Genome-wide CRISPR screens identify CD48 defining susceptibility to NK cytotoxicity in peripheral T-cell lymphomas.

Adult T-cell leukemia/lymphoma (ATLL) is one of the aggressive peripheral T-cell neoplasms with a poor prognosis. Accumulating evidence demonstrates that escape from adaptive immunity is a hallmark of ATLL pathogenesis. However, the mechanisms by which ATLL cells evade natural killer (NK)-cell-mediated immunity have been poorly understood. Here we show that CD48 expression in ATLL cells determines the sensitivity for NK-cell-mediated cytotoxicity against ATLL cells. We performed unbiased genome-wide clustered regularly interspaced short palindromic repeat (CRISPR) screening using 2 ATLL-derived cell lines and discovered CD48 as one of the best-enriched genes whose knockout conferred resistance to YT1-NK cell line-mediated cytotoxicity. The ability of CD48-knockout ATLL cells to evade NK-cell effector function was confirmed using human primary NK cells with reduced interferon-γ (IFNγ) induction and degranulation. We found that primary ATLL cells had reduced CD48 expression along with disease progression. Furthermore, other subgroups among aggressive peripheral T-cell lymphomas (PTCLs) also expressed lower concentrations of CD48 than normal T cells, suggesting that CD48 is a key molecule in malignant T-cell evasion of NK-cell surveillance. Thus, this study demonstrates that CD48 expression is likely critical for malignant T-cell lymphoma cell regulation of NK-cell-mediated immunity and provides a rationale for future evaluation of CD48 as a molecular biomarker in NK-cell-associated immunotherapies.

Protective effect of the Impella on the left ventricular function after acute broad anterior wall ST elevation myocardial infarctions with cardiogenic shock: cardiovascular magnetic resonance imaging strain analysis.

BACKGROUND: The clinical efficacy of the Impella for high-risk percutaneous coronary intervention (PCI) and cardiogenic shock remains under debate. We thus sought to investigate the protective effects on the heart with the Impella's early use pre-PCI using cardiac magnetic resonance imaging (CMRI). METHODS: We retrospectively evaluated the difference in the subacute phase CMR imaging results (19 ± 9 days after admission) between patients undergoing an Impella (n = 7) or not (non-Impella group: n = 18 [12 intra-aortic balloon pumps (1 plus veno-arterial extracorporeal membrane oxygenation) and 6 no mechanical circulation systems]) in broad anterior ST-elevation myocardial infarction (STEMI) cases. A mechanical circulation system was implanted pre-PCI. RESULTS: No differences were found in the door-to-balloon time, peak creatine kinase, and hospital admission days between the Impella and non-Impella groups; however, the CMRI-derived left ventricular ejection fraction was significantly greater (45 ± 13% vs. 34 ± 7.6%, P = 0.034) and end-diastolic and systolic volumes smaller in the Impella group (149 ± 29 vs. 187 ± 41 mL, P = 0.006: 80 ± 29 vs. 121 ± 40 mL, P = 0.012). Although the global longitudinal peak strain did not differ, the global radial (GRS) and circumferential peak strain (GCS) were significantly higher in the IMPELLA than non-IMPELLA group. Greater systolic and diastolic strain rates (SRs) in the Impella than non-Impella group were observed in non-infarcted rather than infarcted areas. CONCLUSIONS: Early implantation of an Impella before PCIs for STEMIs sub-acutely prevented cardiac dysfunction through preserving the GRS, GCS, and systolic and diastolic SRs in the remote myocardium. This study provided mechanistic insight into understanding the usefulness of the Impella to prevent future heart failure.

Absence of coronary angioscopy-derived in-stent thrombi is associated with major bleeding events in acute myocardial infarction.

BACKGROUND AND AIMS: The optimal duration of dual antiplatelet therapy for acute myocardial infarction is controversial because the bleeding risk outweighs the thromboembolic risk. We hypothesized that an in-stent thrombus (IS-thrombus) detected by coronary angioscopy (CAS) after stent implantation would be associated with high bleeding risk. METHODS: This study included 208 patients who underwent CAS at 2 weeks after stent implantation for an acute myocardial infarction. The study was approved by the ethics committee at the Nihon University Itabashi Hospital (reference number RK-200714-10). RESULTS: In 84 patients, in whom no IS-thrombus was identified in the culprit vessel using CAS, the major bleeding event rate was significantly higher than that in patients with IS-thrombi (n = 124). However, no difference was detected in major adverse cardiovascular events (MACE; stroke, hospitalization for a non-fatal myocardial infarction/unstable angina, target lesion revascularization, and cardiovascular death). After adjustments by the propensity score based on patient characteristics, the absence of IS-thrombi remained an independent predictor of major bleeding events (hazard ratio 4.73, 95% confidence interval 2.04-11.00, p < 0.001). CONCLUSIONS: The absence of CAS-detected IS-thrombi in the subacute phase was independently associated with future major bleeding events, but not with MACE. These findings may help optimize the duration of dual antiplatelet therapy.

