Cytokine-induced killer cells (CIK cells) are a heterogeneous subset of ex-vivo expanded T lymphocytes which are characterized with a MHC-unrestricted tumor-killing activity and a mixed T-NK phenotype. Adoptive CIK cells transfer, one of the adoptive immunotherapy represents a promising nontoxic anticancer therapy. However, in clinical studies, the therapeutic activity of adoptive CIK cells transfer is not as efficient as anticipated. Possible explanations are that abnormal tumor vasculature and hypoxic tumor microenvironment could impede the infiltration and efficacy of lymphocytes. We hypothesized that antiangiogenesis therapy could improve the antitumor activity of CIK cells by normalizing tumor vasculature and modulating hypoxic tumor microenvironment. We combined recombinant human endostatin (rh-endostatin) and CIK cells in the treatment of lung carcinoma murine models. Intravital microscopy, dynamic contrast enhanced magnetic resonance imaging, immunohistochemistry, and flow cytometry were used to investigate the tumor vasculature and hypoxic microenvironment as well as the infiltration of immune cells. Our results indicated that rh-endostatin synergized with adoptive CIK cells transfer to inhibit the growth of lung carcinoma. We found that rh-endostatin normalized tumor vasculature and reduced hypoxic area in the tumor microenvironment. Hypoxia significantly inhibited the proliferation, cytotoxicity and migration of CIK cells in vitro and impeded the homing of CIK cells into tumor parenchyma ex vivo. Furthermore, we found that treatment with rh-endostatin significantly increased the homing of CIK cells and decreased the accumulation of suppressive immune cells in the tumor tissue. In addition, combination therapy produced higher level of tumor-infiltration lymphocytes compared with other treatments. Our results demonstrate that rh-endostatin improves the therapeutic effect of adoptive CIK cells therapy against lung carcinomas and unmask the mechanisms of the synergistic antitumor efficacy, providing a new rationale for combining antiangiogenesis therapy with immunotherapy in the treatment of lung cancer.

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide, which lacks effective biomarkers for prognosis. Therefore, it is urgent to explore new potential molecular markers to discriminate patients with poorer survival in ESCC. Bioinformatics analysis, qRT-PCR, and western blot were applied to investigate S1PR1 expression. CCK-8 assay, colony formation assay, flow cytometry dual staining assay, and immunofluorescence were performed to examine cell proliferation ability and apoptosis rate. Mouse xenograft model of TE-13 cells was established to confirm the roles of S1PR1 in vivo. Gene set enrichment analysis (GSEA) was used to investigate the downstream signaling pathways related to S1PR1 functions. Co-IP was performed to verify the direct binding of S1PR1 and STAT3. Western blot was applied to determine the phosphorylation level of STAT3. Immunohistochemistry was conducted to identify protein expression of S1PR1 and p- STAT3 in tumor tissues. In the present study, we found that S1PR1 expression was higher in ESCC patients and was a potential biomarker for poor prognosis. Silencing S1PR1 expression inhibited proliferation, and increased apoptosis of ESCC cells, while overexpression of S1PR1 had opposite effects. Mechanistically, S1PR1 played the roles of promoting proliferation and attenuating apoptosis through directly activating p-STAT3. Furthermore, in vivo experiments verified this mechanism. Our findings indicated that S1PR1 enhanced proliferation and inhibited apoptosis of ESCC cells by activating STAT3 signaling pathway. S1PR1 may serve as a prognostic biomarker for clinical applications.

To investigate the expression and prognostic value of CCL2 in gastric cancer, as well as its relationship with tumor hypoxia. Tumor tissues from 68 gastric cancer patients (GC) were analyzed, and the expression of CCL2 and hypoxia-inducible factor 1 alpha (HIF-1α) in tumor tissues was detected by immunohistochemistry. Statistical evaluations that were used included univariate log-rank tests of Kaplan-Meier curves and multivariate Cox regression model analysis. CCL2 was highly expressed in 66.2% (45/68) of gastric cancer specimens. The distribution of CCL2 expression in tumor tissue was consistent with that of HIF-1α. Patients with high CCL2 expression in GC had a lower overall survival rate [50.6 mo (95%CI: 44.44-56.93) vs 64.6 mo (95%CI: 60.27-68.94), P = 0.013]. CCL2 expression correlates closely with HIF-1α expression in gastric cancer. CCL2 may be an independent prognostic marker for GC.

High blood glucose has long been established as a risk factor for tumor metastasis, yet the molecular mechanisms underlying this association have not been elucidated. Here we describe that hyperglycemia promotes tumor metastasis via increased platelet activity. Administration of glucose, but not fructose, reprogrammed the metabolism of megakaryocytes to indirectly prime platelets into a prometastatic phenotype with increased adherence to tumor cells. In megakaryocytes, a glucose metabolism-related gene array identified the mitochondrial molecular chaperone glucose-regulated protein 75 (GRP75) as a trigger for platelet activation and aggregation by stimulating the Ca2+-PKCα pathway. Genetic depletion of Glut1 in megakaryocytes blocked MYC-induced GRP75 expression. Pharmacologic blockade of platelet GRP75 compromised tumor-induced platelet activation and reduced metastasis. Moreover, in a pilot clinical study, drinking a 5% glucose solution elevated platelet GRP75 expression and activated platelets in healthy volunteers. Platelets from these volunteers promoted tumor metastasis in a platelet-adoptive transfer mouse model. Together, under hyperglycemic conditions, MYC-induced upregulation of GRP75 in megakaryocytes increases platelet activation via the Ca2+-PKCα pathway to promote cancer metastasis, providing a potential new therapeutic target for preventing metastasis. Significance: This study provides mechanistic insights into a glucose–megakaryocyte–platelet axis that promotes metastasis and proposes an antimetastatic therapeutic approach by targeting the mitochondrial protein GRP75.