CD133-directed CAR T cells for advanced metastasis malignancies: A phase I trial.

Expressed by cancer stem cells of various epithelial cell origins, CD133 is an attractive therapeutic target for cancers. Autologous chimeric antigen receptor-modified T-cell directed CD133 (CART-133) was first tested in this trial. The anti-tumor specificity and the postulated toxicities of CART-133 were first assessed. Then, we conducted a phase I clinical study in which patients with advanced and CD133-positive tumors received CART-133 cell-infusion. We enrolled 23 patients (14 with hepatocellular carcinoma [HCC], 7 with pancreatic carcinomas, and 2 with colorectal carcinomas). The 8 initially enrolled patients with HCC were treated by a CART-133 cell dose escalation scheme (0.05-2 × 106/kg). The higher CAR-copy numbers and its reverse relationship with the count of CD133+ cells in peripheral blood led to the determination of an acceptable cell dose is 0.5-2 × 106/kg and reinfusion cycle in 23 patients. The primary toxicity is a decrease in hemoglobin/platelet (≤ grade 3) that is self-recovered within 1 week. Of 23 patients, three achieved partial remission, and 14 achieved stable disease. The 3-month disease control rate was 65.2%, and the median progression-free survival was 5 months. Repeated cell infusions seemed to provide a longer period of disease stability, especially in patients who achieved tumor reduction after the first cell-infusion. 21 out of 23 patients had not developed detectable de novo lesions during this term. Analysis of biopsied tissues by immunohistochemistry showed CD133+ cells were eliminated after CART-133 infusions. This trial showed the feasibility, controllable toxicities, and effective activity of CART-133 transfer for treating patients with CD133-postive and late-stage metastasis malignancies.

Excessive activated T-cell proliferation after anti-CD19 CAR T-cell therapy.

Excessive activated T-cell proliferation was observed in vivo in one patient after an anti-CD19-chimeric antigen receptor (CAR) T-cell infusion. The patient, who had chemotherapy refractory and CD19+ diffuse large B-cell lymphoma (DLBCL), received an anti-CD19 CAR T-cell infusion following conditioning chemotherapy (fludarabine/cyclophosphamide). The lymphocyte count in the peripheral blood (PB) increased to 77 × 109/L on day 13 post infusion, and the proportion of CD8+ actived T cells was 93.06% of the lymphocytes. Then, the patient suffered from fever and hypoxaemia. Significant increases in serum cytokine, lactate dehydrogenase, aspartate aminotransferase (AST), alanine transaminase (ALT), and glutamic-oxalacetic transaminase (γ-GT) levels were observed. A high-throughput sequencing analysis for T-cell receptors (TCRs) and whole-genome sequencing were used to explore the mechanisms underlying this excessive T-cell proliferation. TCR diversity was demonstrated, but no special gene mutation was found. The patient was found to be infected with the John Cunningham polyomavirus (JCV). It cannot be ruled out the bystander activation pathway induced by JCV infections related the excessive activated T-cell proliferation. Although the clinical and laboratory data do not fully explain the reason for excessive T-cell proliferation after the anti-CD19 CAR T-cell infusion, the risk of this type of toxicity should be emphasized. This study was registered at www.clinicaltrials.gov as NCT01864889.

[Clinical Features and Prognosis of t(8;21) AML Patients in China: A Multicenter Retrospective Study].

