Background: Gastric cancer (GC) is one of the most common malignancies in the world, and the fourth most frequent malignancy worldwide. YTHDF2 (YTH domain family 2, YTHDF2) binds to mRNA containing m6A, thereby regulating the localization and stability of the bound mRNA. YTHDF2 was shown to be associated with some cancer patient prognosis. However, the effect of YTHDF2 on gastric cancer and the molecular mechanism of this effect have not been documented.Methods: To conduct this research, YTHDF2 expression levels in public databases and gastric cancer patient samples were analyzed. The effects of YTHDF2 on the growth of gastric cancer cells were detectedin vivoandin vitro.RNA-seq was used to analyze the signal pathways regulated by YTHDF2, and experiments were carried out for verification.Results: In our study, we found that YTHDF2 has lower expression in GC tissues and GC cells, and inhibits the growth of GC cells. In addition, the analysis of clinical data found that the expression level of YTHDF2 is closely related to the stage of GC and the survival of patients with GC. RNA sequencing results showed that overexpression of YTHDF2 significantly reduced protein expression in the FOXC2 (Forkhead box protein C2, FOXC2) signaling pathway. Finally, we found that knockout of FOXC2 reversed the inhibitory effect of YTHDF2 on GC cells.Conclusion: In summary, YTHDF2 inhibits the growth of GC cells by negatively regulating FOXC2 and may serve as a prognostic marker in GC.

Designing theranostic agents that are responsive to weakly acidic tumor microenvironments for optimized imaging and therapeutic effects is of great interest in nanomedicine. In the current study, we constructed a pH-triggered smart theranostic system based on pH-responsive Prussian blue, which shows good performance in the photoacoustic imaging (PAI)-guided photothermal therapy (PTT) of tumors. Precursors to Prussian blue, namely ferrous and ferricyanide ions, were separately encapsulated into pH-responsive hydrogels that only degraded under acidic conditions. In vitro results showed that the encapsulated ions were gradually released in acidic buffer, accompanied by hydrogel degradation. After the resultant hydrogel was mixed and intratumorally injected into tumor-bearing mice, the encapsulated ferrous ions and ferricyanide ions were successfully released in the acidic tumor environment, allowing the in situ formation of Prussian blue in the tumor area. This provided an efficient theranostic agent for PAI-guided PTT of cancer. Our research highlights the potential of Prussian blue-based theranostic agents for the precise diagnosis and treatment of cancer.

Circulating cell-free DNA (ccf-DNA) in plasma may contain both specific and non-specific of tumor markers. The concentration and integrity of ccf-DNA may be clinical useful for detecting and predicting cancer progression. Plasma samples from 40 healthy controls and 73 patients with gastric cancers (two stage 0, 17 stage I, 11 stage II, 33 stage III, and 10 stage IV according to American Joint Committee on Cancer stage) were assessed respectively. qPCR targeting the Alu repeats was performed using two different sets of primers amplifying the long and short segments. DNA integrity was calculated as a ratio of the long to the short fragments of Alu repeats. Plasma DNA concentration was significantly higher in patients with stage III and IV gastric cancers than in healthy controls (p = 0.028 and 0.029 respectively). The receiver operating characteristic (ROC) curve for discriminating patients with stage III and IV gastric cancers from healthy controls had an area under the curve (AUC) of 0.744 (95% CI, 0.64 to 0.85). Circulating cell-free DNA concentration increased within 21 days following surgery and dropped by 3 months after surgery. Concentration of ccf-DNA is a promising molecular marker for assessing gastric cancer progression. Current Controlled Trials ChiCTR-DDT-12002848 , 8 October 2012.

Background: There is no standard reconstruction method following proximal gastrectomy, of which gastroesophageal reflux and anastomotic complications are of great concern. Though several techniques have been devised to overcome these postoperative complications, such as double tract reconstruction, double-flap technique and side overlap fundoplication by Yamashita, none of them is considered a perfect solution. Herein, we designed a novel method of esophagogastrostomy after laparoscopic proximal gastrectomy (LPG), named right-sided overlap and single-flap valvuloplasty (ROSF). Methods: Between March 2021 and December 2021, 20 consecutive patients underwent LPG-ROSF at Department of Gastrointestinal Surgery, Second Affiliated Hospital of Soochow University. Surgical outcomes and postoperative complications were recorded. All patients were followed-up until December 2022. Endoscopy and assessment of gastrointestinal symptoms were performed 1 year after surgery. Nutrition-related parameters including total body weight, hemoglobin, lymphocyte count, serum total protein, serum albumin and serum prealbumin were evaluated 1 year after surgery and compared with those before surgery. Results: The mean surgery time and anastomosis time was 285.3 ± 71.3 and 61.3 ± 11.2 min respectively. None of the patients had gastrointestinal early postoperative complications. Symptomatic reflux was observed in one patient (5%) while reflux esophagitis (Los Angeles Grade A) was observed in another patient (5%). Four patients (20%) had mild dysphagia (Visick score = II) but none of them had anastomotic stenosis. There were no significant changes in nutritional status postoperatively. Conclusions: ROSF can be safely performed after LPG and has satisfactory outcomes in preventing reflux and stenosis, and maintaining nutritional status. This technique requires further validation.