Comparison of the Wiltse Approach and Percutaneous Pedicle Screw Fixation Under O-arm Navigation for the Treatment of Thoracolumbar Fractures.

OBJECTIVES: The aim of this study was to evaluate the clinical outcomes of the Wiltse approach and percutaneous pedicle screw placement under O-arm navigation for the treatment of thoracolumbar fracture. METHODS: We enrolled a total of 54 patients with neurologically intact thoracolumbar fracture who received minimally invasive treatments between October 2014 and October 2018 in this retrospective study. Among these, 28 patients (22 males and six females, with a mean age of 48.6 ± 9.6 years) were treated with pedicle screw fixation through the Wiltse approach (WPSF), and another 26 (15 males and 11 females, with a mean age of 45.7 ± 10.6 years) received percutaneous pedicle screw fixation under O-arm navigation (OPSF). Statistical methods were used to perform a detailed comparison of clinical outcomes, radiologic findings, and complications between the two groups obtained preoperatively, postoperatively, and at last follow-up. RESULTS: All patients underwent surgery successfully and finished a follow-up of more than 12 months. No serious complications, such as infection, blood vessel injury, or spinal cord or nerve root injury occurred. Visual analog scale (VAS) scores, Oswestry disability index (ODI) scores, local Cobb angle (LCA), vertebral wedge angle (VWA), and R value were notably improved after surgery, though there was no clear discrepancy between the groups at each time point (P > 0.05). During the follow-up period, no patients developed neurological impairment or implant-related complications, and no patients underwent revision surgery. The WPSF group had a significantly shorter operation time than the OPSF group (68.1 ± 9.8 vs 76.1 ± 9.0 minutes, P = 0.005). Moreover, the WPSF group showed less cost of surgery than the WPSF group (48142.1 ± 1430.1 vs 59035.4 ± 1152.7 CNY, P < 0.001). There were no significant differences between the two groups in terms of the intraoperative bleeding, length of incision, or postoperative hospitalization time (P > 0.05). The accuracy of pedicle screw placement was 95.2% (160/168) in the WPSF group and 96.8% (151/156) in the OPSF group, with no significant difference between the groups (P = 0.432). CONCLUSION: Both WPSF and OPSF were safe and effective for the treatment of thoracolumbar fracture. Although the two groups showed favorable clinical and radiologic outcomes through to final follow-up, we recommended the minimally invasive WPSF given its shorter operation time and lower cost of surgery.

Pd-PEPPSI-IPentAn Promoted Deactivated Amination of Aryl Chlorides with Amines under Aerobic Conditions.

We report herein a highly efficient Pd-catalyzed amination by "bulky-yet-flexible" Pd-PEPPSI-IPentAn complexes. The relationship between the N-heterocyclic carbenes (NHCs) structure and catalytic properties was discussed. Sterically hindered (hetero)aryl chlorides and a variety of aliphatic and aromatic amines can be applied in this cross-coupling, which smoothly proceeded to provide desired products. The operationally simple protocol highlights the rapid access to CAr-N bond formation under mild conditions without the exclusion of air and moisture.

Bulky Yet Flexible Pd-PEPPSI-IPentAn for the Synthesis of Sterically Hindered Biaryls in Air.

In this report, a type of moisture and air stable Pd-PEPPSI-IPentAn complex (C1) with the combination of acenaphthyl on the backbone and isopentyl groups on N-aryl moieties was described and applied in the Suzuki-Miyaura cross-coupling reaction in air. The reaction conditions were optimized, and the structure-reactivity relationships between C1 and other classical efficient Pd-PEPPSI complexes were investigated intensively. Our study demonstrated that both the backbone and N-aryl moieties gave rise to a significant effect on this transformation when exposed to air. A wide range of sterically hindered (hetero)aryl chlorides with (hetero)arylboronic acids were compatible, giving good to excellent isolated yields of sterically hindered bi(hetero)aryls.

Camphyl-based α-diimine palladium complexes: highly efficient precatalysts for direct arylation of thiazoles in open-air.

Based on the strategy of the development of phosphine-free palladium-catalyzed direct C-H arylation, a series of camphyl-based α-diimine palladium complexes bearing sterically bulky substituents were synthesized and characterized. The palladium complexes were applied for the cross-coupling of thiazole derivatives with aryl bromides. The effect of the sterically bulky substituent on the N-aryl moiety as well as the reaction conditions was screened. Under the optimal protocols, a wide range of aryl bromides can be smoothly coupled with thiazoles in good to excellent yields in the presence of a low palladium loading of 0.2 mol% under open-air conditions.

