Programmed death‐ligand 1 (PD‐L1) plays a crucial role in the host immune system in cancer progression. The gene promoter region of PD‐L1 also contains a binding site for ZEB1, a transcription factor ...related to epithelial‐mesenchymal transition (EMT). The purpose of this study was to clarify the relationship between PD‐L1 and EMT and its clinical importance in esophageal squamous cell carcinoma (ESCC). PD‐L1 and ZEB1 expression at the tumor invasive front was examined by immunohistochemistry in resected specimens from 90 patients with ESCC who underwent surgery without preoperative therapy, and their expression and clinicopathological factors were compared. ZEB1 and PD‐L1 expression was determined in TE8 cells, which demonstrate the EMT phenotype, following ZEB1 knockdown by siZEB1. TE5, TE6 and TE11 cells with non‐EMT phenotype were also used for studies of TGF‐β1‐dependent EMT induction and ZEB1 and PD‐L1 expression. In cases of high PD‐L1 expression at the invasive front, significantly greater depth of tumor invasion, EMT, and less CD8+ lymphocyte infiltration were observed. High PD‐L1 expression was also associated with worse overall and relapse‐free survival. A correlation was observed between PD‐L1 and ZEB1 expression. In TE8 cells, siZEB1 suppressed PD‐L1 and promoted E‐cadherin mRNA and protein expression. TGF‐β1 induced EMT and surface expression of PD‐L1 in TE5, TE6 and TE11 cell lines. PD‐L1 expression at the ESCC invasive front was related to ZEB1 expression, EMT and poor prognosis. We suggest that a cooperative mechanism bridging between tumor immune avoidance and EMT contributes to tumor malignancy in ESCC.
PD‐L1 plays a crucial role in the host immune system in cancer progression. Its gene promoter region contains a binding site for ZEB1. Our report shows that high PD‐L1 expression at the invasive front of esophageal squamous cell carcinoma (ESCC) was associated with greater depth of tumor invasion, epithelial‐mesenchymal transition (EMT), and less CD8+ lymphocyte infiltration.
Necroptosis is a form of programmed cell death that is accompanied by release of intracellular contents, and reportedly contributes to various diseases. Here, we investigate the significance of ...necroptosis in pancreatic cancer.
We used immunohistochemistry and western blot analysis to evaluate expression of the key mediators of necroptosis-receptor-interacting serine/threonine protein kinase 3 (RIP3) and mixed lineage kinase domain-like (MLKL)-in human pancreatic cancer. We also tested the effects of conditioned media (CM) from necroptotic cells on pancreatic cancer cells in Transwell migration and Matrigel invasion assays. Protein array analysis was used to investigate possible mediators derived from necroptotic cells.
RIP3 and MLKL are highly expressed in human pancreatic cancer tissues compared with normal pancreas. MLKL expression was particularly intense at the tumor invasion front. CM derived from necroptotic cells promoted cancer cell migration and invasion, but not CM derived from apoptotic cells. C-X-C motif chemokine 5 (CXCL5) was upregulated in CM derived from necroptotic cells compared with CM derived from control or apoptotic cells. Moreover, expression of the receptor for CXCL5, C-X-C-motif chemokine receptor-2 (CXCR2), was upregulated in pancreatic cancer cells. Inhibition of CXCR2 suppressed cancer cell migratory and invasive behavior enhanced by necroptosis.
These findings indicate that necroptosis at the pancreatic cancer invasion front can promote cancer cell migration and invasion via the CXCL5-CXCR2 axis.
