Nectin-4, also known as PVRL4 (poliovirus-receptor-like 4), is specifically expressed in the embryo and placenta. Recent studies have reported that the Nectin-4 is over-expressed in multiple human cancers, and such abnormal expression is associated with cancer progression and poor prognosis of the patients. In the present study, we aimed to characterize the expression pattern of Nectin-4 in human esophageal cancer (EC) tissues, and to investigate its clinical implications, prognostic value and regulatory effects on cellular functions of EC cells. In the present study, we first examined Nectin-4 expression in human EC tissues by using immunohistochemistry (IHC) assay and analyzed the clinical associations. Then the cellular studies in vitro and the nude mice tumor model in vivo were used to examine the regulatory role of Nectin-4 in the progression of EC. Our results demonstrated that over-expression of Nectin-4 in human EC tissues was significantly associated with tumor size, depth of tumor invasion, and poor prognosis of the patients. The intervention of Nectin-4 expression in EC cell lines showed that the increased Nectin-4 expression could significantly promote the cell viability, migration, invasion and tumor formation. Our present data unveiled that Nectin-4 played an important role in tumor biology and could serve as a useful prognostic predictor of human EC.

α-Fetoprotein-producing gastric cancer (AFPGC) is a rare type of gastric cancer. The largest population of patients with AFPGC is found in China. In the present study, a total of 4,779 GC patients, including 317 AFPGC patients, from 11 clinical studies in China with a general AFPGC/GC ratio of 6.63% were summarized and analyzed. On the basis of analysis of the clinical data, the patients with AFPGC had larger tumor size, weaker cell differentiation, worse histopathological types, deeper serosal infiltration, more lymph node and liver metastases, poorer stages, shorter survival time and more positive expression of vascular endothelial growth factors than the patients without AFPGC. Our observation is consistent with previous results reported in studies of AFPGC. Overall, AFPGC is a subtype of GC with a poor prognosis.

B7-H4 is a novel B7 ligand that plays an important role in the T cell-mediated immune response as a negative regulator. Previous studies have suggested the aberrant expression of membrane B7-H4 in tumor cells. The aim of this study is to determine the expression levels of preoperative soluble B7-H4 (sB7-H4) in circulation and to investigate the correlations between sB7-H4 levels and clinicopathological parameters as well as the survival rate of patients with gastric cancer. Blood specimens from 132 patients with gastric cancer and 63 healthy volunteers were analyzed by sandwich enzyme-linked immunosorbent assay. Median concentrations of sB7-H4 in patients with gastric cancer were significantly higher than those in healthy volunteers (16.85 versus 10.46 ng/mL; P = 0.008). Median levels of sB7-H4 were significantly correlated with tumor size, lymph node metastasis, the depth of tumor invasion and tumor-node-metastasis classification (P = 0.002, P = 0.001, P = 0.041 and P 0.05). Additionally, the overall survival rate was significantly lower in patients with high sB7-H4 levels when compared with low sB7-H4 levels (50.0% versus 77.3%, χ² = 10.78, P = 0.001). Moreover, multivariate analysis demonstrated that the risk of death was significantly higher in patients with high sB7-H4 levels than in those with low sB7-H4 levels (P = 0.039). sB7-H4 is a valuable blood marker for predicting the progression and prognosis of patients with gastric cancer.

Iodine-125 (¹²⁵I) seed brachytherapy has been applied to treat various malignant tumors such as esophageal cancer, however, radioresistance can reduce its efficacy. Endoplasmic reticulum stress (ERS) and subsequent unfolded protein response (UPR) is one of the core mechanisms of ¹²⁵I seed radiation-induced cell death, thus aggravating ERS has been considered a promising sensitization strategy. Herein, we show that combination therapy of an irreversible proteasome inhibitor carfilzomib (CFZ) and ¹²⁵I seed radiation displayed strong anti-tumor effect on esophageal squamous cell carcinoma (ESCC). Mechanistically, ERS and UPR regulated multiple cell death modalities induced by the combination therapy, including apoptosis, paraptosis, and ferroptosis. ¹²⁵I seed radiation induced reactive oxygen species (ROS) production, DNA damage, p53 activation, and apoptosis. CFZ promoted ROS production, and augmented ¹²⁵I seed radiation-induced apoptosis via the mitochondrial pathway, which was mediated by the UPR-C/EBP homologous protein (CHOP) pathway and was independent of the p53 pathway. CFZ enhanced ¹²⁵I seed radiation-induced intracellular Ca²⁺ overload, protein ubiquitination, ERS, and UPR, consequently promoting paraptosis. ¹²⁵I seed radiation induced accumulation of intracellular Fe²⁺ and lipid peroxides but upregulated the expression of ferroptosis inhibitors, SLC7A11 and glutathione peroxidase 4 (GPX4). The combination therapy promoted ferroptosis by enhancing the accumulation of intracellular Fe²⁺ and downregulating GPX4 expression. The mouse experiment demonstrated that CFZ can promote the efficacy of ¹²⁵I seed radiation with good tolerance. Our findings suggest that combination therapy of ¹²⁵I seed radiation and CFZ is associated with multiple cell death modalities and may serve as a promising therapeutic strategy for ESCC.

We aimed to detect CD40 mutant expression and evaluate its clinical significance in gastric cancer.