Silencing of Glucose Transporter Protein-1 by RNA Interference Inhibits Human Osteosarcoma Mg63 Cells Growth in vivo.

While knock-down of glucose transporter protein 1 (GLUT-1) inhibited various human cancer cell growth in vitro and in vivo, including osteosarcoma cell growth in vitro, there has been no report on whether knock-down of GLUT-1 by siRNA may inhibit osteosarcoma cell growth in vivo. We hypothesized that siRNA may inhibit osteosarcoma cell growth in vivo. We introduced siRNA-GLUT-1 by lentivirus into MG63 osteosarcoma cells which were xenograted into nude mice. Immunohistochemical staining, Western blot and reverse transcriptase quantitative (RT-qPCR) were used to determine GLUT-1 protein and mRNA expression of the tumor cells. The results showed the tumor volume of GLUT-1-siRNA-MG63 cells xenorafted nude mice was significantly less than that of siGFP-MG63 or MG63 cells xenografted nude mice (P < 0.05), suggesting that silencing of GLUT-1 inhibited tumor formation and growth of osteosarcoma cells in vivo. Our findings suggest that the lentiviral-mediated siRNA interference against GLUT-1 may be a valuable tool for gene therapy for osteosarcoma.

Glucose transporter protein 1-targeted RNA interference inhibits growth and invasion of the osteosarcoma cell line MG63 in vitro.

Malignant cells show increased glucose uptake, which is thought to be mediated by glucose transporters. Glucose transporter protein 1 (Glut-1) is critical for growth, proliferation, and migration of tumor cells and Glut-1 overexpression is associated with poor overall survival in osteosarcoma patients. The present study was designed to determine the role of Glut-1 in the growth and invasion of the osteosarcoma cell line MG63, using RNA interference technology in vitro. shRNA-expressing lentiviral vectors targeting the Glut-1 gene were constructed, which were stably expressed in MG63 cells. The level of Glut-1 mRNA was investigated using real-time reverse transcription-polymerase chain reaction, and the protein expression of Glut-1 mRNA was observed using western blotting. MG63 cellular glucose uptake, proliferation, and migration were detected by methyl thiazole tetrazolium assay and flow cytometry. A Glut-1-specific shRNA-expressing lentiviral vector was obtained, which could efficiently inhibit the mRNA and protein expression of Glut-1 to ∼82%-85% in MG63 cells. Downregulation of Glut-1 inhibited the cellular glucose uptake, growth, and invasion of MG63 cells in vitro. These results indicate that RNA interference targeting of Glut-1 could be an effective strategy for the treatment of osteoscarcoma patients.

AKR1C2 small interfering RNA (siRNA) inhibited beta-catenin expression and transcriptional activation in human liver cancer cell line QGY7701.

BACKGROUND/AIMS: It has been proved that changes in the Wnt/beta-catenin pathway lead to hepatocarcinogenesis and the AKR1C2 gene may contribute to the occurrence, advancement and invasiveness of liver cancer. The purpose of this study is to investigate AKR1C2 small interfering RNA (siRNA) influence on beta-catenin expression and transcriptional activation in the human liver cancer cell line QGY7701. METHODOLOGY: We constructed AKR1C2 small interfering RNA (siRNA) expression vector pSilence2.1/ U6/AKR1C2 RNAi and then transfected it into the liver cancer cell QGY7701. Beta-catenin mRNA and its protein expression was detected by RT-PCR, western blotting and beta-catenin gene transcriptional activity was analyzed by luciferase assay. RESULTS: AKR1C2 siRNA inhibited the transcriptional expression of beta-catenin and decreased beta-catenin protein stability in QGY7701. AKR1C2 siRNA inhibited beta-catenin gene transcriptional regulation and control activity for TCF gene by influencing on the down-stream gene's function of beta-catenin in QGY7701 liver cancer cells. CONCLUSIONS: It suggests a causative cooperative role for beta-catenin and AKR1C2 in tumorigenesis. Thus, the inhibition of activation of the beta-catenin/ TCF-signaling pathway is believed to be one mechanism by which AKR1C2 siRNA exerts a gatekeeper function during hepatocarcinogenesis.

RTN4-C gene expression in hepatocellular carcinoma and its influence on SMMC7721 cell growth and apoptosis.

