Elderly patients with stage II gastric cancer do not benefit from adjuvant chemotherapy.

BACKGROUND: With the aging of the population, the burden of elderly gastric cancer (EGC) increases worldwide. However, there is no consensus on the definition of EGC and the efficacy of adjuvant chemotherapy in patients with stage II EGC. Here, we investigated the effectiveness of adjuvant chemotherapy in defined EGC patients. METHODS: We enrolled 5762 gastric cancer patients of three independent cohorts from the Sixth Affiliated Hospital of Sun Yat-sen University (local), the Surveillance, Epidemiology, and End Results (SEER), and the Asian Cancer Research Group (ACRG). The optimal age cutoff for EGC was determined using the K-adaptive partitioning algorithm. The defined EGC group and the efficacy of adjuvant chemotherapy for them were confirmed by Cox regression and Kaplan-Meier survival analyses. Furthermore, gene set variation analyses (GSVA) were performed to reveal pathway enrichment between groups. RESULTS: The optimal age partition value for EGC patients was 75. In the local, SEER, and ACRG cohorts, the EGC group exhibited significantly worse overall survival and cancer-specific survival than the non-EGC group (P < 0.05) and was an independent risk factor. Stratified analyses based on chemotherapy showed that EGC patients derived little benefit from adjuvant chemotherapy. Furthermore, GSVA analysis revealed the activation of DNA repair-related pathways and downregulation of the p53 pathway, which may partially contribute to the observed findings. CONCLUSION: In this retrospective, international multi-center study, 75 years old was identified as the optimal age cutoff for EGC definition, and adjuvant chemotherapy proved to be unbeneficial for stage II EGC patients.

DOCK4 stimulates MUC2 production through its effect on goblet cell differentiation.

The intestinal mucosa is in continuous contact with milliard of microorganisms, thus intestinal epithelial barrier is a critical component in the arsenal of defense mechanisms required to prevent infection and inflammation. Mucin 2 (MUC2), which is produced by the goblet cells, forms the skeleton of the intestinal mucus and protects the intestinal tract from self-digestion and numerous microorganisms. Dedicator of cytokinesis 4 (DOCK4) is a member of the DOCK-B subfamily of the DOCK family of guanine nucleotide exchange factors. It is reported that DOCK4 plays a critical role in the repair of the barrier function of the intestinal epithelium after chemical damage. In this study, the role of DOCK4 in the goblet cell differentiation and MUC2 production is explored. Disordered intestinal epithelium and shortage of goblet cells were observed in DOCK4 gene knockout mice. Furthermore, DOCK4 deletion contributed to the low expression of MUC2 and the goblet cell differentiation/maturation factors including growth factor independent 1 (Gfi1) and SAM pointed domain epithelial-specific transcription factor (Spdef) in mouse ileums and colons. Overexpression of DOCK4 caused a marked increase in Gfi1, Spdef, and MUC2, while siRNA knockdown of endogenous DOCK4 significantly decreased Gfi1, Spdef, and MUC2 in HT-29 cells. In addition, MUC2, DOCK4, and the goblet cell differentiation/maturation factors mRNA levels were decreased in colorectal cancer samples compared with normal colons. A significant positive correlation was found between MUC2 and DOCK4. In conclusion, DOCK4 may serve as a critical regulator of goblet cell differentiation and MUC2 production in the intestine.

Adipose-derived mesenchymal stromal cells alleviate intestinal fibrosis: The role of tumor necrosis factor-stimulated gene 6 protein.

BACKGROUND: The therapeutic potential of adipose-derived mesenchymal stromal cells (AMSCs) in the treatment of intestinal fibrosis occured in patients with Crohn's disease (CD) remains unclear. Tumor necrosis factor-stimulated gene 6 (TSG6) protein plays a critical role in inflammation regulation and tissue repair. This study aimed to determine if AMSCs attenuate intestinal fibrosis by secreting paracrine TSG6 protein and explore the underlying mechanisms. METHODS: Two murine models for intestinal fibrosis were established using 2,4,6-trinitrobenzene sulfonic acid in BALB/c mice and dextran sulfate sodium in C57BL/6 mice. Primary human fibroblasts and CCD-18co cells were incubated with transforming growth factor (TGF)-ß1 to build two fibrosis cell models in vitro. RESULTS: Intraperitoneally administered AMSCs attenuated intestinal fibrosis in the two murine models, as evidenced by significant alleviation of colon shortening, collagen protein deposits, and submucosal thickening, and also decrease in the endoscopic and fibrosis scores (P < 0.001). Although intraperitoneally injected AMSCs did not migrate to the colon lesions, high levels of TSG6 expression and secretion were noticed both in vivo and in vitro. Similar to the role of AMSCs, injection of recombinant human TSG6 attenuated intestinal fibrosis in the mouse models, which was not observed with the administration of AMSCs with TSG6 knockdown or TSG6 neutralizing antibody. Mechanistically, TSG6 alleviates TGF-ß1-stimulated upregulation of α-smooth muscle actin (αSMA) and collagen I by inhibiting Smad2 phosphorylation. Furthermore, the expression of TSG6 is lower in intestinal fibrosis tissue of patients with Crohn's disease and can reduce pro-fibrotic protein (αSMA) secretion from primary ileal fibrotic tissue. CONCLUSIONS: AMSCs attenuate intestinal fibrosis by secreting paracrine TSG6 protein, which inhibits Smad2 phosphorylation. TSG6, a novel anti-fibrotic factor, could potentially improve intestinal fibrosis treatments.

Prognostic value of hyperthermic intraperitoneal chemotherapy in gastric cancer with synchronous peritoneal metastases: a real-world retrospective study.

PURPOSE: Peritoneal metastasis in gastric cancer (GC) is a late-stage condition with a poor prognosis. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a popular treatment for peritoneal metastases. Here, we aim to investigate the real-world application and efficacy of HIPEC alone for GC patients with synchronous peritoneal metastases. METHODS: We conducted a retrospective analysis on GC patients with synchronous peritoneal metastasis at the Sixth Affiliated Hospital of Sun Yat-sen University between January 2011 and December 2022. Survival analyses and Cox regression models were performed based on overall survival (OS) and cancer-specific survival (CSS), and subgroup analysis was used to determine the prognostic value of HIPEC across different treatment. RESULTS: We enrolled 250 patients, of whom 120 (48%) received HIPEC while 130 (52%) did not. HIPEC showed no survival benefit for GC patients (P = 0.220 for OS and P = 0.370 for CSS). However, subgroup analysis found that HIPEC can only improve OS and CSS when combined with primary tumor resection (P = 0.034 for OS and P = 0.036 for CSS). Moreover, survival analyses also demonstrated that HIPEC independently improved OS (HR for OS = 0.58, 95% CI 0.37-0.92, P = 0.020) and CSS (HR for CSS = 0.58, 95% CI 0.37-0.93, P = 0.024) for patients who underwent primary site resection, but not for those who did not. CONCLUSION: HIPEC can improve survival in GC patients with synchronous peritoneal metastases who have primary tumor resection, but not in those without primary tumor resection.