ABSTRACT
Objective·To explore the molecular classification and prognostic prediction of gastric cancer based on nonnegative matrix factorization (NMF).Methods·Cases of gastric cancer were acquired from Gene Expression Omnibus (GEO). Expression profiling of lncRNA was performed by using a lncRNA-mining approach. NMF model was built with Consensus Cluster Plus package. The relationship among NMF subgroups and clinical relevance was assessed. Results·According to the molecular classification based on NMF, samples were divided into three subgroups. Significant difference was observed in relapse state, lymph node ratio, Lauren classification, TNM stage and age of onset among three subgroups. High-risk group was identified with shortest relapse time by survival analysis both in GSE62254 and GSE15459. Multivariate Cox proportional-hazards regression showed that NMF model based molecular classfication could be regarded as an independent risk factor for gastric cancer. Gene set variance analysis (GSVA) and gene set enrichment analysis (GSEA) showed that the high-risk subgroup was enriched in several tumor development pathways. Conclusion·Based on NMF model, the molecular classification of gastric cancer can be used for treatment decision and prognostic prediction.
ABSTRACT
Objective·To explore the molecular classification and prognostic prediction of gastric cancer based on nonnegative matrix factorization (NMF).Methods·Cases of gastric cancer were acquired from Gene Expression Omnibus (GEO). Expression profiling of lncRNA was performed by using a lncRNA-mining approach. NMF model was built with Consensus Cluster Plus package. The relationship among NMF subgroups and clinical relevance was assessed. Results·According to the molecular classification based on NMF, samples were divided into three subgroups. Significant difference was observed in relapse state, lymph node ratio, Lauren classification, TNM stage and age of onset among three subgroups. High-risk group was identified with shortest relapse time by survival analysis both in GSE62254 and GSE15459. Multivariate Cox proportional-hazards regression showed that NMF model based molecular classfication could be regarded as an independent risk factor for gastric cancer. Gene set variance analysis (GSVA) and gene set enrichment analysis (GSEA) showed that the high-risk subgroup was enriched in several tumor development pathways. Conclusion·Based on NMF model, the molecular classification of gastric cancer can be used for treatment decision and prognostic prediction.
ABSTRACT
Objective To compare biomechanical properties of the helical and straight long PHILOS (proximal humerus internal locking system) plates (Synthes Inc., Switzerland), so as to provide some biomechanical evidence for treating proximal metaphyseal-diaphyseal humeral shaft fractures in clinic. Methods Twelve Synbone artificial bones of right humerus (SYNBONE Inc., Switzerland) were divided into two groups. In control group (n=6), the humerus was fixed with the 10 hole long straight PHILOS plate, while in experimental group (n=6), the humerus was fixed with the same long PHILOS plate which was precontoured for moulding (i.e. helical PHILOS plate). After the proximal metaphyseal-diaphyseal humeral shaft fractures were made in all artificial bones, the biomechanical properties of the specimens in two groups under 6 loading modes (i.e., axial tension and compression, torsion in the same and reverse direction, medial-lateral and anterior-posterior three-point bending) were tested en bloc and compared. ResultsCompare with control group, under 100-500 N tensile and compressive loads, the axial displacement at the fractured end in experimental group increased by about 95% and 58%, respectively. Under 0.6-3 N•m torsional moment in reversed direction, the tensional angle in experimental group was obviously smaller than that in control group, with a decrease of 55%-64%. Under medial-lateral bending moment of 1.5 and 3 N•m, no significant difference was found in deflection of the experiment and control group, while under medial-lateral bending moment of 4.5, 6 and 7.5 N•m, the deflection in experimental group decreased by 20%-30% as compared to control group. Under 0.6-3 N•m torsional moment in the same direction and 1.5-7.5 N•m anterior-posterior bending moment, both the torsional angle and the deflection in experimental group were larger than those in control group, with a significant difference (P＜0.05). Compared with control group, the tensile stiffness and compressive stiffness decreased by 49% and 36%, the torsional stiffness in the same direction decreased by 19% and that in reversed direction increased by 150%, three-point bending stiffness in medial lateral direction increased by 18% and that in anterior posterior direction decreased by 70% in experimental group, all with a significant difference (P＜0.05). ConclusionsCompared with the long straight PHILO plate, the long helical PHILOS plate has better biomechanical properties, which can meet the clinical need of proximal metaphyseal-diaphyseal humeral shaft fracture fixation and postoperative rehabilitation. This surgical technique is expected to be widely applied in clinic, especially with the advantage of minimal invasive surgery.