Novel chimeric antigen receptor-expressing T cells targeting the malignant mesothelioma-specific antigen sialylated HEG1.

The selection of highly specific target antigens is critical for the development of clinically efficient and safe chimeric antigen receptors (CARs). In search of diagnostic marker for malignant mesothelioma (MM), we have established SKM9-2 monoclonal antibody (mAb) which recognizes a MM-specific molecule, sialylated Protein HEG homolog 1 (HEG1), with high specificity and sensitivity. In this study, to develop a novel therapeutic approach against MM, we generated SKM9-2 mAb-derived CARs that included the CD28 (SKM-28z) or 4-1BB (SKM-BBz) costimulatory domain. SKM-28z CAR-T cells showed continuous growth and enhanced Tim-3, LAG-3, and PD-1 expression in vitro, which might be induced by tonic signaling caused by self-activation; however, these phenotypes were not observed in SKM-BBz CAR-T cells. In addition, SKM-BBz CAR-T cells exhibited slightly stronger in vitro killing activity against MM cell lines than SKM-28z CAR-T cells. More importantly, only SKM-BBz CAR-T cells, but not SKM-28z CAR-T cells, significantly inhibited tumor growth in vivo in a MM cell line xenograft mouse model. Gene expression profiling and reporter assays revealed differential signaling pathway activation; in particular, SKM-BBz CAR-T cells exhibited enhanced NF-kB signaling and reduced NFAT activation. In addition, SKM-BBz CAR-T cells showed upregulation of early memory markers, such as TCF7 and CCR7, as well as downregulation of pro-apoptotic proteins, such as BAK1 and BID, which may be associated with phenotypical and functional differences between SKM-BBz and SKM-28z CAR-T cells. In conclusion, we developed novel SKM9-2-derived CAR-T cells with the 4-1BB costimulatory domain, which could provide a promising therapeutic approach against refractory MM.

Clinical roles of soluble PD-1 and PD-L1 in plasma of NSCLC patients treated with immune checkpoint inhibitors.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have significantly improved the prognosis of non-small cell lung cancer (NSCLC). However, only a limited proportion of patients can benefit from this therapy, and clinically useful predictive biomarkers remain to be elucidated. METHODS: Blood was collected from 189 patients with NSCLC before and six weeks after the initiation of ICI treatment (anti-PD-1 or anti-PD-L1 antibody). Soluble PD-1 (sPD-1) and PD-L1 (sPD-L1) in plasma before and after treatment were analyzed to evaluate their clinical significance. RESULTS: Cox regression analysis demonstrated that higher sPD-L1 levels before treatment significantly predicted unfavorable progression-free survival (PFS; HR 15.4, 95% CI 1.10-86.7, P = 0.009) and overall survival (OS; HR 11.4, 95% CI 1.19-52.3, P = 0.007) in NSCLC patients treated with ICI monotherapy (n = 122) but not in those treated with ICIs combined with chemotherapy (n = 67: P = 0.729 and P = 0.155, respectively). In addition, higher sPD-1 levels after treatment were significantly associated with better OS (HR 0.24, 95% CI 0.06-0.91, P = 0.037) in patients treated with anti-PD-1 monotherapy, whereas higher sPD-L1 levels after treatment were significantly associated with worse PFS (HR 6.09, 95% CI 1.42-21.0, P = 0.008) and OS (HR 42.6, 95% CI 6.83-226, P < 0.001). The levels of sPD-L1 at baseline closely correlated with those of other soluble factors, such as sCD30, IL-2Ra, sTNF-R1, and sTNF-R2, which are known to be released from the cell surface by zinc-binding proteases ADAM10/17. CONCLUSIONS: These findings suggest the clinical significance of pretreatment sPD-L1 as well as posttreatment sPD-1 and sPD-L1 in NSCLC patients treated with ICI monotherapy.

Circulating IL-6 and not its circulating signaling components sIL-6R and sgp130 demonstrate clinical significance in NSCLC patients treated with immune checkpoint inhibitors.

