Secreted protein acidic and rich in cysteine (SPARC) is a secreted protein which is involved in various biological processes. SPARC expression is associated with tumor metastasis and poor prognosis in several types of cancer. However, the SPARC-induced signaling pathway was not fully understood in head and neck cancer. In this study, our results showed that SPARC treatment promoted cell proliferation and migration in head and neck cancer cell lines FaDu and Detroit 562. In addition, SPARC induced expression of epithelial mesenchymal transition (EMT) regulators, including Slug, Snail, and Twist in Detroit 562. The results of phospho-kinase array analysis showed that SPARC treatment increased phosphorylation of some molecules including protein kinase B (PKB/AKT), ribosomal S6 kinase (RSK), and extracellular signal–regulated kinases (ERK). The expression of SPARC-induced EMT regulator Slug was suppressed by AKT inhibitor, but not ERK and RSK inhibitors. The SPARC expression in grade IV tumor samples is higher when compared to that in grade I–III tumor samples. Our results suggest that SPARC treatment enhances the EMT signaling pathway via activation of AKT, and exogenous SPARC and tumor expressing SPARC might be associated with tumor progression in head and neck cancers.
Restoring sufficient vascularity of the ischemia/hypoxia flap is always the critical issue in flap surgeries. In a previous studies microRNA-21 (miR-21) expression was upregulated after rat skin flap surgery. MiR-21 has been reported to be induced by hypoxia and the function of miR-21 involves in the process of angiogenesis. However, the precise regulatory mechanisms in miR-21-mediated pathways are still unclear. These issues were investigated via in vitro and in vivo experiments in this study. In human umbilical vein endothelial cells (HUVEC), the expression of hsa-miR-21-5p was induced after hypoxic culture and the induction of hsa-miR-21-5p was suppressed after sequential normoxic culture. Moreover, transfection of hsa-miR-21-5p mimic enhanced tube formation capacity in normoxia, but attenuated it in hypoxia. Furthermore, bioinformatic analysis suggested that SMAD7 was a predicted target of hsa-miR-21-5p. Our results demonstrated the effect of hsa-miR-21-5p was different on SMAD7 expression in normoxia and hypoxia. In rat skin flaps, blockage of miR-21-5p significantly increased angiogenesis via analysis of color laser Doppler imaging and repressed SMAD7 expression in ischemic skin tissue. Our study showed the opposite effect of miR-21-5p mediating angiogenesis in normoxia and hypoxia, providing important implications regarding the design of novel miRNA-based therapeutic strategies in flap surgeries.
Suture anchors are extensively used in rotator cuff tear surgery. With the advancement of three-dimensional printing technology, biodegradable metal has been developed for orthopedic applications. This study adopted three-dimensional-printed biodegradable Fe suture anchors with double-helical threads and commercialized non-vented screw-type Ti suture anchors with a tapered tip in the experimental and control groups, respectively. The in vitro study showed that the Fe and Ti suture anchors exhibited a similar ultimate failure load in 20-pound-per-cubic-foot polyurethane foam blocks and rabbit bone. In static immersion tests, the corrosion rate of Fe suture anchors was 0.049 ± 0.002 mm/year. The in vivo study was performed on New Zealand white rabbits and SAs were employed to reattach the ruptured supraspinatus tendon. The in vivo ultimate failure load of the Fe suture anchors was superior to that of the Ti suture anchors at 6 weeks. Micro-computed tomography showed that the bone volume fraction and bone surface density in the Fe suture anchors group 2 and 6 weeks after surgery were superior, and the histology confirmed that the increased bone volume around the anchor was attributable to mineralized osteocytes. The three-dimensional-printed Fe suture anchors outperformed the currently used Ti suture anchors.
Introduction Various management strategies have been reported for sternal wound care; however, they exhibit limited effectiveness or are associated with severe complications. Furthermore, it is difficult for the standard pectoralis major (PM) muscle advance flap to reach the lower third of the sternum. This article examines using the PM-rectus abdominis (RA) bipedicle muscle flap to treat lower-third deep sternal wound infection. Methods The outcomes of patients who received a PM-RA bipedicle muscle flap harvest at our institution between 1996 and 2014 were reviewed. The method involves performing a subfascial and subperiosteal dissection of the PM to elevate the muscle flap. Blunt dissection may be performed carefully under an endoscope. Endoscope visualization enables us to identify the critical structures lateral to the PM muscle. In addition, the connective tissue to the RA muscle was preserved. Continuity was carefully preserved from the pectoral-thoracoepigastric fascia to the anterior rectus sheath. The flap could then be transposed to fill the lower-third sternal tissue defect with ease. Results A total of 12 patients, with a mean age of 71 years (45–89 years), were treated using an endoscope-assisted PM-RA bipedicle muscle flap harvest. Wound microbiology of the 12 patients revealed that 3 patients had methicillin-resistant Staphylococcus aureus, 4 had S. aureus, 1 had coagulase-negative Staphylococcus, 1 had Escherichia coli, 1 had Pseudomonas aeruginosa, 1 had Mycobacterium tuberculosis, and 1 had a mixed growth of organisms. One instance of recurrent sternal infection was identified among the patients. Moreover, 1 patient died from heart failure 5 weeks after surgery, but the coverage of the sternal wound was successful. Accidental injury to the surrounding neurovascular structure of the patients was avoided, and only 10 to 15 minutes was required to divide the PM muscle. Conclusions Performing this harvest method under endoscopic assistance has several advantages, such as preventing excess traction of the skin edge to diminish the skin slough. This method could be an effective alternative for harvesting the PM-RA bipedicle muscle flap to reconstruct the lower-third sternal wound.