Erratum: CD31 promotes diffuse large B-cell lymphoma metastasis by upregulating OPN through the AKT pathway and inhibiting CD8+ T cells through the mTOR pathway.

[This corrects the article on p. 2656 in vol. 15, PMID: 37193155.].

CD31 promotes diffuse large B-cell lymphoma metastasis by upregulating OPN through the AKT pathway and inhibiting CD8+ T cells through the mTOR pathway.

OBJECTIVE: Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell non-Hodgkin's lymphoma. Invasive DLBCL cells are likely to metastasize into extranodal tissue (e.g., the central nervous system) that is difficult for chemotherapy drugs to penetrate, seriously affecting patient prognosis. The mechanism of DLBCL invasion remains unclear. This study investigated the association between invasiveness and platelet endothelial cell adhesion molecule-1 (CD31) in DLBCL. METHODS: This study consisted of 40 newly diagnosed DLBCL patients. Differentially expressed genes and pathways in invasive DLBCL cells were identified using real-time polymerase chain reaction, western blotting, immunofluorescence, and immunohistochemical staining, RNA sequencing, and animal experiments. The effect of CD31-overexpressing DLBCL cells on the interactions between endothelial cells was determined using scanning electron microscopy. The interactions between CD8+ T cells and DLBCL cells were examined using xenograft models and single-cell RNA sequencing. RESULTS: CD31 was upregulated in patients with multiple metastatic tumor foci compared to patients with a single tumor focus. CD31-overexpressing DLBCL cells formed more metastatic foci in mice and shortened mouse survival time. CD31 disrupted the tight junctions between endothelial cells of the blood-brain barrier by activating the osteopontin-epidermal growth factor receptor-tight junction protein 1/tight junction protein-2 axis through the protein kinase B (AKT) pathway, enabling DLBCL to enter the central nervous system to form central nervous system lymphoma. Furthermore, CD31-overexpressing DLBCL cells recruited CD31+ CD8+ T cells that failed to synthesize interferon-γ (INF-γ), tumor necrosis factor-α (TNF-α), and perforin via the activated mTOR pathway. Some target genes, such as those encoding S100 calcium-binding protein A4, macrophage-activating factor, and class I b-tubulin, may be used to treat this type of DLBCL surrounded by functionally suppressed CD31+ memory T cells. CONCLUSIONS: Our study suggests that DLBCL invasion is associated with CD31. The presence of CD31 in DLBCL lesions could represent a valuable target for treating central nervous system lymphoma and restoring CD8+ T-cell function.

Discovery of pyrimidine-5-carboxamide derivatives as novel salt-inducible kinases (SIKs) inhibitors for inflammatory bowel disease (IBD) treatment.

Salt-inducible kinases (SIKs) play a crucial role in inflammation process, acting as molecular switches that regulate the transformation of M1/M2 macrophages. HG-9-91-01 is a SIKs inhibitor with potent inhibitory activity against SIKs in the nanomolar range. However, its poor drug-like properties, including a rapid elimination rate, low in vivo exposure and high plasma protein binding rate, have hindered further research and clinical application. To improve the drug-like properties of HG-9-91-01, a series of pyrimidine-5-carboxamide derivatives were designed and synthesized through a molecular hybridization strategy. The most promising compound 8h was obtained with favorable activity and selectivity on SIK1/2, excellent metabolic stability in human liver microsome, enhanced in vivo exposure and suitable plasma protein binding rate. Mechanism research showed that compound 8h significantly up-regulated the expression of anti-inflammatory cytokine IL-10 and reduced the expression of pro-inflammatory cytokine IL-12 in bone marrow-derived macrophages. Furthermore, it significantly elevated expression of cAMP response element-binding protein (CREB) target genes IL-10, c-FOS and Nurr77. Compound 8h also induced the translocation of CREB-regulated transcriptional coactivator 3 (CRTC3) and elevated the expression of LIGHT, SPHK1 and Arginase 1. Additionally, compound 8h demonstrated excellent anti-inflammatory effects in a DSS-induced colitis model. Generally, this research indicated that compound 8h has the potential to be developed as an anti-inflammatory drug candidate.

