BackgroundDll4/Notch and Ephrin-B2/EphB4 pathways play critical roles in tumor vessel development and maturation. This study evaluates the efficacy of the inhibition of both signaling pathways, alone and in combination, in reducing the growth of an autochthonous mouse tumor and assesses potential adverse effects.MethodsWe used the transgenic RIP1-Tag2 tumor model to study the effects of 1) inhibition of Dll4/Notch by either Dll4 allelic deletion or use of a soluble extracellular Dll4 (sDll4), 2) inhibition of Ephrin-B2/EphB4 signaling by a soluble extracellular EphB4 fused to albumin (sEphB4-Alb), and 3) inhibition of both pathways by sEphB4-Alb combined with either Dll4 allelic deletion or sDll4. To investigate adverse effects, we used inducible endothelial-specific Dll4 knock-out mice, treated with sEphB4-Alb, and carried out histopathological analysis.ResultsDll4 allele deletion or soluble Dll4 treatment resulted in increased tumor vessel density, reduced mural cell recruitment and vessel perfusion which resulted in reduced tumor size. The soluble EphB4 instead reduced vessel density and vessel perfusion, leading to reduction of tumor size. Greater efficacy was observed when sEphB4-Alb was combined with either Dll4 allele deletion or sDll4 in regards to tumor size, vessel perfusion and mural cell recruitment. Induced endothelial specific Dll4 loss-of-function caused hepatic vascular alterations, which were prevented by concomitant sEphB4-Alb treatment.ConclusionCombination targeting of Dll4/Notch and Ephrin-B2/EphB4 has potential for clinical investigation, providing cumulative efficacy and increased safety over Dll4/Notch inhibition alone.
EphB4 receptor tyrosine kinase and its cognate ligandEphrinB2 regulate induction and maturation of newly forming vessels. Inhibition of their interaction arrests angiogenesis, vessel maturation, and pericyte recruitment. In addition, EphB4 is expressed in the vast majority of epithelial cancers and provides a survival advantage to most. Here, we describe two anti-EphB4 monoclonal antibodies that inhibit tumor angiogenesis and tumor growth by two distinct pathways. MAb131 binds to fibronectin-like domain 1 and induces degradation of human EphB4, but not murine EphB4. MAb131 inhibits human endothelial tube formation in vitro and growth of human tumors expressing EphB4 in vivo. In contrast, MAb47 targets fibronectin-like domain 2 of both human and murine EphB4 and does not alter EphB4 receptor levels, but inhibits angiogenesis and growth of both EphB4-positive and EphB4-negative tumors in a mouse s.c. xenograft model. Combination of MAb47 and bevacizumab enhances the antitumor activity and induces tumor regression. Indeed, humanized antibodies hAb47 and hAb131 showed similar affinity for EphB4 and retained efficacy in the inhibition of primary tumor development and experimental metastasis.
IntroductionNeoadjuvant chemotherapy (NAC) has become a standard treatment for locally advanced breast cancer. The present study was designed to investigate the predictive value of different peripheral inflammation/immune biomarker responses to NAC and prognosis in breast cancer patients.Materials and methodsA total of 180 breast cancer patients treated with NAC in the First Affiliated Hospital with Nanjing Medical University between January 2008 and March 2015 were enrolled in the study. The associations between inflammation/immune indicators and pathological complete response (pCR) were determined, and the prognostic value of inflammation/immune indicators was also evaluated.ResultsIn the univariate analysis, patients with a high pretreatment peripheral lymphocyte count (.2.06×109/L) showed a higher pCR rate than those with a low lymphocyte count (23.9% vs 10.4%, P=0.023). The pCR rate of patients with a neutrophil: lymphocyte ratio ≤2.15 was significantly higher than that of patients with a high neutrophil: lymphocyte ratio (20% vs 7.8%; P=0.03). However, multivariate analysis revealed that only the high lymphocyte count was predictive for pCR (odds ratio: 4.375, 95% CI: 1.429–13.392, P=0.010). In the survival analysis, patients with a higher neutrophil count (.2.65×109/L) were confirmed to have a shorter disease-free survival (hazard ratio: 4.322, 95% CI: 1.028–18.174, P=0.046), and the high neutrophil count was significantly associated with lymphovascular invasion (P=0.037).ConclusionWe demonstrated that a high level of baseline peripheral lymphocyte count can be a predictor for high efficacy of NAC for breast cancer patients, and low baseline peripheral neutrophil count may contribute to the favorable disease-free survival.
Effective treatment of transitional cell carcinoma (TCC) of the bladder requires early diagnosis. Identifying novel molecular markers in TCC would guide the development of diagnostic and therapeutic targets. Ephrins mediate signals via tyrosine kinase activity that modulates diverse physiologic and developmental processes, and ephrins are increasingly implicated in carcinogenesis. The aim of our study was to examine the differential regulation of EphB4 and EphB2 in normal bladder and in TCC of the bladder in 40 patients undergoing radical cystectomy for curative intent. Immunostaining and Western blotting revealed that normal urothelium expresses EphB2 (20 of 24 cases, 83% of the time) not EphB4 (0 of 24 cases, 0%). In sharp contrast, TCC specimens show loss of EphB2 expression (0 of 34 cases, 0%) and gain of EphB4 expression (32 of 34, 94%). Furthermore, EphB4 signal strength statistically correlated with higher tumor stage, and trended toward the presence of carcinoma in situ (CIS). These results are confirmed by analysis of normal urothelial and tumor cell lines. EphB2 is not a survival factor in normal urothelium, while EphB4 is a survival factor in TCC. Treatment of bladder tumor xenograft with an EphB4 inhibitor sEphB4-HSA leads to 62% tumor regression and complete remission when combined with Bevacizumab. Furthermore, tissue analysis revealed that sEphB4-HSA led to increased apoptosis, decreased proliferation, and reduced vessel density, implicating direct tumor cell targeting as well as anti-angiogenesis effect. In summary loss of EphB2 and gain of EphB4 expression represents an inflection point in the development, growth and possibly progression of TCC. Therapeutic compounds targeting EphB4 have potential for diagnosing and treating TCC.
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