Discordancy and changes in the pattern of programmed death ligand 1 expression before and after platinum-based chemotherapy in metastatic gastric cancer.

BACKGROUND: Our goal was to evaluate changes in PD-L1 expression in primary tumours of metastatic gastric cancer before and after chemotherapy. METHODS: We evaluated the PD-L1 expression of 72 patients with primary gastric cancer, before and after palliative first-line platinum-based chemotherapy, between January 2015 and March 2017. The PD-L1 ratio was defined as pre-chemotherapy PD-L1 expression divided by the post-chemotherapy PD-L1 expression. RESULTS: In 30 patients with PD-L1 negative pre-chemotherapy, 12 (40%) were positive post-chemotherapy; among the 42 patients with PD-L1 positive pre-chemotherapy, 24 (57.1%) were negative post-chemotherapy. The degree of PD-L1 expression decreased from 58.3% before chemotherapy to 41.7% after chemotherapy (P = 0.046). Among patients with complete response/partial response (CR/PR), the degree of PD-L1 expression decreased (P = 0.002), as well as PD-L1 positivity with statistical significance (P = 0.013) after chemotherapy, but not among patients with stable disease/progressive disease (SD/PD). Higher disease control rates (CR/PR/SD) were observed in patients with an elevated PD-L1 ratio (P = 0.043). Patients with a high PD-L1 ratio (> 1) were found to be associated with a better progression-free survival (HR 0.34, 95% CI 0.17-0.67, P = 0.002). CONCLUSIONS: PD-L1 expression can change during chemotherapy. Moreover, changes in patterns of PD-L1 expression might be associated with patient prognosis and response to chemotherapy.

Prognostic value of Dickkopf-1 and ß-catenin expression in advanced gastric cancer.

BACKGROUND: Dickkopf-1 (DKK1) is a Wnt/ß-catenin pathway antagonist related to gastric cancer (GC) carcinogenesis. However, the prognostic role of combined DKK1 and ß-catenin expression in advanced GC (AGC) is not clear. METHODS: In total, 158 patients with AGC who underwent gastric resection were enrolled in this study. DKK1 and ß-catenin expression was evaluated in whole tumor sections by immunohistochemistry. RESULTS: DKK1 expression was high in 73 (46.2%) patients, while ß-catenin expression was positive in 51 (32.3%) patients. The expression of DKK1 was positively correlated with that of ß-catenin (P < 0.001). The combined expression of DKK1 and ß-catenin was significantly associated with high N stage (N2 and N3) (P = 0.042). In addition, patients with high DKK expression demonstrated poorer overall (OS) (P < 0.001) and disease-free survival (DFS) (P = 0.001). However, there were no differences between high DKK1 expression with ß-catenin positivity and high DKK1 expression with ß-catenin negativity (OS, P = 0.379: DFS, P = 0.255). Multivariate analysis revealed that high DKK1 alone or high DKK1 with ß-catenin positivity were independent prognostic factors for both OS (high DKK1: hazard ratio [HR], 2.130; 95% confidence interval [CI]; 1.370-3.312, P = 0.001; high DKK1 with ß-catenin positivity: HR, 2.140; 95% CI, 1.343-3.409: P = 0.001) and DFS (high DKK1: HR, 2.092; 95% CI, 1.180-3.708; P = 0.012; high DKK1 with ß-catenin positivity: HR, 2.357; 95% CI, 1.291-4.306; P = 0.005). CONCLUSION: Our results indicate that high DKK1 expression regardless of ß-catenin positivity is a crucial prognostic factor for predicting tumor recurrence and survival in patients with resected AGC.

Early Increase in Circulating PD-1+CD8+ T Cells Predicts Favorable Survival in Patients with Advanced Gastric Cancer Receiving Chemotherapy.

The clinical significance of PD-1 expression in circulating CD8+ T cells in patients with gastric cancer (GC) receiving chemotherapy remains unelucidated. Therefore, we aimed to examine its prognostic significance in blood samples of 68 patients with advanced GC who received platinum-based chemotherapy. The correlation between peripheral blood mononuclear cells, measured using fluorescence-activated cell sorting, was evaluated. Patients were divided into two groups according to the changes in PD-1+CD8+ T-cell frequencies between day 0 and 7. They were categorized as increased or decreased PD-1+CD8+ T-cell groups. The increased PD-1+CD8+ T-cell group showed longer progression-free survival (PFS) and overall survival (OS) than the decreased PD-1+CD8+ T-cell group (PFS: 8.7 months vs. 6.1 months, p = 0.007; OS: 20.7 months vs. 10.8 months, p = 0.003). The mean duration of response was significantly different between the groups (5.7 months vs. 2.5 months, p = 0.041). Multivariate analysis revealed that an increase in PD-1+CD8+ T-cell frequency was an independent prognostic factor. We concluded that the early increase in PD-1+CD8+ T-cell frequency is a potential predictor of favorable prognoses and durable responses in patients with advanced GC receiving chemotherapy.

