MTHFD1L as a folate cycle enzyme correlates with prognostic outcome and its knockdown impairs cell invasive behaviors in osteosarcoma via mediating the AKT/mTOR pathway.

Osteosarcoma (OS) is the most frequent primary malignancy initially in bone with multiple genomic aberrations. Methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L) is linked with the progression of diverse tumors. However, its function in OS is not understood completely. The expression pattern and prognostic significance of MTHFD1L in OS tissues were analyzed based on GEO database. The expression level of MTHFD1L in OS cell lines was explored by qRT-PCR. The cell proliferation, colony formation ability, invasion as well as migration in OS cells after MTHFD1L knockdown were determined using cell counting kit 8 (CCK-8) assay, colony formation and transwell methods. GSEA analysis was performed to predict the underlying mechanisms of MTHFD1L in OS development. Furthermore, the western blot was utilized to study the influence of MTHFD1L on AKT/mTOR pathway. Our results indicated that MTHFD1L expression was significantly up-regulated in OS tissues and cells compared with normal tissues and cells. High expression of MTHFD1L could lead to poor prognosis of OS patients. Cell proliferation, colony formation ability, migration and invasion were blocked because of reduced MTHFD1L in vitro. Moreover, cell cycle and AKT/mTOR pathway were all associated with MTHFD1L expression. In conclusion, the findings revealed that MTHFD1L might promote the development of OS via mediating cell cycle and AKT/mTOR pathway, indicating that MTHFD1L might act as a promising therapeutic target for OS treatment.

Arbutin suppresses osteosarcoma progression via miR-338-3p/MTHFD1L and inactivation of the AKT/mTOR pathway.

Arbutin, a glycoside extracted from the plant Arctostaphylos uva-ursi, has been previously reported to possess antioxidant, anti-inflammatory and anticancer effects. Here, we investigated whether arbutin affects the proliferation of the cells of the osteosarcoma (OS) cell lines MG-63 and SW1353. Arbutin suppressed OS cell viability in a dose- and time-dependent manner, as shown by Cell Counting Kit-8 assay. Furthermore, arbutin exposure decreased the protein levels of MTHFD1L, CCND1 and phosphorylated-protein kinase B (AKT)/phosphorylated-mammalian target of rapamycin (mTOR). Potential upstream miRNAs of MTHFD1L were predicted using TargetScan, PICTAR5, miRanda and miRWalk. We performed luciferase activity assays to show that miR-338-3p directly targets and negatively regulates the expression of MTHFD1L. Knockdown of miR-338-3p promoted cell invasion, migration and proliferation in arbutin-treated OS cells via MTHFD1L. In summary, our data suggest that arbutin inhibits OS cell proliferation, migration and invasion via miR-338-3p/MTHFD1L and by inactivating the AKT/mTOR pathway.

Serum lipoprotein-associated phospholipase A2 level is positively correlated with the recurrence risk of acute ischemic cerebral infarction in hypertensive patients / 南方医科大学学报

OBJECTIVE@#To explore the relationship between serum lipoprotein-associated phospholipase A2 (Lp-PLA2) level and the risk of acute ischemic stroke (AIS) recurrence in hypertensive patients.@*METHODS@#This retrospective case-control study was conducted among 211 hypertensive patients with AIS treated in Foshan First People's Hospital, including 35 patients with recurrence of AIS during the 1-year follow-up as confirmed by head CT/MR. In the overall patients, 60 had grade 1 hypertension (including 5 recurrent cases), 76 had grade 2 hypertension (with 11 recurrent cases), and 75 had grade 3 hypertension (with 19 recurrent cases). Univariate analysis, multivariate logistic regression analysis, trend analysis, and smooth curve fitting analysis were performed to explore the correlation between serum Lp-PLA2 level within 24 h after admission and the risk of AIS recurrence. The predictive efficacy of serum Lp-PLA2 level for AIS recurrence in different hypertension grades was evaluated using ROC curve analysis.@*RESULTS@#Serum Lp-PLA2 level, age, NIHSS score at admission, mRS scores at 7 days, homocysteine level and smoking status differed significantly between patients with and without AIS recurrence (P < 0.05). After adjustment for confounding factors, multivariate regression analysis showed that the highest tertile of Lp-PLA2 level was associated with a 4.13-fold increase of AIS recurrence risk compared with the lowest tertile (OR=5.13, 95% CI: 1.35-19.40), and each 1 ng/mL increase of Lp-PLA2 level was associated with a 1% increase of AIS recurrence risk (OR= 1.01, 95% CI: 1.01-1.02). Serum Lp-PLA2 level was shown to positively correlate with AIS recurrence risk, and in patients with grade 3 hypertension, its areas under the ROC curve for predicting AIS recurrence was 0.869 with a specificity of 0.893 and a sensitivity of 0.737.@*CONCLUSION@#Serum Lp-PLA2 concentration is an independent risk factor and potentially an effective predictor for AIS recurrence in patients with grade 3 hypertension.