Anticoagulant therapy with dual antiplatelet for left ventricular thrombus following acute myocardial infarction.

Two men aged 71 and 62 years were admitted for ST elevation myocardial infarction and percutaneous coronary intervention was performed to the occlusion of left anterior descending artery. Echocardiogram showed an akinetic or a dyskinetic movement of left ventricular anterior wall with mural thrombus on admission in Case 1 and 10 days from admission in Case 2. A direct oral anticoagulant (DOAC) in addition to dual antiplatelet therapy (DAPT) in both patients was started successfully for the resolution of left ventricular thrombus 3 weeks after the initiation of DOAC in Case 1, and 2 weeks after the initiation of DOAC in Case 2. However, the dose of DOAC was decreased and aspirin was stopped in Case 1 with HAS-BLED score five due to colon polyp bleeding, and there was no bleeding complication in Case 2 with HAS-BLED score two during this triple therapy. The duration of triple therapy was 2 months in Case 1 and 6 months in Case 2, and of DOAC therapy was total 6 months in both cases. .

Novel Interleukin-6 Inducible Gene PDZ-Binding Kinase Promotes Tumor Growth of Multiple Myeloma Cells.

[Figure: see text] Multiple myeloma (MM) remains an intractable hematological malignancy, despite recent advances in anti-MM drugs. Here, we show that role of PDZ binding kinase (PBK) in MM tumor growth. We identified that interleukin-6 (IL-6) readily increases PBK expression. Kaplan-Meier analysis showed that the MM patients with higher expression of PBK have a significant shorter survival time compared with those with moderate/lower expression of PBK. Knockout of PBK dramatically suppressed in vivo tumor growth in MM cells, while genome editing of PBK changing from asparagine to serine substitution (rs3779620) slightly suppresses the tumor formation. Mechanistically, loss of PBK increased the number of apoptotic cells with concomitant decrease in the phosphorylation level of Stat3 as well as caspase activities. A novel PBK inhibitor OTS514 significantly decreased KMS-11-derived tumor growth. These findings highlight the novel oncogenic role of PBK in tumor growth of myeloma, and it might be a novel therapeutic target for the treatment of patients with MM.

ERO1α is a novel endogenous marker of hypoxia in human cancer cell lines.

BACKGROUND: Hypoxia is an important factor that contributes to tumour aggressiveness and correlates with poor prognosis and resistance to conventional therapy. Therefore, identifying hypoxic environments within tumours is extremely useful for understanding cancer biology and developing novel therapeutic strategies. Several studies have suggested that carbonic anhydrase 9 (CA9) is a reliable biomarker of hypoxia and a potential therapeutic target, while pimonidazole has been identified as an exogenous hypoxia marker. However, other studies have suggested that CA9 expression is not directly induced by hypoxia and it is not expressed in all types of tumours. Thus, in this study, we focused on endoplasmic reticulum disulphide oxidase 1α (ERO1α), a protein that localises in the endoplasmic reticulum and is involved in the formation of disulphide bonds in proteins, to determine whether it could serve as a potential tumour-hypoxia biomarker. METHODS: Using quantitative real-time polymerase chain reaction, we analysed the mRNA expression of ERO1α and CA9 in different normal and cancer cell lines. We also determined the protein expression levels of ERO1α and CA9 in these cell lines by western blotting. We then investigated the hypoxia-inducible ERO1α and CA9 expression and localisation in HCT116 and HeLa cells, which express low (CA9-low) and high (CA9-high) levels of CA9, respectively. A comparative analysis was performed using pimonidazole, an exogenous hypoxic marker, as a positive control. The expression and localisation of ERO1α and CA9 in tumour spheres during hypoxia were analysed by a tumour sphere formation assay. Finally, we used a mouse model to investigate the localisation of ERO1α and CA9 in tumour xenografts using several cell lines. RESULTS: We found that ERO1α expression increased under chronic hypoxia. Our results show that ERO1α was hypoxia-induced in all the tested cancer cell lines. Furthermore, in the comparative analysis using CA9 and pimonidazole, ERO1α had a similar localisation to pimonidazole in both CA9-low and CA9-high cell lines. CONCLUSION: ERO1α can serve as a novel endogenous chronic hypoxia marker that is more reliable than CA9 and can be used as a diagnostic biomarker and therapeutic target for cancer.

