The ß5/focal adhesion kinase/glycogen synthase kinase 3ß integrin pathway in high-grade osteosarcoma: a protein expression profile predictive of response to neoadjuvant chemotherapy.

To date, chemosensitivity to neoadjuvant chemotherapy of patients with high-grade osteosarcoma is evaluated on surgical resection by evaluation of the percentage of necrotic cells. As yet, no predictive profile of response to chemotherapy has been used in clinical practice. Because we have previously shown that the integrin pathway controls genotoxic-induced cell death and hypoxia, we hypothesized that in primary biopsies, expression of proteins involved in this pathway could be associated with sensitivity to neoadjuvant chemotherapy in high-grade osteosarcoma. We studied ß1, ß3, and ß5 integrin expression and integrin-linked kinase, focal adhesion kinase (FAK), glycogen synthase kinase 3ß (GSK3ß), Rho B, angiopoietin-2, ß-catenin, and ezrin expression by immunohistochemistry in 36 biopsies of osteosarcomas obtained before treatment. All patients received a chemotherapy regimen in the neoadjuvant setting. An immunoreactive score was assessed, combining the percentage of positive tumor cells and staining intensity. We evaluated the correlation of the biomarkers with response to chemotherapy, metastasis-free survival, and overall survival. A combination of 3 biomarkers (ß5 integrin, FAK, and GSK3ß) discriminated good and poor responders to chemotherapy, with the highest area under the curve (89.9%; 95% confidence interval, 77.4-1.00) and a diagnostic accuracy of 90.3%. Moreover, high expression of ezrin was associated with an increased risk of metastasis (hazard ratio, 3.93; 95% confidence interval, 1.19-12.9; P = .024). We report a protein expression profile in high-grade osteosarcoma associating ß5 integrin, FAK, and GSK3ß that significantly correlates with poor response to neoadjuvant chemotherapy. This biomarker profile could help select patients for whom an alternative protocol using inhibitors of this pathway can be proposed.

French multicenter 22-year experience in stem cell transplantation for beta-thalassemia major: lessons and future directions.

Although hematopoietic stem cell transplantation (HSCT) offers curative potential for beta-thalassemia major (beta-TM), it is associated with a variable but significant incidence of graft rejection. We studied the French national experience for improvement over time and the potential benefit of antithymocyte globulin (ATG). Between December 1985 and December 2007, 108 patients with beta-TM underwent HSCT in 21 different French transplantation centers. The majority of patients received a matched sibling transplant (n = 96) and a busulfan- and cyclophosphamide-based conditioning regimen (n = 95), also with ATG in 57 cases. Ninety-five of the 108 patients survived, with a median follow-up of 12 years. Probabilities of 15-year survival and thalassemia-free survival after first HSCT were 86.8% and 69.4%, respectively. Graft failure occurred in 24 patients, 11 of whom underwent a second HSCT. The use of ATG was associated with a decrease in rejection rate from 35% to 10%. Thalassemia-free survival improved significantly with time, reaching 83% in the 54 patients undergoing HSCT after 1994 (median time of HSCT). In view of the increased risk of graft rejection after matched sibling HSCT, current French national guidelines recommend, for all children at risk for beta-TM, the systematic addition of ATG to the myeloablative conditioning regimen and special attention to optimize transfusion and chelation therapy in the pretransplantation period.