OBJECTIVE: To summarize the clinical characteristics of peripheral blood, immune phenotypes, fusion genes and cytogenetics of patients with t(8;21) acute myeloid leukemia(AML) through the retrospective analysis of 586 patients with t(8;21) AML from 15 blood disease research centers in Northern area of China. METHODS: The factors affecting prognosis of patients with t(8;21) AML were investigated by using univariate and multivariate COX regression. RESULTS: The immune type of t(8;21) AML patients was mainly with HLA-DR+, CD117+, CD34+, MPO+, CD38+, CD13+ and CD33+ (>95%), part of them with CD19+ and CD56+; the most common accompanied mutation of t(8;21) AML patients was C-KIT mutation (37.8%); in addition to t(8;21) ectopic, the most common chromosomal abnormality was sex chromosome deletions (38.9%). The univariate analysis revealed a significant survival superiority of OS and PFS in t(8;21) AML patients of WBC≤3.5×109/L without C-KIT mutation, the newly diagnosed ones achieved HSCT(P<0.05), only survival superiority on OS in t(8;21) AML patients with extramedullary infiltration and CD19 positive; the results of multivariate analysis showed a significant survival superiority on OS and PFS in t(8;21) AML patients with WBC≤3.5×109/L(P<0.05). CONCLUSION: The clinical features of t(8;21) AML patients in China are similar to those in other countries, WBC≤3.5×109/L is a good prognostic factor while the C-KIT mutation is a poor one in t(8;21) AML patients.

Cocktail treatment with EGFR-specific and CD133-specific chimeric antigen receptor-modified T cells in a patient with advanced cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CCA) is one of the most fatal malignant tumors with increasing incidence, mortality, and insensitivity to traditional chemo-radiotherapy and targeted therapy. Chimeric antigen receptor-modified T cell (CART) immunotherapy represents a novel strategy for the management of many malignancies. However, the potential of CART therapy in treating advanced unresectable/metastatic CCA is uncharted so far. CASE PRESENTATION: In this case, a 52-year-old female who was diagnosed as advanced unresectable/metastatic CCA and resistant to the following chemotherapy and radiotherapy was treated with CART cocktail immunotherapy, which was composed of successive infusions of CART cells targeting epidermal growth factor receptor (EGFR) and CD133, respectively. The patient finally achieved an 8.5-month partial response (PR) from the CART-EGFR therapy and a 4.5-month-lasting PR from the CART133 treatment. The CART-EGFR cells induced acute infusion-related toxicities such as mild chills, fever, fatigue, vomiting and muscle soreness, and a 9-day duration of delayed lower fever, accompanied by escalation of IL-6 and C reactive protein (CRP), acute increase of glutamic-pyruvic transaminase and glutamic-oxalacetic transaminase, and grade 2 lichen striatus-like skin pathological changes. The CART133 cells induced an intermittent upper abdominal dull pain, chills, fever, and rapidly deteriorative grade 3 systemic subcutaneous hemorrhages and congestive rashes together with serum cytokine release, which needed emergent medical intervention including intravenous methylprednisolone. CONCLUSIONS: This case suggests that CART cocktail immunotherapy may be feasible for the treatment of CCA as well as other solid malignancies; however, the toxicities, especially the epidermal/endothelial damages, require a further investigation. TRIAL REGISTRATION: ClinicalTrials.gov NCT01869166 and NCT02541370 .

Autologous T Cells Expressing CD30 Chimeric Antigen Receptors for Relapsed or Refractory Hodgkin Lymphoma: An Open-Label Phase I Trial.

Purpose: Relapsed or refractory Hodgkin lymphoma is a challenge for medical oncologists because of poor overall survival. We aimed to assess the feasibility, safety, and efficacy of CD30-targeting CAR T cells in patients with progressive relapsed or refractory Hodgkin lymphoma.Experimental Design: Patients with relapsed or refractory Hodgkin lymphoma received a conditioning chemotherapy followed by the CART-30 cell infusion. The level of CAR transgenes in peripheral blood and biopsied tumor tissues was measured periodically according to an assigned protocol by quantitative PCR (qPCR).Results: Eighteen patients were enrolled; most of whom had a heavy treatment history or multiple tumor lesions and received a mean of 1.56 × 107 CAR-positive T cell per kg (SD, 0.25; range, 1.1-2.1) in total during infusion. CART-30 cell infusion was tolerated, with grade ≥3 toxicities occurring only in two of 18 patients. Of 18 patients, seven achieved partial remission and six achieved stable disease. An inconsistent response of lymphoma was observed: lymph nodes presented a better response than extranodal lesions and the response of lung lesions seemed to be relatively poor. Lymphocyte recovery accompanied by an increase of circulating CAR T cells (peaking between 3 and 9 days after infusion) is a probable indictor of clinical response. Analysis of biopsied tissues by qPCR and immunohistochemistry revealed the trafficking of CAR T cells into the targeted sites and reduction of the expression of CD30 in tumors.Conclusions: CART-30 cell therapy was safe, feasible, and efficient in relapsed or refractory lymphoma and guarantees a large-scale patient recruitment. Clin Cancer Res; 23(5); 1156-66. ©2016 AACR.

