MAT2A inhibits the ferroptosis in osteosarcoma progression regulated by miR-26b-5p.

Osteosarcoma (OS) is the most frequent primary malignant bone tumor. Ferroptosis, a form of regulated cell death, is a key tumor suppression mechanism. Although methionine adenosyltransferase II alpha (MAT2A) has been reported to inhibit several tumor cells, it is unclear whether inhibition of MAT2A in OS cells can reduce ferroptosis. CCK-8, flow cytometry, and Transwell assays were performed to evaluate cell viability, cell apoptosis/cycle, and cell migration, respectively. The levels of ferrous iron and glutathione (GSH) levels in cells were measured to evaluate the degree of cell ferroptosis. Western blot analysis was performed to detect protein levels of MAT2A, p-STAT3 (Ser727)/STAT3, and solute carrier family 7 member 11 (SLC7A11) in OS cells. MAT2A was significantly upregulated in OS specimens and high MAT2A expression was associated with a poorer prognosis in OS patients. shRNA targeting MAT2A significantly increased OS cell apoptosis, triggered cell cycle arrest in the G2 phase, and attenuated migration ability in vitro. MAT2A depletion dramatically inhibited tumor progression of OS in vivo. Overexpression of MAT2A rescued the tumor inhibition caused by miR-26b-5p. MAT2A knockdown promoted OS cell ferroptosis. miR-26b-5p/MAT2A regulates tumor malignant progression and OS cell ferroptosis by controlling p-STAT3 and SLC7A11 expressions. Taken together, our study displayed that miR-26b-5p/MAT2A triggers ferroptosis in OS cells by increasing intracellular ferrous iron levels and inhibiting the STAT3/SLC7A11 axis. Our results reveal a MAT2A-mediated ferroptosis defense mechanism used by OS cells and propose a potential ferroptosis-inducing strategy for the treatment of OS patients.

Conventional versus hybrid knife endoscopic submucosal dissection in large colorectal laterally spreading tumors: A propensity score analysis.

Background: Colorectal endoscopic submucosal dissection (CR-ESD) has become a promising treatment for laterally spreading tumors (LSTs), but is accompanied by great challenges. .: This study aimed to evaluate the efficacy and safety of CR-ESD with a hybrid knife, versus the conventional technique for LSTs ≥30 mm in diameter, and analyze the risk factors for piecemeal resection and perforation. Methods: Patients eligible for CR-ESD were divided into two groups according to the use of the hybrid knife (HK group) or the use of the conventional technique, with an interchange of injection and hook knife (C-group). We performed propensity score matching (PSM) to compare the HK group and the C-group. Risk predictors for perforation and piecemeal resection were identified. Results: PSM identified 61 (132 patients) and 61 (129 patients) patients in the C-group and the HK group, respectively. Resection speed was significantly faster in the HK group than in the C-group (18.86 vs. 13.33 mm2/min, P < 0.001). The rate of knife exchange was significantly lower in the HK group than in the C-group (1.6% vs. 49.2%, P < 0.001). Multivariate analysis revealed that unfavorable locations, including the splenic flexure, hepatic flexure, or cecum, were predictive of piecemeal resection. The presence of severe fibrosis and a semilunar fold were independent risk factors for perforation. Conclusions: : The use of a hybrid knife appears to increase CR-ESD resection speed. The indicators for piecemeal resection or perforation in CR-ESD identified herein might help to assess the technical difficulties of CR-ESD.

Efficacy of K-wire tension band fixation compared with other alternatives for patella fractures: a meta-analysis.

BACKGROUND: To compare the efficacy and safety of K-wire tension band fixation (KTB) with other alternative approaches (cannulated screws, cable pin, and ring pin) for treatment of patella fractures by performing a meta-analysis. METHODS: PubMed and EMBASE databases were searched for all relevant studies. Standardized mean difference (SMD) or relative risk (RR) and their corresponding 95% confidence intervals (CIs) were calculated for continuous or dichotomous outcomes via either a fixed- or random-effect model using Stata 13.0 software. RESULTS: Nine literatures involving 949 patients (581 in the KTB group and 368 in the control group) were included. Pooled analysis showed there were no differences in the success rate, operative time, healing time, and number of infections between patients undergoing KTB and others. However, the incidence of complications (RR = 8.04, 95% CI = 4.45-14.53; p < 0.001) and VAS (SMD = 0.642, 95% CI = 0.22-1.06; p = 0.003) were lower, while flexion degree (SMD = - 0.70 95% CI = - 1.04-- 0.36; p < 0.001), Böstman joint function score (SMD = - 0.68, 95% CI = - 1.10-- 0.27; p = 0.001), Iowa knee score (RR = 0.88, 95% CI = 0.81-0.96; p = 0.004), and Lysholm score (SMD = - 0.71, 95% CI = - 1.10-- 0.32; p < 0.001) were significantly higher in patients undergoing alternative approaches than the KTB. Subgroup analysis also demonstrated the cannulated screw fixation was superior to KTB in reducing the incidence of complications. CONCLUSIONS: Alternative treatments may be effective for management of patella fractures and should be attempted to be popularized in clinic.

Establishing the 3-D finite element solid model of femurs in partial by volume rendering.

OBJECTIVE: It remains rare to report three-dimensional (3-D) finite element solid model of femurs in partial by volume rendering method, though several methods of femoral 3-D finite element modeling are already available. We aim to analyze the advantages of the modeling method by establishing the 3-D finite element solid model of femurs in partial by volume rendering. DESIGN: A 3-D finite element model of the normal human femurs, made up of three anatomic structures: cortical bone, cancellous bone and pulp cavity, was constructed followed by pretreatment of the CT original image. Moreover, the finite-element analysis was carried on different material properties, three types of materials given for cortical bone, six assigned for cancellous bone, and single for pulp cavity. RESULTS: The established 3-D finite element of femurs contains three anatomical structures: cortical bone, cancellous bone, and pulp cavity. The compressive stress primarily concentrated in the medial surfaces of femur, especially in the calcar femorale. CONCLUSIONS: Compared with whole modeling by volume rendering method, the 3-D finite element solid model created in partial is more real and fit for finite element analysis.