Pulmonary Thrombosis Promotes Tumorigenesis via Myeloid Hypoxia-Inducible Factors

Cancer patients have a greater risk of thrombosis than individuals without cancer. Conversely, thrombosis is a diagnostic predictor of cancer, but the mechanisms by which thrombosis promotes tumor propagation are incompletely understood. Our previous studies showed that hypoxia-inducible factors (HIF) 1α and HIF2α are stabilized in myeloid cells of murine thrombi. We also previously showed that pulmonary thrombosis increases the levels of HIF1α and HIF2α in murine lungs, enhances the levels of tumorigenic factors in the circulation, and promotes pulmonary tumorigenesis. In this study, we aimed to investigate the regulation of thrombosis-induced tumorigenesis by myeloid cell-specific HIFs (i.e., HIF1 and HIF2 in neutrophils and macrophages). Our in vitro studies showed that multiple tumorigenic factors are upregulated in the secretome of hypoxic versus normoxic neutrophils and macrophages, which promotes lung cancer cell proliferation and migration in a myeloid-HIF-dependent manner. Next, we used a mouse model of pulmonary microvascular occlusion to study the impact of pulmonary thrombosis and myeloid HIFs on lung tumorigenesis. Experiments on mice lacking either HIF1α or HIF2α in myeloid cells demonstrated that loss of either factor eliminates the advantage given to pulmonary tumor formation by thrombotic insult. The myeloid HIF-dependent and tumorigenic impact of pulmonary thrombosis on tumor burden may be partly driven by paracrine thymidine phosphorylase (TP), given that TP levels were increased by hypoxia in neutrophil and macrophage supernates, and that plasma TP levels were positively correlated with multiple measures of tumor progression in wild type mice but not myeloid cell-specific HIF1α or HIF2α knockout mice. These data together demonstrate the importance of thrombotic insult in a model of pulmonary tumorigenesis and the essential role of myeloid HIFs in mediating tumorigenic success.

Mean platelet volume predicts survival in patients with hepatocellular carcinoma and type 2 diabetes

BACKGROUND

Patients with hepatocellular carcinoma (HCC) having pre-existing type 2 diabetes (T2DM) have a poorer prognosis than those without T2DM. Moreover, accumulating evidence reveals that activated platelets play a crucial role in tumor and T2DM. The mean platelet volume (MPV) indicates platelet activation and is altered in malignancies. The present study aimed to investigate the clinical significance of MPV in patients with HCC having T2DM.

METHODS

This retrospective study performed between January 2010 and December 2013 included 331 patients with HCC (165 with T2DM and 166 without T2DM). The overall survival was compared, and the predictors of overall survival were analyzed.

RESULTS

The patients with T2DM had lower MPV levels than those without T2DM. Furthermore, the MPV levels significantly differentiated T2DM from non-T2DM. In addition, for patients with T2DM, the overall survival was significantly shorter in patients with low MPV levels than in those with high MPV levels. Multivariate analysis identified decreased MPV as an independent prognostic factor for overall survival only in patients with T2DM, but not in those without T2DM.

CONCLUSION

Reduced MPV was a prognostic factor for poor outcome in patients with HCC and T2DM.

Des-gamma-carboxyl prothrombin-promoted vascular endothelial cell proliferation and migration

Des-gamma-carboxyl prothrombin (DCP) is a well recognized tumor marker for hepatocellular carcinoma. Previously, we have demonstrated that DCP stimulates cell proliferation in hepatocellular carcinoma cell lines through Met-Janus kinase 1 signal transducer and activator of transcription 3 signaling pathway. In the present study, we demonstrated that DCP induces both cell proliferation and migration in human umbilical vein endothelial cells. DCP was found to bind with the kinase insert domain receptor (KDR), alternatively referred to as vascular endothelial growth factor receptor-2. Furthermore, DCP induced autophosphorylation of KDR and its downstream effector phospholipase C-gamma and mitogen-activated protein kinase (MAPK). To support these results, we showed that DCP-induced cell proliferation and cell migration were inhibited by KDR short interfering RNA, KDR kinase inhibitor, or MAPK inhibitor. In conclusion, these results indicate that DCP is a novel type of vascular endothelial growth factor that possesses potent mitogenic and migrative activities.

