outcome.

Supplementary Materials

BRD9 occupies promoter regions of target gene.

Purpose:BRD9 is a defining component of the noncanonical SWI/SNF complex, which regulates gene expression by controlling chromatin dynamics. Although recent studies have found an oncogenic role for BRD9 in multiple cancer types including multiple myeloma, its clinical significance and oncogenic mechanism have not yet been elucidated. Here, we sought to identify the clinical and biological impact of BRD9 in multiple myeloma, which may contribute to the development of novel therapeutic strategies.Experimental Design:We performed integrated analyses of BRD9 in vitro and in vivo using multiple myeloma cell lines and primary multiple myeloma cells in established preclinical models, which identified the molecular functions of BRD9 contributing to multiple myeloma cell survival.Results:We found that high BRD9 expression was a poor prognostic factor in multiple myeloma. Depleting BRD9 by genetic (shRNA) and pharmacologic (dBRD9-A; proteolysis-targeting chimera; BRD9 degrader) approaches downregulated ribosome biogenesis genes, decreased the expression of the master regulator MYC, and disrupted the protein-synthesis maintenance machinery, thereby inhibiting multiple myeloma cell growth in vitro and in vivo in preclinical models. Importantly, we identified that the expression of ribosome biogenesis genes was associated with the disease progression and prognosis of patients with multiple myeloma. Our results suggest that BRD9 promotes gene expression by predominantly occupying the promoter regions of ribosome biogenesis genes and cooperating with BRD4 to enhance the transcriptional function of MYC.Conclusions:Our study identifies and validates BRD9 as a novel therapeutic target in preclinical models of multiple myeloma, which provides the framework for the clinical evaluation of BRD9 degraders to improve patient outcome.

GSEA_RNAseq (GOBP)

Univariate and multivariate analysis of BRD9 expression

Supplementary materials

Purpose:Efforts are required to improve the potency and durability of CD38- and BCMA-based immunotherapies in human multiple myeloma. We here delineated the molecular and cellular mechanisms underlying novel immunomodulatory effects triggered by BCMA pyrrolobenzodiazepine (PBD) antibody drug conjugate (ADC) MEDI2228 which can augment efficacy of these immunotherapies.Experimental Design:MEDI2228-induced transcriptional and protein changes were investigated to define significantly impacted genes and signaling cascades in multiple myeloma cells. Mechanisms whereby MEDI2228 combination therapies can enhance cytotoxicity or overcome drug resistance in multiple myeloma cell lines and patient multiple myeloma cells were defined using in vitro models of tumor in the bone marrow (BM) microenvironment, as well as in human natural killer (NK)-reconstituted NOD/SCID gamma (NSG) mice bearing MM1S tumors.Results:MEDI2228 enriched IFN I signaling and enhanced expression of IFN-stimulated genes in multiple myeloma cell lines following the induction of DNA damage–ATM/ATR-CHK1/2 pathways. It activated cGAS-STING-TBK1-IRF3 and STAT1-IRF1–signaling cascades and increased CD38 expression in multiple myeloma cells but did not increase CD38 expression in BCMA-negative NK effector cells. It overcame CD38 downregulation on multiple myeloma cells triggered by IL6 and patient BM stromal cell-culture supernatant via activation of STAT1-IRF1, even in immunomodulatory drug (IMiD)- and bortezomib-resistant multiple myeloma cells. In vitro and in vivo upregulation of NKG2D ligands and CD38 in MEDI2228-treated multiple myeloma cells was further associated with synergistic daratumumab (Dara) CD38 MoAb-triggered NK-mediated cytotoxicity of both cell lines and autologous drug-resistant patient multiple myeloma cells.Conclusions:These results provide the basis for clinical evaluation of combination MEDI2228 with Dara to further improve patient outcome in multiple myeloma.