Signal regulatory protein alpha (SIRPα) is a type I transmembrane protein that inhibits macrophage phagocytosis of tumor cells upon interaction with CD47, and the CD47‐SIRPα pathway acts as an immune ...checkpoint factor in cancers. This study aims to clarify the clinical significance of SIRPα expression in esophageal squamous cell carcinoma (ESCC). First, we assessed SIRPα expression using RNA sequencing data of 95 ESCC tissues from The Cancer Genome Atlas (TCGA) and immunohistochemical analytic data from our cohort of 131 patients with ESCC. Next, we investigated the correlation of SIRPα expression with clinicopathological factors, patient survival, infiltration of tumor immune cells, and expression of programmed cell death‐ligand 1 (PD‐L1). Overall survival was significantly poorer with high SIRPα expression than with low expression in both TCGA and our patient cohort (P < .001 and P = .027, respectively). High SIRPα expression was associated with greater depth of tumor invasion (P = .0017). Expression of SIRPα was also significantly correlated with the tumor infiltration of M1 macrophages, M2 macrophages, CD8+ T cells, and PD‐L1 expression (P < .001, P < .001, P = .03, and P < .001, respectively). Moreover, patients with SIRPα/PD‐L1 coexpression tended to have a worse prognosis than patients with expression of either protein alone or neither. Taken together, SIRPα indicates poor prognosis in ESCC, possibly through inhibiting macrophage phagocytosis of tumor cells and inducing suppression of antitumor immunity. Signal regulatory protein alpha should be considered as a potential therapeutic target in ESCC, especially if combined with PD‐1‐PD‐L1 blockade.
This article highlights the clinical significance of signal regulatory protein alpha (SIRPα) in esophageal squamous cell carcinoma (ESCC). The results showed that high SIRPα expression was a significant indicator of poor prognosis in ESCC and SIRPα/programmed cell death‐ligand 1 (PD‐L1) coexpression had a negative synergistic impact on prognosis in ESCC. Thus, SIRPα could be a novel clinical biomarker and a potential therapeutic target in ESCC, especially if combined with PD‐1‐PD‐L1 blockade.
The clinicopathological features of carcinomas expressing programmed death ligand 1 (PD-L1) and their associations with common driver mutations, such as mutations in the EGFR gene, in lung ...adenocarcinoma are not clearly understood. Here, we examined PD-L1 protein expression in surgically resected primary lung adenocarcinoma and the association of PD-L1 protein expression with clinicopathological features, EGFR mutation status, and patient outcomes.
The expression of PD-L1 protein in 417 surgically resected primary lung adenocarcinomas was evaluated by immunohistochemical analysis. The cutoff value for defining PD-L1 positivity was determined according to the histogram of proportions of PD-L1–positive cancer cells.
Samples from 85 patients (20.4%) and 144 patients (34.5%) were positive for PD-L1 protein expression according to 5% and 1% PD-L1 cutoff values, respectively. Fisher’s exact tests showed that PD-L1 positivity was significantly associated with male sex, smoking, higher tumor grade, advanced T status, advanced N status, advanced stage, the presence of pleural and vessel invasions, micropapillary or solid predominant histological subtypes, and wild-type EGFR. Univariate and multivariate survival analyses revealed that patients with PD-L1 positivity had poorer prognoses than those without PD-L1 protein expression at the 1% cutoff value (disease-free survival p < 0.0001, overall survival p < 0.0001).
PD-L1 protein expression was significantly higher in smoking-associated adenocarcinoma and in EGFR mutation–negative adenocarcinoma. PD-L1 protein expression was associated with poor survival in patients with lung adenocarcinoma. The PD-L1/programmed cell death 1 pathway may contribute to the progression of smoking-associated tumors in lung adenocarcinoma.
Background
Osteosarcoma (OS) is the most common malignant bone tumor and the prognosis of advanced cases is still poor. Recently, there have been several reports suggesting the relationship between ...innate immunity and OS, but the detailed mechanism is unknown. We demonstrate the relationship between OS and Toll-like receptor 4 (TLR4) which is one of the most important factors in innate immunity.
Methods
We established a syngenic mouse tumor model using C3H/HeN, C3H/HeJ mouse and a highly metastatic OS cell line, LM8. TLR4 activation with lipopolysaccharide (LPS) was performed on both mice and its influence on the progression of OS was evaluated. We also performed CD8 + cells depletion to examine the influence on TLR4 activation effects.
Results
Tumor volume of C3H/HeN mice was significantly smaller and overall survival of C3H/HeN mice was significantly longer than C3H/HeJ mice. We found more CD8+ cells infiltrating in lung metastases of C3H/HeN mice and depletion of CD8+ cells canceled the antitumor effects of LPS.