Prognostic value of soluble PD-L1 and exosomal PD-L1 in advanced gastric cancer patients receiving systemic chemotherapy.

The prognostic role of soluble PD-L1 (sPD-L1) and exosomal PD-L1 (exoPD-L1) in patients with gastric cancer (GC) receiving systemic chemotherapy remains unelucidated. Thus, we examined their prognostic significance in patients with advanced GC. Blood samples were obtained from 99 patients with advanced GC receiving first-line chemotherapy. Serum-derived exosomes were isolated by centrifugation and polymer precipitation. The correlation between serum-derived exoPD-L1, plasma sPD-L1, immune-related markers, and circulating immune cells was evaluated. Patients were divided into two groups according to pretreatment sPD-L1 and exoPD-L1 levels: low sPD-L1 and high sPD-L1 groups, low exoPD-L1 and high exoPD-L1 groups. Patients with low sPD-L1 level before treatment (< 9.32 pg/mL) showed significantly better overall survival (OS) and progression-free survival (PFS) than those with high sPD-L1 level (≥ 9.32 pg/mL). The low exoPD-L1 group (< 10.21 pg/mL) showed a tendency of longer PFS than the high exoPD-L1 group (≥ 10.21 pg/mL). Pretreatment sPD-L1 was an independent prognostic factor for OS in multivariate analysis. exoPD-L1 was associated with systemic inflammation markers, immunomodulatory cytokines, and T cells, while sPD-L1 was associated with tumor markers. Pretreatment plasma-derived sPD-L1 level could be used as a prognostic marker for patients receiving cytotoxic chemotherapy. Serum-derived exoPD-L1 may reflect the immunosuppressive state of patients with advanced GC.

EGFR-Tyrosine Kinase Inhibitors Induced Activation of the Autocrine CXCL10/CXCR3 Pathway through Crosstalk between the Tumor and the Microenvironment in EGFR-Mutant Lung Cancer.

CXCL10 is a cytokine that is elevated during EGFR-TKI treatment in the tumor microenvironment of lung cancer. Here, we report an original study that the impact of the CXCL10/CXCR3 pathway on EGFR-TKI resistance in EGFR-mutant lung cancer through a cytokine array analysis during in vitro coculture with tumor cells and activated PBMCs treated with EGFR-TKI, as well as the serial analysis of CXCL10 in EGFR-mutant lung cancer transgenic mice during EGFR-TKI treatment. In EGFR-mutant tumor cells cocultured with activated PBMCs, EGFR-TKI treatment increased CXCL10 in the supernatant; this activated CXCR3 in the tumor cells to induce the phosphorylation of Src and the NF-κB subunit, p65, and the expression of HIF-1α. CXCL10 siRNA treatment of EGFR-mutant tumor cells also decreased CXCL10 in the supernatant from coculturing with activated PBMCs, suggesting that the effects of CXCL10 occur via autocrine and paracrine pathways. Importantly, elevated CXCL10/CXCR3 signaling was recapitulated in a transgenic lung cancer mouse model. Our results show that increased CXCL10 levels during early EGFR-TKI treatment stimulate oncogenic signaling of persistent tumor cells to contribute to EGFR-TKI resistance via autocrine and paracrine pathways.

Prognostic Impact of APOBEC3B Expression in Metastatic Urothelial Carcinoma and Its Association with Tumor-Infiltrating Cytotoxic T Cells.