High-voltage and fast-switching silicon carbide (SiC) power modules are needed to construct high-voltage and high power-density converters. Stacking multiple low-voltage SiC devices to increase the equivalent blocking voltage shows advantages in on -state resistance, current capacity, and cost over one single high-voltage device. An indirect series-connected SiC MOSFET power module using quasi-two-level hybrid-clamp topology is proposed in this article. The voltages across the devices are automatically balanced with an open-loop modulation strategy to avoid sensors and control algorithm. Moreover, only ceramic capacitors are needed besides the MOSFETs and diodes in the topology. Thanks to this, the topology was highly integrated into a power module using SiC dies, which is equivalent to a general-purpose two-level medium-voltage SiC MOSFET power module. The switching losses of the power module show advantages over other stacking methods and even a single high-voltage switch and it can be evaluated with a two-level half-bridge (HB). To achieve this, the automatic voltage-balancing performance is analyzed in detail and the parasitic output capacitance in the topology is investigated, based on which the design considerations are presented. The simulation results from LTspice confirm the voltage-balancing and a 3600V/20A HB power module is built in the lab and the experimental results verify the design.

As fluorescence in the second near-infrared window (NIR-II, 1000–1400 nm) could image deep tissue with high signal-to-noise ratios compared with that in NIR-I (750–900 nm), Ag2Se quantum dots (QDs) with fluorescence in the NIR-II could be ideal fluorophores. Here, we described a biosynthesis method to prepare the Ag2Se QDs by using temporally coupling the irrelated biochemical reactions, whose photoluminescence (PL) emission can reach NIR-II. The nanoparticles were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results showed that the nanoparticles obtained by extracellular purification were Ag2Se QDs with a uniform size of 3.9 ± 0.6 nm. In addition, the fluorescence intensity of Saccharomyces cerevisiae was improved successfully by nearly 4-fold by constructed engineering strain. In particular, the biosynthesis of Ag2Se QDs had good biocompatibility because it was capped by protein. Furthermore, investigating the toxicity of Ag2Se on cells and NIR images of nude mice showed that the Ag2Se synthesized using S. cerevisiae had low toxicity and could be used for in vivo imaging. In this work, the synthesis pathway of biocompatible Ag2Se was broadened and laid a foundation for the enlarged applicability of bioimaging in the biosynthesis of NIR-II QDs.

Multiple myeloma (MM) is an incurable cancer of the plasma cells. In the last twenty years, treatment strategies have evolved toward targeting MM cells—from the shotgun chemotherapy approach to the slightly more targeted approach of disrupting important MM molecular pathways to the immunotherapy approach that specifically targets MM cells based on protein expression. Antibody-drug conjugates (ADCs) are introduced as immunotherapeutic drugs which utilize an antibody to deliver cytotoxic agents to cancer cells distinctively. Recent investigations of ADCs for MM treatment focus on targeting B cell maturation antigen (BCMA), which regulates B cell proliferation, survival, maturation, and differentiation into plasma cells (PCs). Given its selective expression in malignant PCs, BCMA is one of the most promising targets in MM immunotherapy. Compared to other BCMA-targeting immunotherapies, ADCs have several benefits, such as lower price, shorter production period, fewer infusions, less dependence on the patient’s immune system, and they are less likely to over-activate the immune system. In clinical trials, anti-BCMA ADCs have shown safety and remarkable response rates in patients with relapsed and refractory MM. Here, we review the properties and clinical applications of anti-BCMA ADC therapies and discuss the potential mechanisms of resistance and ways to overcome them.

With the development of renewable energy generation, medium-voltage dc collection in large-scale photovoltaic (PV) plants has become a research focus with less losses and less system complexity. Maximum power point tracking control of PV panels requires converters with a large input voltage range and a stable output, among which active-clamp isolated boost converters qualify for PV applications, due to their high and variable step-up ratio. In this paper, an improved dual-active-clamp quasi-resonant isolated boost converter is proposed to increase the efficiency and decrease the voltage pressure across switches. The proposed topology has an additional resonant branch with a small resonant capacitor on top of the conventional active-clamp isolated boost converters, where the capacitor resonates with the leakage inductor of the transformer to improve the voltage and current waveforms during switching transients. The proposed converter achieves soft switching of all the switches at both turn-on and turn-off transients, while retaining good voltage regulation ability. Additionally, the induced voltage spikes due to the parasitic inductors in the conventional topology are suppressed well. Discussions on detailed steady-state operation, zero-voltage switching (ZVS) regions, and design considerations are given to show the advantages of the proposed converter. Simulation and experimental results are presented to verify the expected performances.

