Ubiquitination of NOTCH2 by DTX3 suppresses the proliferation and migration of human esophageal carcinoma.

The NOTCH2 gene plays a role in the development of many tumors. Deltex E3 ubiquitin ligase 3 (DTX3) was identified as a novel E3 ligase for NOTCH2 and as a potential therapeutic target for esophageal cancer. However, whether DTX3 could regulate NOTCH2 to suppress the progression of esophageal carcinoma remains unknown. In our study, NOTCH2 had higher expression in human esophageal carcinoma cell lines compared to normal human esophageal epithelial cell line, and ablation of NOTCH2 suppressed the proliferation and migration of esophageal carcinoma cells. A novel E3 ligase for NOTCH2 was identified by yeast two-hybrid (Y2H) screening, and DTX3 promoted the ubiquitination and degradation of NOTCH2. Further study showed that DTX3 overexpression suppressed the proliferation and tumorigenicity of human oesophageal carcinoma cells. The analysis of tissue samples from patients revealed that the expression of NOTCH2 was high while the expression of DTX3 was low in esophageal cancer. Furthermore, the expression of DTX3 and NOTCH2 showed a significant negative correlation in human oesophageal cancer samples. Our study suggested that the DTX3-NOTCH2 axis plays an important role in the progression of esophageal cancer, and DTX3 acts as an anti-oncogene in esophageal carcinoma, potentially offering a therapeutic target for esophageal cancer.

A novel scoring system predicts postsurgical survival and adjuvant chemotherapeutic benefits in patients with pancreatic adenocarcinoma: Implications for AJCC-TNM staging.

BACKGROUND: We evaluated the application of the latest 8th American Joint Committee on Cancer (AJCC) staging system in Chinese patients and determined whether the addition of biologic markers could improve the prediction of postsurgical survival in pancreatic adenocarcinoma (PC). METHODS: This multicenter study involved 1,223 consecutive patients who underwent margin-negative pancreatectomy for PC. A scoring system was devised based on AJCC pathologic parameters and biologic markers and defined using a Cox proportional hazards model. Prognostic accuracies were evaluated by concordance index (C-index) and Akaike information criterion (AIC). RESULTS: The 8th edition AJCC staging system had a better survival distribution of PC with different stages and a similar C-index (0.62 in the training cohort, 0.60 in the validation cohort) than the 7th edition (0.59 in the training cohort, 0.58 in the validation cohort). Nevertheless, survival of resected patients with stage IIA or IIB disease was indistinguishable. Incorporation of postoperative carbohydrate antigen 19-9 (CA19-9) levels and tumor grade into the 8th edition AJCC staging system generated a scoring system with better predictive accuracy for overall survival (OS) (C-index of 0.73 and AIC of 4301.05 in the training cohort, C-index of 0.71 and AIC of 3309.23 in the validation cohort). More importantly, patients with median or higher scores experienced OS benefits from adjuvant chemotherapy. CONCLUSION: Postoperative CA19-9 levels and tumor grade are two well-known PC biologic markers that could be incorporated into a standard AJCC staging system to refine risk stratification and predict OS benefit from adjuvant chemotherapy in resected PC.