Conclusion
TLR4 activation by LPS increased CD8+ cells infiltrating into lung metastases and suppressed OS progression in the mouse model. TLR4 activation may suppress the progression of OS via stimulating CD8+ cells and can be expected as a novel treatment for OS.
Angiosarcoma is a rare, life-threatening soft tissue sarcoma with malignant endothelial cells that is mainly found in the skin. Multidisciplinary approaches are used to treat patients with ...unresectable metastasized lesions; considering the cellular origin of angiosarcoma, anti-angiogenic therapy has also been used recently. However, these treatments have limited efficacy, and the survival rate remains low. Thus, more effective treatments need to be developed. Nectin cell adhesion molecule 4 (NECTIN4) is highly expressed in malignant tumors and promotes tumor progression. Thus, NECTIN4 is expected to be a novel therapeutic target for cancer. However, the significance of NECTIN4 in angiosarcoma remains unknown. Using immunohistochemistry, we investigated NECTIN4 expression in 74 tissue samples from angiosarcoma patients, finding variable NECTIN4 expression. In addition, we investigated NECTIN4 expression and function in human angiosarcoma cell lines. NECTIN4 expression was higher in angiosarcoma cells than normal endothelial cells, and angiosarcoma cells were sensitive to monomethyl auristatin E, the cytotoxic part of a NECTIN4-targetting antibody-drug conjugate. NECTIN4 knockdown inhibited the proliferation and angiogenesis of angiosarcoma cells, and Src kinase signaling was shown to be involved in NECTIN4 function, at least in part. NECTIN4-targeted therapy has the potential to be a novel treatment strategy for angiosarcoma.
Anti-PD-1 monoclonal antibody, nivolumab, has shown efficacy for advanced gastric cancer (AGC). However, the specific immune cell subsets predominantly activated during the period of anti-PD-1 ...therapy for AGC have not been clarified.
Peripheral blood of 30 AGC patients treated with nivolumab was prospectively obtained before the initial and second administrations and at the time of progressive disease (PD). The proportions of immune cell subsets and the serum concentrations of cytokines were systematically analysed by flow cytometry. Associations of subsets and serum cytokines with therapeutic effects were evaluated.
After the initial administration, significant increases in activated central/effector memory, activated effector T cells, and activated T-helper 1 subsets were observed. At the time of PD, activated regulatory T cells, LAG3-positive CD4+/CD8+ T cells, and TIM3-positive CD4+/CD8+ T cells increased significantly. Significant positive correlations were shown between progression-free survival and proportions of LAG3-positive CD4+/CD8+ T cells and of OX40-positive CD4+/CD8+ T cells (log-rank p = 0.0008, 0.0003, 0.0035 and 0.0040).
Nivolumab therapy enhances activation of central/effector memory and effector subsets of CD4+/CD8+ T cells. The expression levels of LAG-3 and OX40 on T cells correlated with the efficacy of nivolumab therapy and could be reasonable biomarkers for anti-PD-1 therapy.
Tumor microvessel density (MVD) is a prognostic factor for patients with intrahepatic cholangiocarcinoma (ICC). Tumor-infiltrating lymphocytes (TILs) are also key components of the tumor ...microenvironment that play important roles in ICC progression. This study aimed to clarify the relationships between the MVD and immune status and prognosis in patients with ICC. Immunohistochemical staining for cluster of differentiation 34 (CD34), cluster of differentiation 8 (CD8), forkhead box protein P3 (Foxp3), and programmed death-ligand 1 (PD-L1) was performed. The relationships between the MVD and clinicopathological characteristics and outcomes were analyzed. Additionally, the correlations between the MVD, CD8+ and Foxp3+ TIL counts, and PD-L1 expression were evaluated. One hundred ICC patients were classified into high (n = 50) and low (n = 50) MVD groups. The serum platelet and carbohydrate antigen 19-9 levels were higher in the low MVD group than in the high MVD group (P = 0.017 and P = 0.008, respectively). The low MVD group showed a significantly larger tumor size (P = 0.016), more frequent microvascular invasion (P = 0.001), and a higher rate of intrahepatic (P = 0.023) and lymph node (P < 0.001) metastasis than the high MVD group. Moreover, the MVD showed a high positive correlation with CD8+ TILs (r = 0.754, P < 0.001) and a negative correlation with Foxp3+ TILs (r = −0.302, P = 0.003). In contrast, no significant correlation was observed between the MVD and PD-L1 expression in cancer cells (P = 0.817). Patients with low MVDs had a significantly worse prognosis than those with high MVDs. Furthermore, multivariable analyses revealed that a low MVD influenced recurrence-free survival. A decreased intratumoral MVD might predict ICC patient outcomes. Tumor microvessels might be associated with ICC progression, possibly by altering TIL recruitment.
