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AIMS: Patients with haemochromatosis (HFE) are known to have an increased risk of developing hepatocellular carcinoma (HCC). Available data are conflicting on whether such patients have poorer prognosis, and there is lack of data regarding the biology of HFE-HCC. We compared the course of HFE-HCC with a matched non-HFE-HCC control group and examined tumour characteristics using immunohistochemistry. METHODS: In this tertiary care-based retrospective analysis, 12 patients with HFE and 34 patients with alcohol/non-alcoholic steatohepatitis who underwent initially successful curative HCC therapy with ablation or resection were identified from our registry. Time to tumour progression was compared. Resected liver tissue from a separate cohort of 11 matched patients with HFE-HCC and without HFE-HCC was assessed for the expression of progenitor and epithelial-mesenchymal transition markers using immunohistochemistry. RESULTS: The median follow-up was 24.39 and 24.28 months for patients with HFE-HCC and those without HFE-HCC, respectively (p>0.05). The mean time to progression was shorter in the HFE group compared with the non-HFE group (12.87 months vs 17.78 months; HR 3.322, p<0.05). Patients with HFE-HCC also progressed to more advanced disease by the end of follow-up (p<0.05). Immunohistochemical analysis of matched HFE-HCC and non-HFE-HCC explants demonstrated increased expression of the cancer stem cell markers EpCAM (epithelial cell adhesion molecule) and EpCAM/SALL4 (spalt-like transcription factor 4) coexpression in HFE-HCC specimens (p<0.05). There was a high frequency of combined tumour subtypes within the HFE cohort. CONCLUSIONS: This study demonstrates that the clinical course of patients with HFE-HCC is more aggressive and provides the first data indicating that their tumours have increased expression of progenitor markers. These findings suggest patients with HFE-HCC may need to be considered for transplant at an earlier stage.
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BACKGROUND CONTEXT: The nonunion rate after posterolateral spinal fusion can be as high as 35%. This has stimulated interest in the development of techniques for enhancing new bone formation, including the addition of bioactive peptides or the use of cell-based therapies, including genetically modified cells. In previous studies we have demonstrated that exposing autologous, marrow-derived osteoprogenitor cells to a recombinant human bone morphogenetic protein-6 (rhBMP-6) containing extracellular matrix induces osteoblastic differentiation, and that these cells are capable of increasing new bone formation. Growth of autologous cells on a synthetic rhBMP-6 containing matrix yields a population of stimulated osteoprogenitor cells, without the expense of adding large amounts of rhBMP-6 directly, or the risks inherent in the use of genetically altered cells. PURPOSE: This study was performed to evaluate the potential of rhBMP-6 stimulated osteoprogenitor cells (stOPC) to enhance the rate and strength of posterolateral spinal fusion. STUDY DESIGN: Prospective in vivo animal study OUTCOME MEASURES: Radiographic evidence of spinal fusion, biomechanical testing of explanted spines, histological analysis of new bone formation METHODS: Single-level posterolateral spinal arthrodeses were performed in 69 New Zealand white rabbits. Autologous marrow stem cells were concentrated and then plated on an rhBMP-6-rich extracellular matrix synthesized by genetically engineered mouse C3H10T1/2 cells. Animals in Groups I (n=18) and II (n=18) received autografts of 30M and 60M rhBMP-6 stOPCs in guanidine extracted demineralized bone matrix (gDBM), respectively, whereas those in Group III (n=13) received iliac crest bone graft (ICBG). Those in Group IV (n=10) received gDBM, and those in Group V (n=10) underwent decortication only. Assessment of fusion was made with serial radiographs, manual palpation of the explanted spines, and biomechanical testing. The fusion masses from two animals each in Groups I, II, and IV were evaluated histologically. RESULTS: Fifty-three animals were available for analysis at the conclusion of the study. In these animals, the arthrodesis rate was significantly higher after treatment with rhBMP-6 stOPCs (77% for both Groups I and II by palpation) than ICBG, gDBM, or decortication alone (Group III=55%, IV=20% and V=0%, respectively). Similarly, the peak loads to failure of the fusion masses in Groups I and II (212.5+/-37.8 N and 234.6+/-45.7 N) were significantly greater than the corresponding values in the other groups (Group III=155.9+/-36.4N, Group IV=132.7+/-59.9N, and Group V=92.8+/-18.4N), though when only the fused specimens in Groups I, II, and III were compared, only Group II was significantly different than Group III (234.6+/-45.7N and 155.9+/-36.4N, respectively). The fusion masses in the rhBMP-6 stOPC-treated animals were typified by a thin, fusiform cortical shell, newly formed trabecular bone emanating from the decorticated transverse processes, and residual unremodeled gDBM carrier particles. The fusion masses in the gDBM treated bones were morphologically similar, though they contained less newly formed bone. CONCLUSIONS: The use of rhBMP-6 stOPCs in a carrier of gDBM significantly enhanced the rate and strength of single-level posterolateral spinal arthrodeses in the New Zealand white rabbit, compared with ICBG, gDBM, and decortication alone. Our results confirm that the stimulation of marrow-derived osteoprogenitor cells by growing them on a rhBMP-6 containing extracellular matrix is feasible. Further investigation is warranted to determine the relative contribution of rhBMP-6 stimulation and the number of cells implanted, as well as strategies for optimizing the technique for clinical application.