In this paper, an archetypal aseismic system is proposed with 2-degree of freedom based on a smooth and discontinuous (SD) oscillator to avoid the failure of electric power system under the complex excitation of seismic waves. This model comprises two vibration isolation units for the orthogonal horizontal directions, and each of them admits the stable quasi-zero stiffness (SQZS) with a pair of inclined linear elastic springs. The equation of motion is formulated by using Lagrange equation, and the SQZS condition is obtained by optimizing the parameters of the system. The analysis shows that the system behaves a remarkable vibration isolation performance with low resonant frequency and a large stroke of SQZS interval. The experimental investigations are carried out to show a high sonsistency with the theoretical results, which demonstrates the improvement of aseismic behavior of the proposed model under the seismic wave.

In urban rail transit, there is a large number of harmonics brought by diode rectifiers, and shunt active power filters (APFs) are an effective method of harmonics rejection. Traditional shunt APFs work with a dedicated DC link leading to complexity, while those with a common DC bus but using non-isolated topologies bring serious problems of zero-sequence circulating current (ZSCC), which introduce losses and provoke poor quality. Consequently, this paper first analyzes the limitations of traditional non-isolated APFs on modulation radio. Based on the analysis, this paper put forward a novel isolated APF with a common DC link based on existing diode rectifiers in urban rail transit, which realizes braking energy recovery as an additional function. To this end, harmonics brought by diode rectifiers are reduced while rejecting ZSCC. Meanwhile, braking energy can feedback to the city grid with lower harmonics. Finally, simulation and experiment using a 1-kW prototype converter verify the feasibility and validity of the proposed converter on harmonics suppression and braking energy recovery.

Daratumumab (Dara) is the first-in-class monoclonal antibody targeting CD38 which triggers both direct and immune mediated cytotoxicity in preclinical in vitro and in vivo models of multiple myeloma (MM) in the bone marrow (BM) milieu. Importantly, Dara combination therapies can achieve high frequency and extent of response in both relapsed/refractory and newly diagnosed MM. However, relapse of MM is commonly observed due, at least in part, to downregulation of CD38 on MM cells. Here we utilize genome-wide CRISPR-cas9 knockout (KO) screening to identify novel regulators mediating CD38 expression and Dara sensitivity in MM cells. We identified 46 different sgRNAs to be positively correlated with MM cytotoxicity triggered by Dara and NK cells treatment. We further performed second round screening using the cell population with lowest 5% CD38 expression after CRISPR lentiviral library transduction. Importantly, KDM6A was the top ranked of the overlapping genes from these two screenings. Next, we individually KO of KDM6A in MM cells and found that both mRNA and protein levels of CD38 were significantly decreased, as well as the cell surface CD38 expression detected by flow cytometry. Re-introduction of KDM6A into KDM6A KO cells restored the expression level of CD38 and Dara-induced cytotoxicity, indicating that KDM6A positively regulates CD38 expression in MM cells. Since KDM6A regulates demethylation of lysine 27 at histone H3 (H3K27) to activate gene expression, we next examined whether CD38 expression was altered by methylation status of H3K27. From our ChIP-seq and ChIP Q-PCR data, we identified that H3K27me3 level was highly enriched on the promotor area of CD38 in KDM6A KO cells compared to control cells. These data indicate that KDM6A modulates CD38 expression by regulating H3K27me3 level on the CD38 promotor, thereby mediating sensitivity of MM cells to Dara-induced cytotoxicity. H3K27me3 is regulated by the balance of demethylase (KDM6A) and methyltransferase (EZH2). However, downregulating H3K27me3 on the CD38 promoter by enhancing KDM6A activity is challenging. Therefore, we next explored whether EZH2 inhibitor can restore CD38 expression and overcome Dara resistance in KDM6A KO cells. Indeed, H3K27me3 level on the CD38 promotor area was significantly decreased by EZH2 inhibitor. Moreover, EZH2 inhibitor treatment upregulated both CD38 mRNA and protein levels in KDM6A KO cells. Importantly, EZH2 inhibitor also restored sensitivity of KDM6A KO cells to Dara-mediated NK cell cytotoxicity. Taken together, our studies demonstrate that KDM6A regulates H3K27me3 level on CD38 promotor area and CD38 expression in MM. Moreover, we validate that combination treatment with EZH2 inhibitor and Dara can overcome Dara resistance in preclinical MM models, providing the rationale for combination clinical trials to overcome Dara resistance and improve patient outcome. Citation Format: Jiye Liu, Lijie Xing, Teru Hideshima, Kenneth Carl Anderson. Genome-wide CRISPR-cas9 screening identifies KDM6A as a modulator of CD38 expression in multiple myeloma: Therapeutic implications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5352.