Comparison of Clinical Efficacy of Cytarabine with Different Regimens in Postremission Consolidation Therapy for Adult t(8;21) AML Patients: A Multicenter Retrospective Study in China.

BACKGROUND: The survival of patients with acute myeloid leukemia (AML) with t(8;21) was reported to be shorter in China than in other countries. PATIENTS: We analyzed the correlation between different cytarabine (Ara-c) regimens and outcome in 255 t(8;21) AML patients in China who received postremission consolidation chemotherapy only. RESULTS: The 5-year overall survival (OS) of the high-dose Ara-c group (HDAC; 2≤ Ara-c ≤3 g/m2), intermediate-dose Ara-c group (MDAC; 1.0≤ Ara-c <2.0 g/m2), low-dose Ara-c group (LDAC; 0.2< Ara-c <1.0 g/m2) and standard-dose Ara-c group (SDAC; 0.1≤ Ara-c ≤0.2 g/m2) were 65.3, 39.4, 25.2 and 27.9%, respectively (p = 0.003). In the HDAC group, but not in the MDAC group, the 5-year OS of patients who achieved 3-4 cycles of chemotherapy was superior to those who underwent 1-2 cycles (84.4 vs. 43.6%, p < 0.05), and the 3-year OS of patients who achieved an accumulated 36 g/m2 of Ara-c was significantly higher compared to those who did not (85.3 vs. 39.2%, p < 0.05). Multivariate analysis indicated that factors such as WBC >3.5 × 109/l, PLT ≤30 × 109/l, and extramedullary infiltration were associated with a poor prognosis. CONCLUSION: The survival of t(8;21) AML patients treated with high-dose Ara-c (≥2 g/m2) was superior to other dose levels in postremission consolidation chemotherapy. Patient survival was improved by 3-4 cycles of chemotherapy with an accumulated concentration of 36 g/m2 of Ara-c. WBC >3.5 × 109/l, PLT ≤30 × 109/l and extramedullary infiltration could be indicative of a poor clinical prognosis.

Treatment of CD20-directed Chimeric Antigen Receptor-modified T cells in patients with relapsed or refractory B-cell non-Hodgkin lymphoma: an early phase IIa trial report.

Patients with relapsed or refractory non-Hodgkin lymphoma have a dismal prognosis. Chimeric Antigen Receptor (CAR)-modified T cells (CART cells) that targeted CD20 were effective in a phase I clinical trial for patients with advanced B-cell lymphomas. We performed a phase IIa trial to further assess the safety and efficacy of administering autologous anti-CD20 CART (CART-20) cells to patients with refractory or relapsed CD20+ B-cell lymphoma. Eleven patients were enrolled, and seven patients underwent cytoreductive chemotherapy to debulk the tumors and deplete the lymphocytes before receiving T-cell infusions. The overall objective response rate was 9 of 11 (81.8%), with 6 complete remissions (CRs) and 3 partial remissions; no severe toxicity was observed. The median progression-free survival lasted for >6 months, and 1 patient had a 27-month continuous CR. A significant inverse correlation between the levels of the CAR gene and disease recurrence or progression was observed. Clinically, the lesions in special sites, specifically the spleen and testicle, were refractory to CART-20 treatment. Collectively, these results together with our data from phase I strongly demonstrated the feasibility and efficacy of CART-20 treatment in lymphomas and suggest large-scale patient recruitment in a future study. This study was registered at www.clinicaltrials.org as NCT01735604.