APOBEC3B enzymes are endogenous carcinogenic mutagens. Metastatic urothelial carcinomas often harbor APOBEC3B-mediated mutations in which tCw to T or G substitution occurs. Here, we evaluated patient survival and CD8+ T-cell density according to APOBEC3B expression in patients with metastatic urothelial carcinoma who underwent cytotoxic chemotherapy. We performed a retrospective study on 94 patients with urothelial carcinoma who were treated with first line palliative chemotherapy. APOBEC3B expression and CD8+/CD3+ ratio of tumor-infiltrating lymphocytes were evaluated using immunohistochemistry. Kaplan-Meier survival curves were generated and the log-rank test was employed. The association between APOBEC3B expression and tumor-infiltrating lymphocytes was analyzed using Pearson's chi-squared test. High APOBEC3B expression was detected in 71 of the 94 patients (75.5%). The median overall survival was longer in patients with high APOBEC3B expression (15 months) than in those with low expression (p = 0.045). The hazard ratio obtained based on the Cox regression analysis was 0.292 (95% confidence interval 0.118-0.723, p = 0.008). APOBEC3B expression was associated with the CD8+/CD3+ ratio (2.914, 95% confidence interval 1.030-8.249, p = 0.039). Collectively, APOBEC3B expression was an independent prognostic factor in patients with metastatic urothelial carcinoma treated with platinum-based chemotherapy. Tumor-infiltrating cytotoxic T cells were associated with APOBEC3B expression.

A Standardized Lindera obtusiloba Extract Improves Endothelial Dysfunction and Attenuates Plaque Development in Hyperlipidemic ApoE-Knockout Mice.

Lindera obtusiloba extract (LOE), a traditional herbal medicine used to enhance blood circulation and to reduce inflammation, induced NO-mediated endothelium-dependent relaxation, and reduced the formation of reactive oxygen species (ROS). The study investigated whether LOE improves endothelial dysfunction and reduces plaque inflammation and progression by inhibiting ROS generation in a mouse model of atherosclerosis. Eight-week-old apolipoprotein E-deficient (apoE-/-) mice fed with a western diet (WD) were randomized into different groups by administering vehicle (0.5% carboxymethylcellulose (CMC)), LOE (100 mg/kg/day), or losartan (30 mg/kg/day) by gavage until the age of 28 weeks. Fourteen male C57BL/6 mice that were fed normal chow and treated with CMC were used as negative controls. Similar to losartan treatment, LOE treatment induced the concentration-dependent relaxation of aorta rings in WD-fed apoE-/- mice. LOE treatment significantly reduced the vascular ROS formation and expression of NADPH oxidase subunits, including p22phox and p47phox. Compared with WD-fed apoE-/- mice, mice exposed to chronic LOE treatment exhibited reductions in plaque inflammation-related fluorescence signals and atherosclerotic lesions. These effects were greater than those of losartan treatment. In conclusion, LOE treatment improves endothelial dysfunction and reduces plaque inflammation as well as lesion areas by reducing vascular NADPH oxidase-induced ROS generation in a mouse model of atherosclerosis.

Prognostic implications of stromal hyaluronic acid protein expression in resected oropharyngeal and oral cavity cancers.

BACKGROUND/AIMS: Hyaluronic acid (HA) regulates cell adhesion, migration and proliferation in various cancers. The clinical implications of HA in resected head and neck squamous cell carcinoma have not been elucidated. We investigated the clinical significance and prognostic value of the expression of tumoral and stromal HA and its related proteins in oropharyngeal and oral cavity cancer. METHODS: Resected tissues from oropharyngeal or oral cavity cancer patients undergoing surgery were analysed in tissue microarrays divided into stroma and cancer panels. The expression levels of HA, HA synthases and hyaluronidases were also assessed by immunohistochemistry. RESULTS: A total of 160 resected oropharyngeal or oral cavity cancer tissues were analysed. Stromal HA expression was observed more frequently in human papilloma virus (HPV)-negative tumors, but other clinicopathological characteristics did not differ. In patients with HPV-negative oral cavity cancers, high stromal HA expression was associated with significantly shorter recurrence-free survival and overall survival compared with low stromal HA expression. The expression of HA in both tumors and stroma was significantly correlated with poorer outcomes than other combinations in patients with HPV-negative oral cavity cancers. However, these prognostic roles of HA were not observed in patients with HPV-negative oropharyngeal cancers. In the HPV-stratified multivariate analysis, high stromal HA expression remained an independent indicator of poor prognosis in terms of recurrence-free survival. CONCLUSION: High stromal HA and expression of HA in both tumors and stroma were correlated with poor prognosis in HPV-negative oral cavity cancer, but not in HPV-negative oropharyngeal cancers.