Hypoxia-inducible ERO1α promotes cancer progression through modulation of integrin-ß1 modification and signalling in HCT116 colorectal cancer cells.

Endoplasmic reticulum disulphide oxidase 1α (ERO1α) is an oxidase localized in the endoplasmic reticulum that plays a role in the formation of disulphide bonds of secreted and cell-surface proteins. We previously showed that ERO1α is overexpressed in various types of cancer and we further identified ERO1α expression as a novel factor related to poor prognosis in cancer. However, the biological functions of ERO1α in cancer remain unclear. Here, we investigated the cell biological roles of ERO1α in the human colon-cancer cell line HCT116. ERO1α knockout (KO) by using CRISPR/Cas9 resulted in decreased tumourigenicity in vivo and reduced cell proliferation only under hypoxia in vitro, which suggested that ERO1α promotes cancer progression specifically in a low-oxygen environment. Thus, we evaluated the function of ERO1α in cell proliferation under hypoxia, and found that under hypoxic conditions, ERO1α KO resulted in a contact-inhibited morphology and diminished motility of cells. We further showed that ERO1α KO induced a change in integrin-ß1 glycosylation and thus an attenuation of cell-surface integrin-ß1 expression, which resulted in the aforementioned phenotype. Our study has established a previously unrecognized link between ERO1α expression and integrin activation, and thus provides new evidence for the effectiveness of ERO1α-targeted therapy for colorectal carcinoma.

Endoplasmic reticulum oxidase 1α is critical for collagen secretion from and membrane type 1-matrix metalloproteinase levels in hepatic stellate cells.

Upon liver injury, excessive deposition of collagen from activated hepatic stellate cells (HSCs) is a leading cause of liver fibrosis. An understanding of the mechanism by which collagen biosynthesis is regulated in HSCs will provide important clues for practical anti-fibrotic therapy. Endoplasmic reticulum oxidase 1α (ERO1α) functions as an oxidative enzyme of protein disulfide isomerase, which forms intramolecular disulfide bonds of membrane and secreted proteins. However, the role of ERO1α in HSCs remains unclear. Here, we show that ERO1α is expressed and mainly localized in the endoplasmic reticulum in human HSCs. When HSCs were transfected with ERO1α siRNA or an ERO1α shRNA-expressing plasmid, expression of ERO1α was completely silenced. Silencing of ERO1α expression in HSCs markedly suppressed their proliferation but did not induce apoptosis, which was accompanied by impaired secretion of collagen type 1. Silencing of ERO1α expression induced impaired disulfide bond formation and inhibited autophagy via activation of the Akt/mammalian target of rapamycin signaling pathway, resulting in intracellular accumulation of collagen type 1 in HSCs. Furthermore, silencing of ERO1α expression also promoted proteasome-dependent degradation of membrane type 1-matrix metalloproteinase (MT1-MMP), which stimulates cell proliferation through cleavage of secreted collagens. The inhibition of HSC proliferation was reversed by treatment with MT1-MMP-cleaved collagen type 1. The results suggest that ERO1α plays a crucial role in HSC proliferation via posttranslational modification of collagen and MT1-MMP and, therefore, may be a suitable therapeutic target for managing liver fibrosis.

Spatiotemporal Regulation of Hsp90-Ligand Complex Leads to Immune Activation.

Although heat shock proteins (HSPs) primarily play a pivotal role in the maintenance of cellular homeostasis while reducing extracellular as well as intracellular stresses, their role in immunologically relevant scenarios, including activation of innate immunity as danger signals, antitumor immunity, and autoimmune diseases, is now gaining much attention. The most prominent feature of HSPs is that they function both in their own and as an HSP-ligand complex. We here show as a unique feature of extracellular HSPs that they target chaperoned molecules into a particular endosomal compartment of dendritic cells, thereby inducing innate and adaptive immune responses via spatiotemporal regulation.