Association of asthma with the risk of acute leukemia and non-Hodgkin lymphoma.

An increasing incidence of hematological malignancies has been observed in children and adults worldwide over the last few decades. Asthma is a common chronic inflammatory disease. The aim of the present meta-analysis was to evaluate the potential association between a history of asthma and the risk of acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) and non-Hodgkin lymphoma (NHL). A literature search was performed through PubMed and the Cochrane Database of Systematic Reviews and the Newcastle-Ottawa Scale was used to evaluate the quality of the selected studies. The I2 index was used to evaluate heterogeneity and the outcome was measured as the odds ratio (OR) by the random-effects model. A total of 16 case-control studies were included. All the studies were of high quality. The OR for ALL was 0.90 [95% confidence interval (CI): 0.68-1.19; P=0.45; I2=79%]. The OR for AML was 0.85 (95% CI: 0.67-1.08; P=0.19; I2=8%). The OR for NHL was 0.91 (95% CI: 0.83-1.00; P=0.05; I2=0%). Asthma was found to be inversely associated with the risk of NHL. A negative trend of association of asthma with ALL and AML was also observed. However, additional large prospective studies are required to confirm these findings.

Brentuximab vedotin for relapsed or refractory CD30+ Hodgkin lymphoma: a multicenter analysis from Asia.

INTRODUCTION: Brentuximab vedotin (SGN-35), an anti-cluster of differentiation (CD)-30 antibody conjugated to the anti-tubulin agent monomethyl auristatin E, has demonstrated promising efficacy and tolerability in relapsed and heavily treated Hodgkin lymphoma (HL). In this study, we report the Asian experience with brentuximab vedotin in patients with relapsed or refractory CD30-positive (CD30+) HL. METHODS: This is an observational, multicenter, retrospective study. Between October 2011 and June 2013, a total of 22 patients were treated with brentuximab vedotin under a named patient program in Asia. Patients received a 30 min infusion of brentuximab vedotin at a dose of 1.8 mg/kg of body weight every 3 weeks. RESULTS: Four patients (18.2%) showed a complete response, and the overall response rate was 72.7%. The median duration of response was 4.4 months (range 1.0-17.4). The median progression-free survival was 5.7 months, and the median overall survival has not yet been reached. The 1-year expected survival rate was 67.2%. The most common grade 3/4 adverse events were neutropenia (n=7; 31.8%). No patients experienced grade 3/4 sensory neuropathy. CONCLUSIONS: These results confirm that brentuximab vedotin as a single agent is also effective and well tolerated when used in Asian patients with relapsed and refractory CD30+ HL.

NUP214 fusion genes in acute leukemia (Review).

Nucleoporin 214 (NUP214), previously termed CAN, is required for cell cycle and nucleocytoplasmic transport. The genetic features and clinical implications of five NUP214-associated fusion genes are described in this review. SET-NUP214 was most frequently observed in T-cell acute lymphoblastic leukemia (T-ALL), concomitant with the elevated expression of HOXA cluster genes. Furthermore, the fusion transcript may be regarded as a potential minimal residual disease marker for SET-NUP214-positive patients. Episomal amplifications of NUP214-ABL1 are specific to T-ALL patients. The NUP214-ABL1 gene is observed in ~6% of T-ALL, in children and adults. Targeted tyrosine kinase inhibitors plus standard chemotherapy appear to present a promising treatment strategy. DEK-NUP214 is formed by the fusion of exon 2 of DEK and exon 6 of NUP214. Achieving molecular negativity of DEK-NUP214 is of great importance for individual management. SQSTM1-NUP214 and NUP214-XKR3 were only identified in one T-ALL patient and one cell line, respectively. The NUP214 fusions have significant diagnostic and therapeutic implications for leukemia patients. Additional NUP214-associated fusions require identification in future studies.

A Chinese patient with relapsed and refractory Hodgkin lymphoma treated with brentuximab vedotin.