Angiogenesis and antiangiogenic therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular tumor characterized by neovascularization, which plays an important role in the growth and progression of HCC. Angiogenesis provides a target for novel prognostic and therapeutic approaches to HCC. Assessment of microvessel density using immunohistochemical staining for specific endothelial cell markers such as CD34 has been shown to provide prognostic information independent of conventional pathological parameters in HCC patients. Recent studies have unveiled the important angiogenic factors involved in the regulation of angiogenesis in HCC, although the exact molecular pathways are far from clear. Current data suggest that vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis of HCC. Tumor expression of VEGF has been shown to correlate with tumor invasiveness and prognosis in patients with HCC. VEGF is an important molecular target for antiangiogenic therapy. Studies in animal models have demonstrated the efficacy of antiangiogenic agents such as anti-VEGF antibody and antagonists of VEGF receptors in suppressing hepatocarcinogenesis and growth of HCC. Antiangiogenic therapy has already entered clinical trials in HCC patients and holds the promise of providing an effective novel treatment for HCC, which is of great clinical significance because there is no existing effective systemic therapy for HCC.

Opportunities for targeted therapies in hepatocellular carcinoma

Hepatocellular cancer (HCC) is the fifth most common solid tumor worldwide, accounting for 500,000 new cases annually. Although less common in the United States, HCC is expected to increase in incidence over the next two decades largely because of the prevalence of hepatitis C virus infection. A majority of patients present with advanced disease and are not candidates for liver transplantation, surgical resection, or regional therapy. In 60% to 80% of patients with HCC, treatment is complicated by underlying liver cirrhosis and hepatic dysfunction. Systemic treatments are minimally effective, can have significant toxicity, and have not been shown to improve patient survival. New approaches targeting molecular abnormalities specific to HCC are needed to improve patient outcome. This review summarizes the state of knowledge of those key aspects of the molecular pathogenesis of HCC that may represent rational therapeutic targets in this disease. Relevant preclinical and clinical information on novel compounds directed toward abnormalities in HCC is reviewed.

Monitoring of circulating angiogenic factors in dendritic cell-based cancer immunotherapy

BACKGROUND

A promising treatment approach for patients with malignant disease that recently has found its way into clinical trials is based on vaccination with autologous dendritic cells loaded with tumor antigens. However, adequate assays for monitoring clinical and immunologic responses still are under debate. In recent years, the determination of angiogenic markers has shown considerable potential in the diagnosis and prognosis of patients with malignant disease, because tumor growth and spread are promoted by angiogenesis, the formation of new blood vessels.

METHODS

The authors established a method for measuring the plasma levels of three modulators of angiogenesis: vascular endothelial growth factor, platelet-derived endothelial cell growth factor, and thrombospondin-1. The angiogenic blood profile of a healthy control group was characterized and compared with a group of patients with malignant disease. Ultimately, levels of circulating angiogenic factors were monitored in the course of dendritic cell-based cancer immunotherapy.

RESULTS

Baseline levels of angiogenic mediators varied substantially among healthy individuals but showed consistent values for each individual. Blood levels of circulating angiogenic factors were elevated significantly in patients with advanced disease and were highly sensitive to dendritic cell-based immunotherapy.

CONCLUSIONS

To our knowledge, the current report was the first to analyze circulating levels of angiogenic factors during dendritic cell-based immunotherapy. The authors observed a noteworthy change in the angiogenic blood profile with treatment, and this change was correlated with the induction of an immunologic response.

Prognostic significance of serum thymidine phosphorylase concentration in esophageal squamous cell carcinoma

BACKGROUND

Thymidine phosphorylase (dThdPase), which also is referred to as platelet-derived endothelial cell growth factor, is a potent inducer of angiogenesis in malignant tumors. Increased dThdPase expression and activity have been found to be associated with poor prognosis in various solid tumor tissues. Because very little was known about the significance of serum dThdPase concentration (S-dThdPase), the objective of this study was to analyze the clinicopathologic significance of S-dThdPase in the patients with esophageal squamous cell carcinoma.