Prognostic Value of Metastatic Tumoral Caveolin-1 Expression in Patients with Resected Gastric Cancer.

OBJECTIVE: Caveolin-1 (Cav-1), as the main component of caveolae, has complex roles in tumourigenesis in human malignancies. We investigated Cav-1 in primary and metastatic tumor cells of gastric cancer (GC) and its association with clinical outcomes. METHODS: We retrieved 145 cases of GC who had undergone curative gastrectomy. The expression levels of Cav-1 was evaluated by immunohistochemistry, and its association with clinicopathological parameters and patient survival was analyzed. RESULTS: High expression of Cav-1 protein of the GC in the stomach and metastatic lymph node was 12.4% (18/145) and 16.5% (15/91). In the multivariate analysis, tumoral Cav-1 protein in metastatic lymph node showed prognostic significance for relapse-free survival (RFS, HR, 3.934; 95% CI, 1.882-8.224; P = 0.001) and cancer-specific survival outcome (CSS, HR, 2.681; 95% CI, 1.613-8.623; P = 0.002). Among the GCs with metastatic lymph node, it remained as a strong indicator of poor prognosis for RFS (HR, 3.136; 95% CI, 1.444-6.810; P = 0.004) and CSS (HR, 2.509; 95% CI, 1.078-5.837; P = 0.032). CONCLUSION: High expression of tumoral Cav-1 protein in metastatic lymph node is associated with unfavorable prognosis of curative resected GC, indicating the potential of novel prognostic markers.

Changes in PD-L1 expression according to tumor infiltrating lymphocytes of acquired EGFR-TKI resistant EGFR-mutant non-small-cell lung cancer.

BACKGROUNDS: EGFR-mutant non-small cell lung cancer (NSCLC) that developed acquired resistance to EGFR-tyrosine kinase (TKI) are potential candidates for programmed death 1 (PD1) inhibitor. RESULTS: TPS≥1% for PD-L1 and low CD8 + TIL in post-TKI tumor showed a trend for a lower PFS of EGFR-TKIs (14.2 vs 9.9 months; P = 0.060) (cohort A). Only 2 of 22 specimens (9.1%) with an acquired EGFR exon 20 T790M mutation exhibited in post-TKI TPS≥50% for PD-L1. The degree in post-TKI tumor of PD-L1 expression was varied in 19 patients (40.5%), with 10 (21.2%) showing higher levels in the resistant biopsy (cohort B). Among the post-TKI high TPS groups, median PFS with low post- TKI CD8 + TIL scores treated with EGFR-TKIs (6.6 months) was significantly lower than that for the other patients (14.2 months; P = 0.015). CONCLUSIONS: The change of PD-L1 expression was accompanied by dynamic change in CD8 + TILs and might reflect diverse mechanism of resistance to EGFR-TKI therapy. MATERIAL AND METHODS: We identified 69 patients (cohort A) with sufficient post-TKI tumor tissues and 47 patients (cohort B) with paired tumor tissues available. TPS for PD-L1 expression of tumor cells and CD8 + TILs score in tumor specimens were determined by immunohistochemistry.

Effects of candesartan cilexetil and amlodipine orotate on receptor for advanced glycation end products expression in the aortic wall of Otsuka Long-Evans Tokushima Fatty (OETFF) type 2 diabetic rats.

The receptor for advanced glycation end products (RAGE) plays a key role in the development of vascular inflammation and acceleration of atherosclerosis in type 2 diabetes. We investigated the effect of candesartan cilexetil (CDRT) and amlodipine orotate (AMDP) on the expression of RAGE in the aortic walls of Otsuka Long-Evans Tokushima Fatty (OLETF) rats and AGE-treated endothelial cells. Twenty five-week-old OLETF rats were randomized to 8 week treatments consisting of CDRT (n = 8), AMDP (n = 8) or saline (control, n = 8). Immunohistochemical and dihydroethidine staining revealed reduced RAGE and reactive oxygen species (ROS) signals in rats treated with CDRT or AMDP compared with control rats. Both CDRT and AMDP suppressed the expression of p22phox and p47phox NADPH oxidase subunits. However, only CDRT significantly reduced expression of phosphorylated extracellular signal regulated kinase (pERK)1/2 in the aortic wall of OLETF rats. In addition, both drugs reduced RAGE expression and total and mitochondrial ROS production in the AGE-treated endothelial cells. Both ARBs and CCBs reduced RAGE expression in the aortic walls of OLETF rats, which was attributed to decreased ROS production through inhibition of NADPH oxidase. In addition, only CDRT reduced aortic expression of RAGE via suppression of the ERK1/2 pathway unlike AMDP.

