C. Le Goff

Étude comparative de cinq techniques de préparation plaquettaire (platelet-rich plasma)

AIM OF THE STUDY Injections of platelet-rich plasma (PRP) constitute a new therapeutic for treating chronic tendinopathies. The injection being carried out in the tendon, the volume of PRP should thus be minimal (to decrease the intratendinous pressure and to minimize pain). This PRP should also have a raised platelet count. The quantity of released growth factors could be related to the system of preparation employed. We thus carried out a comparative study of five techniques of preparation of PRP described in the literature. MATERIALS AND METHODS Samples of venous blood were taken among five patients in order to compare five techniques of preparation of PRP: University Hospital of Liège technique, Curasan(®) PRP Kit, Plateltex(®), GPS(®)II and RegenLab(®). RESULTS The various techniques make it possible to obtain more important platelet concentration than in blood, with variable volumes (0,3 to 6ml). The number of platelets per microlitre appears higher with Plateltex(®) and obtains smallest volume of PRP. The other techniques also give small volumes except for the GPS(®)II. The number of collected platelets with this technique appears thus higher. The best collect efficiency is obtained with RegenLab(®). CONCLUSION The technique Plateltex(®) makes it possible to collect the highest concentration of platelets in the smallest volume available.

Using platelet-rich plasma to treat jumper's knees: Exploring the effect of a second closely-timed infiltration

OBJECTIVES Some clinical series have evaluated the effect of platelet-rich plasma (PRP) in the treatment of proximal patellar tendinopathy. Although it is possible that a single infiltrative administration may prove to be an effective treatment for this indication, most of the existing studies evaluated the effects of two or three successive infiltrations. The aim of this study was to evaluate whether two infiltrations of PRP proves more effective than a single treatment. DESIGN Prospective, randomized and comparative study of level 2. METHODS Twenty patients suffering from chronic proximal patellar tendinopathy were enrolled into the study and split into two randomized groups (one or two infiltrations of PRP, respectively). The 3-month follow-up evaluation consisted of VAS, IKDC and VISA-P scores, along with algometer, isokinetic and ultrasounds evaluations. After 1 year, subjects were contacted to define their functional evolution. RESULTS The concentration of the PRP used for each infiltration was similar in both groups, and contained no red or white cells. Results revealed no difference in treatment efficacy between the groups. CONCLUSIONS The comparison between one or two infiltrations of PRP did not reveal any difference between the two groups at short to mid term. A second closely-timed infiltration of PRP to treat proximal patellar tendinopathies is not necessary to improve the efficacy of this treatment in the short term.

Myoferlin regulates cellular lipid metabolism and promotes metastases in triple-negative breast cancer.

Myoferlin is a multiple C2-domain-containing protein that regulates membrane repair, tyrosine kinase receptor function and endocytosis in myoblasts and endothelial cells. Recently it has been reported as overexpressed in several cancers and shown to contribute to proliferation, migration and invasion of cancer cells. We have previously demonstrated that myoferlin regulates epidermal growth factor receptor activity in breast cancer. In the current study, we report a consistent overexpression of myoferlin in triple-negative breast cancer cells (TNBC) over cells originating from other breast cancer subtypes. Using a combination of proteomics, metabolomics and electron microscopy, we demonstrate that myoferlin depletion results in marked alteration of endosomal system and metabolism. Mechanistically, myoferlin depletion caused impaired vesicle traffic that led to a misbalance of saturated/unsaturated fatty acids. This provoked mitochondrial dysfunction in TNBC cells. As a consequence of the major metabolic stress, TNBC cells rapidly triggered AMP activated protein kinase-mediated metabolic reprogramming to glycolysis. This reduced their ability to balance between oxidative phosphorylation and glycolysis, rendering TNBC cells metabolically inflexible, and more sensitive to metabolic drug targeting in vitro. In line with this, our in vivo findings demonstrated a significantly reduced capacity of myoferlin-deficient TNBC cells to metastasise to lungs. The significance of this observation was further supported by clinical data, showing that TNBC patients whose tumors overexpress myoferlin have worst distant metastasis-free and overall survivals. This novel insight into myoferlin function establishes an important link between vesicle traffic, cancer metabolism and progression, offering new diagnostic and therapeutic concepts to develop treatments for TNBC patients.