A systematic review on performance analysis of critical time points in multiple myeloma treated by CAR-T cell immunotherapy.

BACKGROUND: Multiple myeloma (MM) is the second most common hematological malignancy without cure, and Chimeric Antigen Receptor T Cell (CAR-T) therapy has been shown great promising in MM. Unlike previous published studies mainly focusing on efficacy and safety, this study aims to summarize time points in the process of CAR-T therapy in MM and establish a standardized time-related CAR-T therapy platform to provide a reference for CAR-T treatment in MM. METHODS: All the literatures were retrieved from PubMed, Web of Science, Embase, American Society of Hematology (ASH), American Society of Clinical Oncology (ASCO) and European Hematology Association (EHA). Relevant median detection time of efficacy and safety-related indicators of CAR-T therapy in MM were extracted from included literatures, and median values were applied to represent detection time points of indicators. Notably, the median values were not the certain and optimal detection time points, while the significance is that indicators could be detected more frequently around the median values to obtain the ideal results. RESULTS: This review presented the median detection time points of efficacy and safety-related indicators of CAR-T therapy in MM according to the chronological order. For short-term effects on inflammation status within 1 month after CAR-T initiation, the median time points of cytokine release syndrome onset, immune effector cell-associated neurotoxicity syndrome onset, neutrophils recovery and CAR-T expansion peak were 4.5, 8, 10 and 12 days, respectively. For medium-term effects on clinical response in MM beyond 1 month and up to 3 months following CAR-T infusion, the median time points of minimal residual disease negativity, the reduction of serum light chain to minimum, platelet recovery and the reduction of M protein to minimum were 30, 30, 44 and 90 days, respectively. CONCLUSIONS: This systematic review summarized the median detection time points of efficacy and safety-related indicators of CAR-T therapy in MM and constructed the time-related CAR-T therapy platform, providing an evidence-based standard for establishment of CAR-T treatment regimen in MM.

HDAC I/IIb selective inhibitor Purinostat Mesylate combined with GLS1 inhibition effectively eliminates CML stem cells.

Purinostat Mesylate (PM) is a novel highly selective and active HDAC I/IIb inhibitor, and the injectable formulation of PM (PMF) based on the compound prescription containing cyclodextrin completely can overcome PM's poor solubility and improves its stability and pharmacokinetic properties. Here, we showed that PM effectively repressed the survival of Ph+ leukemia cells and CD34+ leukemia cells from CML patients in vitro. In vivo studies demonstrated that PMF significantly prevented BCR-ABL(T315I) induced CML progression by restraining leukemia stem cells (LSCs), which are insensitive to chemotherapy and responsible for CML relapse. Mechanism studies revealed that targeting HDAC I/IIb repressed several important factors for LSCs survival including c-Myc, ß-Catenin, E2f, Ezh2, Alox5, and mTOR, as well as interrupted some critical biologic processes. Additionally, PMF increased glutamate metabolism in LSCs by increasing GLS1. The combination of PMF and glutaminase inhibitor BPTES synergistically eradicated LSCs by altering multiple key proteins and signaling pathways which are critical for LSC survival and self-renewal. Overall, our findings represent a new therapeutic strategy for eliminating LSCs by targeting HDAC I/IIb and glutaminolysis, which potentially provides a guidance for PMF clinical trials in the future for TKI resistance CML patients.

Targeting glutaminase1 and synergizing with clinical drugs achieved more promising antitumor activity on multiple myeloma.