DC collection network offers an attractive alternative to AC network for photovoltaic, as it avoids the charging current issues and reduces the size and weight. Variable voltage gain DC/DC converters play an important role in DC collection network. Two topologies suitable for photovoltaic DC collection are studied. Boost and LLC converter and active clamp isolated full-bridge boost converter are two converters with high and variable voltage conversion ratio suitable for the photovoltaic system. This work investigates the two converters comprehensively. The topologies are analysed so as to summarise and compare the characteristic of the converters. Soft switching condition is compared to help extend the zero voltage switching range. Voltage and current stress of the two converters are calculated. Loss comparison is made with the theoretical analysis. Advantages and disadvantages are summarised to get a deep insight into their application field.

Purpose: Efforts are required to improve the potency and durability of CD38- and BCMA-based immunotherapies in human multiple myeloma. We here delineated the molecular and cellular mechanisms underlying novel immunomodulatory effects triggered by BCMA pyrrolobenzodiazepine (PBD) antibody drug conjugate (ADC) MEDI2228 which can augment efficacy of these immunotherapies. Experimental Design: MEDI2228-induced transcriptional and protein changes were investigated to define significantly impacted genes and signaling cascades in multiple myeloma cells. Mechanisms whereby MEDI2228 combination therapies can enhance cytotoxicity or overcome drug resistance in multiple myeloma cell lines and patient multiple myeloma cells were defined using in vitro models of tumor in the bone marrow (BM) microenvironment, as well as in human natural killer (NK)-reconstituted NOD/SCID gamma (NSG) mice bearing MM1S tumors. Results: MEDI2228 enriched IFN I signaling and enhanced expression of IFN-stimulated genes in multiple myeloma cell lines following the induction of DNA damage–ATM/ATR-CHK1/2 pathways. It activated cGAS-STING-TBK1-IRF3 and STAT1-IRF1–signaling cascades and increased CD38 expression in multiple myeloma cells but did not increase CD38 expression in BCMA-negative NK effector cells. It overcame CD38 downregulation on multiple myeloma cells triggered by IL6 and patient BM stromal cell-culture supernatant via activation of STAT1-IRF1, even in immunomodulatory drug (IMiD)- and bortezomib-resistant multiple myeloma cells. In vitro and in vivo upregulation of NKG2D ligands and CD38 in MEDI2228-treated multiple myeloma cells was further associated with synergistic daratumumab (Dara) CD38 MoAb-triggered NK-mediated cytotoxicity of both cell lines and autologous drug-resistant patient multiple myeloma cells. Conclusions: These results provide the basis for clinical evaluation of combination MEDI2228 with Dara to further improve patient outcome in multiple myeloma.