Introduction: Clinical roles of plasma IL-6 levels have been reported in patients with various cancers, including non-small cell lung cancer (NSCLC), treated with immune checkpoint inhibitors (ICIs). However, the roles of other IL-6 signaling components, soluble IL-6 receptor (sIL-6R) and soluble gp130 (sgp130), in the plasma have not been elucidated. Methods: Blood was collected from 106 patients with NSCLC before initiation of ICI treatment (anti-PD-1 or anti-PD-L1 antibody). Plasma levels of IL-6, sIL-6R, sgp130, and their complexes were assessed by Cox regression hazard model to evaluate their clinical significance. The clinical role of IL-6 or IL-6R genetic polymorphisms was also analyzed. Results: Cox regression analysis showed that higher plasma IL-6 levels significantly predicted unfavorable overall survival (OS; hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.05-1.68, p = 0.012) in NSCLC patients treated with ICIs. However, plasma sIL-6R and sgp130 levels showed no prognostic significance (p = 0.882 and p = 0.934, respectively). In addition, the estimated concentrations of binary IL-6:sIL-6R and ternary IL-6:sIL-6R:sgp130 complexes and their ratios (binary/ternary complex) were not significantly associated with OS (p = 0.647, p = 0.727, and p = 0.273, respectively). Furthermore, the genetic polymorphisms of IL-6 (-634G>C) and IL-6R (48892A>C) showed no clinical role by Kaplan-Meier survival analysis (p = 0.908 and p = 0.639, respectively). Discussion: These findings demonstrated the clinical significance of plasma levels of IL-6, but not of other IL-6 signaling components, sIL-6R and sgp130, suggesting that classical IL-6 signaling, but not trans-signaling, may be related to anti-tumor immune responses in cancer patients treated with ICIs.

BHLHA15-Positive Secretory Precursor Cells Can Give Rise to Tumors in Intestine and Colon in Mice.

BACKGROUND & AIMS: The intestinal epithelium is maintained by long-lived intestinal stem cells (ISCs) that reside near the crypt base. Above the ISC zone, there are short-lived progenitors that normally give rise to lineage-specific differentiated cell types but can dedifferentiate into ISCs in certain circumstances. However, the role of epithelial dedifferentiation in cancer development has not been fully elucidated. METHODS: We performed studies with Bhlha15-CreERT, Lgr5-DTR-GFP, Apcflox/flox, LSL-Notch (IC), and R26-reporter strains of mice. Some mice were given diphtheria toxin to ablate Lgr5-positive cells, were irradiated, or were given 5-fluorouracil, hydroxyurea, doxorubicin, or dextran sodium sulfate to induce intestinal or colonic tissue injury. In intestinal tissues, we analyzed the fate of progeny that expressed Bhlha15. We used microarrays and reverse-transcription PCR to analyze gene expression patterns in healthy and injured intestinal tissues and in tumors. We analyzed gene expression patterns in human colorectal tumors using The Cancer Genome Atlas data set. RESULTS: Bhlha15 identified Paneth cells and short-lived secretory precursors (including pre-Paneth label-retaining cells) located just above the ISC zone in the intestinal epithelium. Bhlha15+ cells had no plasticity after loss of Lgr5-positive cells or irradiation. However, Bhlha15+ secretory precursors started to supply the enterocyte lineage after doxorubicin-induced epithelial injury in a Notch-dependent manner. Sustained activation of Notch converts Bhlha15+ secretory precursors to long-lived enterocyte progenitors. Administration of doxorubicin and expression of an activated form of Notch resulted in a gene expression pattern associated with enterocyte progenitors, whereas only sustained activation of Notch altered gene expression patterns in Bhlha15+ precursors toward those of ISCs. Bhlha15+ enterocyte progenitors with sustained activation of Notch formed intestinal tumors with serrated features in mice with disruption of Apc. In the colon, Bhlha15 marked secretory precursors that became stem-like, cancer-initiating cells after dextran sodium sulfate-induced injury, via activation of Src and YAP signaling. In analyses of human colorectal tumors, we associated activation of Notch with chromosome instability-type tumors with serrated features in the left colon. CONCLUSIONS: In mice, we found that short-lived precursors can undergo permanent reprogramming by activation of Notch and YAP signaling. These cells could mediate tumor formation in addition to traditional ISCs.

Nicorandil prevents sirolimus-induced production of reactive oxygen species, endothelial dysfunction, and thrombus formation.