Multiple myeloma (MM) pathogenesis remains incompletely understood and biomarkers predicting treatment response still remain lacking. Here we describe the rational mechanisms of combining targeting glautaminase1 (GLS1) with other chemo-reagents for MM treatment. Gls1 is highly expressed cMYC/KRAS12V-drived plasmacytoma (PCT) cells. Down-regulation of Gls1 with miRNAi in cMYC/KRAS12V-expressing BaF3 cells prevented them from growing independence of interleukin 3 (IL3). By using our cMYC/KRAS12V-transduced adoptive plasmacytoma mouse model, we found that Gls1 is involved in PCT pathogenesis. Down-regulation of Gls1 significantly prolonged the survival of PCT recipients. Knockdown of Gls1 increased the expression of Cdkn1a and Cdkn1b and decreased the expression of some critical oncogenes for cancer cell survival, such as c-Myc, Cdk4, and NfκB, as well as some genes which are essential for MM cell survival, such as Irf4, Prdm1, Csnk1α1, and Rassf5. Combination of Gls1 inhibition with LBH589, Bortezomib, or Lenalidomide significantly impaired tumor growth in a MM xenograft mouse model. Our data strongly suggest that Gls1 plays an important role for MM pathogenesis and that combination of GLS1 inhibitor with other MM therapy agents could benefit to MM patients.

Purinostat Mesylate Is a Uniquely Potent and Selective Inhibitor of HDACs for the Treatment of BCR-ABL-Induced B-Cell Acute Lymphoblastic Leukemia.

PURPOSE: This study was to perform preclinical evaluation of a novel class I and IIb HDAC-selective inhibitor, purinostat mesylate, for the treatment of Ph+ B-cell acute lymphoblastic leukemia (B-ALL). EXPERIMENTAL DESIGN: Biochemical assays were used to test enzymatic activity inhibition of purinostat mesylate. Ph+ leukemic cell lines and patient cells were used to evaluate purinostat mesylate activity in vitro. BL-2 secondary transplantation Ph+ B-ALL mouse model was used to validate its efficacy, mechanism, and pharmacokinetics properties in vivo. BCR-ABL(T315I)-induced primary B-ALL mouse model and PDX mouse model derived from relapsed Ph+ B-ALL patient post TKI treatment were used to determine the antitumor effect of purinostat mesylate for refractory or relapsed Ph+ B-ALL. Long-term toxicity and hERG blockade assays were used to safety evaluation of purinostat mesylate. RESULTS: Purinostat mesylate, a class I and IIb HDAC highly selective inhibitor, exhibited robust antitumor activity in hematologic cancers. Purinostat mesylate at low nanomolar concentration induced apoptosis, and downregulated BCR-ABL and c-MYC expression in Ph+ leukemia cell lines and primary Ph+ B-ALL cells from relapsed patients. Purinostat mesylate efficiently attenuated Ph+ B-ALL progression and significantly prolonged the survival both in BL-2 secondary transplantation model with clinical patient symptoms of Ph+ B-ALL, BCR-ABL(T315I)-induced primary B-ALL mouse model, and PDX model derived from patients with relapsed Ph+ B-ALL post TKI treatment. In addition, purinostat mesylate possesses favorable pharmacokinetics and low toxicity properties. CONCLUSIONS: Purinostat mesylate provides a new therapeutic strategy for patients with Ph+ B-ALL, including those who relapse after TKI treatment.

SKLB-23bb, A HDAC6-Selective Inhibitor, Exhibits Superior and Broad-Spectrum Antitumor Activity via Additionally Targeting Microtubules.

Our previous study reported that SKLB-23bb, an orally bioavailable HDAC6-selective inhibitor, exhibited superior antitumor efficiency both in vitro and in vivo in comparison with ACY1215, a HDAC6-selective inhibitor recently in phase II clinical trial. This study focused on the mechanism related to the activity of SKLB-23bb. We discovered that despite having HDAC6-selective inhibition equal to ACY1215, SKLB-23bb showed cytotoxic effects against a panel of solid and hematologic tumor cell lines at the low submicromolar level. Interestingly, in contrast to the reported HDAC6-selective inhibitors, SKLB-23bb was more efficient against solid tumor cells. Utilizing HDAC6 stably knockout cell lines constructed by CRISPR-Cas9 gene editing, we illustrated that SKLB-23bb could remain cytotoxic independent of HDAC6 status. Investigation of the mechanism confirmed that SKLB-23bb exerted its cytotoxic activity by additionally targeting microtubules. SKLB-23bb could bind to the colchicine site in ß-tubulin and act as a microtubule polymerization inhibitor. Consistent with its microtubule-disrupting ability, SKLB-23bb also blocked tumor cell cycle at G2-M phase and triggered cellular apoptosis. In solid tumor xenografts, oral administration of SKLB-23bb efficiently inhibited tumor growth. These results suggested that SKLB-23bb was an orally bioavailable HDAC6 and microtubule dual targeting agent. The microtubule targeting profile enhanced the antitumor activity and expanded the antitumor spectrum of SKLB-23bb, thus breaking through the limitation of HDAC6 inhibitors. Mol Cancer Ther; 17(4); 763-75. ©2018 AACR.