METHODS

The S-dThdPase was measured by enzyme-linked immunosorbent assay in 77 healthy controls and 153 patients with primary esophageal squamous cell carcinoma. A total of 80 patients underwent surgery alone; 46 patients received chemoradiotherapy alone; 17 patients received chemoradiotherapy followed by surgery; and 10 patients did not receive any treatment. Thymidine phosphorylase expression in esophageal carcinoma tissues was examined by immunohistochemistry. The clinicopathologic value and prognostic value of S-dThdPase was determined in 80 patients treated by surgery alone.

RESULTS

The S-dThdPase is significantly higher in patients with esophageal carcinoma than in healthy controls (30.8 +/- 31.8 ng/mL vs. 13.8 +/- 7.6 ng/mL; P < 0.001). Statistically significant differences in S-dThdPases were observed depending on tumor size (P < 0.01) and tumor depth (P < 0.01). A S-dThdPase of more than 29.0 ng/mL (which represented the mean plus 2 standard deviation of the concentration in healthy controls) was associated with dThdPase expression (P = 0.022), poor response (P = 0.022), and poor survival (P < 0.01). Because S-dThdPase was associated with tumor depth, S-dThdPase was not an independent prognostic factor (P = 0.095).

CONCLUSIONS

A high S-dThdPase is associated with depth of tumor invasion and poor response to treatment.

Correlation of serum basic fibroblast growth factor levels with clinicopathologic features and postoperative recurrence in hepatocellular carcinoma

BACKGROUND

Basic fibroblast growth factor (bFGF) is an important positive regulator of tumor angiogenesis. This study evaluated the role of serum bFGF as a biological marker of tumor invasiveness and postresection recurrence in hepatocellular carcinoma (HCC).

METHODS

Concentrations of bFGF in preoperative serum samples in 88 patients undergoing resection of HCC were measured by a quantitative enzyme-linked immunosorbent assay. A single pathologist performed histopathologic examination of all tumor specimens. All patients were prospectively monitored for tumor recurrence.

RESULTS

The preoperative serum bFGF levels ranged from <0.22 to 71.2 pg/mL (median 10.8 pg/mL). There was significant correlation between high serum bFGF levels and large tumor >5 cm, presence of venous invasion or advanced pTNM stage. Patients with a serum bFGF level >10.8 pg/mL had worse disease-free survival than those with a level <10.8 pg/mL (median disease-free survival 11.2 versus 20 months, P = 0.044). Serum bFGF level >10.8 pg/mL (P = 0.035) and tumor size >5 cm (P = 0.004) were independent preoperative factors that predicted early recurrence after resection of HCC.

CONCLUSIONS

This study supports a role of bFGF in tumor growth and invasion in HCC. A high preoperative serum bFGF level appears to be predictive of invasive tumor and early postoperative recurrence. The clinical implications of serum bFGF level in HCC warrant further investigation.

Clinical implications of circulating angiogenic factors in cancer patients

PURPOSE

Angiogenesis, a process fundamental to tumor growth, is regulated by angiogenic factors. This article reviews prognostic and other clinical implications of circulating angiogenic factors in cancer patients.

METHODS

A MEDLINE search of literature was performed using the names of various angiogenic factors as the key words. Studies pertaining to circulating angiogenic factors in cancer patients were reviewed. Pertinent literature regarding tumor expression of common angiogenic factors and their prognostic relevance in human cancers were also examined.

RESULTS

A substantial number of studies have demonstrated a strong association between elevated tumor expression of vascular endothelial growth factor (VEGF) and advanced disease or poor prognosis in various cancers. This supports the pivotal role of VEGF in regulating tumor angiogenesis. More recently, there is mounting evidence that the level of circulating VEGF in patients with different types of cancer may be predictive of tumor status and prognosis. Preliminary data also suggest that circulating VEGF may be useful in predicting and monitoring tumor response to anticancer therapies and in follow-up surveillance for tumor relapse. There are reports supporting the prognostic value of other circulating angiogenic factors such as basic fibroblast growth factor, platelet-derived endothelial cell growth factor, transforming growth factor-beta, and angiogenin, but their clinical significance is less conclusive because of limited data.

CONCLUSION

Circulating VEGF seems to be a reliable surrogate marker of angiogenic activity and tumor progression in cancer patients. Evaluation of circulating angiogenic factors is a promising novel approach of prognostication in cancer patients that has the advantages of being convenient and noninvasive, and it may provide new prognostic information that is not afforded by conventional clinicopathologic prognostic indicators.