At present, approximately 20% of Hodgkin lymphomas (HL) are relapsed and refractory, and therapeutic methods including chemotherapy, radiotherapy, and even stem cell transplantation are unsatisfactory. Brentuximab vedotin, composed of CD30 antibody and a chemotherapeutic agent, is a new targeted drug that eradicates tumor cells by binding to the CD30 antigen on their surface. In clinical trials, the response rate and complete remission rate of this drug were 73% and 40%, respectively, for relapsed and refractory HL. Here we report a case of CD30-positive relapsed and refractory HL that was treated with brentuximab. Before the treatment with brentuximab, the patient underwent chemotherapy, radiotherapy, and autologous stem cell transplantation. However, the disease continued to progress, affecting multiple organs and prompting symptoms such as persistent fever. After the treatment with brentuximab, the patient's condition improved. Body temperature returned to normal after 4 days. Lung nodules were reduced in size and number after a single course of treatment, and PET/CT showed partial remission and complete remission after 3 and 6 courses of treatment, respectively. The entire treatment process progressed smoothly, though the patient experienced some symptoms due to chemotherapy, including peripheral neuritis of the limbs, irritating dry cough, and mild increase in aminotransferase. No serious adverse effects were observed. The current general condition of the patient is good; the continuous complete remission has amounted to 6 months.

Results of selective hip arthroplasty revision in isolated acetabular failure.

BACKGROUND: Controversy exists over whether to remove well-fixed components at the time of revision of a failed total hip arthroplasty (THA). The purpose of this study was to evaluate the results of selective acetabular revision after acetabular failure in which only the failed component was replaced. MATERIALS AND METHODS: Thirty-six isolated acetabular component revisions were performed and prospectively followed for a mean of 4.7 y (range, 2-9.3 y). The components had been in place for a mean of 10.8 y. All femoral components and some metal-backed acetabular shells were well fixed at the time of revision and left in place. Surgery involved cementation of an acetabular liner into a well-fixed acetabular shell in 16 cases, and acetabular revision in 20 cases. Morselized cancellous allograft was used to fill acetabular defects in 27 hips, and proximal femoral defects in 17 hips. Bulk allografts were used to reconstruct the proximal femur in two hips. RESULTS: The mean Harris hip score improved from 57.8 preoperatively to 89.1 at the final follow-up visit. The results were rated excellent in 24 patients, good in nine patients, and fair in three patients. The unrevised femoral components and acetabular shells remained well fixed, and final follow-up radiographs revealed no cases of osteolytic lesion progression around the femoral and acetabular components. CONCLUSIONS: Revision of only the failed acetabular component is recommended in cases of isolated acetabular failure, providing excellent results over the medium term, and allowing preservation of bone stock with lower surgical morbidity.

[Amifostine used in the treatment of patients with myelodysplastic syndrome].

The study was aimed to investigate the curative effects and adverse effects of amifostine in the treatment of patients with myelodysplastic syndrome (MDS). Amifostine (AMF) was used alone (4/12) or combined with recombinant human erythropoietin (rh-EPO) (8/12) in 12 MDS patients. The therapeutic regimen was adopted with AMF 0.4 g/day for 5 days, then took a break of 2 days and then went on for 3 weeks consecutively, that was reputed as one treatment cycle. rh-EPO 6 000 U was used for 3 days per week. The results showed that 12 patients all attained hematological improvement in peripheral blood. 11 cases showed major effective response rate (91.7%), while 1 case showed minor response rate (8.3%). The effective response rate of hemoglobin, leukocytes and platelets was 100%, 75% and 58.3% respectively. The intervals of red cell transfusions (RCT) in 2 cases living on red cell transfusion before AMF treatment were prolonged after AMF treatments, and the amount of each RCT was decreased obviously. The side effect was usually discomfort of digestive system, but all patients can endure. In conclusion, Amifostine is a potential drug in the treatment of MDS patients with safety especially to those elder patients who often suffered from other multiple organ disfunctions, and the curative effect will be improved by more treatment cycles.