Sirolimus (SRL) is widely used to prevent restenosis after percutaneous coronary intervention. However, its beneficial effect is hampered by complications of thrombosis. Several studies imply that reactive oxygen species (ROS) play a critical role in endothelial dysfunction and thrombus formation. The present study investigated the protective effect of nicorandil (NIC), an anti-angina agent, on SRL-associated thrombosis. In human coronary artery endothelial cells (HCAECs), SRL stimulated ROS production, which was prevented by co-treatment with NIC. The preventive effect of NIC on ROS was abolished by 5-hydroxydecanoate but not by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one. NIC also inhibited SRL-induced up-regulation of NADPH oxidase subunit p22(phox) mRNA. Co-treatment with NIC and SRL significantly up-regulated superoxide dismutase 2. NIC treatment significantly improved SRL-induced decrease in viability of HCAECs. The functional relevance of the preventive effects of NIC on SRL-induced ROS production and impairment of endothelial viability was investigated in a mouse model of thrombosis. Pretreatment with NIC inhibited the SRL-induced acceleration of FeCl3-initiated thrombus formation and ROS production in the testicular arteries of mice. In conclusion, NIC prevented SRL-induced thrombus formation, presumably due to the reduction of ROS and to endothelial protection. The therapeutic efficacy of NIC could represent an additional option in the prevention of SRL-related thrombosis.

Nicorandil attenuates FeCl(3)-induced thrombus formation through the inhibition of reactive oxygen species production.

BACKGROUND: Although nicorandil has a number of beneficial cardiovascular actions, its effects on endothelial cells in the context of thrombosis have not been elucidated. METHODS AND RESULTS: Arterial thrombosis was induced by endothelial injury caused by FeCl(3) in the mouse testicular artery. Thrombus growth led to complete occlusion 12 min after endothelial injury in control mice. The antiplatelet agent, tirofiban, and nicorandil significantly slowed the growth of thrombi, resulting in arterial occlusion after 58 min and 55 min, respectively. In the absence of endothelial cells, nicorandil did not inhibit platelet aggregation. Diazoxide and high-dose isosorbide dinitrate both showed a similar effect to that of nicorandil. The beneficial effect of nicorandil was prevented by 5-hydroxydecanoate, but not by L-NAME. The production of reactive oxygen species by FeCl(3) treatment was measured with the specific fluorescent probe, dihydrorhodamine 123. After FeCl(3) treatment, nicorandil significantly inhibited the increase in fluorescence. In further experiments, incubation of human umbilical vein endothelial cells with nicorandil did not change the endothelial nitric oxide synthase (eNOS) mRNA levels, eNOS phosphorylation or nitrite production. CONCLUSIONS: Nicorandil attenuates FeCl(3)-induced thrombus formation in the mouse testicular artery, which suggests that it may inhibit the generation of reactive oxygen species by FeCl(3)-treated endothelial cells through activation of the mitochondrial ATP-sensitive potassium channels.

Na+/H+ exchanger inhibitor cariporide attenuates the mitochondrial Ca2+ overload and PTP opening.

The Na(+)/H(+) exchanger (NHE) inhibitor cariporide has a cardioprotective effect in various animal models of myocardial ischemia-reperfusion. Recent studies have suggested that cariporide interacts with mitochondrial Ca(2+) overload and the mitochondrial permeability transition (MPT); however, the precise mechanisms remain unclear. Therefore, we examined whether cariporide affects mitochondrial Ca(2+) overload and MPT. Isolated adult rat ventricular myocytes were used to study the effects of cariporide on hypercontracture induced by ouabain or phenylarsine oxide (PAO). Mitochondrial Ca(2+) concentration ([Ca(2+)](m)) and the mitochondrial membrane potential (DeltaPsi(m)) were measured by loading myocytes with rhod-2 and JC-1, respectively. We also examined the effect of cariporide on the MPT using tetramethylrhodamine methyl ester (TMRM) and oxidative stress generated by laser illumination. Cariporide (1 microM) prevented ouabain-induced hypercontracture (from 40 +/- 2 to 24 +/- 2%, P < 0.05) and significantly attenuated ouabain-induced [Ca(2+)](m) overload (from 149 +/- 6 to 121 +/- 5% of the baseline value, P < 0.05) but did not affect DeltaPsi(m). These results indicate that cariporide attenuates the [Ca(2+)](m) overload without the accompanying depolarization of DeltaPsi(m). Moreover, cariporide increased the time taken to induce the MPT (from 79 +/- 11 to 137 +/- 20 s, P < 0.05) and also attenuated PAO-induced hypercontracture (from 59 +/- 3 to 50 +/- 4%, P < 0.05). Our data indicate that cariporide attenuates [Ca(2+)](m) overload and MPT. Thus these effects might potentially contribute to the mechanisms of cardioprotection afforded by NHE inhibitors.

Direct nitric oxide release from nipradilol in human coronary arterial smooth muscle cells observed with fluorescent NO probe and NO-electrode.

