Comprehensive study of clinicopathological and immune cell infiltration and lactate dehydrogenase expression in patients with thymic epithelial tumours.

BACKGROUND: Lactate dehydrogenase (LDH) has emerged as a promising biomarker for cancer. However, the current understanding of LDH and circulating LDH expression in thymic epithelial tumour (TET) is lacking. METHODS: A comprehensive literature review and meta-analysis were performed to evaluate the clinical significance of circulating LDH levels in patients with TET. Circulating LDH levels were measured using a laboratory analyser (Cobas8000, Roche, Basel, Switzerland). The maximum standardised uptake value (SUVmax) was determined in patients who underwent whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Multiplex immunohistochemistry (IHC) was performed using a commercially available kit (Opal 6-plex Detection Kit, Akoya Biosciences, Marlborough, MA, USA) and slide scanner (Slideview VS200, Olympus, Tokyo, Japan). All statistical analyses were performed using SPSS (IBM Corp., Armonk, NY, USA) and Prism version 9.0 (GraphPad Inc., San Diego, CA, USA). Differences with p < 0.05 were considered to be statistically significant. RESULTS: Meta-analysis revealed that elevated circulating serum levels of LDH predicted poor prognosis in patients with TET. Circulating levels of LDH were analysed in the serum of 313 patients with TET and 87 with benign mediastinal mass. The mean circulating LDH level in patients with thymic carcinoma (TC) was significantly higher than that in those with thymoma (TM) and the benign group (p < 0.001). Expression levels of circulating LDH were significantly reduced in postoperative samples compared with that in preoperative samples (p < 0.05). Receiver operating characteristic (ROC) curve analysis for diagnosing TC yielded an area under the curve of 0.74, with a sensitivity of 54 % and specificity of 86 %. Furthermore, patients with TC exhibited higher 18F-FDG PET/CT SUVmax values compared to those with TM. Correlation analysis demonstrated a positive association between SUVmax values and circulating LDH levels. In addition, the percentages of LDH-positive cells in TC and type B1 TM tissues were higher than those in other subtypes of TM, and a significant positive correlation between the percentages of LDH-positive and CD20-positive cells was detected in patients with TET (p < 0.05). CONCLUSION: Circulating serum LDH level may serve as a non-invasive biomarker for the diagnosis and prognosis of TET. The relationship between LDH expression and immune cell infiltration merits further regarding its application in companion diagnosis for immunotherapy.

Kaempferol protects ethanol-induced gastric ulcers in mice via pro-inflammatory cytokines and NO.

Gastric ulcers (GUs) are common pathologies that affect many people around the world. Excessive alcohol consumption is one of the main causes of GUs; however, there are still lack of effective drugs for the prevention or therapy of GUs. In this study, we evaluated the protective effects and possible mechanisms of kaempferol (KAE) against acute ethanol-induced lesions to the gastric mucosa in mice. Fasted mice were orally given vehicle (0.9% saline), omeprazole (20 mg/kg), or KAE (40, 80, or 160 mg/kg) for 1 h in different experimental sets prior to the establishment of the GU model by challenge with absolute ethanol (10 ml/kg). Animals were euthanized 1 h after ethanol intake, and their plasma and stomach tissues were subject to further examination. Macroscopic and microscopic lesions, and immunological and biochemical parameters were observed. The effects of inflammation were investigated using the following indicators: tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-6, myeloperoxidase (MPO), and nitric oxide (NO). Results showed that KAE significantly decreased the ulcer index, increased the preventive index, completely protected the mucosa from lesions, and preserved gastric mucosal glycoprotein. KAE decreased MPO activity and pro-inflammatory cytokine (TNF-α, and IL-1ß) levels, and improved NO levels. The gastroprotective activity of KAE might be attributed to the preservation of gastric mucous glycoproteins levels, thus by inhibiting neutrophil accumulation and MPO activity, adjusting the levels of pro-inflammatory cytokines, and improving NO production.