A Revised Fibrinogen Cutoff Value in the Chinese Disseminated Intravascular Coagulation Scoring System May Provide a Better Prognostic Value for Hematological Malignancies.

To retrospectively validate the prognostic value of the latest Chinese disseminated intravascular coagulation (DIC) scoring system (CDSS) in hematological malignancies, 260 patients with confirmed hematological malignancies and suspected DIC in West China Hospital between 2011 and 2015 were included in this study. We evaluated via univariate and multivariate analyses the diagnostic biomarkers, and the cutoff levels used in the CDSS, except those for fibrinogen, were found to be valid. In subgroup analyses, the value of fibrinogen was found to be mainly unfit for the acute promyelocytic leukemia group. Forty-six patients (17.7%) had elevated fibrinogen levels (>4 g/L) and tended to have a poor prognosis, and thus we redetermined the cutoff value of fibrinogen (<1 g/L or >4 g/L was defined as abnormal). As a result, all of the markers used in the CDSS had prognostic value (including for the promyelocytic leukemia group); meanwhile, this modification also resulted in a larger area under the receiver operating characteristic curve compared to the CDSS and the International Society on Thrombosis and Haemostasis score. We believe that, with regard to prognosis prediction, this cutoff value modification for fibrinogen is preferable for DIC patients with a tendency toward severe hypofibrinogenemia. However, a multicenter, prospective study is needed to validate this possibility.

Development of Purine-Based Hydroxamic Acid Derivatives: Potent Histone Deacetylase Inhibitors with Marked in Vitro and in Vivo Antitumor Activities.

In the present study, a series of novel histone deacetylase (HDAC) inhibitors using the morpholinopurine as the capping group were designed and synthesized. Several compounds demonstrated significant HDAC inhibitory activities and antiproliferative effects against diverse human tumor cell lines. Among them, compound 10o was identified as a potent class I and class IIb HDAC inhibitor with good pharmaceutical profile and druglike properties. Western blot analysis further confirmed that 10o more effectively increased acetylated histone H3 than panobinostat (LBH-589) and vorinostat (SAHA) at the same concentration in vitro. In in vivo efficacy evaluations of HCT116, MV4-11, Ramos, and MM1S xenograft models, 10o showed higher efficacy than SAHA or LBH-589 without causing significant loss of body weight and toxicity. All the results indicated that 10o could be a suitable candidate for treatment of both solid and hematological cancer.

Discovery of Selective Histone Deacetylase 6 Inhibitors Using the Quinazoline as the Cap for the Treatment of Cancer.

Novel selective histone deacetylase 6 (HDAC6) inhibitors using the quinazoline as the cap were designed, synthesized, and evaluated for HDAC enzymatic assays. N-Hydroxy-4-(2-methoxy-5-(methyl(2-methylquinazolin-4-yl)amino)phenoxy)butanamide, 23bb, was the most potent selective inhibitor for HDAC6 with an IC50 of 17 nM and showed 25-fold and 200-fold selectivity relative to HDAC1 and HDAC8, respectively. In vitro, 23bb presented low nanomolar antiproliferative effects against panel of cancer cell lines. Western blot analysis further confirmed that 23bb increased acetylation level of α-tubulin in vitro. 23bb has a good pharmacokinetic profile with oral bioavailability of 47.0% in rats. In in vivo efficacy evaluations of colorectal HCT116, acute myelocytic leukemia MV4-11, and B cell lymphoma Romas xenografts, 23bb more effectively inhibited the tumor growth than SAHA even at a 4-fold reduced dose or ACY-1215 at the same dose. Our results indicated that 23bb is a potent oral anticancer candidate for selective HDAC6 inhibitor and deserves further investigation.