BACKGROUND:: Nipradilol (3,4-dihydro-8-[2-hydroxy-3-isopropyl-amino]propoxy-3-nitroxy-2-H-1-benzopyran), a potent non-selective beta-adrenoceptor antagonist, has been shown to increase NO production. The mechanisms are up-regulation of nitric oxide synthase (NOS) and direct release of NO from nipradilol. The process of direct NO release from nipradilol requires a reductase, such as glutathione S-transferase (GST) in some cells but non-enzymatic NO release was reported in pig coronary arteries. Direct NO release from nipradilol in human coronary arteries has not been examined yet, though this information is of importance. PURPOSE:: To demonstrate direct NO release from nipradilol in human coronary arterial smooth muscle cells (HCASMC) by using a fluorescent NO probe (DAF-2) and an NO-electrode. METHODS AND RESULTS:: HCASMC were loaded with DAF-2 and images of fluorescence (515nm) were obtained under excitation at 488nm through an intensified CCD with an inverted phase-contrast microscope. Concomitantly, NO was measured using an NO-electrode (0.2mm o.d.; 501, Inter Medical Co. Ltd., Nagoya, Japan) after addition of various concentrations of nipradilol (1, 5 or 10microM) with or without ethacrynic acid (GST inhibitor). The cells showed no fluorescence at baseline, but intense fluorescence appeared at 30min after addition of 10microM nipradilol. The intensities of fluorescence at 30min in the control, nipradilol and nipradilol with ethacrynic acid groups were 98 +/- 6, 163 +/- 10 and 128 +/- 6% of the baseline level, respectively. Ethacrynic acid itself did not affect the fluorescence. Continuous measurements of NO by the electrode showed the NO generation peaked at about 30min, remained at the same level till about 45min and then gradually declined. Nipradilol did not produce NO at all in the absence of cells. The dose-dependency study of NO release from nipradilol showed 45 +/- 12, 72 +/- 24 and 157 +/- 23nM, respectively, at 1, 5 and 10microM nipradilol. All experiments were performed under conditions where endogenous formation of NO was inhibited by an NOS inhibitor (10(-4)M N(G)-monomethyl-l-arginine (l-NMMA)). CONCLUSION:: Nipradilol can release NO in the presence of human coronary arterial smooth muscle cells and the denitration reaction catalyzed by a reductase such as glutathione S-transferase contributes substantially to NO release from nipradilol.

Nicorandil attenuates the mitochondrial Ca2+ overload with accompanying depolarization of the mitochondrial membrane in the heart.

The anti-anginal drug nicorandil has been demonstrated to protect the myocardium against ischemic injury in both experimental and clinical studies. Although nicorandil seems to protect the myocardium via activation of mitochondrial ATP-sensitive K+ (mitoKATP) channels, the mechanisms underlying its cardioprotection have remained elusive. We therefore examined whether nicorandil depolarizes the mitochondrial membrane and attenuates the mitochondrial Ca2+ overload. With the use of a Nipkow confocal system, the mitochondrial Ca2+ concentration ([Ca2+]m) and the mitochondrial membrane potential (DeltaPsim) in rat ventricular myocytes were measured by loading cells with rhod-2 and JC-1 respectively. The number of cell hypercontractures resulting from mitochondrial Ca2+ overload was counted. Exposing cells to ouabain (1 mM) evoked mitochondrial Ca2+ overload and increased the intensity of rhod-2 fluorescence to 180+/-15% of baseline ( p<0.001). Nicorandil (100 microM) significantly attenuated the ouabain-induced mitochondrial Ca2+ overload (129+/-4% of baseline; p<0.001 vs. ouabain). Nicorandil decreased the DeltaPsim during application of ouabain, thereby reducing the intensity of JC-1 fluorescence to 89+/-2% of baseline ( p<0.05). Exposure of myocytes to ouabain eventually resulted in cell hypercontracture (51+/-2%). This ouabain-induced cell hypercontracture was blunted by application of nicorandil (37+/-2%, p<0.05 vs. ouabain). Moreover, these effects of nicorandil were abolished by 5-hydroxydecanoate (500 microM), a putative mitoKATP channel blocker, and by glibenclamide (10 microM), a nonselective KATP channel blocker. Our results suggest that nicorandil attenuates the matrix Ca2+ overload with accompanying depolarization of the mitochondrial membrane. Such effect might potentially be attributed to the mechanism of cardioprotection afforded by nicorandil.