Effect and Mechanism of EGFL7 Downregulation in Human Osteosarcoma Cells on the Biological Function of Co-cultured HUVEC.

BACKGROUND: Even though epidermal growth factor-like domain 7 is known to be overexpressed in osteosarcoma and is associated with poor clinical outcome, few reports are available regarding its mechanism. AIMS: The objective of this study was to explore the effect and mechanism of downregulating epidermal growth factor-like domain 7 expression in a human osteosarcoma cell line on the biological function of co-cultured human umbilical vein endothelial cells. STUDY DESIGN: Cell study. METHODS: In the present study, human osteosarcoma cell lines U2OS, Saos-2, HOS, and MG63, and normal human osteoblasts were cultured in Dulbecco's Modified Eagle Medium containing 10% fetal bovine serum and 1x antibiotics at 37 °C and 5% CO2 in an incubator. Of the four osteosarcoma cell lines, U2OS expresses the highest level of epidermal growth factor-like domain 7 mRNA as determined using quantitative reverse transcription polymerase chain reaction. With the knockdown of epidermal growth factor-like domain 7 in U2OS and human umbilical vein endothelial cells by lentivirus, the proliferation and apoptosis of U2OS and human umbilical vein endothelial cells were investigated using MTT and flow cytometry assays. After the co-culture of human umbilical vein endothelial cells and epidermal growth factor-like domain 7-knockdown U2OS, the in vitro effects on cell proliferation, apoptosis, adhesion, migration, and the angiogenic ability of human umbilical vein endothelial cells were detected using MTT, flow cytometry, Transwell, and tube formation assays, respectively. The expressions of phosphoinositide 3-kinase, phospho-Akt, total Akt, and vascular endothelial growth factor in human umbilical vein endothelial cells were detected using western blot assay. RESULTS: Lentivirus with epidermal growth factor-like domain 7 shRNA could not significantly affect the proliferation and apoptosis of both U2OS and human umbilical vein endothelial cells, whereas the knockdown of epidermal growth factor-like domain 7 in U2OS could significantly inhibit the migration, adhesion, and angiogenic ability of co-cultured human umbilical vein endothelial cells. In addition, the expressions of phosphoinositide 3-kinase, phospho-Akt, and vascular endothelial growth factor in human umbilical vein endothelial cells decreased after co-culturing with epidermal growth factor-like domain 7-knockdown U2OS. CONCLUSION: Epidermal growth factor-like domain 7-knockdown U2OS cells inhibit the migration, adhesion, and angiogenesis of co-cultured human umbilical vein endothelial cells by diminishing phosphoinositide 3-kinase, Akt signaling pathway activity and vascular endothelial growth factor expression.

[Arthroscopic surgery on traumatic anterior instability of shoulder].

OBJECTIVE: To study the principle of arthroscopic surgery and its clinical importance on the traumatic anterior shoulder instability. METHODS: From September 2002 to May 2005, 18 patients with injury history of 15 weeks averagely, were involved in the study. Twelve of the patients had a history of sports injuries, 5 had shoulder injuries during working time, and 1 had a traffic accident. Among them, 18 had shoulder pain, 15 had limitation of range of motion (ROM) of shoulder, 18 had positive apprehension test and 5 had positive speed test. Three patients had Hill-Satch lesion in X-ray. Double contrast CT: I degree: 1; II degree: 15; III degree: 2. On arthroscopic view, 18 had anterior glenoid labrum detachment, 4 had anterior capsular laxity, 4 had combined superior labral anterior posterior (SLAP) injury, 3 had free body, 2 had humeral head or glenoid cartilage lesion. Anterior glenoid labrum detachment in 18 patients was reduced and sutured by the fixed anchor technique, 3 had anterior capsule shrinkage, 2 had debridement of frayed long head tendon of biceps, and 2 had reattachment of the long head tendon of biceps outside the capsule. SLAP injuries were sutured in 3 and debridement of frayed superior labrum in 1. RESULTS: All of the patients were followed up with an average of 18 months (10 - 32 months). All the patients felt free of the pain of their shoulder, except one felt shoulder aching after strenuous exercise. The loss of the external-rotation of the operated shoulder was less than 20 degrees in 2 patients and the posterior extension was 10 degrees in 1 patient. One patient had a positive result of Apprehension Sign. UCLA score: 14 +/- 3 preoperatively, 32 +/- 5 postoperatively (t = 14.081, P < 0.01). All patients returned to pre-injured sports activities and original work. CONCLUSIONS: Traumatic anterior shoulder instability can obtain good effects when treated with the arthroscopic surgery of shoulder. Complete reduction, and reliable fixation of the anterior glenoid labrum complex is the key point. Fixation with the suture anchor is reliable and makes the operation simple.

Analysis of differentially expressed genes between rheumatoid arthritis and osteoarthritis based on the gene co-expression network.

The aim of the current study was to investigate disease-associated genes and related molecular mechanisms of osteoarthritis (OA) and rheumatoid arthritis (RA). Using GSE7669 datasets downloaded from Gene Expression Omnibus databases, the differentially expressed genes (DEGs) between RA and OA synovial fibroblasts (SFBs) (n=6 each) were screened. DEG-associated co-expression and topological properties were analyzed to determine the rank of disease-associated genes. Specifically, the fold change of differentially expressed genes, the clustering coefficient and the degree of differential gene co-expression were integrated to determine the disease-associated gene ranking. The underlying molecular mechanisms of these crucial disease-associated genes were investigated by gene ontology (GO) enrichment analysis. A total of 1313 DEGs, including 1068 upregulated genes and 245 downregulated genes were observed. The top 20 disease-associated genes were identified, including proteoglycan 4, inhibin ß B, carboxypeptidase M, alcohol dehydrogenase 1C and integrin ß2. The major GO biological processes of these top 20 disease-associated genes were highly involved in the immune system, such as responses to stimuli, immune responses and inflammatory responses. This large-scale gene expression study observed disease-associated genes and their associated GO function in RA and OA, which may provide opportunities for biomarker development and novel insights into the molecular mechanisms of these two diseases.

Comparison of proximal femoral nail antirotation blade and reverse less invasive stabilization system-distal femur systems in the treatment of proximal femoral fractures.

OBJECTIVE: To compare the effects of proximal femoral nail antirotation blade (PFNA) and reverse less invasive stabilization system-distal femur (Liss-DF) systems in the treatment of proximal femoral fractures. METHODS: Between June 2007 and October 2009, 41 proximal femoral fractures were treated, 22 with PFNA (group A) and 19 with reverse LISS-DF plates (group B). The time to starting full weight-bearing, fracture healing time, functional recovery (Parker and Palmer mobility score), neck-shaft angle discrepancies with the intact contralateral hip, preoperative American Society of Anesthesiologists (ASA) scores, the operation durations and amount of intraoperative bleeding were recorded and compared. RESULTS: The mean follow-up period was 11.2 months (range, 10-12 months). Compared with Group A, Group B showed a statistically longer mean time to bear full body weight and heal their fractures, but a smaller neck-shaft angle discrepancy (all P < 0.05). The groups were similar in ASA score, operation duration, amount of intraoperative bleeding and Parker and Palmer mobility score. CONCLUSION: Both PFNA and reverse Liss-DF were satisfactory for the treatment of proximal femoral fractures, but had different advantages. PFNA allowed earlier weight-bearing and accelerated fracture healing. Reverse Liss-DF more effectively avoided coxa vara and may be indicated for patients with very severe osteoporosis.