Targeting CTGF in Cancer: An Emerging Therapeutic Opportunity

14-3-3σ Functions as an Intestinal Tumor Suppressor

Although the 14-3-3σ gene was initially identified as a p53 target gene in colorectal cancer cells, its potential role in intestinal tumorigenesis has remained unknown. Here we determined that 14-3-3σ expression is significantly downregulated in primary human colorectal cancer when compared with adjacent normal colonic tissue in patient samples. Downregulation of 14-3-3σ in primary colorectal cancers was significantly associated with p53 mutation, increasing tumor stage, distant metastasis, and poor patient survival. Poor survival was more significantly associated with decreased 14-3-3σ expression in p53 wild-type than in p53-mutant colorectal cancers. 14-3-3σ expression was detected in enterocytes of the transit amplifying zone and gradually increased towards the apical villi in the small intestinal epithelium. In small and large intestinal epithelia and adenomas, 14-3-3σ expression was upregulated in differentiated areas. Deletion of 14-3-3σ in Apc^Min mice increased the number and size of adenomas in the small intestine and colon, shortening the median survival by 64 days. 14-3-3σ-deficient adenomas displayed increased proliferation and decreased apoptosis, as well as increased dysplasia. In adenomas, loss of 14-3-3σ promoted acquisition of a mesenchymal-like gene expression signature, which was also found in colorectal cancers from patients with poor relapse-free survival. The transcriptional programs controlled by the 14-3-3σ-interacting factors SNAIL, c-JUN, YAP1, and FOXO1 were activated by deletion of 14-3-3σ, potentially contributing to the enhanced tumor formation and growth. Taken together, these results provide genetic evidence of a tumor-suppressor function of 14-3-3σ in the intestine. SIGNIFICANCE: Downregulation of 14-3-3σ in colorectal cancer is associated with metastasis and poor survival of patients, and its inactivation in a murine tumor model drives intestinal tumor formation and epithelial-mesenchymal transition.

Development and Validation of a Robust Immune-Related Prognostic Signature for Gastric Cancer

Background

An increasing number of reports have found that immune-related genes (IRGs) have a significant impact on the prognosis of a variety of cancers, but the prognostic value of IRGs in gastric cancer (GC) has not been fully elucidated.

Methods

Univariate Cox regression analysis was adopted for the identification of prognostic IRGs in three independent cohorts (GSE62254, n = 300; GSE15459, n = 191; and GSE26901, n = 109). After obtaining the intersecting prognostic genes, the three independent cohorts were merged into a training cohort (n = 600) to establish a prognostic model. The risk score was determined using multivariate Cox and LASSO regression analyses. Patients were classified into low-risk and high-risk groups according to the median risk score. The risk score performance was validated externally in the three independent cohorts (GSE26253, n = 432; GSE84437, n = 431; and TCGA, n = 336). Immune cell infiltration (ICI) was quantified by the CIBERSORT method.

Results

A risk score comprising nine genes showed high accuracy for the prediction of the overall survival (OS) of patients with GC in the training cohort (AUC > 0.7). The risk of death was found to have a positive correlation with the risk score. The univariate and multivariate Cox regression analyses revealed that the risk score was an independent indicator of the prognosis of patients with GC (p < 0.001). External validation confirmed the universal applicability of the risk score. The low-risk group presented a lower infiltration level of M2 macrophages than the high-risk group (p < 0.001), and the prognosis of patients with GC with a higher infiltration level of M2 macrophages was poor (p = 0.011). According to clinical correlation analysis, compared with patients with the diffuse and mixed type of GC, those with the Lauren classification intestinal GC type had a significantly lower risk score (p = 0.00085). The patients' risk score increased with the progression of the clinicopathological stage.

Conclusion

In this study, we constructed and validated a robust prognostic signature for GC, which may help improve the prognostic assessment system and treatment strategy for GC.