Discovery of AL-GDa62 as a Potential Synthetic Lethal Lead for the Treatment of Gastric Cancer

Correlation between platelet distribution width and long-term survival in patients with gastric cancer after radical surgery

BACKGROUND

Gastric cancer is a common digestive system tumor, and surgery is the first choice of treatment, but the long-term survival of patients after surgery is still not satisfactory. Previous studies have showed that platelet distribution width (PDW) plays an important role in the occurrence and development of tumor. This study aimed to analyze the correlation between PDW and long-term survival of patients with stage Ⅱ-ⅢA gastric cancer after radical surgery.

AIM

To explore the relationship between PDW and long-term survival in patients with stage Ⅱ-ⅢA gastric cancer after radical surgery.

METHODS

This is a prospective cohort study, in which 124 patients with gastric cancer who received surgical treatment at our hospital from January 2016 to December 2017 were included as the study subjects. All patients were followed for 5 years and their survival time was recorded. The patients were divided into three groups according to whether their PDW increased or not after surgery: PDW decrease group, PDW normal group, and PDW increase group. The clinicopathological characteristics and long-term survival of patients in different groups were compared. Point binary correlation and COX regression were used to test the correlation between postoperative PDW and long-term survival of patients and the impact of PDW on long-term survival. Receiver operating characteristic (ROC) curve analysis was performed to analyze the value of postoperative PDW in predicting long-term survival.

RESULTS

The levels of CEA, CA199, and PDW in gastric cancer patients after treatment were significantly lower than those before treatment (P < 0.05). Among 111 patients with gastric cancer, 35 (31.53%) had decreased PDW, 24 (21.62%) had normal PDW, and 52 (46.85%) had increased PDW. The rates of lymph node metastasis and advanced tumor-node-metastasis (TNM) stage (ⅢA) in the PDW increase group were significantly higher than those of the PDW normal group and PDW decrease group (P < 0.05). However, there were no statistical significant differences among the three groups in terms of age, sex, degree of differentiation, tumor diameter, depth of muscle invasion, TNM stage, and lymph node metastasis (P > 0.05). Among 111 cases of gastric cancer, 31 survived, with a survival rate of 27.93%; the survival time was 11-60 mo, and the median survival time was 43.00 (31.00, 60.00) mo. Point binary correlation test showed that PDW, lymph node metastasis, and TNM stage were positively correlated with long-term survival after radical surgery(r > 0, P < 0.05). COX regression analysis showed that after adjusting for TNM stage and lymph node metastasis, taking the normal PDW group as a reference, the increase of PDW was a risk factor for long-term survival of gastric cancer patients. The median survival time of the patients with decreased, normal, and increased PDW was 49.50 (33.00, 60.00) mo, 53.50 (49.25, 58.00) mo, and 29.00 (20.00, 35.00) mo, respectively, and the difference among the three groups was statistically significant (P < 0.05). ROC curve analysis showed that postoperative PDW level had appreciated value in predicting long-term survival of gastric cancer patients (AUC = 0.718, 95%CI: 0.614-0.822, P < 0.001).

CONCLUSION

PDW is related to the long-term survival of patients with gastric cancer after radical surgery. Increased PDW indicates that the long-term prognosis of gastric cancer patients is poor and the survival period is short. TNM stage and lymph node metastasis are also closely related to the long-term survival of gastric cancer patients.

Synthesis of Selenyl-Substituted Quinoline Derivatives via Substrate-Controlled Three-Component Domino Reactions

A simple and efficient method for the preparation of selenyl-substituted quinoline derivatives through a CSp3-H selenylation of in situ-generated 3-acetyl quinoline has been developed. This protocol is easy to handle, scalable, and good functional group tolerant, providing a rapid method to 3-selenoacetyl quinoline and 3-diselenoacetyl quinoline derivatives.

E-Cadherin-Deficient Cells Are Sensitive to the Multikinase Inhibitor Dasatinib

The CDH1 gene, encoding the cell adhesion protein E-cadherin, is one of the most frequently mutated genes in gastric cancer and inactivating germline CDH1 mutations are responsible for the cancer syndrome hereditary diffuse gastric cancer (HDGC). CDH1-deficient gastric cancers exhibit high AKT serine/threonine kinase 3 (AKT3) expression, but specific drugs against this AKT isoform are not available. We therefore used two publicly available datasets to identify AKT3-associated genes which could be used to indirectly target AKT3. Reactome analysis identified an enrichment of extracellular matrix remodelling genes in AKT3-high gastric cancers. Of the 51 genes that were significantly correlated with AKT3 (but not AKT1), discoidin domain receptor tyrosine kinase 2 (DDR2) showed the strongest positive association. Treatment of isogenic human cells and mouse gastric and mammary organoids with dasatinib, a small molecule inhibitor of multiple kinases including SRC, BCR-ABL and DDR2, preferentially slowed the growth and induced apoptosis of E-cadherin-deficient cells. Dasatinib treatment also preferentially slowed the growth of gastric and mammary organoids harbouring both Cdh1 and Tp53 mutations. In organoid models, dasatinib treatment was associated with decreased phosphorylation of total AKT, with a stronger effect seen in Cdh1-deficient organoids. Treatment with combinations of dasatinib and an inhibitor of AKT, MK2206, enhanced the effect of dasatinib in breast MCF10A cells. In conclusion, targeting the DDR2-SRC-AKT3 axis with dasatinib represents a promising approach for the chemoprevention and chemotherapy of gastric and breast cancers lacking E-cadherin.

E-Cadherin-Deficient Epithelial Cells Are Sensitive to HDAC Inhibitors

Inactivating germline mutations in the CDH1 gene (encoding the E-cadherin protein) are the genetic hallmark of hereditary diffuse gastric cancer (HDGC), and somatic CDH1 mutations are an early event in the development of sporadic diffuse gastric cancer (DGC) and lobular breast cancer (LBC). In this study, histone deacetylase (HDAC) inhibitors were tested for their ability to preferentially inhibit the growth of human cell lines (MCF10A and NCI-N87) and murine organoids lacking CDH1 expression. CDH1^-/- breast and gastric cells were more sensitive to the pan-HDAC inhibitors entinostat, pracinostat, mocetinostat and vorinostat than wild-type cells, with an elevated growth inhibition that was, in part, attributable to increased apoptosis. CDH1-null cells were also sensitive to more class-specific HDAC inhibitors, but compared to the pan-inhibitors, these effects were less robust to genetic background. Increased sensitivity to entinostat was also observed in gastric organoids with both Cdh1 and Tp53 deletions. However, the deletion of Tp53 largely abrogated the sensitivity of the Cdh1-null organoids to pracinostat and mocetinostat. Finally, entinostat enhanced Cdh1 expression in heterozygous Cdh1^+/- murine organoids. In conclusion, entinostat is a promising drug for the chemoprevention and/or treatment of HDGC and may also be beneficial for the treatment of sporadic CDH1-deficient cancers.