The CXCR4/CXCR7/CXCL12 chemokine axis plays important roles in the migration of tumor cells during cancer development by modulating site‐specific distant metastasis including to regional lymph nodes. ...We investigated the correlation of these chemokine expressions to prognosis in lymph‐node‐positive non‐small‐cell lung cancer (NSCLC) patients. A total of 140 surgically resected specimens of primary site (PS) and metastatic lymph nodes (MLN) of NSCLC involving hilar and/or mediastinal lymph nodes (N1‐2) were collected. CXCR4, CXCR7 and CXCL12 expressions were evaluated. Cox regression analysis was performed to determine whether these chemokines were independent prognostic factors in N1‐2 NSCLC. High expression of CXCR4 in PS and CXCL12 in MLN was associated with poor overall survival (OS) (P = .025 and .033, respectively). Significant correlations between CXCR4 expression in PS and CXCL12 expression in MLN were observed (P = .040). There was significant difference in OS between 2 groups according to expressions of CXCR4 in PS and CXCL12 in MLN (P = .0033). Expression of CXCL12 in MLN was identified as an independent prognostic factor (HR 1.79, 95% CI 1.08‐3.04, P = .023). CXCL12 in MLN was mainly expressed by tumor cells compared with stromal cells (56% vs 25%, respectively, P < .0001). CXCR4/CXCL12 may play roles in tumor progression in MLN and is associated with poor prognosis of lymph‐node‐positive NSCLC patients.
CXCR4/CXCR7/CXCL12 chemokine axis plays important roles in the migration of cancer cells during cancer development. We investigated the correlation of these chemokine expressions to prognosis in lymph‐node‐positive non‐small‐cell lung cancer (NSCLC) patients. CXCR4/CXCL12 may play roles in tumor progression in MLN and are associated with poor prognosis of lymph‐node‐positive NSCLC patients.
Background
Pancreatic ductal adenocarcinoma (PDAC) is a lethal neoplasm because of difficulties in early detection. Several studies have recently suggested that exosomes may have potential as novel ...biomarkers. This study aimed to isolate exosomes from pancreatic juice and to investigate whether exosomal microRNAs (ex-miRs) could be used as biomarkers for PDAC.
Methods
Pancreatic juice was collected from patients with PDAC and chronic pancreatitis (CP) by endoscopic retrograde pancreatography. Exosomes were extracted by ultracentrifugation. The presence of exosomes was confirmed by electron microscopy and Western blotting using anti-CD63, -CD81, and -TSG101 antibodies. Relative levels of ex-miR-21 and ex-miR-155 were quantified and compared between PDAC and CP patients.
Results
A total of 35 pancreatic juice samples (27 PDAC and 8 CP) were collected. Relative levels of both ex-miR-21 and ex-miR-155 were significantly higher in PDAC patients compared with CP patients (
p
< 0.001 and
p
= 0.008, respectively). By contrast, no significant difference was apparent in relative levels of miR-21 and miR-155 in whole pancreatic juice from PDAC patients compared with CP patients (
p
= 0.08 and
p
= 0.61, respectively). Ex-miR-21 and ex-miR-155 levels discriminated PDAC patients from CP patients with area under the curve values of 0.90 and 0.89, respectively. The accuracies of ex-miR-21 levels, ex-miR-155 levels, and pancreatic juice cytology were 83%, 89%, and 74%, respectively. When combining the results of ex-miR profiling with pancreatic juice cytology, the accuracy was improved to 91%.
Conclusions
We successfully extracted exosomes from pancreatic juice. Ex-miRs, including ex-miR-21 and ex-miR-155, in pancreatic juice may be developed as biomarkers for PDAC.
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