RTN4-C gene is a member of RTNs. To investigate its expression in human hepatocellular carcinoma tissues and study its function on SMMC7721 cells, RT-PCR was conducted to detect its expressions in human hepatocellular carcinoma tissues. RTN4-C-pcDNA3. 1 plasmid was reconstructed and stably transfected into SMMC7721 cells by Lipofect AMINE. Growth curve of SMMC7721 measured by MTT and apoptosis indentified with acridine orange staining were examined to demonstrate the effect of RTN4-C on SMMC7721. Immunocytochemical analysis for mutant p53, c-Fos, Hsp70 proteins were conducted. The results showed that the transfected SMMC7721 cells grew more slowly than control and the average inhibition rate at the 1st, 2nd and 3rd day were 33.8% +/- 0.026, 56.2% +/- 0. 094, 34.8% +/- 0.077 respectively. In transfected SMMC7721 cell line, the apoptosis was strengthened,mutant p53 protein tranferred from nucleus to cytoplasm and c-Fos, Hsp70 proteins were decreased. Our data indicated RTN4-C gene was expressed differently in hepatocellular carcinoma and its paracancerous tissues. By tranferring mutant p53 protein from nucleus to cytoplasm and decreasing c-Fos, Hsp70 protein expression, RTN4-C inhibited SMMC7721 cells growth and promoted its apoptosis.

Growth factor NUN increased AKR1C2 expression by activated CDK2 related RB signal transduction pathway in human liver cancer cell line.

BACKGROUND/AIMS: The investigation is to understand whether polypeptide growth factor NUN can enhance AKR1C2 transcriptional expression in human SMMC7721 liver cancer cell line or not. METHODOLOGY: SMMC7721 cell was starved in serum-free medium overnight before NUN treatment, and cells were then incubated with NUN for different times and dosage. These cells lysates were prepared to examine AKR1C2 expression by Western blot. Total RNA was extracted from these cells to analyze the change of AKR1C2 mRNA by Northern blot. RESULTS: NUN increased expression of AKR1C2 in SMMC7721 liver cancer cell in a time- and dosage-dependent manner and this increase resulted from up-regulation of AKR1C2 mRNA expression. The inhibitor of CDK2 inhibited the up-regulation of AKR1C2 by NUN. CONCLUSIONS: These results showed that NUN can enhance AKR1C2 transcription by activated CDK2 related RB signaling pathway, leading to increased AKR1C2 expression in SMMC7721 liver cancer cell.

Down regulation of DRET gene in human hepatocellular carcinoma tissues samples from Qidong area, China.

OBJECTIVE: To analyze the expression of DRET gene in hepatocellular carcinomas (HCCs) tissue specimens in comparison with normal liver tissue to evaluate the relationship between DRET gene and HCC. METHODS: 250 primary HCCs and 50 normal liver tissue samples from Qidong area, China, were studied for DRET mRNA and protein expression with the use of Northern blot analysis, in situ hybridization and immunohistochemistry. RESULTS: By Northern analysis, moderate to strong DRET mRNA expression was present in normal liver samples. In contrast, DRET mRNA expression in tissue samples of primary HCCs was markedly decreased compared with normal controls. Primary HCCs that gave rise to metastasis showed significantly lower DRET mRNA levels than nonmetastasizing HCCs. By in situ hybridization analysis, nonmetastatic HCCs samples didn't differ from controls. In contrast, most of the primary metastasizing HCC showed only faint or moderate DRET mRNA expression. Tissue sections of nonmetastatic HCC exhibited lower DRET immunoreactivity than control samples, but higher labeling index than metastatic HCC samples. CONCLUSIONS: Expression of DRET on mRNA and protein levels in HCC cells is related to HCC metastatic ability.

Expression of TN4 gene and its role in human hepatocarcinogenesis from Qidong, a liver cancer risk area.

BACKGROUND: We investigated the expression and role of TN4 in the oncogenesis of human hepatocellular carcinoma (HCC) from Qidong which is a HCC risk area. METHODS: The expression of TN4 in HCC was observed using immunohistochemical staining (IHC). TN4 levels were manipulated in human liver cancer cell SMMC7721, using pcDNA3.1 eukaryotic expression constructs designed to express the complete TN4 cDNA. The biological changes of the cells were observed before and after transfection of TN4 and the change of gene expression was analysed by atlas cDNA expression array. RESULTS: Among 100 pairs of samples of HCC, TN4 down-regulation expression and up-regulation expression positive rate were 81% (81/100), 19% (19/100), respectively (P < 0.01). TN4 protein was mainly localized in cytoplasm and membrane. The positive rate of TN4 were 10% (3/30), 100% (70/70) in lymph node metastasis and no lymph node metastasis, respectively (P < 0.01). The growth rates of the derivative SMMC7721-TN4 cell lines were decreased in comparison with that of normal SMMC7721 cells and pcDNA-SMMC7721. Some gene expression was changed before and after transfection of TN4. At 30 days of post-implantation of SMMC7721-TN4, SMMC7721-pcDNA3, SMMC7721 group produced tumors of (301.9 +/- 143.4) mm(3), (2418.7 +/- 362.8) mm(3), (2317.4 +/- 587.8) mm(3), respectively, (P < 0.01). Tumor inhibiting rate was 82.4% in TN4 transfection group. Sections of tumors were observed for their degree of tissue necrosis and there was higher degree of necrosis in tumors of the TN4-SMMC7721 cell group than those of the SMMC7721, SMMC7721-pcDNA groups. CONCLUSIONS: TN4 may play an important role in the oncogenesis of human HCC, especially in Qidong, the HCC risk area and TN4 could be a candidate tumor suppressor gene for HCC.

