Preoperative differentiation of gastric schwannomas and gastrointestinal stromal tumors based on computed tomography: a retrospective multicenter observational study.

Introduction: Gastric schwannoma is a rare benign tumor accounting for only 1-2% of alimentary tract mesenchymal tumors. Owing to their low incidence rate, most cases are misdiagnosed as gastrointestinal stromal tumors (GISTs), especially tumors with a diameter of less than 5 cm. Therefore, this study aimed to develop and validate a diagnostic nomogram based on computed tomography (CT) imaging features for the preoperative prediction of gastric schwannomas and GISTs (diameters = 2-5 cm). Methods: Gastric schwannomas in 47 patients and GISTs in 230 patients were confirmed by surgical pathology. Thirty-four patients with gastric schwannomas and 167 with GISTs admitted between June 2009 and August 2022 at Hospital 1 were retrospectively analyzed as the test and training sets, respectively. Seventy-six patients (13 with gastric schwannomas and 63 with GISTs) were included in the external validation set (June 2017 to September 2022 at Hospital 2). The independent factors for differentiating gastric schwannomas from GISTs were obtained by multivariate logistic regression analysis, and a corresponding nomogram model was established. The accuracy of the nomogram was evaluated using receiver operating characteristic and calibration curves. Results: Logistic regression analysis showed that the growth pattern (odds ratio [OR] 3.626; 95% confidence interval [CI] 1.105-11.900), absence of necrosis (OR 4.752; 95% CI 1.464-15.424), presence of tumor-associated lymph nodes (OR 23.978; 95% CI 6.499-88.466), the difference between CT values during the portal and arterial phases (OR 1.117; 95% CI 1.042-1.198), and the difference between CT values during the delayed and portal phases (OR 1.159; 95% CI 1.080-1.245) were independent factors in differentiating gastric schwannoma from GIST. The resulting individualized prediction nomogram showed good discrimination in the training (area under the curve [AUC], 0.937; 95% CI, 0.900-0.973) and validation (AUC, 0.921; 95% CI, 0.830-1.000) datasets. The calibration curve showed that the probability of gastric schwannomas predicted using the nomogram agreed well with the actual value. Conclusion: The proposed nomogram model based on CT imaging features can be used to differentiate gastric schwannoma from GIST before surgery.

Intravoxel incoherent motion diffusion-weighted imaging of solitary pulmonary lesions: initial study with gradient- and spin-echo sequences.

AIM: To evaluate the feasibility and image quality of intravoxel incoherent motion diffusion-weighted imaging (IVIM) using gradient- and spin-echo (GRASE) in solitary pulmonary lesions (SPLs) compared to echo planar imaging (EPI) and turbo spin-echo (TSE) at 3 T. MATERIALS AND METHODS: Forty-two patients with SPLs underwent lung magnetic resonance imaging (MRI) using TSE-IVIM, GRASE-IVIM, and EPI-IVIM at 3 T. Signal ratio (SR), contrast ratio (CR), and image distortion ratio (DR) of three sequences were compared. The reproducibility and repeatability of the apparent diffusion coefficient (ADC) and IVIM-derived parameters were assessed using the interclass correlation coefficient (ICC) and coefficient of variation (CV). The repeatability of the ADC and IVIM-derived parameters between all sequences was evaluated using the Bland-Altman method. RESULTS: EPI-IVIM had a higher SR, lower CR, and higher DR (p<0.05); however, there was no significant difference between TSE-IVIM and GRASE-IVIM (p>0.05). Compared to the D and f values of TSE-IVIM (ICC lower limit >0.90), GRASE-IVIM and EPI-IVIM showed poor reproducibility (ICC lower limit<0.90). The repeatability of the ADC and D values obtained by TSE-IVIM (CV, 1.93-2.96% and 2.44-3.18%, respectively) and GRASE-IVIM (CV, 2.56-3.12% and 3.21-3.51%, respectively) were superior to those of EPI-IVIM (CV, 10.03-10.2% and 11.30-11.57%). The repeatability of D∗ and f values for all sequences was poor. Bland-Altman analysis showed wide limits of agreement between the ADC and IVIM-derived parameters for all sequences. CONCLUSION: GRASE-IVIM reduced the DR, improved the stability of the ADC and D values on repeated scans, and had the shortest scanning time.

TNF+ regulatory T cells regulate the stemness of gastric cancer cells through the IL13/STAT3 pathway.

Regulatory T cells (Tregs) are an important component of the tumor microenvironment; however, the interaction between Tregs and gastric cancer cells is not completely understood. Recent studies have shown that Tregs participate in cancer cell stemness maintenance. In this study, we performed single-cell RNA sequencing of gastric cancer and adjacent tissues and found that Tregs with high TNF expression were recruited to gastric cancer tissues and were significantly correlated with patient survival. TNF+ Tregs significantly contribute to tumor growth and progression. Our studies have further demonstrated that TNF+ Tregs promote the stemness of gastric cancer cells through the IL13/STAT3 pathway. Therefore, blocking the interaction between TNF+ Tregs and gastric cancer cells may be a new approach in the treatment of gastric cancer.

miR-204 enhances p27 mRNA stability by targeting Brd4 in head and neck squamous cell carcinoma.

The present study aimed to explore the function of microRNA (miR)-204 in modulating cyclin-dependent kinase inhibitor 1B (p27) mRNA stability in head and neck squamous cell carcinoma (HNSCC). Briefly, reverse transcription quantitative polymerase chain reaction and western blot analysis were used to detect miR-204 and Brd4 level. Cell viability, cell cycle and cell apoptosis were used to investigate the effects of miR-204. Additional luciferase reporter and mRNA stability assays were used to explore the mechanisms contributing to miR-204 effects. Here, miR-204 was downregulated in HNSCC tissues compared with the adjacent normal tissues. The expression levels of miR-204 and bromodomain-containing protein 4 (Brd4) were negatively associated in HNSCC tissues. Ectopic expression of miR-204 inhibited HNSCC cell proliferation, promoted cell cycle arrest at the G1/S phase and promoted cell apoptosis compared with control cells. Additionally, upregulation of miR-204 expression levels enhanced p27 mRNA stability. Notably, Brd4 was identified as a target of miR-204, and the co-expression of Brd4 with miR-204 mimics attenuated the inhibitory effects of miR-204 on cell proliferation and enhanced p27 mRNA stability compared with control cells. Thus, it was concluded that miR-204 functions as a tumor suppressor by enhancing p27 mRNA stability through targeting Brd4 in HNSCC.