The clinicopathological significance of Jagged1 and DLL4 in gallbladder cancer

Biomedical engineering approaches for the delivery of JAGGED1 as a potential tissue regenerative therapy

JAG1 is a ligand that activates the NOTCH signaling pathway which plays a crucial role in determining cell fate behavior through cell-to-cell signaling. JAG1-NOTCH signaling is required for mesenchymal stem cell (MSC) differentiation into cardiomyocytes and cranial neural crest (CNC) cells differentiation into osteoblasts, making it a regenerative candidate for clinical therapy to treat craniofacial bone loss and myocardial infarction. However, delivery of soluble JAG1 has been found to inhibit NOTCH signaling due to the requirement of JAG1 presentation in a bound form. For JAG1-NOTCH signaling to occur, JAG1 must be immobilized within a scaffold and the correct orientation between the NOTCH receptor and JAG1 must be achieved. The lack of clinically translatable JAG1 delivery methods has driven the exploration of alternative immobilization approaches. This review discusses the role of JAG1 in disease, the clinical role of JAG1 as a treatment, and summarizes current approaches for JAG1 delivery. An in-depth review was conducted on literature that used both in vivo and in vitro delivery models and observed the canonical versus non-canonical NOTCH pathway activated by JAG1. Studies were then compared and evaluated based on delivery success, functional outcomes, and translatability. Delivering JAG1 to harness its ability to control cell fate has the potential to serve as a therapeutic for many diseases.

Clinicopathologic significance of the delta-like ligand 4, vascular endothelial growth factor, and hypoxia-inducible factor-2α in gallbladder cancer

BACKGROUND

Gallbladder cancer (GBC) is usually detected in advanced stages with a low 5-year survival rate. Delta-like ligand 4 (DLL4), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor-2alpha (HIF2α) have been studied for their role in tumorigenesis and potential for therapeutic target, and multiple clinical trials of the agents targeting them are ongoing. We investigated the expression of these markers in surgically resected GBC and tried to reveal their association with the clinicopathologic features, mutual correlation of their expression, and prognosis of the GBC patients by their expression.

METHODS

We constructed the tissue microarray blocks of 99 surgically resected GBC specimens and performed immunohistochemistry of DLL4, VEGF, and HIF2α. We used the quantitative digital image analysis to evaluate DLL4 and VEGF expression, while the expression of HIF2α was scored manually.

RESULTS

The expression of VEGF and HIF2α showed a significant trend with tumor differentiation (p= .028 and p= .006, respectively). We found that the high DLL4 and VEGF expression were significantly correlated with lymph node metastasis (p= .047, both). The expression of VEGF and HIF2α were significantly correlated (p < .001). The GBC patients with low HIF2α expression showed shorter recurrence-free survival than those with high HIF2α expression.

CONCLUSIONS

This study suggested the possibility of the usage of DLL4 and VEGF to predict the lymph node metastasis and the possibility of VEGF and HIF2α to predict the expression level mutually. Further studies may be needed to validate our study results and eventually accelerate the introduction of the targeted therapy in GBC.

Comparative Outcomes of Adenosquamous Carcinoma of the Gallbladder: an Analysis of the National Cancer Database

BACKGROUND

A paucity of data exists regarding adenosquamous carcinoma of the gallbladder, a histology comprising under 10% of gallbladder cancer diagnoses. The aim of this study is to characterize the clinicopathological features of these tumors utilizing a population-based dataset compared with gallbladder adenocarcinoma.

METHODS

We identified patients with gallbladder adenosquamous and adenocarcinoma from the National Cancer Database from 2004 to 2015. Patient demographics, tumor characteristics, treatment regimens, and overall survival were analyzed between the groups.

RESULTS

We identified 13,158 patients: 12,455 (95%) with a diagnosis of gallbladder adenocarcinoma and 703 (5%) with adenosquamous carcinoma. Adenosquamous tumors were larger, poorly differentiated, and presented with Stage III/IV disease (75% vs 69%, p < 0.001). Overall 1-, 3-, and 5-year survival for adenosquamous and adenocarcinoma were 24%, 11%, and 9% vs 37%, 16%, and 11%, respectively (p < 0.001). Following surgical resection, adenosquamous carcinoma had more positive margins (31% vs 25%, p < 0.001), and median overall survival was 10.3 months vs 20.5 months for adenocarcinoma (p < 0.001). Overall survival at 1-, 3-, and 5-years for surgically resected adenosquamous and adenocarcinoma were 43%, 23%, and 18% versus 63%, 35%, and 25%, respectively (p < 0.001). In resected adenosquamous carcinoma, positive lymph nodes and margins were associated with worse survival, while adjuvant chemoradiation (HR 0.457, 95% CI 0.31-0.69, p < 0.001) was associated with improved survival.

CONCLUSION

Adenosquamous gallbladder cancer presented with larger tumors at advanced clinical stages when compared with adenocarcinoma. Overall survival was worse for adenosquamous tumors both overall, and following curative intent resection. Adjuvant chemoradiation was associated with improved survival in adenosquamous tumors.

Delta-Like 4-Notch signaling regulates trophoblast migration and invasion by targeting EphrinB2

The migration and invasion of trophoblasts during early pregnancy in known to play an important role in placental development, which ensures the oxygen and nutrients to the fetus. Accumulating evidences suggest that Delta-Like 4(DLL4)-Notch signaling may be involved in the process of trophoblast regulation. However, the potential role of DLL4-Notch signaling as well as its molecular mechanism in trophoblast controlling has not been fully studied. This study is designed to investigate the effects of DLL4-Notch signaling on trophoblast functions in human extravillous trophoblast cell line, HTR-8/SVneo. The possible molecular mechanism of DLL4-Notch signaling in trophoblast was also explored. We observed that activation of DLL4-Notch signaling enhanced cell migration and invasion ability while blockage of DLL4-Notch signaling impaired. Control of DLL4-Notch signaling did not affect cell viability. The expression of EphrinB2 was regulated by DLL4-Notch signaling. In addition, up-regulation of EphrinB2 resulted in the similar effects on trophoblast cell functions as DLL4-Notch signaling activation. Moreover, activation of DLL4-Notch signaling reversed the negative impact of EphrinB2 knock-down on trophoblasts migration and invasion. Our study suggested that DLL4-Notch signaling involved in the regulation of trophoblast migration and invasion, which may be induced by direct regulation of EphrinB2 expression.

The Role of DLLs in Cancer: A Novel Therapeutic Target

Delta-like ligands (DLLs) control Notch signaling. DLL1, DLL3 and DLL4 are frequently deregulated in cancer and influence tumor growth, the tumor vasculature and tumor immunity, which play different roles in cancer progression. DLLs have attracted intense research interest as anti-cancer therapeutics. In this review, we discuss the role of DLLs in cancer and summarize the emerging DLL-relevant targeting methods to aid future studies.