Background Efforts are required to improve potency and durability of CD38- and BCMA-based immunotherapies in human multiple myeloma (MM). Methods We here delineated the molecular and cellular mechanisms underlying novel immunomodulatory effects triggered by BCMA pyrrolobenzodiazepine (PBD) antibody drug conjugate MEDI2228 which may augment efficacy of these immunotherapies. RNA sequencing followed by gene set enrichment analysis showed that MEDI2228 significantly enriched IFN I-signaling and induced type I interferon (IFN I)-stimulated genes (ISGs) in MM cell lines. The most MEDI2228-enhanced IFN-driven genes include chemokines/cytokines and receptors (i.e., CXCL9/10, CCL4L1/2, CCL22, CCL1/3/4/5, CCL3L1/3, TNFSF9/10, CSF2 (GM-CSF), CCR7), RSAD2, CASP1, ISGs (i.e., XAF1, TRIMs, IFITs, ISG15, GBP2/3, OAS1/2/L, RNASEL, MX1/2, FAS), RUNX3, GZMB, IKBKE, IRF1/6/7/9, STAT1/2/4/6, MB21D1(CGAS), TMEM173 (STING), IFIT1/2/3/5, and SOCS1/2/3. Results Regardless of genetic heterogeneity and resistance to current anti-MM therapies, MEDI2228 induced dose- and time-dependent DNA damage-ATM/ATR-CHK1/2 pathways, activation of cGAS-STING-TBK1-IRF3 and STAT1-IRF1-signaling cascades, as well as increased CD38 expression. It overcame CD38 downregulation triggered by IL6 and bone marrow stromal cell culture supernatant (BMSC-sup), via activation of STAT1-IRF1 without phosphorylation of STAT3 in immunomodulatory drugs (IMiDs)- and bortezomib-resistant MM cell lines. In contrast, MEDI2228 did not change CD38 expression and survival in BCMA-negative NK effector cells. Significantly, MEDI2228 with anti-CD38 monoclonal antibody Daratumumab (Dara) synergistically induced NK-mediated lysis of MM cell lines and autologous resistant patient MM cells, even in the presence of BMSC-sup and BMSCs. In parallel, MEDI2228 increased membrane expression of NKG2D ligands (NKG2DLs), i.e., MICA/B and ULBPs, in all MM cells tested, including Dara-resistant patient cells, correlating with enhanced MM cell susceptibility to NK cell killing. Since MEDI2228, but not its MMAF-ADC homolog M3 even used at >1-log higher concentrations enhanced surface expression of CD38 and NKG2DLs on MM cells, the potent DDR-mediated immunomodulation triggered by MEDI2228 vs M3 is critical in rendering MM cells more susceptible to Dara-induced NK cell killing. Importantly, M2 still activated STAT1/IRF1 signaling to induce CD38 and MICA/B expression in MM tumors grown in mice. All MM1S tumor-bearing NSG mice reconsituted with human NK cells became tumor-free following a single low dose M2 with Dara treatment, with 100% host survival. Conclusions Taken together, our data showed that MEDI2228 restored MM sensitivity to CD38 targeting by Dara without depleting NK cells and potentiated immunogenic cell death of MM cells. These results therefore provide the mechanistic rationale for clinical evaluation of combination CD38- and BCMA-directed immunotherapies to further improve patient outcome in MM.

Blocking of MEK-ERK pathway overcomes myeloma cells resistance to immunomodulatory drugs in the bone marrow microenvironment., Immunomodulatory drugs (IMiDs) have markedly improved patient outcome in multiple myeloma (MM); however, resistance to IMiDs commonly underlies relapse of disease. Here, we identify that tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) knockdown (KD)/knockout (KO) in MM cells mediates IMiD resistance via activation of noncanonical nuclear factor κB (NF-κB) and extracellular signal–regulated kinase (ERK) signaling. Within MM bone marrow (BM) stromal cell supernatants, TNF-α induces proteasomal degradation of TRAF2, noncanonical NF-κB, and downstream ERK signaling in MM cells, whereas interleukin-6 directly triggers ERK activation. RNA sequencing of MM patient samples shows nearly universal ERK pathway activation at relapse on lenalidomide maintenance therapy, confirming its clinical relevance. Combination MEK inhibitor treatment restores IMiD sensitivity of TRAF2 KO cells both in vitro and in vivo. Our studies provide the framework for clinical trials of MEK inhibitors to overcome IMiD resistance in the BM microenvironment and improve patient outcome in MM.

As fluorescence in the second near-infrared window (NIR-II, 1000-1400 nm) could image deep tissue with high signal-to-noise ratios compared with that in NIR-I (750-900 nm), Ag