Imatinib mesylate attenuates myocardial remodeling through inhibition of platelet-derived growth factor and transforming growth factor activation in a rat model of hypertension.

Imatinib mesylate is a specific tyrosine kinase inhibitor that may block the platelet-derived growth factor and transforming growth factor pathways. These pathways are known to provoke fibroblast activation. We evaluated whether imatinib, by inhibiting these pathways, prevents diastolic dysfunction and attenuates myocardial remodeling using spontaneously hypertensive rats (SHRs). Eight-week-old male SHRs were randomly assigned to either imatinib treatment group (30 mg/kg per day; n=10; SHR-I) or hypertensive control group (distilled water, n=10; SHR-C). Wistar-Kyoto rats were used as normal controls (n=10). At 16 weeks, all rats underwent hemodynamic studies and Doppler echocardiography and then were euthanized. Their hearts were extracted for histopathologic, immunoblotting, and quantitative reverse transcriptase polymerase chain reaction analyses. Although imatinib did not affect blood pressure, it markedly reduced perivascular and interstitial fibrosis in the hearts of SHR. Echocardiogram showed that imatinib significantly reduced the left ventricular wall thickness (septal/posterior wall; SHR-C versus SHR-I, 18±1/19±2 versus 15±1/15±1 mm; P<0.001) and increased the E/A ratio (SHR-C versus SHR-I, 1.59±0.11 versus 1.84±0.16; P=0.001). Also, imatinib significantly reduced the mRNA expression of collagen type I, III, and platelet-derived growth factor receptor-ß phosphorylation in the hearts of SHR. In addition, imatinib reduced collagen production by inhibiting the phosphorylation of c-abl and platelet-derived growth factor receptor-ß in rat cardiac fibroblasts. In conclusion, these results suggest that imatinib could attenuate myocardial remodeling and improve left ventricular diastolic dysfunction in a hypertensive rat model by affecting platelet-derived growth factor and transforming growth factor-ß1 pathway without the blood pressure-lowering effect.

Decaffeinated green tea extract improves hypertension and insulin resistance in a rat model of metabolic syndrome.

BACKGROUND: Oxidative stress and endothelial dysfunction are closely associated with hypertension and insulin resistance (IR) in metabolic syndrome (MetS). It is still controversial whether green tea extract (GTE) may have blood pressure (BP) lowering effect. Decaffeinated GTE might be presumed to have strong antioxidative effect and BP-lowering effect as compared with catechins. Thus we investigated whether decaffeinated-GTE could attenuate hypertension and IR by improving endothelial dysfunction and reducing oxidative stress in a rat model of MetS. METHODS AND RESULTS: 20 Otsuka Long-Evans Tokushima Fatty (OLETF) rats at 13 weeks old, MetS rats, were randomized into a saline treated group (OLETF; n = 10) and a group treated with decaffeinated-GTE (25 mg/kg/day) (GTE-OLETF; n = 10). Intraperitoneal glucose tolerance tests and BP measurements were performed at 13 and 25 weeks. Decaffeinated-GTE significantly reduced BP (OLETF vs. GTE-OLETF; 130 ± 7 vs. 121 ± 3 mmHg, p = 0.01), fasting/postprandial 2 h glucose (141 ± 18/159 ± 13 vs. 115 ± 7/132 ± 16 mg/dL, p = 0.009/0.002) and insulin levels (4.8 ± 2.3 vs. 2.4 ± 1.3 ng/mL, p < 0.001). Decaffeinated-GTE significantly reduced vascular reactive oxygen species (ROS) formation and NADPH oxidase activity, and improved endothelium dependent relaxation in the thoracic aorta of OLETF rats. Decaffeinated-GTE also suppressed the expression of p47 and p22phox (NADPH oxidase subunits) in the immunohistochemical staining, and stimulated phosphorylation of endothelial nitric oxide synthase (eNOS) and Akt in the immunoblotting of aortas. CONCLUSIONS: Decaffeinated-GTE reduced the formation of ROS and NADPH oxidase activity and stimulated phosphorylation of eNOS and Akt in the aorta of a rat model of MetS, which resulted in improved endothelial dysfunction and IR, and eventually lowered BP.