Codon 249 mutation in exon 7 of p53 gene in plasma DNA: maybe a new early diagnostic marker of hepatocellular carcinoma in Qidong risk area, China.

AIM: One of the characteristics of hepatocellular carcinoma (HCC) in Qidong area is the selective mutation resulting in a serine substitution at codon 249 of the p53 gene (1, 20), and it has been identified as a "hotspot" mutation in heptocellular carcinomas occurring in populations exposed to aflatoxin and with high prevalence of hepatitis B virus carriers (2,3,9, 10,16,24). We evaluated in this paper whether this "hotspot" mutation could be detected in cell-free DNA circulating in plasma of patients with hepatocellular carcinoma and cirrhosis in Qidong, China, and tried to illustrate the significance of the detection of this molecular biomarker. METHODS: We collected blood samples from 25 hepatocellular carcinoma patients, 20 cirrhotic patients and 30 healthy controls in Qidong area. DNA was extracted and purified from 200 microl of plasma from each sample. The 249(Ser) p53 mutation was detected by restriction digestion analysis and direct sequencing of exon-7 PCR products. RESULTS: We found in exon 7 of p53 gene G-T transversion at the third base of codon 249 resulting 249(Arg) - 249(Ser) mutation in 10/25 (40 %) hepatocellular carcinoma cases, 4/20 (20 %) cirrhotics, and 2/30 (7 %) healthy controls. The adjusted odds ratio for having the mutation was 22.1(95 % CI, 3.2-91.7) for HCC cases compared to controls. CONCLUSION: These data show that the 249(Ser) p53 mutation in plasma is strongly associated with hepatocellular carcinoma in Qidong patients. We found this mutation was also detected, although it was at a much lower frequency, in plasma DNA of Qidong cirrhotics and healthy controls; We consider that these findings, together with the usual method of HCC diagnosis, will give more information in early diagnosis of HCC, and 249(Ser) p53 mutation should be developed to a new early diagnostic marker for HCC.

The relationship between metallothionein-1F (MT1F) gene and hepatocellular carcinoma.

To investigate the expression of MT1F gene in hepatocellular carcinoma tissue and the growth suppression effect of exogenous introduction of MT1F gene on liver cell line HepG2 and to explore the potential application of MT1F gene in gene therapy of tumor. Eukaryotic expression vector of pCMV-MT1F plasmid was introduced into HepG2 line which expressed no MT1F protein originally with lipofectamine transfection method. The cell growth curve, soft agar colony formation rate and tumorigenicity in SCID mice were examined to demonstrate the growth suppression effect of exogenous MT1F gene on HepG2 cell line. The MT1F mRNA and MT1F protein were also detected in 60 pairs of surgical specimens of hepatocellular carcinoma by in situ hybridization and immunohistochemistry. The transfected HepG2 cell line grew more slowly than control HepG2 as shown by cell growth curves, the soft agar colony formation rate (3.8 percent vs. 7.4 percent, p <.01) and the average growth rate of tumor in SCID mice (30.9 +/- 6.9 vs. 70.3 +/- 5.6, p <.01). The expression level of MT1F mRNA and protein significantly increased in paracancerous tissue, normal tissue than in cancer tissues (75 percent, 70 percent vs. 16.7 percent by ISH and 66.7 percent, 60 percent vs. 10 percent by IHC, p <.01). Exogenous MT1F gene shows the strong effect of growth inhibition on HepG2 cell line. In the liver cancer tissue, MT1F shows down-regulated expression that supports the inhibited function of MT1F in cancer growth and suggests MT1F may have an important role in gene therapy of hepatocellular carcinoma.