[Experimental study of core binding factor a1 gene-modified rabbit skin fibroblasts enhance bone defect repair].

OBJECTIVE: To investigate bone defect healing by true bone ceramic complex carrying core binding factor a1 (Cbfa1) gene modified rabbit skin fibroblasts. METHODS: Transfect rabbit skin fibroblasts (RSF) with both eukaryotic expression vector pSG5 which could express Cbfa1 gene and pSG5. After being cultured for 48 h, the transfected RSF were seeded into true bone ceramic (TBC) of 2 cm in length and 4 mm in diameter to construct pSG5-Cbfa1/RSF/TBC complex and pSG5/RSF/TBC complex. Forty-eight bone defect model rabbits were randomized into four groups, each has 6 rabbits (12 radius), due to different treatment. group I: with pSG5-Cbfa1/RSF/TBC complex, group II: with pSG5/RSF/TBC complex, group III: with TBC, Group IV: empty control. After being seeded and cultured for about 24 h the complexes were implanted into 2 cm long bone defects in the middle of bilateral radius of rabbits. The radius were inspected by X-ray and then the specimens were collected at the end of the fourth and twelfth weeks after operation. Then, the specimens were decalcified and histologically investigated with Hematoxylin eosin staining and Masson staining methods. Newly synthesized trabecular bone was inspected by image analysis system and the strength of bone defect area treated with graft-implantation was tested with biomechanical method-three point bending test. RESULTS: In group I, trabecular bone was actively synthesized to generate a great amount of trabecular bone and osteon. Preliminary union and bone defect healing were completed with good biomechanical characteristics. There were no newly synthesized trabecular in the other three groups, and bone defect healing were not discovered. The amount of newly synthesized trabecular bone and the results of biomechanical testing differed significantly between group I and the other three (P < 0.01). The efficacy of group I was significantly better than that of the other three groups. CONCLUSION: True bone ceramic complex composed with Cbfa1 gene modified rabbit skin fibroblasts can effectively heal bone defect in rabbits.

[Analysis of the results of hemiarthroplasty in the treatment of proximal humeral fractures].

OBJECTIVES: To evaluate the clinical results of hemiarthroplasty in the treatment of severe proximal humeral fracture, and to analyze the influencing factors. METHODS: Forty-two cases with mean age of 63 years old were included. Mean follow-up duration was 29 months (12 - 48 months). Subjective satisfaction, ROM, muscle strength, stability, smoothness of motion were all evaluated. Radiographs of anterio-posterior view and axial view of shoulder were taken. Total-length radiographs of bilateral humerus were taken for 27 cases and CT for 15 cases. RESULTS: With Constant-Murley score 19 cases (45%) were excellent, 17 cases (40%) good, 6 cases (15%) poor, and the rate of total satisfactory was 85%. Post-operative active ROM, anterior flexion was (100 +/- 32) degrees , external rotation (16 +/- 11) degrees , external rotation and posterior extension to the level of L2. CONCLUSIONS: The reasons for the poor results include improper restoration of humeral length, over retroversion of prosthesis, poor fixation of tuberosity, malunion, absorption of greater tuberosity and heterotopic ossification.

[Experiment on induction of fibroblasts on 3-D cell-foam structures to express osteoblastic phenotype and its mechanism].

OBJECTIVE: To study the feasibility of osteogenic phenotype expression by human skin fibroblasts induced in polyglycolic acid (PGA) foams and the effect of tumor necrosis factor-alpha (TNF-alpha) on the expression of bone morphogenetic protein (BMP) receptors. METHODS: The fibroblasts were isolated, purified from human skin. (1) Fibroblasts were seeded onto PGA foams. The cell-PGA complexes were cultured in RCCS for 6 weeks, in the media of TNF-alpha (50 U/ml) and BMP-2 (0.1 microg/ml). 1 d, 3 and 6 weeks later, cells and extracellular matrix were investigated by electron microscopic and histochemistry observation respectively. Secretion of osteogenic markers were analyzed by biochemical methods. (2) Fibroblasts were seeded on the glass fragments or culture flasks and treated with TNF-alpha (50 U/ml) in different usage (one-time, all-time). The RT-PCR method and the immunohistochemistry fluorescence staining were used to examine the influence of TNF-alpha on the mRNA expression and the protein expression of the type I BMP receptors at 2, 4, 6, 8 d after treatment. RESULTS: Fibroblasts seeded on the PGA foams formed 3-dimensional matrix 3 weeks after seeding, which was demonstrated as osteo-tissue by tetracycline labeling and ARS staining. Cells secreted much more bone-specific alkaline phosphatase (B-AKP) and osteocalcin (OCN) into supernatant than the cells that were cultured in the media without TNF-a and BMP2. Eight days after all-time usage, the TNF-alpha (50 U/ml) increased the expression of the mRNA and protein of the type IB BMP receptor. CONCLUSIONS: Fibroblasts on 3-D cell-foam structures can express osteoblastic phenotype under certain inducing conditions. The numerous fibroblasts in body would be a promising resource for cell seeds candidate of tissue- engineered bone. TNF-alpha provides the essential condition for BMP2's target effect on fibroblasts, and combined use of TNF-alpha and BMP2 is one of the regulating factors.

[Experimental study on the osseointegration of nanophase hydroxyapatite biograde-coated implants].

OBJECTIVE: To study the osseointegration of the nanophase hydroxyapatite biograde-coated implants and host bone. METHODS: Nanophase hydroxyapatite biograde-coated implants, hydroxyapatite biograde-coated implants and noncoated Ti-6Al-4V implants were inserted into both femoral of Beagle canines the tissue response, dynamic osteogensis and SEM were studied at 4, 8 and 12 weeks. RESULTS: The degradation of nanophase hydroxyapatite was slower than hydroxyapatite, dynamic osteogensis and the form of osteoblast were better than the control groups. CONCLUSION: The biological reaction of Nanophase hydroxyapatite biograde-coated implants is better than hydroxyapatite coated implant.

[Osteogenesis of rabbit skin fibroblast transfected with core binding factor a1/osteoblast specific transplanting factor-2 gene].

OBJECTIVE: To study osteoblastic phenotype expression of New Zealand rabbit skin fibroblasts transfected with mouse core binding factor a1/osteoblast specific transplanting factor-2 gene (Cbfa1/Osf2). METHODS: Cbfa1/Osf2 gene, engineered into eukaryotic expression vector pSG5, was introduced into New Zealand rabbit skin fibroblasts with catholyte liposomes-Lipofectamine 2000. Meanwhile, those transfected pSG5 and un-transfected were set the control groups. The expression of Cbfa1 gene, osteocalcin (OCN) gene, alkaline phosphatase (ALP) gene and pre-peptide 2 alpha gene of collagen type I were detected by RT-PCR assay. Cbfa1 protein was detected by Western-Blot assay, in-cell ALP activity by p-nitrophenyl phosphate (PNPP) assay and OCN content in the supernatant by radio-immunity method. The ossification nodules was detected by Alizarin-Red staining and scanning electron microscope. RESULTS: Cbfa 1mRNA and Cbfa1 protein were expressed in New Zealand rabbit skin fibroblasts transfected with pSG5-Cbfa1/Osf2 from the first day to the fifth day, but they were not detected in the control groups. In the pSG5-Cbfa1/Osf2 transfected group, the expression of ALP gene and OCN gene were respectively induced from the third day and the forth day, pre-peptide 2 alpha gene of collagen type I was enhanced from the third day. From the sixth day, ALP activity greatly increased, OCN strongly secreted, and they were maintained at a high level for about 4 weeks, and the difference was significant compared with the control group (P < 0.05). On the forty-second day, ossification nodules were found on the surface of pSG5-Cbfa1/Osf2 gene transfected cells. CONCLUSIONS: New Zealand rabbit skin fibroblasts transfected with pSG5-Cbfa1/Osf2 can express osteogenesis-related genes and proteins, and form ossification nodules on their surface.